104 строки
3.3 KiB
C
104 строки
3.3 KiB
C
#ifndef LINUX_PREEMPT_MASK_H
|
|
#define LINUX_PREEMPT_MASK_H
|
|
|
|
#include <linux/preempt.h>
|
|
#include <asm/hardirq.h>
|
|
|
|
/*
|
|
* We put the hardirq and softirq counter into the preemption
|
|
* counter. The bitmask has the following meaning:
|
|
*
|
|
* - bits 0-7 are the preemption count (max preemption depth: 256)
|
|
* - bits 8-15 are the softirq count (max # of softirqs: 256)
|
|
*
|
|
* The hardirq count could in theory be the same as the number of
|
|
* interrupts in the system, but we run all interrupt handlers with
|
|
* interrupts disabled, so we cannot have nesting interrupts. Though
|
|
* there are a few palaeontologic drivers which reenable interrupts in
|
|
* the handler, so we need more than one bit here.
|
|
*
|
|
* PREEMPT_MASK: 0x000000ff
|
|
* SOFTIRQ_MASK: 0x0000ff00
|
|
* HARDIRQ_MASK: 0x000f0000
|
|
* NMI_MASK: 0x00100000
|
|
* PREEMPT_ACTIVE: 0x00200000
|
|
*/
|
|
#define PREEMPT_BITS 8
|
|
#define SOFTIRQ_BITS 8
|
|
#define HARDIRQ_BITS 4
|
|
#define NMI_BITS 1
|
|
|
|
#define PREEMPT_SHIFT 0
|
|
#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
|
|
#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
|
|
#define NMI_SHIFT (HARDIRQ_SHIFT + HARDIRQ_BITS)
|
|
|
|
#define __IRQ_MASK(x) ((1UL << (x))-1)
|
|
|
|
#define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
|
|
#define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
|
|
#define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
|
|
#define NMI_MASK (__IRQ_MASK(NMI_BITS) << NMI_SHIFT)
|
|
|
|
#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
|
|
#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
|
|
#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
|
|
#define NMI_OFFSET (1UL << NMI_SHIFT)
|
|
|
|
#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
|
|
|
|
#define PREEMPT_ACTIVE_BITS 1
|
|
#define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS)
|
|
#define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
|
|
|
|
#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
|
|
#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
|
|
#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
|
|
| NMI_MASK))
|
|
|
|
/*
|
|
* Are we doing bottom half or hardware interrupt processing?
|
|
* Are we in a softirq context? Interrupt context?
|
|
* in_softirq - Are we currently processing softirq or have bh disabled?
|
|
* in_serving_softirq - Are we currently processing softirq?
|
|
*/
|
|
#define in_irq() (hardirq_count())
|
|
#define in_softirq() (softirq_count())
|
|
#define in_interrupt() (irq_count())
|
|
#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
|
|
|
|
/*
|
|
* Are we in NMI context?
|
|
*/
|
|
#define in_nmi() (preempt_count() & NMI_MASK)
|
|
|
|
#if defined(CONFIG_PREEMPT_COUNT)
|
|
# define PREEMPT_CHECK_OFFSET 1
|
|
#else
|
|
# define PREEMPT_CHECK_OFFSET 0
|
|
#endif
|
|
|
|
/*
|
|
* Are we running in atomic context? WARNING: this macro cannot
|
|
* always detect atomic context; in particular, it cannot know about
|
|
* held spinlocks in non-preemptible kernels. Thus it should not be
|
|
* used in the general case to determine whether sleeping is possible.
|
|
* Do not use in_atomic() in driver code.
|
|
*/
|
|
#define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
|
|
|
|
/*
|
|
* Check whether we were atomic before we did preempt_disable():
|
|
* (used by the scheduler, *after* releasing the kernel lock)
|
|
*/
|
|
#define in_atomic_preempt_off() \
|
|
((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET)
|
|
|
|
#ifdef CONFIG_PREEMPT_COUNT
|
|
# define preemptible() (preempt_count() == 0 && !irqs_disabled())
|
|
#else
|
|
# define preemptible() 0
|
|
#endif
|
|
|
|
#endif /* LINUX_PREEMPT_MASK_H */
|