1#ifndef __ASM_PREEMPT_H 2#define __ASM_PREEMPT_H 3 4#include <linux/thread_info.h> 5 6#define PREEMPT_ENABLED (0) 7 8static __always_inline int preempt_count(void) 9{ 10 return current_thread_info()->preempt_count; 11} 12 13static __always_inline int *preempt_count_ptr(void) 14{ 15 return ¤t_thread_info()->preempt_count; 16} 17 18static __always_inline void preempt_count_set(int pc) 19{ 20 *preempt_count_ptr() = pc; 21} 22 23/* 24 * must be macros to avoid header recursion hell 25 */ 26#define init_task_preempt_count(p) do { \ 27 task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ 28} while (0) 29 30#define init_idle_preempt_count(p, cpu) do { \ 31 task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \ 32} while (0) 33 34static __always_inline void set_preempt_need_resched(void) 35{ 36} 37 38static __always_inline void clear_preempt_need_resched(void) 39{ 40} 41 42static __always_inline bool test_preempt_need_resched(void) 43{ 44 return false; 45} 46 47/* 48 * The various preempt_count add/sub methods 49 */ 50 51static __always_inline void __preempt_count_add(int val) 52{ 53 *preempt_count_ptr() += val; 54} 55 56static __always_inline void __preempt_count_sub(int val) 57{ 58 *preempt_count_ptr() -= val; 59} 60 61static __always_inline bool __preempt_count_dec_and_test(void) 62{ 63 /* 64 * Because of load-store architectures cannot do per-cpu atomic 65 * operations; we cannot use PREEMPT_NEED_RESCHED because it might get 66 * lost. 67 */ 68 return !--*preempt_count_ptr() && tif_need_resched(); 69} 70 71/* 72 * Returns true when we need to resched and can (barring IRQ state). 73 */ 74static __always_inline bool should_resched(void) 75{ 76 return unlikely(!preempt_count() && tif_need_resched()); 77} 78 79#ifdef CONFIG_PREEMPT 80extern asmlinkage void preempt_schedule(void); 81#define __preempt_schedule() preempt_schedule() 82 83#ifdef CONFIG_CONTEXT_TRACKING 84extern asmlinkage void preempt_schedule_context(void); 85#define __preempt_schedule_context() preempt_schedule_context() 86#endif 87#endif /* CONFIG_PREEMPT */ 88 89#endif /* __ASM_PREEMPT_H */ 90