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asm-generic: ticket-lock: Use the same struct definitions with qspinlock
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Let ticket_lock use the same struct definitions with qspinlock, and then
we could move to combo spinlock (combine ticket & queue).

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
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guoren83 authored and intel-lab-lkp committed Jul 24, 2022
1 parent 9508afa commit e6277b2
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Showing 2 changed files with 9 additions and 17 deletions.
14 changes: 7 additions & 7 deletions include/asm-generic/spinlock.h
Expand Up @@ -32,7 +32,7 @@

static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
{
u32 val = atomic_fetch_add(1<<16, lock);
u32 val = atomic_fetch_add(1<<16, &lock->val);
u16 ticket = val >> 16;

if (ticket == (u16)val)
Expand All @@ -46,31 +46,31 @@ static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
* have no outstanding writes due to the atomic_fetch_add() the extra
* orderings are free.
*/
atomic_cond_read_acquire(lock, ticket == (u16)VAL);
atomic_cond_read_acquire(&lock->val, ticket == (u16)VAL);
smp_mb();
}

static __always_inline bool arch_spin_trylock(arch_spinlock_t *lock)
{
u32 old = atomic_read(lock);
u32 old = atomic_read(&lock->val);

if ((old >> 16) != (old & 0xffff))
return false;

return atomic_try_cmpxchg(lock, &old, old + (1<<16)); /* SC, for RCsc */
return atomic_try_cmpxchg(&lock->val, &old, old + (1<<16)); /* SC, for RCsc */
}

static __always_inline void arch_spin_unlock(arch_spinlock_t *lock)
{
u16 *ptr = (u16 *)lock + IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
u32 val = atomic_read(lock);
u32 val = atomic_read(&lock->val);

smp_store_release(ptr, (u16)val + 1);
}

static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
{
u32 val = lock.counter;
u32 val = lock.val.counter;

return ((val >> 16) == (val & 0xffff));
}
Expand All @@ -84,7 +84,7 @@ static __always_inline int arch_spin_is_locked(arch_spinlock_t *lock)

static __always_inline int arch_spin_is_contended(arch_spinlock_t *lock)
{
u32 val = atomic_read(lock);
u32 val = atomic_read(&lock->val);

return (s16)((val >> 16) - (val & 0xffff)) > 1;
}
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12 changes: 2 additions & 10 deletions include/asm-generic/spinlock_types.h
Expand Up @@ -3,15 +3,7 @@
#ifndef __ASM_GENERIC_SPINLOCK_TYPES_H
#define __ASM_GENERIC_SPINLOCK_TYPES_H

#include <linux/types.h>
typedef atomic_t arch_spinlock_t;

/*
* qrwlock_types depends on arch_spinlock_t, so we must typedef that before the
* include.
*/
#include <asm/qrwlock_types.h>

#define __ARCH_SPIN_LOCK_UNLOCKED ATOMIC_INIT(0)
#include <asm-generic/qspinlock_types.h>
#include <asm-generic/qrwlock_types.h>

#endif /* __ASM_GENERIC_SPINLOCK_TYPES_H */

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