diff options
Diffstat (limited to 'arch/riscv/include')
-rw-r--r-- | arch/riscv/include/asm/fence.h | 12 | ||||
-rw-r--r-- | arch/riscv/include/asm/spinlock.h | 29 |
2 files changed, 27 insertions, 14 deletions
diff --git a/arch/riscv/include/asm/fence.h b/arch/riscv/include/asm/fence.h new file mode 100644 index 000000000000..2b443a3a487f --- /dev/null +++ b/arch/riscv/include/asm/fence.h @@ -0,0 +1,12 @@ +#ifndef _ASM_RISCV_FENCE_H +#define _ASM_RISCV_FENCE_H + +#ifdef CONFIG_SMP +#define RISCV_ACQUIRE_BARRIER "\tfence r , rw\n" +#define RISCV_RELEASE_BARRIER "\tfence rw, w\n" +#else +#define RISCV_ACQUIRE_BARRIER +#define RISCV_RELEASE_BARRIER +#endif + +#endif /* _ASM_RISCV_FENCE_H */ diff --git a/arch/riscv/include/asm/spinlock.h b/arch/riscv/include/asm/spinlock.h index 2fd27e8ef1fd..8eb26d1ede81 100644 --- a/arch/riscv/include/asm/spinlock.h +++ b/arch/riscv/include/asm/spinlock.h @@ -17,6 +17,7 @@ #include <linux/kernel.h> #include <asm/current.h> +#include <asm/fence.h> /* * Simple spin lock operations. These provide no fairness guarantees. @@ -28,10 +29,7 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) { - __asm__ __volatile__ ( - "amoswap.w.rl x0, x0, %0" - : "=A" (lock->lock) - :: "memory"); + smp_store_release(&lock->lock, 0); } static inline int arch_spin_trylock(arch_spinlock_t *lock) @@ -39,7 +37,8 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) int tmp = 1, busy; __asm__ __volatile__ ( - "amoswap.w.aq %0, %2, %1" + " amoswap.w %0, %2, %1\n" + RISCV_ACQUIRE_BARRIER : "=r" (busy), "+A" (lock->lock) : "r" (tmp) : "memory"); @@ -68,8 +67,9 @@ static inline void arch_read_lock(arch_rwlock_t *lock) "1: lr.w %1, %0\n" " bltz %1, 1b\n" " addi %1, %1, 1\n" - " sc.w.aq %1, %1, %0\n" + " sc.w %1, %1, %0\n" " bnez %1, 1b\n" + RISCV_ACQUIRE_BARRIER : "+A" (lock->lock), "=&r" (tmp) :: "memory"); } @@ -82,8 +82,9 @@ static inline void arch_write_lock(arch_rwlock_t *lock) "1: lr.w %1, %0\n" " bnez %1, 1b\n" " li %1, -1\n" - " sc.w.aq %1, %1, %0\n" + " sc.w %1, %1, %0\n" " bnez %1, 1b\n" + RISCV_ACQUIRE_BARRIER : "+A" (lock->lock), "=&r" (tmp) :: "memory"); } @@ -96,8 +97,9 @@ static inline int arch_read_trylock(arch_rwlock_t *lock) "1: lr.w %1, %0\n" " bltz %1, 1f\n" " addi %1, %1, 1\n" - " sc.w.aq %1, %1, %0\n" + " sc.w %1, %1, %0\n" " bnez %1, 1b\n" + RISCV_ACQUIRE_BARRIER "1:\n" : "+A" (lock->lock), "=&r" (busy) :: "memory"); @@ -113,8 +115,9 @@ static inline int arch_write_trylock(arch_rwlock_t *lock) "1: lr.w %1, %0\n" " bnez %1, 1f\n" " li %1, -1\n" - " sc.w.aq %1, %1, %0\n" + " sc.w %1, %1, %0\n" " bnez %1, 1b\n" + RISCV_ACQUIRE_BARRIER "1:\n" : "+A" (lock->lock), "=&r" (busy) :: "memory"); @@ -125,7 +128,8 @@ static inline int arch_write_trylock(arch_rwlock_t *lock) static inline void arch_read_unlock(arch_rwlock_t *lock) { __asm__ __volatile__( - "amoadd.w.rl x0, %1, %0" + RISCV_RELEASE_BARRIER + " amoadd.w x0, %1, %0\n" : "+A" (lock->lock) : "r" (-1) : "memory"); @@ -133,10 +137,7 @@ static inline void arch_read_unlock(arch_rwlock_t *lock) static inline void arch_write_unlock(arch_rwlock_t *lock) { - __asm__ __volatile__ ( - "amoswap.w.rl x0, x0, %0" - : "=A" (lock->lock) - :: "memory"); + smp_store_release(&lock->lock, 0); } #endif /* _ASM_RISCV_SPINLOCK_H */ |