forked from mirrors/linux
92cf211874
preempt_mask.h defines all the preempt_count semantics and related symbols: preempt, softirq, hardirq, nmi, preempt active, need resched, etc... preempt.h defines the accessors and mutators of preempt_count. But there is a messy dependency game around those two header files: * preempt_mask.h includes preempt.h in order to access preempt_count() * preempt_mask.h defines all preempt_count semantic and symbols except PREEMPT_NEED_RESCHED that is needed by asm/preempt.h Thus we need to define it from preempt.h, right before including asm/preempt.h, instead of defining it to preempt_mask.h with the other preempt_count symbols. Therefore the preempt_count semantics happen to be spread out. * We plan to introduce preempt_active_[enter,exit]() to consolidate preempt_schedule*() code. But we'll need to access both preempt_count mutators (preempt_count_add()) and preempt_count symbols (PREEMPT_ACTIVE, PREEMPT_OFFSET). The usual place to define preempt operations is in preempt.h but then we'll need symbols in preempt_mask.h which already includes preempt.h. So we end up with a ressource circle dependency. Lets merge preempt_mask.h into preempt.h to solve these dependency issues. This way we gather semantic symbols and operation definition of preempt_count in a single file. This is a dumb copy-paste merge. Further merge re-arrangments are performed in a subsequent patch to ease review. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431441711-29753-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
82 lines
1.7 KiB
C
82 lines
1.7 KiB
C
#ifndef LINUX_HARDIRQ_H
|
|
#define LINUX_HARDIRQ_H
|
|
|
|
#include <linux/preempt.h>
|
|
#include <linux/lockdep.h>
|
|
#include <linux/ftrace_irq.h>
|
|
#include <linux/vtime.h>
|
|
#include <asm/hardirq.h>
|
|
|
|
|
|
extern void synchronize_irq(unsigned int irq);
|
|
extern bool synchronize_hardirq(unsigned int irq);
|
|
|
|
#if defined(CONFIG_TINY_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_irq_enter_time(current); \
|
|
preempt_count_add(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_irq_exit_time(current); \
|
|
preempt_count_sub(HARDIRQ_OFFSET); \
|
|
} while (0)
|
|
|
|
/*
|
|
* Exit irq context and process softirqs if needed:
|
|
*/
|
|
extern void irq_exit(void);
|
|
|
|
#define nmi_enter() \
|
|
do { \
|
|
lockdep_off(); \
|
|
ftrace_nmi_enter(); \
|
|
BUG_ON(in_nmi()); \
|
|
preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \
|
|
rcu_nmi_enter(); \
|
|
trace_hardirq_enter(); \
|
|
} while (0)
|
|
|
|
#define nmi_exit() \
|
|
do { \
|
|
trace_hardirq_exit(); \
|
|
rcu_nmi_exit(); \
|
|
BUG_ON(!in_nmi()); \
|
|
preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \
|
|
ftrace_nmi_exit(); \
|
|
lockdep_on(); \
|
|
} while (0)
|
|
|
|
#endif /* LINUX_HARDIRQ_H */
|