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

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 <[email protected]>
Suggested-by: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/linux-riscv/CAK8P3a2rnz9mQqhN6-e0CGUUv9rntRELFdxt_weiD7FxH7fkfQ@mail.gmail.com/
Signed-off-by: Guo Ren <[email protected]>
Signed-off-by: Guo Ren <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Reviewed-by: Andrea Parri <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

Author: guoren83

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)
@@ -46,31 +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;
 }

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 */