diff options
| -rw-r--r-- | xen/include/asm-arm/arm32/spinlock.h | 25 | ||||
| -rw-r--r-- | xen/include/asm-arm/arm64/spinlock.h | 3 |
2 files changed, 16 insertions, 12 deletions
diff --git a/xen/include/asm-arm/arm32/spinlock.h b/xen/include/asm-arm/arm32/spinlock.h index 4a11a97b93..ba11ad612f 100644 --- a/xen/include/asm-arm/arm32/spinlock.h +++ b/xen/include/asm-arm/arm32/spinlock.h @@ -34,17 +34,20 @@ static always_inline void _raw_spin_unlock(raw_spinlock_t *lock) static always_inline int _raw_spin_trylock(raw_spinlock_t *lock) { - unsigned long tmp; - - __asm__ __volatile__( -" ldrex %0, [%1]\n" -" teq %0, #0\n" -" strexeq %0, %2, [%1]" - : "=&r" (tmp) - : "r" (&lock->lock), "r" (1) - : "cc"); - - if (tmp == 0) { + unsigned long contended, res; + + do { + __asm__ __volatile__( + " ldrex %0, [%2]\n" + " teq %0, #0\n" + " strexeq %1, %3, [%2]\n" + " movne %1, #0\n" + : "=&r" (contended), "=r" (res) + : "r" (&lock->lock), "r" (1) + : "cc"); + } while (res); + + if (!contended) { smp_mb(); return 1; } else { diff --git a/xen/include/asm-arm/arm64/spinlock.h b/xen/include/asm-arm/arm64/spinlock.h index 717f2fe604..3a36cfd4d6 100644 --- a/xen/include/asm-arm/arm64/spinlock.h +++ b/xen/include/asm-arm/arm64/spinlock.h @@ -40,9 +40,10 @@ static always_inline int _raw_spin_trylock(raw_spinlock_t *lock) unsigned int tmp; asm volatile( - " ldaxr %w0, %1\n" + "2: ldaxr %w0, %1\n" " cbnz %w0, 1f\n" " stxr %w0, %w2, %1\n" + " cbnz %w0, 2b\n" "1:\n" : "=&r" (tmp), "+Q" (lock->lock) : "r" (1) |