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asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock

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The arch_spinlock_t of qspinlock has contained the atomic_t val, which
satisfies the ticket-lock requirement. Thus, unify the arch_spinlock_t
into qspinlock_types.h. This is the preparation for the next combo
spinlock.

Reviewed-by: Leonardo Bras <leobras@redhat.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-riscv/CAK8P3a2rnz9mQqhN6-e0CGUUv9rntRELFdxt_weiD7FxH7fkfQ@mail.gmail.com/
Signed-off-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20241103145153.105097-10-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Guo Ren 2024-11-03 15:51:49 +01:00 committed by Palmer Dabbelt
parent 97ddab7fbe
commit cbe82e140b
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
2 changed files with 9 additions and 17 deletions
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14
include/asm-generic/spinlock.h
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@ -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)
@ -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));
}
@ -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;
}

12
include/asm-generic/spinlock_types.h
View File

@ -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 */