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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qspinlock.h (2064B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _ASM_POWERPC_QSPINLOCK_H
      3#define _ASM_POWERPC_QSPINLOCK_H
      4
      5#include <asm-generic/qspinlock_types.h>
      6#include <asm/paravirt.h>
      7
      8#define _Q_PENDING_LOOPS	(1 << 9) /* not tuned */
      9
     10#ifdef CONFIG_PARAVIRT_SPINLOCKS
     11extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
     12extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
     13extern void __pv_queued_spin_unlock(struct qspinlock *lock);
     14
     15static __always_inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
     16{
     17	if (!is_shared_processor())
     18		native_queued_spin_lock_slowpath(lock, val);
     19	else
     20		__pv_queued_spin_lock_slowpath(lock, val);
     21}
     22
     23#define queued_spin_unlock queued_spin_unlock
     24static inline void queued_spin_unlock(struct qspinlock *lock)
     25{
     26	if (!is_shared_processor())
     27		smp_store_release(&lock->locked, 0);
     28	else
     29		__pv_queued_spin_unlock(lock);
     30}
     31
     32#else
     33extern void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
     34#endif
     35
     36static __always_inline void queued_spin_lock(struct qspinlock *lock)
     37{
     38	u32 val = 0;
     39
     40	if (likely(arch_atomic_try_cmpxchg_lock(&lock->val, &val, _Q_LOCKED_VAL)))
     41		return;
     42
     43	queued_spin_lock_slowpath(lock, val);
     44}
     45#define queued_spin_lock queued_spin_lock
     46
     47#ifdef CONFIG_PARAVIRT_SPINLOCKS
     48#define SPIN_THRESHOLD (1<<15) /* not tuned */
     49
     50static __always_inline void pv_wait(u8 *ptr, u8 val)
     51{
     52	if (*ptr != val)
     53		return;
     54	yield_to_any();
     55	/*
     56	 * We could pass in a CPU here if waiting in the queue and yield to
     57	 * the previous CPU in the queue.
     58	 */
     59}
     60
     61static __always_inline void pv_kick(int cpu)
     62{
     63	prod_cpu(cpu);
     64}
     65
     66extern void __pv_init_lock_hash(void);
     67
     68static inline void pv_spinlocks_init(void)
     69{
     70	__pv_init_lock_hash();
     71}
     72
     73#endif
     74
     75/*
     76 * Queued spinlocks rely heavily on smp_cond_load_relaxed() to busy-wait,
     77 * which was found to have performance problems if implemented with
     78 * the preferred spin_begin()/spin_end() SMT priority pattern. Use the
     79 * generic version instead.
     80 */
     81
     82#include <asm-generic/qspinlock.h>
     83
     84#endif /* _ASM_POWERPC_QSPINLOCK_H */