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Viewing changes to include/asm-generic/preempt.h

  • Committer: Package Import Robot
  • Author(s): Ben Hutchings
  • Date: 2014-02-02 16:57:49 UTC
  • mfrom: (1.1.10) (0.1.21 sid)
  • Revision ID: package-import@ubuntu.com-20140202165749-tw94o9t1t0a8txk6
Tags: 3.13-1~exp2
Merge changes from sid up to 3.12.6-3

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include/asm-generic/preempt.h
 
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#ifndef __ASM_PREEMPT_H
 
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#define __ASM_PREEMPT_H
 
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#include <linux/thread_info.h>
 
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#define PREEMPT_ENABLED (0)
 
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static __always_inline int preempt_count(void)
 
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{
 
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        return current_thread_info()->preempt_count;
 
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}
 
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static __always_inline int *preempt_count_ptr(void)
 
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{
 
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        return &current_thread_info()->preempt_count;
 
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}
 
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static __always_inline void preempt_count_set(int pc)
 
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{
 
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        *preempt_count_ptr() = pc;
 
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}
 
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/*
 
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 * must be macros to avoid header recursion hell
 
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 */
 
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#define task_preempt_count(p) \
 
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        (task_thread_info(p)->preempt_count & ~PREEMPT_NEED_RESCHED)
 
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#define init_task_preempt_count(p) do { \
 
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        task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \
 
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} while (0)
 
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#define init_idle_preempt_count(p, cpu) do { \
 
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        task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \
 
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} while (0)
 
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static __always_inline void set_preempt_need_resched(void)
 
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{
 
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}
 
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static __always_inline void clear_preempt_need_resched(void)
 
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{
 
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}
 
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static __always_inline bool test_preempt_need_resched(void)
 
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{
 
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        return false;
 
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}
 
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/*
 
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 * The various preempt_count add/sub methods
 
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 */
 
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static __always_inline void __preempt_count_add(int val)
 
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{
 
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        *preempt_count_ptr() += val;
 
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}
 
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static __always_inline void __preempt_count_sub(int val)
 
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{
 
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        *preempt_count_ptr() -= val;
 
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}
 
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static __always_inline bool __preempt_count_dec_and_test(void)
 
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{
 
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        /*
 
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         * Because of load-store architectures cannot do per-cpu atomic
 
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         * operations; we cannot use PREEMPT_NEED_RESCHED because it might get
 
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         * lost.
 
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         */
 
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        return !--*preempt_count_ptr() && tif_need_resched();
 
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}
 
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/*
 
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 * Returns true when we need to resched and can (barring IRQ state).
 
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 */
 
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static __always_inline bool should_resched(void)
 
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{
 
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        return unlikely(!preempt_count() && tif_need_resched());
 
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}
 
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#ifdef CONFIG_PREEMPT
 
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extern asmlinkage void preempt_schedule(void);
 
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#define __preempt_schedule() preempt_schedule()
 
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#ifdef CONFIG_CONTEXT_TRACKING
 
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extern asmlinkage void preempt_schedule_context(void);
 
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#define __preempt_schedule_context() preempt_schedule_context()
 
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#endif
 
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#endif /* CONFIG_PREEMPT */
 
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#endif /* __ASM_PREEMPT_H */