WSL2-Linux-Kernel/kernel/irq/manage.c

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/*
* linux/kernel/irq/manage.c
*
* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
* Copyright (C) 2005-2006 Thomas Gleixner
*
* This file contains driver APIs to the irq subsystem.
*/
#define pr_fmt(fmt) "genirq: " fmt
#include <linux/irq.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/task_work.h>
#include "internals.h"
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
#ifdef CONFIG_IRQ_FORCED_THREADING
__read_mostly bool force_irqthreads;
static int __init setup_forced_irqthreads(char *arg)
{
force_irqthreads = true;
return 0;
}
early_param("threadirqs", setup_forced_irqthreads);
#endif
/**
* synchronize_irq - wait for pending IRQ handlers (on other CPUs)
* @irq: interrupt number to wait for
*
* This function waits for any pending IRQ handlers for this interrupt
* to complete before returning. If you use this function while
* holding a resource the IRQ handler may need you will deadlock.
*
* This function may be called - with care - from IRQ context.
*/
void synchronize_irq(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
bool inprogress;
if (!desc)
return;
do {
unsigned long flags;
/*
* Wait until we're out of the critical section. This might
* give the wrong answer due to the lack of memory barriers.
*/
while (irqd_irq_inprogress(&desc->irq_data))
cpu_relax();
/* Ok, that indicated we're done: double-check carefully. */
raw_spin_lock_irqsave(&desc->lock, flags);
inprogress = irqd_irq_inprogress(&desc->irq_data);
raw_spin_unlock_irqrestore(&desc->lock, flags);
/* Oops, that failed? */
} while (inprogress);
/*
* We made sure that no hardirq handler is running. Now verify
* that no threaded handlers are active.
*/
wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
}
EXPORT_SYMBOL(synchronize_irq);
#ifdef CONFIG_SMP
cpumask_var_t irq_default_affinity;
/**
* irq_can_set_affinity - Check if the affinity of a given irq can be set
* @irq: Interrupt to check
*
*/
int irq_can_set_affinity(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
if (!desc || !irqd_can_balance(&desc->irq_data) ||
!desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
return 0;
return 1;
}
/**
* irq_set_thread_affinity - Notify irq threads to adjust affinity
* @desc: irq descriptor which has affitnity changed
*
* We just set IRQTF_AFFINITY and delegate the affinity setting
* to the interrupt thread itself. We can not call
* set_cpus_allowed_ptr() here as we hold desc->lock and this
* code can be called from hard interrupt context.
*/
void irq_set_thread_affinity(struct irq_desc *desc)
{
struct irqaction *action = desc->action;
while (action) {
if (action->thread)
set_bit(IRQTF_AFFINITY, &action->thread_flags);
action = action->next;
}
}
#ifdef CONFIG_GENERIC_PENDING_IRQ
static inline bool irq_can_move_pcntxt(struct irq_data *data)
{
return irqd_can_move_in_process_context(data);
}
static inline bool irq_move_pending(struct irq_data *data)
{
return irqd_is_setaffinity_pending(data);
}
static inline void
irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
{
cpumask_copy(desc->pending_mask, mask);
}
static inline void
irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
{
cpumask_copy(mask, desc->pending_mask);
}
#else
static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
static inline bool irq_move_pending(struct irq_data *data) { return false; }
static inline void
irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
static inline void
irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
#endif
int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
bool force)
{
struct irq_desc *desc = irq_data_to_desc(data);
struct irq_chip *chip = irq_data_get_irq_chip(data);
int ret;
ret = chip->irq_set_affinity(data, mask, false);
switch (ret) {
case IRQ_SET_MASK_OK:
cpumask_copy(data->affinity, mask);
case IRQ_SET_MASK_OK_NOCOPY:
irq_set_thread_affinity(desc);
ret = 0;
}
return ret;
}
int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
{
struct irq_chip *chip = irq_data_get_irq_chip(data);
struct irq_desc *desc = irq_data_to_desc(data);
int ret = 0;
if (!chip || !chip->irq_set_affinity)
return -EINVAL;
if (irq_can_move_pcntxt(data)) {
ret = irq_do_set_affinity(data, mask, false);
} else {
irqd_set_move_pending(data);
irq_copy_pending(desc, mask);
}
if (desc->affinity_notify) {
kref_get(&desc->affinity_notify->kref);
schedule_work(&desc->affinity_notify->work);
}
irqd_set(data, IRQD_AFFINITY_SET);
return ret;
}
/**
* irq_set_affinity - Set the irq affinity of a given irq
* @irq: Interrupt to set affinity
* @mask: cpumask
*
*/
int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
int ret;
if (!desc)
return -EINVAL;
raw_spin_lock_irqsave(&desc->lock, flags);
ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask);
raw_spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
{
unsigned long flags;
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc)
return -EINVAL;
desc->affinity_hint = m;
irq_put_desc_unlock(desc, flags);
return 0;
}
EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
static void irq_affinity_notify(struct work_struct *work)
{
struct irq_affinity_notify *notify =
container_of(work, struct irq_affinity_notify, work);
struct irq_desc *desc = irq_to_desc(notify->irq);
cpumask_var_t cpumask;
unsigned long flags;
if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
goto out;
raw_spin_lock_irqsave(&desc->lock, flags);
if (irq_move_pending(&desc->irq_data))
irq_get_pending(cpumask, desc);
else
cpumask_copy(cpumask, desc->irq_data.affinity);
raw_spin_unlock_irqrestore(&desc->lock, flags);
notify->notify(notify, cpumask);
free_cpumask_var(cpumask);
out:
kref_put(&notify->kref, notify->release);
}
/**
* irq_set_affinity_notifier - control notification of IRQ affinity changes
* @irq: Interrupt for which to enable/disable notification
* @notify: Context for notification, or %NULL to disable
* notification. Function pointers must be initialised;
* the other fields will be initialised by this function.
*
* Must be called in process context. Notification may only be enabled
* after the IRQ is allocated and must be disabled before the IRQ is
* freed using free_irq().
*/
int
irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irq_affinity_notify *old_notify;
unsigned long flags;
/* The release function is promised process context */
might_sleep();
if (!desc)
return -EINVAL;
/* Complete initialisation of *notify */
if (notify) {
notify->irq = irq;
kref_init(&notify->kref);
INIT_WORK(&notify->work, irq_affinity_notify);
}
raw_spin_lock_irqsave(&desc->lock, flags);
old_notify = desc->affinity_notify;
desc->affinity_notify = notify;
raw_spin_unlock_irqrestore(&desc->lock, flags);
if (old_notify)
kref_put(&old_notify->kref, old_notify->release);
return 0;
}
EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
#ifndef CONFIG_AUTO_IRQ_AFFINITY
/*
* Generic version of the affinity autoselector.
*/
static int
setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
{
struct cpumask *set = irq_default_affinity;
int node = desc->irq_data.node;
/* Excludes PER_CPU and NO_BALANCE interrupts */
if (!irq_can_set_affinity(irq))
return 0;
/*
* Preserve an userspace affinity setup, but make sure that
* one of the targets is online.
*/
if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
if (cpumask_intersects(desc->irq_data.affinity,
cpu_online_mask))
set = desc->irq_data.affinity;
else
irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
}
cpumask_and(mask, cpu_online_mask, set);
if (node != NUMA_NO_NODE) {
const struct cpumask *nodemask = cpumask_of_node(node);
/* make sure at least one of the cpus in nodemask is online */
if (cpumask_intersects(mask, nodemask))
cpumask_and(mask, mask, nodemask);
}
irq_do_set_affinity(&desc->irq_data, mask, false);
return 0;
}
#else
static inline int
setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
{
return irq_select_affinity(irq);
}
#endif
/*
* Called when affinity is set via /proc/irq
*/
int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
int ret;
raw_spin_lock_irqsave(&desc->lock, flags);
ret = setup_affinity(irq, desc, mask);
raw_spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
#else
static inline int
setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
{
return 0;
}
#endif
void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
{
if (suspend) {
if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
return;
desc->istate |= IRQS_SUSPENDED;
}
if (!desc->depth++)
irq_disable(desc);
}
static int __disable_irq_nosync(unsigned int irq)
{
unsigned long flags;
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc)
return -EINVAL;
__disable_irq(desc, irq, false);
irq_put_desc_busunlock(desc, flags);
return 0;
}
/**
* disable_irq_nosync - disable an irq without waiting
* @irq: Interrupt to disable
*
* Disable the selected interrupt line. Disables and Enables are
* nested.
* Unlike disable_irq(), this function does not ensure existing
* instances of the IRQ handler have completed before returning.
*
* This function may be called from IRQ context.
*/
void disable_irq_nosync(unsigned int irq)
{
__disable_irq_nosync(irq);
}
EXPORT_SYMBOL(disable_irq_nosync);
/**
* disable_irq - disable an irq and wait for completion
* @irq: Interrupt to disable
*
* Disable the selected interrupt line. Enables and Disables are
* nested.
* This function waits for any pending IRQ handlers for this interrupt
* to complete before returning. If you use this function while
* holding a resource the IRQ handler may need you will deadlock.
*
* This function may be called - with care - from IRQ context.
*/
void disable_irq(unsigned int irq)
{
if (!__disable_irq_nosync(irq))
synchronize_irq(irq);
}
EXPORT_SYMBOL(disable_irq);
void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
{
if (resume) {
if (!(desc->istate & IRQS_SUSPENDED)) {
if (!desc->action)
return;
if (!(desc->action->flags & IRQF_FORCE_RESUME))
return;
/* Pretend that it got disabled ! */
desc->depth++;
}
desc->istate &= ~IRQS_SUSPENDED;
}
switch (desc->depth) {
case 0:
err_out:
WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
break;
case 1: {
if (desc->istate & IRQS_SUSPENDED)
goto err_out;
/* Prevent probing on this irq: */
irq_settings_set_noprobe(desc);
irq_enable(desc);
check_irq_resend(desc, irq);
/* fall-through */
}
default:
desc->depth--;
}
}
/**
* enable_irq - enable handling of an irq
* @irq: Interrupt to enable
*
* Undoes the effect of one call to disable_irq(). If this
* matches the last disable, processing of interrupts on this
* IRQ line is re-enabled.
*
genirq: Add buslock support Some interrupt chips are connected to a "slow" bus (i2c, spi ...). The bus access needs to sleep and therefor cannot be called in atomic contexts. Some of the generic interrupt management functions like disable_irq(), enable_irq() ... call interrupt chip functions with the irq_desc->lock held and interrupts disabled. This does not work for such devices. Provide a separate synchronization mechanism for such interrupt chips. The irq_chip structure is extended by two optional functions (bus_lock and bus_sync_and_unlock). The idea is to serialize the bus access for those operations in the core code so that drivers which are behind that bus operated interrupt controller do not have to worry about it and just can use the normal interfaces. To achieve this we add two function pointers to the irq_chip: bus_lock and bus_sync_unlock. bus_lock() is called to serialize access to the interrupt controller bus. Now the core code can issue chip->mask/unmask ... commands without changing the fast path code at all. The chip implementation merily stores that information in a chip private data structure and returns. No bus interaction as these functions are called from atomic context. After that bus_sync_unlock() is called outside the atomic context. Now the chip implementation issues the bus commands, waits for completion and unlocks the interrupt controller bus. The irq_chip implementation as pseudo code: struct irq_chip_data { struct mutex mutex; unsigned int irq_offset; unsigned long mask; unsigned long mask_status; } static void bus_lock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); mutex_lock(&data->mutex); } static void mask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask |= (1 << irq); } static void unmask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask &= ~(1 << irq); } static void bus_sync_unlock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); if (data->mask != data->mask_status) { do_bus_magic_to_set_mask(data->mask); data->mask_status = data->mask; } mutex_unlock(&data->mutex); } The device drivers can use request_threaded_irq, free_irq, disable_irq and enable_irq as usual with the only restriction that the calls need to come from non atomic context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:48 +04:00
* This function may be called from IRQ context only when
* desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
*/
void enable_irq(unsigned int irq)
{
unsigned long flags;
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc)
return;
if (WARN(!desc->irq_data.chip,
KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
goto out;
__enable_irq(desc, irq, false);
out:
irq_put_desc_busunlock(desc, flags);
}
EXPORT_SYMBOL(enable_irq);
static int set_irq_wake_real(unsigned int irq, unsigned int on)
{
struct irq_desc *desc = irq_to_desc(irq);
int ret = -ENXIO;
if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
return 0;
if (desc->irq_data.chip->irq_set_wake)
ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
return ret;
}
/**
* irq_set_irq_wake - control irq power management wakeup
* @irq: interrupt to control
* @on: enable/disable power management wakeup
*
* Enable/disable power management wakeup mode, which is
* disabled by default. Enables and disables must match,
* just as they match for non-wakeup mode support.
*
* Wakeup mode lets this IRQ wake the system from sleep
* states like "suspend to RAM".
*/
int irq_set_irq_wake(unsigned int irq, unsigned int on)
{
unsigned long flags;
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
int ret = 0;
if (!desc)
return -EINVAL;
/* wakeup-capable irqs can be shared between drivers that
* don't need to have the same sleep mode behaviors.
*/
if (on) {
if (desc->wake_depth++ == 0) {
ret = set_irq_wake_real(irq, on);
if (ret)
desc->wake_depth = 0;
else
irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
}
} else {
if (desc->wake_depth == 0) {
WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
} else if (--desc->wake_depth == 0) {
ret = set_irq_wake_real(irq, on);
if (ret)
desc->wake_depth = 1;
else
irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
}
}
irq_put_desc_busunlock(desc, flags);
return ret;
}
EXPORT_SYMBOL(irq_set_irq_wake);
/*
* Internal function that tells the architecture code whether a
* particular irq has been exclusively allocated or is available
* for driver use.
*/
int can_request_irq(unsigned int irq, unsigned long irqflags)
{
unsigned long flags;
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
int canrequest = 0;
if (!desc)
return 0;
if (irq_settings_can_request(desc)) {
if (!desc->action ||
irqflags & desc->action->flags & IRQF_SHARED)
canrequest = 1;
}
irq_put_desc_unlock(desc, flags);
return canrequest;
}
int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
unsigned long flags)
{
struct irq_chip *chip = desc->irq_data.chip;
int ret, unmask = 0;
if (!chip || !chip->irq_set_type) {
/*
* IRQF_TRIGGER_* but the PIC does not support multiple
* flow-types?
*/
pr_debug("No set_type function for IRQ %d (%s)\n", irq,
chip ? (chip->name ? : "unknown") : "unknown");
return 0;
}
flags &= IRQ_TYPE_SENSE_MASK;
if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
if (!irqd_irq_masked(&desc->irq_data))
mask_irq(desc);
if (!irqd_irq_disabled(&desc->irq_data))
unmask = 1;
}
/* caller masked out all except trigger mode flags */
ret = chip->irq_set_type(&desc->irq_data, flags);
switch (ret) {
case IRQ_SET_MASK_OK:
irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
irqd_set(&desc->irq_data, flags);
case IRQ_SET_MASK_OK_NOCOPY:
flags = irqd_get_trigger_type(&desc->irq_data);
irq_settings_set_trigger_mask(desc, flags);
irqd_clear(&desc->irq_data, IRQD_LEVEL);
irq_settings_clr_level(desc);
if (flags & IRQ_TYPE_LEVEL_MASK) {
irq_settings_set_level(desc);
irqd_set(&desc->irq_data, IRQD_LEVEL);
}
ret = 0;
break;
default:
pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
flags, irq, chip->irq_set_type);
}
if (unmask)
unmask_irq(desc);
return ret;
}
#ifdef CONFIG_HARDIRQS_SW_RESEND
int irq_set_parent(int irq, int parent_irq)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
if (!desc)
return -EINVAL;
desc->parent_irq = parent_irq;
irq_put_desc_unlock(desc, flags);
return 0;
}
#endif
genirq: Add oneshot support For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:22 +04:00
/*
* Default primary interrupt handler for threaded interrupts. Is
* assigned as primary handler when request_threaded_irq is called
* with handler == NULL. Useful for oneshot interrupts.
*/
static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
{
return IRQ_WAKE_THREAD;
}
genirq: Support nested threaded irq handling Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 15:21:38 +04:00
/*
* Primary handler for nested threaded interrupts. Should never be
* called.
*/
static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
{
WARN(1, "Primary handler called for nested irq %d\n", irq);
return IRQ_NONE;
}
static int irq_wait_for_interrupt(struct irqaction *action)
{
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
if (test_and_clear_bit(IRQTF_RUNTHREAD,
&action->thread_flags)) {
__set_current_state(TASK_RUNNING);
return 0;
}
schedule();
set_current_state(TASK_INTERRUPTIBLE);
}
__set_current_state(TASK_RUNNING);
return -1;
}
genirq: Add oneshot support For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:22 +04:00
/*
* Oneshot interrupts keep the irq line masked until the threaded
* handler finished. unmask if the interrupt has not been disabled and
* is marked MASKED.
*/
static void irq_finalize_oneshot(struct irq_desc *desc,
struct irqaction *action)
genirq: Add oneshot support For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:22 +04:00
{
if (!(desc->istate & IRQS_ONESHOT))
return;
genirq: Prevent oneshot irq thread race Lars-Peter pointed out that the oneshot threaded interrupt handler code has the following race: CPU0 CPU1 hande_level_irq(irq X) mask_ack_irq(irq X) handle_IRQ_event(irq X) wake_up(thread_handler) thread handler(irq X) runs finalize_oneshot(irq X) does not unmask due to !(desc->status & IRQ_MASKED) return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This leaves the interrupt line masked forever. The reason for this is the inconsistent handling of the IRQ_MASKED flag. Instead of setting it in the mask function the oneshot support sets the flag after waking up the irq thread. The solution for this is to set/clear the IRQ_MASKED status whenever we mask/unmask an interrupt line. That's the easy part, but that cleanup opens another race: CPU0 CPU1 hande_level_irq(irq) mask_ack_irq(irq) handle_IRQ_event(irq) wake_up(thread_handler) thread handler(irq) runs finalize_oneshot_irq(irq) unmask(irq) irq triggers again handle_level_irq(irq) mask_ack_irq(irq) return from irq due to IRQ_INPROGRESS return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This requires that we synchronize finalize_oneshot_irq() with the primary handler. If IRQ_INPROGESS is set we wait until the primary handler on the other CPU has returned before unmasking the interrupt line again. We probably have never seen that problem because it does not happen on UP and on SMP the irqbalancer protects us by pinning the primary handler and the thread to the same CPU. Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2010-03-09 21:45:54 +03:00
again:
chip_bus_lock(desc);
raw_spin_lock_irq(&desc->lock);
genirq: Prevent oneshot irq thread race Lars-Peter pointed out that the oneshot threaded interrupt handler code has the following race: CPU0 CPU1 hande_level_irq(irq X) mask_ack_irq(irq X) handle_IRQ_event(irq X) wake_up(thread_handler) thread handler(irq X) runs finalize_oneshot(irq X) does not unmask due to !(desc->status & IRQ_MASKED) return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This leaves the interrupt line masked forever. The reason for this is the inconsistent handling of the IRQ_MASKED flag. Instead of setting it in the mask function the oneshot support sets the flag after waking up the irq thread. The solution for this is to set/clear the IRQ_MASKED status whenever we mask/unmask an interrupt line. That's the easy part, but that cleanup opens another race: CPU0 CPU1 hande_level_irq(irq) mask_ack_irq(irq) handle_IRQ_event(irq) wake_up(thread_handler) thread handler(irq) runs finalize_oneshot_irq(irq) unmask(irq) irq triggers again handle_level_irq(irq) mask_ack_irq(irq) return from irq due to IRQ_INPROGRESS return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This requires that we synchronize finalize_oneshot_irq() with the primary handler. If IRQ_INPROGESS is set we wait until the primary handler on the other CPU has returned before unmasking the interrupt line again. We probably have never seen that problem because it does not happen on UP and on SMP the irqbalancer protects us by pinning the primary handler and the thread to the same CPU. Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2010-03-09 21:45:54 +03:00
/*
* Implausible though it may be we need to protect us against
* the following scenario:
*
* The thread is faster done than the hard interrupt handler
* on the other CPU. If we unmask the irq line then the
* interrupt can come in again and masks the line, leaves due
* to IRQS_INPROGRESS and the irq line is masked forever.
*
* This also serializes the state of shared oneshot handlers
* versus "desc->threads_onehsot |= action->thread_mask;" in
* irq_wake_thread(). See the comment there which explains the
* serialization.
genirq: Prevent oneshot irq thread race Lars-Peter pointed out that the oneshot threaded interrupt handler code has the following race: CPU0 CPU1 hande_level_irq(irq X) mask_ack_irq(irq X) handle_IRQ_event(irq X) wake_up(thread_handler) thread handler(irq X) runs finalize_oneshot(irq X) does not unmask due to !(desc->status & IRQ_MASKED) return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This leaves the interrupt line masked forever. The reason for this is the inconsistent handling of the IRQ_MASKED flag. Instead of setting it in the mask function the oneshot support sets the flag after waking up the irq thread. The solution for this is to set/clear the IRQ_MASKED status whenever we mask/unmask an interrupt line. That's the easy part, but that cleanup opens another race: CPU0 CPU1 hande_level_irq(irq) mask_ack_irq(irq) handle_IRQ_event(irq) wake_up(thread_handler) thread handler(irq) runs finalize_oneshot_irq(irq) unmask(irq) irq triggers again handle_level_irq(irq) mask_ack_irq(irq) return from irq due to IRQ_INPROGRESS return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This requires that we synchronize finalize_oneshot_irq() with the primary handler. If IRQ_INPROGESS is set we wait until the primary handler on the other CPU has returned before unmasking the interrupt line again. We probably have never seen that problem because it does not happen on UP and on SMP the irqbalancer protects us by pinning the primary handler and the thread to the same CPU. Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2010-03-09 21:45:54 +03:00
*/
if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
genirq: Prevent oneshot irq thread race Lars-Peter pointed out that the oneshot threaded interrupt handler code has the following race: CPU0 CPU1 hande_level_irq(irq X) mask_ack_irq(irq X) handle_IRQ_event(irq X) wake_up(thread_handler) thread handler(irq X) runs finalize_oneshot(irq X) does not unmask due to !(desc->status & IRQ_MASKED) return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This leaves the interrupt line masked forever. The reason for this is the inconsistent handling of the IRQ_MASKED flag. Instead of setting it in the mask function the oneshot support sets the flag after waking up the irq thread. The solution for this is to set/clear the IRQ_MASKED status whenever we mask/unmask an interrupt line. That's the easy part, but that cleanup opens another race: CPU0 CPU1 hande_level_irq(irq) mask_ack_irq(irq) handle_IRQ_event(irq) wake_up(thread_handler) thread handler(irq) runs finalize_oneshot_irq(irq) unmask(irq) irq triggers again handle_level_irq(irq) mask_ack_irq(irq) return from irq due to IRQ_INPROGRESS return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This requires that we synchronize finalize_oneshot_irq() with the primary handler. If IRQ_INPROGESS is set we wait until the primary handler on the other CPU has returned before unmasking the interrupt line again. We probably have never seen that problem because it does not happen on UP and on SMP the irqbalancer protects us by pinning the primary handler and the thread to the same CPU. Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2010-03-09 21:45:54 +03:00
raw_spin_unlock_irq(&desc->lock);
chip_bus_sync_unlock(desc);
genirq: Prevent oneshot irq thread race Lars-Peter pointed out that the oneshot threaded interrupt handler code has the following race: CPU0 CPU1 hande_level_irq(irq X) mask_ack_irq(irq X) handle_IRQ_event(irq X) wake_up(thread_handler) thread handler(irq X) runs finalize_oneshot(irq X) does not unmask due to !(desc->status & IRQ_MASKED) return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This leaves the interrupt line masked forever. The reason for this is the inconsistent handling of the IRQ_MASKED flag. Instead of setting it in the mask function the oneshot support sets the flag after waking up the irq thread. The solution for this is to set/clear the IRQ_MASKED status whenever we mask/unmask an interrupt line. That's the easy part, but that cleanup opens another race: CPU0 CPU1 hande_level_irq(irq) mask_ack_irq(irq) handle_IRQ_event(irq) wake_up(thread_handler) thread handler(irq) runs finalize_oneshot_irq(irq) unmask(irq) irq triggers again handle_level_irq(irq) mask_ack_irq(irq) return from irq due to IRQ_INPROGRESS return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This requires that we synchronize finalize_oneshot_irq() with the primary handler. If IRQ_INPROGESS is set we wait until the primary handler on the other CPU has returned before unmasking the interrupt line again. We probably have never seen that problem because it does not happen on UP and on SMP the irqbalancer protects us by pinning the primary handler and the thread to the same CPU. Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2010-03-09 21:45:54 +03:00
cpu_relax();
goto again;
}
/*
* Now check again, whether the thread should run. Otherwise
* we would clear the threads_oneshot bit of this thread which
* was just set.
*/
if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
goto out_unlock;
desc->threads_oneshot &= ~action->thread_mask;
if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
irqd_irq_masked(&desc->irq_data))
unmask_irq(desc);
out_unlock:
raw_spin_unlock_irq(&desc->lock);
chip_bus_sync_unlock(desc);
genirq: Add oneshot support For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:22 +04:00
}
#ifdef CONFIG_SMP
/*
* Check whether we need to chasnge the affinity of the interrupt thread.
*/
static void
irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
{
cpumask_var_t mask;
bool valid = true;
if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
return;
/*
* In case we are out of memory we set IRQTF_AFFINITY again and
* try again next time
*/
if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
set_bit(IRQTF_AFFINITY, &action->thread_flags);
return;
}
raw_spin_lock_irq(&desc->lock);
/*
* This code is triggered unconditionally. Check the affinity
* mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
*/
if (desc->irq_data.affinity)
cpumask_copy(mask, desc->irq_data.affinity);
else
valid = false;
raw_spin_unlock_irq(&desc->lock);
if (valid)
set_cpus_allowed_ptr(current, mask);
free_cpumask_var(mask);
}
#else
static inline void
irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
#endif
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
/*
* Interrupts which are not explicitely requested as threaded
* interrupts rely on the implicit bh/preempt disable of the hard irq
* context. So we need to disable bh here to avoid deadlocks and other
* side effects.
*/
static irqreturn_t
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
{
irqreturn_t ret;
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
local_bh_disable();
ret = action->thread_fn(action->irq, action->dev_id);
irq_finalize_oneshot(desc, action);
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
local_bh_enable();
return ret;
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
}
/*
* Interrupts explicitely requested as threaded interupts want to be
* preemtible - many of them need to sleep and wait for slow busses to
* complete.
*/
static irqreturn_t irq_thread_fn(struct irq_desc *desc,
struct irqaction *action)
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
{
irqreturn_t ret;
ret = action->thread_fn(action->irq, action->dev_id);
irq_finalize_oneshot(desc, action);
return ret;
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
}
static void wake_threads_waitq(struct irq_desc *desc)
{
if (atomic_dec_and_test(&desc->threads_active) &&
waitqueue_active(&desc->wait_for_threads))
wake_up(&desc->wait_for_threads);
}
static void irq_thread_dtor(struct callback_head *unused)
{
struct task_struct *tsk = current;
struct irq_desc *desc;
struct irqaction *action;
if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
return;
action = kthread_data(tsk);
pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
tsk->comm, tsk->pid, action->irq);
desc = irq_to_desc(action->irq);
/*
* If IRQTF_RUNTHREAD is set, we need to decrement
* desc->threads_active and wake possible waiters.
*/
if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
wake_threads_waitq(desc);
/* Prevent a stale desc->threads_oneshot */
irq_finalize_oneshot(desc, action);
}
/*
* Interrupt handler thread
*/
static int irq_thread(void *data)
{
struct callback_head on_exit_work;
struct irqaction *action = data;
struct irq_desc *desc = irq_to_desc(action->irq);
irqreturn_t (*handler_fn)(struct irq_desc *desc,
struct irqaction *action);
if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
&action->thread_flags))
handler_fn = irq_forced_thread_fn;
else
handler_fn = irq_thread_fn;
init_task_work(&on_exit_work, irq_thread_dtor);
task_work_add(current, &on_exit_work, false);
irq_thread_check_affinity(desc, action);
while (!irq_wait_for_interrupt(action)) {
irqreturn_t action_ret;
irq_thread_check_affinity(desc, action);
action_ret = handler_fn(desc, action);
if (!noirqdebug)
note_interrupt(action->irq, desc, action_ret);
wake_threads_waitq(desc);
}
/*
* This is the regular exit path. __free_irq() is stopping the
* thread via kthread_stop() after calling
* synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
* oneshot mask bit can be set. We cannot verify that as we
* cannot touch the oneshot mask at this point anymore as
* __setup_irq() might have given out currents thread_mask
* again.
*/
task_work_cancel(current, irq_thread_dtor);
return 0;
}
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
static void irq_setup_forced_threading(struct irqaction *new)
{
if (!force_irqthreads)
return;
if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
return;
new->flags |= IRQF_ONESHOT;
if (!new->thread_fn) {
set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
new->thread_fn = new->handler;
new->handler = irq_default_primary_handler;
}
}
/*
* Internal function to register an irqaction - typically used to
* allocate special interrupts that are part of the architecture.
*/
static int
__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
{
struct irqaction *old, **old_ptr;
unsigned long flags, thread_mask = 0;
int ret, nested, shared = 0;
cpumask_var_t mask;
if (!desc)
return -EINVAL;
if (desc->irq_data.chip == &no_irq_chip)
return -ENOSYS;
if (!try_module_get(desc->owner))
return -ENODEV;
/*
genirq: Support nested threaded irq handling Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 15:21:38 +04:00
* Check whether the interrupt nests into another interrupt
* thread.
*/
nested = irq_settings_is_nested_thread(desc);
genirq: Support nested threaded irq handling Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 15:21:38 +04:00
if (nested) {
if (!new->thread_fn) {
ret = -EINVAL;
goto out_mput;
}
genirq: Support nested threaded irq handling Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 15:21:38 +04:00
/*
* Replace the primary handler which was provided from
* the driver for non nested interrupt handling by the
* dummy function which warns when called.
*/
new->handler = irq_nested_primary_handler;
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-24 02:52:23 +03:00
} else {
if (irq_settings_can_thread(desc))
irq_setup_forced_threading(new);
genirq: Support nested threaded irq handling Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 15:21:38 +04:00
}
/*
genirq: Support nested threaded irq handling Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 15:21:38 +04:00
* Create a handler thread when a thread function is supplied
* and the interrupt does not nest into another interrupt
* thread.
*/
genirq: Support nested threaded irq handling Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 15:21:38 +04:00
if (new->thread_fn && !nested) {
struct task_struct *t;
static const struct sched_param param = {
.sched_priority = MAX_USER_RT_PRIO/2,
};
t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
new->name);
if (IS_ERR(t)) {
ret = PTR_ERR(t);
goto out_mput;
}
sched_setscheduler(t, SCHED_FIFO, &param);
/*
* We keep the reference to the task struct even if
* the thread dies to avoid that the interrupt code
* references an already freed task_struct.
*/
get_task_struct(t);
new->thread = t;
/*
* Tell the thread to set its affinity. This is
* important for shared interrupt handlers as we do
* not invoke setup_affinity() for the secondary
* handlers as everything is already set up. Even for
* interrupts marked with IRQF_NO_BALANCE this is
* correct as we want the thread to move to the cpu(s)
* on which the requesting code placed the interrupt.
*/
set_bit(IRQTF_AFFINITY, &new->thread_flags);
}
if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
ret = -ENOMEM;
goto out_thread;
}
/*
* Drivers are often written to work w/o knowledge about the
* underlying irq chip implementation, so a request for a
* threaded irq without a primary hard irq context handler
* requires the ONESHOT flag to be set. Some irq chips like
* MSI based interrupts are per se one shot safe. Check the
* chip flags, so we can avoid the unmask dance at the end of
* the threaded handler for those.
*/
if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
new->flags &= ~IRQF_ONESHOT;
/*
* The following block of code has to be executed atomically
*/
raw_spin_lock_irqsave(&desc->lock, flags);
old_ptr = &desc->action;
old = *old_ptr;
if (old) {
/*
* Can't share interrupts unless both agree to and are
* the same type (level, edge, polarity). So both flag
* fields must have IRQF_SHARED set and the bits which
* set the trigger type must match. Also all must
* agree on ONESHOT.
*/
if (!((old->flags & new->flags) & IRQF_SHARED) ||
((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
((old->flags ^ new->flags) & IRQF_ONESHOT))
goto mismatch;
/* All handlers must agree on per-cpuness */
if ((old->flags & IRQF_PERCPU) !=
(new->flags & IRQF_PERCPU))
goto mismatch;
/* add new interrupt at end of irq queue */
do {
/*
* Or all existing action->thread_mask bits,
* so we can find the next zero bit for this
* new action.
*/
thread_mask |= old->thread_mask;
old_ptr = &old->next;
old = *old_ptr;
} while (old);
shared = 1;
}
/*
* Setup the thread mask for this irqaction for ONESHOT. For
* !ONESHOT irqs the thread mask is 0 so we can avoid a
* conditional in irq_wake_thread().
*/
if (new->flags & IRQF_ONESHOT) {
/*
* Unlikely to have 32 resp 64 irqs sharing one line,
* but who knows.
*/
if (thread_mask == ~0UL) {
ret = -EBUSY;
goto out_mask;
}
/*
* The thread_mask for the action is or'ed to
* desc->thread_active to indicate that the
* IRQF_ONESHOT thread handler has been woken, but not
* yet finished. The bit is cleared when a thread
* completes. When all threads of a shared interrupt
* line have completed desc->threads_active becomes
* zero and the interrupt line is unmasked. See
* handle.c:irq_wake_thread() for further information.
*
* If no thread is woken by primary (hard irq context)
* interrupt handlers, then desc->threads_active is
* also checked for zero to unmask the irq line in the
* affected hard irq flow handlers
* (handle_[fasteoi|level]_irq).
*
* The new action gets the first zero bit of
* thread_mask assigned. See the loop above which or's
* all existing action->thread_mask bits.
*/
new->thread_mask = 1 << ffz(thread_mask);
} else if (new->handler == irq_default_primary_handler &&
!(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
/*
* The interrupt was requested with handler = NULL, so
* we use the default primary handler for it. But it
* does not have the oneshot flag set. In combination
* with level interrupts this is deadly, because the
* default primary handler just wakes the thread, then
* the irq lines is reenabled, but the device still
* has the level irq asserted. Rinse and repeat....
*
* While this works for edge type interrupts, we play
* it safe and reject unconditionally because we can't
* say for sure which type this interrupt really
* has. The type flags are unreliable as the
* underlying chip implementation can override them.
*/
pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
irq);
ret = -EINVAL;
goto out_mask;
}
if (!shared) {
init_waitqueue_head(&desc->wait_for_threads);
/* Setup the type (level, edge polarity) if configured: */
if (new->flags & IRQF_TRIGGER_MASK) {
ret = __irq_set_trigger(desc, irq,
new->flags & IRQF_TRIGGER_MASK);
if (ret)
goto out_mask;
}
desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
IRQS_ONESHOT | IRQS_WAITING);
irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
if (new->flags & IRQF_PERCPU) {
irqd_set(&desc->irq_data, IRQD_PER_CPU);
irq_settings_set_per_cpu(desc);
}
genirq: Add oneshot support For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:22 +04:00
if (new->flags & IRQF_ONESHOT)
desc->istate |= IRQS_ONESHOT;
genirq: Add oneshot support For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:22 +04:00
if (irq_settings_can_autoenable(desc))
irq_startup(desc, true);
else
/* Undo nested disables: */
desc->depth = 1;
/* Exclude IRQ from balancing if requested */
if (new->flags & IRQF_NOBALANCING) {
irq_settings_set_no_balancing(desc);
irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
}
/* Set default affinity mask once everything is setup */
setup_affinity(irq, desc, mask);
} else if (new->flags & IRQF_TRIGGER_MASK) {
unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
unsigned int omsk = irq_settings_get_trigger_mask(desc);
if (nmsk != omsk)
/* hope the handler works with current trigger mode */
pr_warning("irq %d uses trigger mode %u; requested %u\n",
irq, nmsk, omsk);
}
new->irq = irq;
*old_ptr = new;
/* Reset broken irq detection when installing new handler */
desc->irq_count = 0;
desc->irqs_unhandled = 0;
/*
* Check whether we disabled the irq via the spurious handler
* before. Reenable it and give it another chance.
*/
if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
desc->istate &= ~IRQS_SPURIOUS_DISABLED;
__enable_irq(desc, irq, false);
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
/*
* Strictly no need to wake it up, but hung_task complains
* when no hard interrupt wakes the thread up.
*/
if (new->thread)
wake_up_process(new->thread);
register_irq_proc(irq, desc);
new->dir = NULL;
register_handler_proc(irq, new);
free_cpumask_var(mask);
return 0;
mismatch:
if (!(new->flags & IRQF_PROBE_SHARED)) {
pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
irq, new->flags, new->name, old->flags, old->name);
#ifdef CONFIG_DEBUG_SHIRQ
dump_stack();
#endif
}
ret = -EBUSY;
out_mask:
raw_spin_unlock_irqrestore(&desc->lock, flags);
free_cpumask_var(mask);
out_thread:
if (new->thread) {
struct task_struct *t = new->thread;
new->thread = NULL;
kthread_stop(t);
put_task_struct(t);
}
out_mput:
module_put(desc->owner);
return ret;
}
/**
* setup_irq - setup an interrupt
* @irq: Interrupt line to setup
* @act: irqaction for the interrupt
*
* Used to statically setup interrupts in the early boot process.
*/
int setup_irq(unsigned int irq, struct irqaction *act)
{
int retval;
struct irq_desc *desc = irq_to_desc(irq);
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
return -EINVAL;
chip_bus_lock(desc);
retval = __setup_irq(irq, desc, act);
chip_bus_sync_unlock(desc);
return retval;
}
EXPORT_SYMBOL_GPL(setup_irq);
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
/*
* Internal function to unregister an irqaction - used to free
* regular and special interrupts that are part of the architecture.
*/
static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action, **action_ptr;
unsigned long flags;
WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
if (!desc)
return NULL;
raw_spin_lock_irqsave(&desc->lock, flags);
/*
* There can be multiple actions per IRQ descriptor, find the right
* one based on the dev_id:
*/
action_ptr = &desc->action;
for (;;) {
action = *action_ptr;
if (!action) {
WARN(1, "Trying to free already-free IRQ %d\n", irq);
raw_spin_unlock_irqrestore(&desc->lock, flags);
return NULL;
}
if (action->dev_id == dev_id)
break;
action_ptr = &action->next;
}
[PATCH] uml: add and use generic hw_controller_type->release With Chris Wedgwood <cw@f00f.org> Currently UML must explicitly call the UML-specific free_irq_by_irq_and_dev() for each free_irq call it's done. This is needed because ->shutdown and/or ->disable are only called when the last "action" for that irq is removed. Instead, for UML shared IRQs (UML IRQs are very often, if not always, shared), for each dev_id some setup is done, which must be cleared on the release of that fd. For instance, for each open console a new instance (i.e. new dev_id) of the same IRQ is requested(). Exactly, a fd is stored in an array (pollfds), which is after read by a host thread and passed to poll(). Each event registered by poll() triggers an interrupt. So, for each free_irq() we must remove the corresponding host fd from the table, which we do via this -release() method. In this patch we add an appropriate hook for this, and remove all uses of it by pointing the hook to the said procedure; this is safe to do since the said procedure. Also some cosmetic improvements are included. This is heavily based on some work by Chris Wedgwood, which however didn't get the patch merged for something I'd call a "misunderstanding" (the need for this patch wasn't cleanly explained, thus adding the generic hook was felt as undesirable). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> CC: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-22 04:16:19 +04:00
/* Found it - now remove it from the list of entries: */
*action_ptr = action->next;
/* If this was the last handler, shut down the IRQ line: */
if (!desc->action)
irq_shutdown(desc);
#ifdef CONFIG_SMP
/* make sure affinity_hint is cleaned up */
if (WARN_ON_ONCE(desc->affinity_hint))
desc->affinity_hint = NULL;
#endif
raw_spin_unlock_irqrestore(&desc->lock, flags);
unregister_handler_proc(irq, action);
/* Make sure it's not being used on another CPU: */
synchronize_irq(irq);
#ifdef CONFIG_DEBUG_SHIRQ
/*
* It's a shared IRQ -- the driver ought to be prepared for an IRQ
* event to happen even now it's being freed, so let's make sure that
* is so by doing an extra call to the handler ....
*
* ( We do this after actually deregistering it, to make sure that a
* 'real' IRQ doesn't run in * parallel with our fake. )
*/
if (action->flags & IRQF_SHARED) {
local_irq_save(flags);
action->handler(irq, dev_id);
local_irq_restore(flags);
}
#endif
if (action->thread) {
kthread_stop(action->thread);
put_task_struct(action->thread);
}
module_put(desc->owner);
return action;
}
/**
* remove_irq - free an interrupt
* @irq: Interrupt line to free
* @act: irqaction for the interrupt
*
* Used to remove interrupts statically setup by the early boot process.
*/
void remove_irq(unsigned int irq, struct irqaction *act)
{
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
struct irq_desc *desc = irq_to_desc(irq);
if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
__free_irq(irq, act->dev_id);
}
EXPORT_SYMBOL_GPL(remove_irq);
/**
* free_irq - free an interrupt allocated with request_irq
* @irq: Interrupt line to free
* @dev_id: Device identity to free
*
* Remove an interrupt handler. The handler is removed and if the
* interrupt line is no longer in use by any driver it is disabled.
* On a shared IRQ the caller must ensure the interrupt is disabled
* on the card it drives before calling this function. The function
* does not return until any executing interrupts for this IRQ
* have completed.
*
* This function must not be called from interrupt context.
*/
void free_irq(unsigned int irq, void *dev_id)
{
genirq: Add buslock support Some interrupt chips are connected to a "slow" bus (i2c, spi ...). The bus access needs to sleep and therefor cannot be called in atomic contexts. Some of the generic interrupt management functions like disable_irq(), enable_irq() ... call interrupt chip functions with the irq_desc->lock held and interrupts disabled. This does not work for such devices. Provide a separate synchronization mechanism for such interrupt chips. The irq_chip structure is extended by two optional functions (bus_lock and bus_sync_and_unlock). The idea is to serialize the bus access for those operations in the core code so that drivers which are behind that bus operated interrupt controller do not have to worry about it and just can use the normal interfaces. To achieve this we add two function pointers to the irq_chip: bus_lock and bus_sync_unlock. bus_lock() is called to serialize access to the interrupt controller bus. Now the core code can issue chip->mask/unmask ... commands without changing the fast path code at all. The chip implementation merily stores that information in a chip private data structure and returns. No bus interaction as these functions are called from atomic context. After that bus_sync_unlock() is called outside the atomic context. Now the chip implementation issues the bus commands, waits for completion and unlocks the interrupt controller bus. The irq_chip implementation as pseudo code: struct irq_chip_data { struct mutex mutex; unsigned int irq_offset; unsigned long mask; unsigned long mask_status; } static void bus_lock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); mutex_lock(&data->mutex); } static void mask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask |= (1 << irq); } static void unmask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask &= ~(1 << irq); } static void bus_sync_unlock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); if (data->mask != data->mask_status) { do_bus_magic_to_set_mask(data->mask); data->mask_status = data->mask; } mutex_unlock(&data->mutex); } The device drivers can use request_threaded_irq, free_irq, disable_irq and enable_irq as usual with the only restriction that the calls need to come from non atomic context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:48 +04:00
struct irq_desc *desc = irq_to_desc(irq);
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
genirq: Add buslock support Some interrupt chips are connected to a "slow" bus (i2c, spi ...). The bus access needs to sleep and therefor cannot be called in atomic contexts. Some of the generic interrupt management functions like disable_irq(), enable_irq() ... call interrupt chip functions with the irq_desc->lock held and interrupts disabled. This does not work for such devices. Provide a separate synchronization mechanism for such interrupt chips. The irq_chip structure is extended by two optional functions (bus_lock and bus_sync_and_unlock). The idea is to serialize the bus access for those operations in the core code so that drivers which are behind that bus operated interrupt controller do not have to worry about it and just can use the normal interfaces. To achieve this we add two function pointers to the irq_chip: bus_lock and bus_sync_unlock. bus_lock() is called to serialize access to the interrupt controller bus. Now the core code can issue chip->mask/unmask ... commands without changing the fast path code at all. The chip implementation merily stores that information in a chip private data structure and returns. No bus interaction as these functions are called from atomic context. After that bus_sync_unlock() is called outside the atomic context. Now the chip implementation issues the bus commands, waits for completion and unlocks the interrupt controller bus. The irq_chip implementation as pseudo code: struct irq_chip_data { struct mutex mutex; unsigned int irq_offset; unsigned long mask; unsigned long mask_status; } static void bus_lock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); mutex_lock(&data->mutex); } static void mask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask |= (1 << irq); } static void unmask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask &= ~(1 << irq); } static void bus_sync_unlock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); if (data->mask != data->mask_status) { do_bus_magic_to_set_mask(data->mask); data->mask_status = data->mask; } mutex_unlock(&data->mutex); } The device drivers can use request_threaded_irq, free_irq, disable_irq and enable_irq as usual with the only restriction that the calls need to come from non atomic context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:48 +04:00
return;
#ifdef CONFIG_SMP
if (WARN_ON(desc->affinity_notify))
desc->affinity_notify = NULL;
#endif
chip_bus_lock(desc);
kfree(__free_irq(irq, dev_id));
chip_bus_sync_unlock(desc);
}
EXPORT_SYMBOL(free_irq);
/**
* request_threaded_irq - allocate an interrupt line
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* Primary handler for threaded interrupts
genirq: Add oneshot support For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:22 +04:00
* If NULL and thread_fn != NULL the default
* primary handler is installed
* @thread_fn: Function called from the irq handler thread
* If NULL, no irq thread is created
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
*
* This call allocates interrupt resources and enables the
* interrupt line and IRQ handling. From the point this
* call is made your handler function may be invoked. Since
* your handler function must clear any interrupt the board
* raises, you must take care both to initialise your hardware
* and to set up the interrupt handler in the right order.
*
* If you want to set up a threaded irq handler for your device
* then you need to supply @handler and @thread_fn. @handler is
* still called in hard interrupt context and has to check
* whether the interrupt originates from the device. If yes it
* needs to disable the interrupt on the device and return
* IRQ_WAKE_THREAD which will wake up the handler thread and run
* @thread_fn. This split handler design is necessary to support
* shared interrupts.
*
* Dev_id must be globally unique. Normally the address of the
* device data structure is used as the cookie. Since the handler
* receives this value it makes sense to use it.
*
* If your interrupt is shared you must pass a non NULL dev_id
* as this is required when freeing the interrupt.
*
* Flags:
*
* IRQF_SHARED Interrupt is shared
* IRQF_TRIGGER_* Specify active edge(s) or level
*
*/
int request_threaded_irq(unsigned int irq, irq_handler_t handler,
irq_handler_t thread_fn, unsigned long irqflags,
const char *devname, void *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
int retval;
/*
* Sanity-check: shared interrupts must pass in a real dev-ID,
* otherwise we'll have trouble later trying to figure out
* which interrupt is which (messes up the interrupt freeing
* logic etc).
*/
if ((irqflags & IRQF_SHARED) && !dev_id)
return -EINVAL;
desc = irq_to_desc(irq);
if (!desc)
return -EINVAL;
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
if (!irq_settings_can_request(desc) ||
WARN_ON(irq_settings_is_per_cpu_devid(desc)))
return -EINVAL;
genirq: Add oneshot support For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:22 +04:00
if (!handler) {
if (!thread_fn)
return -EINVAL;
handler = irq_default_primary_handler;
}
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
action->thread_fn = thread_fn;
action->flags = irqflags;
action->name = devname;
action->dev_id = dev_id;
chip_bus_lock(desc);
retval = __setup_irq(irq, desc, action);
chip_bus_sync_unlock(desc);
genirq: Add buslock support Some interrupt chips are connected to a "slow" bus (i2c, spi ...). The bus access needs to sleep and therefor cannot be called in atomic contexts. Some of the generic interrupt management functions like disable_irq(), enable_irq() ... call interrupt chip functions with the irq_desc->lock held and interrupts disabled. This does not work for such devices. Provide a separate synchronization mechanism for such interrupt chips. The irq_chip structure is extended by two optional functions (bus_lock and bus_sync_and_unlock). The idea is to serialize the bus access for those operations in the core code so that drivers which are behind that bus operated interrupt controller do not have to worry about it and just can use the normal interfaces. To achieve this we add two function pointers to the irq_chip: bus_lock and bus_sync_unlock. bus_lock() is called to serialize access to the interrupt controller bus. Now the core code can issue chip->mask/unmask ... commands without changing the fast path code at all. The chip implementation merily stores that information in a chip private data structure and returns. No bus interaction as these functions are called from atomic context. After that bus_sync_unlock() is called outside the atomic context. Now the chip implementation issues the bus commands, waits for completion and unlocks the interrupt controller bus. The irq_chip implementation as pseudo code: struct irq_chip_data { struct mutex mutex; unsigned int irq_offset; unsigned long mask; unsigned long mask_status; } static void bus_lock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); mutex_lock(&data->mutex); } static void mask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask |= (1 << irq); } static void unmask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask &= ~(1 << irq); } static void bus_sync_unlock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); if (data->mask != data->mask_status) { do_bus_magic_to_set_mask(data->mask); data->mask_status = data->mask; } mutex_unlock(&data->mutex); } The device drivers can use request_threaded_irq, free_irq, disable_irq and enable_irq as usual with the only restriction that the calls need to come from non atomic context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13 14:17:48 +04:00
genirq: fix irq_desc->depth handling with DEBUG_SHIRQ When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 <ME,IR,DR> CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 22:58:28 +04:00
if (retval)
kfree(action);
#ifdef CONFIG_DEBUG_SHIRQ_FIXME
if (!retval && (irqflags & IRQF_SHARED)) {
/*
* It's a shared IRQ -- the driver ought to be prepared for it
* to happen immediately, so let's make sure....
genirq: fix irq_desc->depth handling with DEBUG_SHIRQ When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 <ME,IR,DR> CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 22:58:28 +04:00
* We disable the irq to make sure that a 'real' IRQ doesn't
* run in parallel with our fake.
*/
request_irq: fix DEBUG_SHIRQ handling Mariusz Kozlowski reported lockdep's warning: > ================================= > [ INFO: inconsistent lock state ] > 2.6.23-rc2-mm1 #7 > --------------------------------- > inconsistent {in-hardirq-W} -> {hardirq-on-W} usage. > ifconfig/5492 [HC0[0]:SC0[0]:HE1:SE1] takes: > (&tp->lock){+...}, at: [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > {in-hardirq-W} state was registered at: > [<c0138eeb>] __lock_acquire+0x949/0x11ac > [<c01397e7>] lock_acquire+0x99/0xb2 > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c0147a5d>] handle_IRQ_event+0x28/0x59 > [<c01493ca>] handle_level_irq+0xad/0x10b > [<c0105a13>] do_IRQ+0x93/0xd0 > [<c010441e>] common_interrupt+0x2e/0x34 ... > other info that might help us debug this: > 1 lock held by ifconfig/5492: > #0: (rtnl_mutex){--..}, at: [<c0451778>] mutex_lock+0x1c/0x1f > > stack backtrace: ... > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c01480fd>] free_irq+0x11b/0x146 > [<de871d59>] rtl8139_close+0x8a/0x14a [8139too] > [<c03bde63>] dev_close+0x57/0x74 ... This shows that a driver's irq handler was running both in hard interrupt and process contexts with irqs enabled. The latter was done during free_irq() call and was possible only with CONFIG_DEBUG_SHIRQ enabled. This was fixed by another patch. But similar problem is possible with request_irq(): any locks taken from irq handler could be vulnerable - especially with soft interrupts. This patch fixes it by disabling local interrupts during handler's run. (It seems, disabling softirqs should be enough, but it needs more checking on possible races or other special cases). Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Jarek Poplawski <jarkao2@o2.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 10:56:34 +04:00
unsigned long flags;
genirq: fix irq_desc->depth handling with DEBUG_SHIRQ When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 <ME,IR,DR> CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 22:58:28 +04:00
disable_irq(irq);
request_irq: fix DEBUG_SHIRQ handling Mariusz Kozlowski reported lockdep's warning: > ================================= > [ INFO: inconsistent lock state ] > 2.6.23-rc2-mm1 #7 > --------------------------------- > inconsistent {in-hardirq-W} -> {hardirq-on-W} usage. > ifconfig/5492 [HC0[0]:SC0[0]:HE1:SE1] takes: > (&tp->lock){+...}, at: [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > {in-hardirq-W} state was registered at: > [<c0138eeb>] __lock_acquire+0x949/0x11ac > [<c01397e7>] lock_acquire+0x99/0xb2 > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c0147a5d>] handle_IRQ_event+0x28/0x59 > [<c01493ca>] handle_level_irq+0xad/0x10b > [<c0105a13>] do_IRQ+0x93/0xd0 > [<c010441e>] common_interrupt+0x2e/0x34 ... > other info that might help us debug this: > 1 lock held by ifconfig/5492: > #0: (rtnl_mutex){--..}, at: [<c0451778>] mutex_lock+0x1c/0x1f > > stack backtrace: ... > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c01480fd>] free_irq+0x11b/0x146 > [<de871d59>] rtl8139_close+0x8a/0x14a [8139too] > [<c03bde63>] dev_close+0x57/0x74 ... This shows that a driver's irq handler was running both in hard interrupt and process contexts with irqs enabled. The latter was done during free_irq() call and was possible only with CONFIG_DEBUG_SHIRQ enabled. This was fixed by another patch. But similar problem is possible with request_irq(): any locks taken from irq handler could be vulnerable - especially with soft interrupts. This patch fixes it by disabling local interrupts during handler's run. (It seems, disabling softirqs should be enough, but it needs more checking on possible races or other special cases). Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Jarek Poplawski <jarkao2@o2.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 10:56:34 +04:00
local_irq_save(flags);
genirq: fix irq_desc->depth handling with DEBUG_SHIRQ When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 <ME,IR,DR> CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 22:58:28 +04:00
request_irq: fix DEBUG_SHIRQ handling Mariusz Kozlowski reported lockdep's warning: > ================================= > [ INFO: inconsistent lock state ] > 2.6.23-rc2-mm1 #7 > --------------------------------- > inconsistent {in-hardirq-W} -> {hardirq-on-W} usage. > ifconfig/5492 [HC0[0]:SC0[0]:HE1:SE1] takes: > (&tp->lock){+...}, at: [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > {in-hardirq-W} state was registered at: > [<c0138eeb>] __lock_acquire+0x949/0x11ac > [<c01397e7>] lock_acquire+0x99/0xb2 > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c0147a5d>] handle_IRQ_event+0x28/0x59 > [<c01493ca>] handle_level_irq+0xad/0x10b > [<c0105a13>] do_IRQ+0x93/0xd0 > [<c010441e>] common_interrupt+0x2e/0x34 ... > other info that might help us debug this: > 1 lock held by ifconfig/5492: > #0: (rtnl_mutex){--..}, at: [<c0451778>] mutex_lock+0x1c/0x1f > > stack backtrace: ... > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c01480fd>] free_irq+0x11b/0x146 > [<de871d59>] rtl8139_close+0x8a/0x14a [8139too] > [<c03bde63>] dev_close+0x57/0x74 ... This shows that a driver's irq handler was running both in hard interrupt and process contexts with irqs enabled. The latter was done during free_irq() call and was possible only with CONFIG_DEBUG_SHIRQ enabled. This was fixed by another patch. But similar problem is possible with request_irq(): any locks taken from irq handler could be vulnerable - especially with soft interrupts. This patch fixes it by disabling local interrupts during handler's run. (It seems, disabling softirqs should be enough, but it needs more checking on possible races or other special cases). Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Jarek Poplawski <jarkao2@o2.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 10:56:34 +04:00
handler(irq, dev_id);
genirq: fix irq_desc->depth handling with DEBUG_SHIRQ When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 <ME,IR,DR> CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 22:58:28 +04:00
request_irq: fix DEBUG_SHIRQ handling Mariusz Kozlowski reported lockdep's warning: > ================================= > [ INFO: inconsistent lock state ] > 2.6.23-rc2-mm1 #7 > --------------------------------- > inconsistent {in-hardirq-W} -> {hardirq-on-W} usage. > ifconfig/5492 [HC0[0]:SC0[0]:HE1:SE1] takes: > (&tp->lock){+...}, at: [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > {in-hardirq-W} state was registered at: > [<c0138eeb>] __lock_acquire+0x949/0x11ac > [<c01397e7>] lock_acquire+0x99/0xb2 > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c0147a5d>] handle_IRQ_event+0x28/0x59 > [<c01493ca>] handle_level_irq+0xad/0x10b > [<c0105a13>] do_IRQ+0x93/0xd0 > [<c010441e>] common_interrupt+0x2e/0x34 ... > other info that might help us debug this: > 1 lock held by ifconfig/5492: > #0: (rtnl_mutex){--..}, at: [<c0451778>] mutex_lock+0x1c/0x1f > > stack backtrace: ... > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c01480fd>] free_irq+0x11b/0x146 > [<de871d59>] rtl8139_close+0x8a/0x14a [8139too] > [<c03bde63>] dev_close+0x57/0x74 ... This shows that a driver's irq handler was running both in hard interrupt and process contexts with irqs enabled. The latter was done during free_irq() call and was possible only with CONFIG_DEBUG_SHIRQ enabled. This was fixed by another patch. But similar problem is possible with request_irq(): any locks taken from irq handler could be vulnerable - especially with soft interrupts. This patch fixes it by disabling local interrupts during handler's run. (It seems, disabling softirqs should be enough, but it needs more checking on possible races or other special cases). Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Jarek Poplawski <jarkao2@o2.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 10:56:34 +04:00
local_irq_restore(flags);
genirq: fix irq_desc->depth handling with DEBUG_SHIRQ When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 <ME,IR,DR> CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 22:58:28 +04:00
enable_irq(irq);
}
#endif
return retval;
}
EXPORT_SYMBOL(request_threaded_irq);
/**
* request_any_context_irq - allocate an interrupt line
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* Threaded handler for threaded interrupts.
* @flags: Interrupt type flags
* @name: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
*
* This call allocates interrupt resources and enables the
* interrupt line and IRQ handling. It selects either a
* hardirq or threaded handling method depending on the
* context.
*
* On failure, it returns a negative value. On success,
* it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
*/
int request_any_context_irq(unsigned int irq, irq_handler_t handler,
unsigned long flags, const char *name, void *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
int ret;
if (!desc)
return -EINVAL;
if (irq_settings_is_nested_thread(desc)) {
ret = request_threaded_irq(irq, NULL, handler,
flags, name, dev_id);
return !ret ? IRQC_IS_NESTED : ret;
}
ret = request_irq(irq, handler, flags, name, dev_id);
return !ret ? IRQC_IS_HARDIRQ : ret;
}
EXPORT_SYMBOL_GPL(request_any_context_irq);
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
void enable_percpu_irq(unsigned int irq, unsigned int type)
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
{
unsigned int cpu = smp_processor_id();
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
if (!desc)
return;
type &= IRQ_TYPE_SENSE_MASK;
if (type != IRQ_TYPE_NONE) {
int ret;
ret = __irq_set_trigger(desc, irq, type);
if (ret) {
WARN(1, "failed to set type for IRQ%d\n", irq);
goto out;
}
}
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
irq_percpu_enable(desc, cpu);
out:
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
irq_put_desc_unlock(desc, flags);
}
EXPORT_SYMBOL_GPL(enable_percpu_irq);
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
void disable_percpu_irq(unsigned int irq)
{
unsigned int cpu = smp_processor_id();
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
if (!desc)
return;
irq_percpu_disable(desc, cpu);
irq_put_desc_unlock(desc, flags);
}
EXPORT_SYMBOL_GPL(disable_percpu_irq);
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
/*
* Internal function to unregister a percpu irqaction.
*/
static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action;
unsigned long flags;
WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
if (!desc)
return NULL;
raw_spin_lock_irqsave(&desc->lock, flags);
action = desc->action;
if (!action || action->percpu_dev_id != dev_id) {
WARN(1, "Trying to free already-free IRQ %d\n", irq);
goto bad;
}
if (!cpumask_empty(desc->percpu_enabled)) {
WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
irq, cpumask_first(desc->percpu_enabled));
goto bad;
}
/* Found it - now remove it from the list of entries: */
desc->action = NULL;
raw_spin_unlock_irqrestore(&desc->lock, flags);
unregister_handler_proc(irq, action);
module_put(desc->owner);
return action;
bad:
raw_spin_unlock_irqrestore(&desc->lock, flags);
return NULL;
}
/**
* remove_percpu_irq - free a per-cpu interrupt
* @irq: Interrupt line to free
* @act: irqaction for the interrupt
*
* Used to remove interrupts statically setup by the early boot process.
*/
void remove_percpu_irq(unsigned int irq, struct irqaction *act)
{
struct irq_desc *desc = irq_to_desc(irq);
if (desc && irq_settings_is_per_cpu_devid(desc))
__free_percpu_irq(irq, act->percpu_dev_id);
}
/**
* free_percpu_irq - free an interrupt allocated with request_percpu_irq
* @irq: Interrupt line to free
* @dev_id: Device identity to free
*
* Remove a percpu interrupt handler. The handler is removed, but
* the interrupt line is not disabled. This must be done on each
* CPU before calling this function. The function does not return
* until any executing interrupts for this IRQ have completed.
*
* This function must not be called from interrupt context.
*/
void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
if (!desc || !irq_settings_is_per_cpu_devid(desc))
return;
chip_bus_lock(desc);
kfree(__free_percpu_irq(irq, dev_id));
chip_bus_sync_unlock(desc);
}
/**
* setup_percpu_irq - setup a per-cpu interrupt
* @irq: Interrupt line to setup
* @act: irqaction for the interrupt
*
* Used to statically setup per-cpu interrupts in the early boot process.
*/
int setup_percpu_irq(unsigned int irq, struct irqaction *act)
{
struct irq_desc *desc = irq_to_desc(irq);
int retval;
if (!desc || !irq_settings_is_per_cpu_devid(desc))
return -EINVAL;
chip_bus_lock(desc);
retval = __setup_irq(irq, desc, act);
chip_bus_sync_unlock(desc);
return retval;
}
/**
* request_percpu_irq - allocate a percpu interrupt line
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* @devname: An ascii name for the claiming device
* @dev_id: A percpu cookie passed back to the handler function
*
* This call allocates interrupt resources, but doesn't
* automatically enable the interrupt. It has to be done on each
* CPU using enable_percpu_irq().
*
* Dev_id must be globally unique. It is a per-cpu variable, and
* the handler gets called with the interrupted CPU's instance of
* that variable.
*/
int request_percpu_irq(unsigned int irq, irq_handler_t handler,
const char *devname, void __percpu *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
int retval;
if (!dev_id)
return -EINVAL;
desc = irq_to_desc(irq);
if (!desc || !irq_settings_can_request(desc) ||
!irq_settings_is_per_cpu_devid(desc))
return -EINVAL;
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
genirq: Add support for per-cpu dev_id interrupts The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-09-23 20:03:06 +04:00
action->name = devname;
action->percpu_dev_id = dev_id;
chip_bus_lock(desc);
retval = __setup_irq(irq, desc, action);
chip_bus_sync_unlock(desc);
if (retval)
kfree(action);
return retval;
}