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Subject[PATCH V7 2/5] asm-generic: ticket-lock: Use the same struct definitions with qspinlock
Date
From: Guo Ren <guoren@linux.alibaba.com>

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>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
---
include/asm-generic/spinlock.h | 16 ++++++++--------
include/asm-generic/spinlock_types.h | 12 ++----------
2 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/include/asm-generic/spinlock.h b/include/asm-generic/spinlock.h
index f1e4fa100f5a..4caeb8cebe53 100644
--- a/include/asm-generic/spinlock.h
+++ b/include/asm-generic/spinlock.h
@@ -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)
@@ -46,45 +46,45 @@ 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_is_locked(arch_spinlock_t *lock)
{
- u32 val = atomic_read(lock);
+ u32 val = atomic_read(&lock->val);

return ((val >> 16) != (val & 0xffff));
}

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;
}

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));
}
diff --git a/include/asm-generic/spinlock_types.h b/include/asm-generic/spinlock_types.h
index 8962bb730945..f534aa5de394 100644
--- a/include/asm-generic/spinlock_types.h
+++ b/include/asm-generic/spinlock_types.h
@@ -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 */
--
2.36.1
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