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spinlock: Add trylock

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Change-Id: If349d7c0065609615f5df229f70c59f92bf97adf
This commit is contained in:
Masamichi Takagi
2018-09-03 13:12:03 +09:00
parent ff383d96ba
commit b080e0f301
1 changed files with 52 additions and 0 deletions
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52
arch/x86_64/kernel/include/arch-lock.h
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@ -37,6 +37,58 @@ static void ihk_mc_spinlock_init(ihk_spinlock_t *lock)
}
#define SPIN_LOCK_UNLOCKED { .head_tail = 0 }
#ifdef DEBUG_SPINLOCK
#define ihk_mc_spinlock_trylock_noirq(l) { int rc; \
__kprintf("[%d] call ihk_mc_spinlock_trylock_noirq %p %s:%d\n", ihk_mc_get_processor_id(), (l), __FILE__, __LINE__); \
rc = __ihk_mc_spinlock_trylock_noirq(l); \
__kprintf("[%d] ret ihk_mc_spinlock_trylock_noirq\n", ihk_mc_get_processor_id()); rc; \
}
#else
#define ihk_mc_spinlock_trylock_noirq __ihk_mc_spinlock_trylock_noirq
#endif
static int __ihk_mc_spinlock_trylock_noirq(ihk_spinlock_t *lock)
{
ihk_spinlock_t cur = { .head_tail = lock->head_tail };
ihk_spinlock_t next = { .tickets.head = cur.tickets.head, .tickets.tail = cur.tickets.tail + 2 };
int success;
if (cur.tickets.head != cur.tickets.tail) {
return 0;
}
preempt_disable();
/* Use the same increment amount as other functions! */
success = __sync_bool_compare_and_swap((__ticketpair_t*)lock, cur.head_tail, next.head_tail);
if (!success) {
preempt_enable();
}
return success;
}
#ifdef DEBUG_SPINLOCK
#define ihk_mc_spinlock_trylock(l, result) ({ unsigned long rc; \
__kprintf("[%d] call ihk_mc_spinlock_trylock %p %s:%d\n", ihk_mc_get_processor_id(), (l), __FILE__, __LINE__); \
rc = __ihk_mc_spinlock_trylock(l, result); \
__kprintf("[%d] ret ihk_mc_spinlock_trylock\n", ihk_mc_get_processor_id()); rc;\
})
#else
#define ihk_mc_spinlock_trylock __ihk_mc_spinlock_trylock
#endif
static unsigned long __ihk_mc_spinlock_trylock(ihk_spinlock_t *lock, int *result)
{
unsigned long flags;
flags = cpu_disable_interrupt_save();
*result = __ihk_mc_spinlock_trylock_noirq(lock);
return flags;
}
#ifdef DEBUG_SPINLOCK
#define ihk_mc_spinlock_lock_noirq(l) { \
__kprintf("[%d] call ihk_mc_spinlock_lock_noirq %p %s:%d\n", ihk_mc_get_processor_id(), (l), __FILE__, __LINE__); \