diff options
Diffstat (limited to 'include/asm-arm/spinlock.h')
| -rw-r--r-- | include/asm-arm/spinlock.h | 224 |
1 files changed, 0 insertions, 224 deletions
diff --git a/include/asm-arm/spinlock.h b/include/asm-arm/spinlock.h deleted file mode 100644 index 2b41ebb..0000000 --- a/include/asm-arm/spinlock.h +++ /dev/null @@ -1,224 +0,0 @@ -#ifndef __ASM_SPINLOCK_H -#define __ASM_SPINLOCK_H - -#if __LINUX_ARM_ARCH__ < 6 -#error SMP not supported on pre-ARMv6 CPUs -#endif - -/* - * ARMv6 Spin-locking. - * - * We exclusively read the old value. If it is zero, we may have - * won the lock, so we try exclusively storing it. A memory barrier - * is required after we get a lock, and before we release it, because - * V6 CPUs are assumed to have weakly ordered memory. - * - * Unlocked value: 0 - * Locked value: 1 - */ - -#define __raw_spin_is_locked(x) ((x)->lock != 0) -#define __raw_spin_unlock_wait(lock) \ - do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0) - -#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) - -static inline void __raw_spin_lock(raw_spinlock_t *lock) -{ - unsigned long tmp; - - __asm__ __volatile__( -"1: ldrex %0, [%1]\n" -" teq %0, #0\n" -#ifdef CONFIG_CPU_32v6K -" wfene\n" -#endif -" strexeq %0, %2, [%1]\n" -" teqeq %0, #0\n" -" bne 1b" - : "=&r" (tmp) - : "r" (&lock->lock), "r" (1) - : "cc"); - - smp_mb(); -} - -static 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) { - smp_mb(); - return 1; - } else { - return 0; - } -} - -static inline void __raw_spin_unlock(raw_spinlock_t *lock) -{ - smp_mb(); - - __asm__ __volatile__( -" str %1, [%0]\n" -#ifdef CONFIG_CPU_32v6K -" mcr p15, 0, %1, c7, c10, 4\n" /* DSB */ -" sev" -#endif - : - : "r" (&lock->lock), "r" (0) - : "cc"); -} - -/* - * RWLOCKS - * - * - * Write locks are easy - we just set bit 31. When unlocking, we can - * just write zero since the lock is exclusively held. - */ - -static inline void __raw_write_lock(raw_rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__( -"1: ldrex %0, [%1]\n" -" teq %0, #0\n" -#ifdef CONFIG_CPU_32v6K -" wfene\n" -#endif -" strexeq %0, %2, [%1]\n" -" teq %0, #0\n" -" bne 1b" - : "=&r" (tmp) - : "r" (&rw->lock), "r" (0x80000000) - : "cc"); - - smp_mb(); -} - -static inline int __raw_write_trylock(raw_rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__( -"1: ldrex %0, [%1]\n" -" teq %0, #0\n" -" strexeq %0, %2, [%1]" - : "=&r" (tmp) - : "r" (&rw->lock), "r" (0x80000000) - : "cc"); - - if (tmp == 0) { - smp_mb(); - return 1; - } else { - return 0; - } -} - -static inline void __raw_write_unlock(raw_rwlock_t *rw) -{ - smp_mb(); - - __asm__ __volatile__( - "str %1, [%0]\n" -#ifdef CONFIG_CPU_32v6K -" mcr p15, 0, %1, c7, c10, 4\n" /* DSB */ -" sev\n" -#endif - : - : "r" (&rw->lock), "r" (0) - : "cc"); -} - -/* write_can_lock - would write_trylock() succeed? */ -#define __raw_write_can_lock(x) ((x)->lock == 0) - -/* - * Read locks are a bit more hairy: - * - Exclusively load the lock value. - * - Increment it. - * - Store new lock value if positive, and we still own this location. - * If the value is negative, we've already failed. - * - If we failed to store the value, we want a negative result. - * - If we failed, try again. - * Unlocking is similarly hairy. We may have multiple read locks - * currently active. However, we know we won't have any write - * locks. - */ -static inline void __raw_read_lock(raw_rwlock_t *rw) -{ - unsigned long tmp, tmp2; - - __asm__ __volatile__( -"1: ldrex %0, [%2]\n" -" adds %0, %0, #1\n" -" strexpl %1, %0, [%2]\n" -#ifdef CONFIG_CPU_32v6K -" wfemi\n" -#endif -" rsbpls %0, %1, #0\n" -" bmi 1b" - : "=&r" (tmp), "=&r" (tmp2) - : "r" (&rw->lock) - : "cc"); - - smp_mb(); -} - -static inline void __raw_read_unlock(raw_rwlock_t *rw) -{ - unsigned long tmp, tmp2; - - smp_mb(); - - __asm__ __volatile__( -"1: ldrex %0, [%2]\n" -" sub %0, %0, #1\n" -" strex %1, %0, [%2]\n" -" teq %1, #0\n" -" bne 1b" -#ifdef CONFIG_CPU_32v6K -"\n cmp %0, #0\n" -" mcreq p15, 0, %0, c7, c10, 4\n" -" seveq" -#endif - : "=&r" (tmp), "=&r" (tmp2) - : "r" (&rw->lock) - : "cc"); -} - -static inline int __raw_read_trylock(raw_rwlock_t *rw) -{ - unsigned long tmp, tmp2 = 1; - - __asm__ __volatile__( -"1: ldrex %0, [%2]\n" -" adds %0, %0, #1\n" -" strexpl %1, %0, [%2]\n" - : "=&r" (tmp), "+r" (tmp2) - : "r" (&rw->lock) - : "cc"); - - smp_mb(); - return tmp2 == 0; -} - -/* read_can_lock - would read_trylock() succeed? */ -#define __raw_read_can_lock(x) ((x)->lock < 0x80000000) - -#define _raw_spin_relax(lock) cpu_relax() -#define _raw_read_relax(lock) cpu_relax() -#define _raw_write_relax(lock) cpu_relax() - -#endif /* __ASM_SPINLOCK_H */ |