211 lines
5.7 KiB
C
211 lines
5.7 KiB
C
#ifndef LINUX_HARDIRQ_H
|
|
#define LINUX_HARDIRQ_H
|
|
|
|
#include <linux/preempt.h>
|
|
#include <linux/lockdep.h>
|
|
#include <linux/ftrace_irq.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 can in theory reach the same as NR_IRQS.
|
|
* In reality, the number of nested IRQS is limited to the stack
|
|
* size as well. For archs with over 1000 IRQS it is not practical
|
|
* to expect that they will all nest. We give a max of 10 bits for
|
|
* hardirq nesting. An arch may choose to give less than 10 bits.
|
|
* m68k expects it to be 8.
|
|
*
|
|
* - bits 16-25 are the hardirq count (max # of nested hardirqs: 1024)
|
|
* - bit 26 is the NMI_MASK
|
|
* - bit 28 is the PREEMPT_ACTIVE flag
|
|
*
|
|
* PREEMPT_MASK: 0x000000ff
|
|
* SOFTIRQ_MASK: 0x0000ff00
|
|
* HARDIRQ_MASK: 0x03ff0000
|
|
* NMI_MASK: 0x04000000
|
|
*/
|
|
#define PREEMPT_BITS 8
|
|
#define SOFTIRQ_BITS 8
|
|
#define NMI_BITS 1
|
|
|
|
#define MAX_HARDIRQ_BITS 10
|
|
|
|
#ifndef HARDIRQ_BITS
|
|
# define HARDIRQ_BITS MAX_HARDIRQ_BITS
|
|
#endif
|
|
|
|
#if HARDIRQ_BITS > MAX_HARDIRQ_BITS
|
|
#error HARDIRQ_BITS too high!
|
|
#endif
|
|
|
|
#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)
|
|
|
|
#ifndef PREEMPT_ACTIVE
|
|
#define PREEMPT_ACTIVE_BITS 1
|
|
#define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS)
|
|
#define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
|
|
#endif
|
|
|
|
#if PREEMPT_ACTIVE < (1 << (NMI_SHIFT + NMI_BITS))
|
|
#error PREEMPT_ACTIVE is too low!
|
|
#endif
|
|
|
|
#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())
|
|
# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
|
|
#else
|
|
# define preemptible() 0
|
|
# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
|
|
#endif
|
|
|
|
#if defined(CONFIG_SMP) || defined(CONFIG_GENERIC_HARDIRQS)
|
|
extern void synchronize_irq(unsigned int irq);
|
|
#else
|
|
# define synchronize_irq(irq) barrier()
|
|
#endif
|
|
|
|
struct task_struct;
|
|
|
|
#if !defined(CONFIG_VIRT_CPU_ACCOUNTING) && !defined(CONFIG_IRQ_TIME_ACCOUNTING)
|
|
static inline void account_system_vtime(struct task_struct *tsk)
|
|
{
|
|
}
|
|
#else
|
|
extern void account_system_vtime(struct task_struct *tsk);
|
|
#endif
|
|
|
|
#if defined(CONFIG_TINY_RCU) || defined(CONFIG_TINY_PREEMPT_RCU)
|
|
|
|
static inline void rcu_nmi_enter(void)
|
|
{
|
|
}
|
|
|
|
static inline void rcu_nmi_exit(void)
|
|
{
|
|
}
|
|
|
|
#else
|
|
extern void rcu_nmi_enter(void);
|
|
extern void rcu_nmi_exit(void);
|
|
#endif
|
|
|
|
/*
|
|
* It is safe to do non-atomic ops on ->hardirq_context,
|
|
* because NMI handlers may not preempt and the ops are
|
|
* always balanced, so the interrupted value of ->hardirq_context
|
|
* will always be restored.
|
|
*/
|
|
#define __irq_enter() \
|
|
do { \
|
|
account_system_vtime(current); \
|
|
add_preempt_count(HARDIRQ_OFFSET); \
|
|
trace_hardirq_enter(); \
|
|
} while (0)
|
|
|
|
/*
|
|
* Enter irq context (on NO_HZ, update jiffies):
|
|
*/
|
|
extern void irq_enter(void);
|
|
|
|
/*
|
|
* Exit irq context without processing softirqs:
|
|
*/
|
|
#define __irq_exit() \
|
|
do { \
|
|
trace_hardirq_exit(); \
|
|
account_system_vtime(current); \
|
|
sub_preempt_count(HARDIRQ_OFFSET); \
|
|
} while (0)
|
|
|
|
/*
|
|
* Exit irq context and process softirqs if needed:
|
|
*/
|
|
extern void irq_exit(void);
|
|
|
|
#define nmi_enter() \
|
|
do { \
|
|
ftrace_nmi_enter(); \
|
|
BUG_ON(in_nmi()); \
|
|
add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
|
|
lockdep_off(); \
|
|
rcu_nmi_enter(); \
|
|
trace_hardirq_enter(); \
|
|
} while (0)
|
|
|
|
#define nmi_exit() \
|
|
do { \
|
|
trace_hardirq_exit(); \
|
|
rcu_nmi_exit(); \
|
|
lockdep_on(); \
|
|
BUG_ON(!in_nmi()); \
|
|
sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
|
|
ftrace_nmi_exit(); \
|
|
} while (0)
|
|
|
|
#endif /* LINUX_HARDIRQ_H */
|