cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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preempt.h (1995B)

      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
      9static __always_inline int preempt_count(void)
     10{
     11	return READ_ONCE(current_thread_info()->preempt_count);
     12}
     13
     14static __always_inline volatile int *preempt_count_ptr(void)
     15{
     16	return &current_thread_info()->preempt_count;
     17}
     18
     19static __always_inline void preempt_count_set(int pc)
     20{
     21	*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
     35static __always_inline void set_preempt_need_resched(void)
     36{
     37}
     38
     39static __always_inline void clear_preempt_need_resched(void)
     40{
     41}
     42
     43static __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
     52static __always_inline void __preempt_count_add(int val)
     53{
     54	*preempt_count_ptr() += val;
     55}
     56
     57static __always_inline void __preempt_count_sub(int val)
     58{
     59	*preempt_count_ptr() -= val;
     60}
     61
     62static __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 */
     75static __always_inline bool should_resched(int preempt_offset)
     76{
     77	return unlikely(preempt_count() == preempt_offset &&
     78			tif_need_resched());
     79}
     80
     81#ifdef CONFIG_PREEMPTION
     82extern asmlinkage void preempt_schedule(void);
     83#define __preempt_schedule() preempt_schedule()
     84extern asmlinkage void preempt_schedule_notrace(void);
     85#define __preempt_schedule_notrace() preempt_schedule_notrace()
     86#endif /* CONFIG_PREEMPTION */
     87
     88#endif /* __ASM_PREEMPT_H */