Line data    Source code

       1             : /* SPDX-License-Identifier: GPL-2.0 */
       2             : #ifndef __ASM_PREEMPT_H
       3             : #define __ASM_PREEMPT_H
       4             : 
       5             : #include <linux/thread_info.h>
       6             : 
       7             : #define PREEMPT_ENABLED (0)
       8             : 
       9             : static __always_inline int preempt_count(void)
      10             : {
      11       12850 :         return READ_ONCE(current_thread_info()->preempt_count);
      12             : }
      13             : 
      14             : static __always_inline volatile int *preempt_count_ptr(void)
      15             : {
      16        2597 :         return &current_thread_info()->preempt_count;
      17             : }
      18             : 
      19             : static __always_inline void preempt_count_set(int pc)
      20             : {
      21           0 :         *preempt_count_ptr() = pc;
      22             : }
      23             : 
      24             : /*
      25             :  * must be macros to avoid header recursion hell
      26             :  */
      27             : #define init_task_preempt_count(p) do { \
      28             :         task_thread_info(p)->preempt_count = FORK_PREEMPT_COUNT; \
      29             : } while (0)
      30             : 
      31             : #define init_idle_preempt_count(p, cpu) do { \
      32             :         task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \
      33             : } while (0)
      34             : 
      35             : static __always_inline void set_preempt_need_resched(void)
      36             : {
      37             : }
      38             : 
      39             : static __always_inline void clear_preempt_need_resched(void)
      40             : {
      41             : }
      42             : 
      43             : static __always_inline bool test_preempt_need_resched(void)
      44             : {
      45             :         return false;
      46             : }
      47             : 
      48             : /*
      49             :  * The various preempt_count add/sub methods
      50             :  */
      51             : 
      52             : static __always_inline void __preempt_count_add(int val)
      53             : {
      54         921 :         *preempt_count_ptr() += val;
      55             : }
      56             : 
      57             : static __always_inline void __preempt_count_sub(int val)
      58             : {
      59        1676 :         *preempt_count_ptr() -= val;
      60             : }
      61             : 
      62             : static __always_inline bool __preempt_count_dec_and_test(void)
      63             : {
      64             :         /*
      65             :          * Because of load-store architectures cannot do per-cpu atomic
      66             :          * operations; we cannot use PREEMPT_NEED_RESCHED because it might get
      67             :          * lost.
      68             :          */
      69             :         return !--*preempt_count_ptr() && tif_need_resched();
      70             : }
      71             : 
      72             : /*
      73             :  * Returns true when we need to resched and can (barring IRQ state).
      74             :  */
      75             : static __always_inline bool should_resched(int preempt_offset)
      76             : {
      77        1182 :         return unlikely(preempt_count() == preempt_offset &&
      78             :                         tif_need_resched());
      79             : }
      80             : 
      81             : #ifdef CONFIG_PREEMPTION
      82             : extern asmlinkage void preempt_schedule(void);
      83             : #define __preempt_schedule() preempt_schedule()
      84             : extern asmlinkage void preempt_schedule_notrace(void);
      85             : #define __preempt_schedule_notrace() preempt_schedule_notrace()
      86             : #endif /* CONFIG_PREEMPTION */
      87             : 
      88             : #endif /* __ASM_PREEMPT_H */