irqchip: Add per-cpu interrupt partitioning library
We've unfortunately started seeing a situation where percpu interrupts are partitioned in the system: one arbitrary set of CPUs has an interrupt connected to a type of device, while another disjoint set of CPUs has the same interrupt connected to another type of device. This makes it impossible to have a device driver requesting this interrupt using the current percpu-interrupt abstraction, as the same interrupt number is now potentially claimed by at least two drivers, and we forbid interrupt sharing on per-cpu interrupt. A solution to this is to turn things upside down. Let's assume that our system describes all the possible partitions for a given interrupt, and give each of them a unique identifier. It is then possible to create a namespace where the affinity identifier itself is a form of interrupt number. At this point, it becomes easy to implement a set of partitions as a cascaded irqchip, each affinity identifier being the HW irq. This allows us to keep a number of nice properties: - Each partition results in a separate percpu-interrupt (with a restrictied affinity), which keeps drivers happy. - Because the underlying interrupt is still per-cpu, the overhead of the indirection can be kept pretty minimal. - The core code can ignore most of that crap. For that purpose, we implement a small library that deals with some of the boilerplate code, relying on platform-specific drivers to provide a description of the affinity sets and a set of callbacks. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: devicetree@vger.kernel.org Cc: Jason Cooper <jason@lakedaemon.net> Cc: Will Deacon <will.deacon@arm.com> Cc: Rob Herring <robh+dt@kernel.org> Link: http://lkml.kernel.org/r/1460365075-7316-4-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Marc Zyngier
Thomas Gleixner
Родитель
222df54fd8
Коммит
9e2c986cb4
|
|
@ -244,3 +244,6 @@ config IRQ_MXS
|
|||
config MVEBU_ODMI
|
||||
bool
|
||||
select GENERIC_MSI_IRQ_DOMAIN
|
||||
|
||||
config PARTITION_PERCPU
|
||||
bool
|
||||
|
|
|
|||
|
|
@ -27,6 +27,7 @@ obj-$(CONFIG_REALVIEW_DT) += irq-gic-realview.o
|
|||
obj-$(CONFIG_ARM_GIC_V2M) += irq-gic-v2m.o
|
||||
obj-$(CONFIG_ARM_GIC_V3) += irq-gic-v3.o irq-gic-common.o
|
||||
obj-$(CONFIG_ARM_GIC_V3_ITS) += irq-gic-v3-its.o irq-gic-v3-its-pci-msi.o irq-gic-v3-its-platform-msi.o
|
||||
obj-$(CONFIG_PARTITION_PERCPU) += irq-partition-percpu.o
|
||||
obj-$(CONFIG_HISILICON_IRQ_MBIGEN) += irq-mbigen.o
|
||||
obj-$(CONFIG_ARM_NVIC) += irq-nvic.o
|
||||
obj-$(CONFIG_ARM_VIC) += irq-vic.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,256 @@
|
|||
/*
|
||||
* Copyright (C) 2016 ARM Limited, All Rights Reserved.
|
||||
* Author: Marc Zyngier <marc.zyngier@arm.com>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
|
||||
#include <linux/bitops.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/irqchip.h>
|
||||
#include <linux/irqchip/chained_irq.h>
|
||||
#include <linux/irqchip/irq-partition-percpu.h>
|
||||
#include <linux/irqdomain.h>
|
||||
#include <linux/seq_file.h>
|
||||
#include <linux/slab.h>
|
||||
|
||||
struct partition_desc {
|
||||
int nr_parts;
|
||||
struct partition_affinity *parts;
|
||||
struct irq_domain *domain;
|
||||
struct irq_desc *chained_desc;
|
||||
unsigned long *bitmap;
|
||||
struct irq_domain_ops ops;
|
||||
};
|
||||
|
||||
static bool partition_check_cpu(struct partition_desc *part,
|
||||
unsigned int cpu, unsigned int hwirq)
|
||||
{
|
||||
return cpumask_test_cpu(cpu, &part->parts[hwirq].mask);
|
||||
}
|
||||
|
||||
static void partition_irq_mask(struct irq_data *d)
|
||||
{
|
||||
struct partition_desc *part = irq_data_get_irq_chip_data(d);
|
||||
struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
|
||||
struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
|
||||
|
||||
if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
|
||||
chip->irq_mask)
|
||||
chip->irq_mask(data);
|
||||
}
|
||||
|
||||
static void partition_irq_unmask(struct irq_data *d)
|
||||
{
|
||||
struct partition_desc *part = irq_data_get_irq_chip_data(d);
|
||||
struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
|
||||
struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
|
||||
|
||||
if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
|
||||
chip->irq_unmask)
|
||||
chip->irq_unmask(data);
|
||||
}
|
||||
|
||||
static int partition_irq_set_irqchip_state(struct irq_data *d,
|
||||
enum irqchip_irq_state which,
|
||||
bool val)
|
||||
{
|
||||
struct partition_desc *part = irq_data_get_irq_chip_data(d);
|
||||
struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
|
||||
struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
|
||||
|
||||
if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
|
||||
chip->irq_set_irqchip_state)
|
||||
return chip->irq_set_irqchip_state(data, which, val);
|
||||
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static int partition_irq_get_irqchip_state(struct irq_data *d,
|
||||
enum irqchip_irq_state which,
|
||||
bool *val)
|
||||
{
|
||||
struct partition_desc *part = irq_data_get_irq_chip_data(d);
|
||||
struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
|
||||
struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
|
||||
|
||||
if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
|
||||
chip->irq_get_irqchip_state)
|
||||
return chip->irq_get_irqchip_state(data, which, val);
|
||||
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static int partition_irq_set_type(struct irq_data *d, unsigned int type)
|
||||
{
|
||||
struct partition_desc *part = irq_data_get_irq_chip_data(d);
|
||||
struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
|
||||
struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
|
||||
|
||||
if (chip->irq_set_type)
|
||||
return chip->irq_set_type(data, type);
|
||||
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static void partition_irq_print_chip(struct irq_data *d, struct seq_file *p)
|
||||
{
|
||||
struct partition_desc *part = irq_data_get_irq_chip_data(d);
|
||||
struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
|
||||
struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
|
||||
|
||||
seq_printf(p, " %5s-%lu", chip->name, data->hwirq);
|
||||
}
|
||||
|
||||
static struct irq_chip partition_irq_chip = {
|
||||
.irq_mask = partition_irq_mask,
|
||||
.irq_unmask = partition_irq_unmask,
|
||||
.irq_set_type = partition_irq_set_type,
|
||||
.irq_get_irqchip_state = partition_irq_get_irqchip_state,
|
||||
.irq_set_irqchip_state = partition_irq_set_irqchip_state,
|
||||
.irq_print_chip = partition_irq_print_chip,
|
||||
};
|
||||
|
||||
static void partition_handle_irq(struct irq_desc *desc)
|
||||
{
|
||||
struct partition_desc *part = irq_desc_get_handler_data(desc);
|
||||
struct irq_chip *chip = irq_desc_get_chip(desc);
|
||||
int cpu = smp_processor_id();
|
||||
int hwirq;
|
||||
|
||||
chained_irq_enter(chip, desc);
|
||||
|
||||
for_each_set_bit(hwirq, part->bitmap, part->nr_parts) {
|
||||
if (partition_check_cpu(part, cpu, hwirq))
|
||||
break;
|
||||
}
|
||||
|
||||
if (unlikely(hwirq == part->nr_parts)) {
|
||||
handle_bad_irq(desc);
|
||||
} else {
|
||||
unsigned int irq;
|
||||
irq = irq_find_mapping(part->domain, hwirq);
|
||||
generic_handle_irq(irq);
|
||||
}
|
||||
|
||||
chained_irq_exit(chip, desc);
|
||||
}
|
||||
|
||||
static int partition_domain_alloc(struct irq_domain *domain, unsigned int virq,
|
||||
unsigned int nr_irqs, void *arg)
|
||||
{
|
||||
int ret;
|
||||
irq_hw_number_t hwirq;
|
||||
unsigned int type;
|
||||
struct irq_fwspec *fwspec = arg;
|
||||
struct partition_desc *part;
|
||||
|
||||
BUG_ON(nr_irqs != 1);
|
||||
ret = domain->ops->translate(domain, fwspec, &hwirq, &type);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
part = domain->host_data;
|
||||
|
||||
set_bit(hwirq, part->bitmap);
|
||||
irq_set_chained_handler_and_data(irq_desc_get_irq(part->chained_desc),
|
||||
partition_handle_irq, part);
|
||||
irq_set_percpu_devid_partition(virq, &part->parts[hwirq].mask);
|
||||
irq_domain_set_info(domain, virq, hwirq, &partition_irq_chip, part,
|
||||
handle_percpu_devid_irq, NULL, NULL);
|
||||
irq_set_status_flags(virq, IRQ_NOAUTOEN);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void partition_domain_free(struct irq_domain *domain, unsigned int virq,
|
||||
unsigned int nr_irqs)
|
||||
{
|
||||
struct irq_data *d;
|
||||
|
||||
BUG_ON(nr_irqs != 1);
|
||||
|
||||
d = irq_domain_get_irq_data(domain, virq);
|
||||
irq_set_handler(virq, NULL);
|
||||
irq_domain_reset_irq_data(d);
|
||||
}
|
||||
|
||||
int partition_translate_id(struct partition_desc *desc, void *partition_id)
|
||||
{
|
||||
struct partition_affinity *part = NULL;
|
||||
int i;
|
||||
|
||||
for (i = 0; i < desc->nr_parts; i++) {
|
||||
if (desc->parts[i].partition_id == partition_id) {
|
||||
part = &desc->parts[i];
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (WARN_ON(!part)) {
|
||||
pr_err("Failed to find partition\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
return i;
|
||||
}
|
||||
|
||||
struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
|
||||
struct partition_affinity *parts,
|
||||
int nr_parts,
|
||||
int chained_irq,
|
||||
const struct irq_domain_ops *ops)
|
||||
{
|
||||
struct partition_desc *desc;
|
||||
struct irq_domain *d;
|
||||
|
||||
BUG_ON(!ops->select || !ops->translate);
|
||||
|
||||
desc = kzalloc(sizeof(*desc), GFP_KERNEL);
|
||||
if (!desc)
|
||||
return NULL;
|
||||
|
||||
desc->ops = *ops;
|
||||
desc->ops.free = partition_domain_free;
|
||||
desc->ops.alloc = partition_domain_alloc;
|
||||
|
||||
d = irq_domain_create_linear(fwnode, nr_parts, &desc->ops, desc);
|
||||
if (!d)
|
||||
goto out;
|
||||
desc->domain = d;
|
||||
|
||||
desc->bitmap = kzalloc(sizeof(long) * BITS_TO_LONGS(nr_parts),
|
||||
GFP_KERNEL);
|
||||
if (WARN_ON(!desc->bitmap))
|
||||
goto out;
|
||||
|
||||
desc->chained_desc = irq_to_desc(chained_irq);
|
||||
desc->nr_parts = nr_parts;
|
||||
desc->parts = parts;
|
||||
|
||||
return desc;
|
||||
out:
|
||||
if (d)
|
||||
irq_domain_remove(d);
|
||||
kfree(desc);
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
struct irq_domain *partition_get_domain(struct partition_desc *dsc)
|
||||
{
|
||||
if (dsc)
|
||||
return dsc->domain;
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
|
@ -0,0 +1,59 @@
|
|||
/*
|
||||
* Copyright (C) 2016 ARM Limited, All Rights Reserved.
|
||||
* Author: Marc Zyngier <marc.zyngier@arm.com>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
|
||||
#include <linux/fwnode.h>
|
||||
#include <linux/cpumask.h>
|
||||
#include <linux/irqdomain.h>
|
||||
|
||||
struct partition_affinity {
|
||||
cpumask_t mask;
|
||||
void *partition_id;
|
||||
};
|
||||
|
||||
struct partition_desc;
|
||||
|
||||
#ifdef CONFIG_PARTITION_PERCPU
|
||||
int partition_translate_id(struct partition_desc *desc, void *partition_id);
|
||||
struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
|
||||
struct partition_affinity *parts,
|
||||
int nr_parts,
|
||||
int chained_irq,
|
||||
const struct irq_domain_ops *ops);
|
||||
struct irq_domain *partition_get_domain(struct partition_desc *dsc);
|
||||
#else
|
||||
static inline int partition_translate_id(struct partition_desc *desc,
|
||||
void *partition_id)
|
||||
{
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static inline
|
||||
struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
|
||||
struct partition_affinity *parts,
|
||||
int nr_parts,
|
||||
int chained_irq,
|
||||
const struct irq_domain_ops *ops)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static inline
|
||||
struct irq_domain *partition_get_domain(struct partition_desc *dsc)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
#endif
|
||||
Загрузка…
Ссылка в новой задаче