diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-06-07 12:22:15 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-06-07 12:22:15 +0200 |
commit | 5f4457a4f62cc9d78e04c0eb12ff0540899aad89 (patch) | |
tree | 0b973d527ea6b2ae31e08da0746b4965a3c5a6d8 /arch/m32r/include/asm/spinlock.h | |
parent | 9b94b3a19b13e094c10f65f24bc358f6ffe4eacd (diff) | |
parent | b87297fb405ef13cac375f202d114323b076a56d (diff) |
Merge branch 'linus' into x86/cpu
Diffstat (limited to 'arch/m32r/include/asm/spinlock.h')
-rw-r--r-- | arch/m32r/include/asm/spinlock.h | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/arch/m32r/include/asm/spinlock.h b/arch/m32r/include/asm/spinlock.h new file mode 100644 index 00000000000..dded923883b --- /dev/null +++ b/arch/m32r/include/asm/spinlock.h @@ -0,0 +1,326 @@ +#ifndef _ASM_M32R_SPINLOCK_H +#define _ASM_M32R_SPINLOCK_H + +/* + * linux/include/asm-m32r/spinlock.h + * + * M32R version: + * Copyright (C) 2001, 2002 Hitoshi Yamamoto + * Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org> + */ + +#include <linux/compiler.h> +#include <asm/atomic.h> +#include <asm/page.h> + +/* + * Your basic SMP spinlocks, allowing only a single CPU anywhere + * + * (the type definitions are in asm/spinlock_types.h) + * + * Simple spin lock operations. There are two variants, one clears IRQ's + * on the local processor, one does not. + * + * We make no fairness assumptions. They have a cost. + */ + +#define __raw_spin_is_locked(x) (*(volatile int *)(&(x)->slock) <= 0) +#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) +#define __raw_spin_unlock_wait(x) \ + do { cpu_relax(); } while (__raw_spin_is_locked(x)) + +/** + * __raw_spin_trylock - Try spin lock and return a result + * @lock: Pointer to the lock variable + * + * __raw_spin_trylock() tries to get the lock and returns a result. + * On the m32r, the result value is 1 (= Success) or 0 (= Failure). + */ +static inline int __raw_spin_trylock(raw_spinlock_t *lock) +{ + int oldval; + unsigned long tmp1, tmp2; + + /* + * lock->slock : =1 : unlock + * : <=0 : lock + * { + * oldval = lock->slock; <--+ need atomic operation + * lock->slock = 0; <--+ + * } + */ + __asm__ __volatile__ ( + "# __raw_spin_trylock \n\t" + "ldi %1, #0; \n\t" + "mvfc %2, psw; \n\t" + "clrpsw #0x40 -> nop; \n\t" + DCACHE_CLEAR("%0", "r6", "%3") + "lock %0, @%3; \n\t" + "unlock %1, @%3; \n\t" + "mvtc %2, psw; \n\t" + : "=&r" (oldval), "=&r" (tmp1), "=&r" (tmp2) + : "r" (&lock->slock) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r6" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); + + return (oldval > 0); +} + +static inline void __raw_spin_lock(raw_spinlock_t *lock) +{ + unsigned long tmp0, tmp1; + + /* + * lock->slock : =1 : unlock + * : <=0 : lock + * + * for ( ; ; ) { + * lock->slock -= 1; <-- need atomic operation + * if (lock->slock == 0) break; + * for ( ; lock->slock <= 0 ; ); + * } + */ + __asm__ __volatile__ ( + "# __raw_spin_lock \n\t" + ".fillinsn \n" + "1: \n\t" + "mvfc %1, psw; \n\t" + "clrpsw #0x40 -> nop; \n\t" + DCACHE_CLEAR("%0", "r6", "%2") + "lock %0, @%2; \n\t" + "addi %0, #-1; \n\t" + "unlock %0, @%2; \n\t" + "mvtc %1, psw; \n\t" + "bltz %0, 2f; \n\t" + LOCK_SECTION_START(".balign 4 \n\t") + ".fillinsn \n" + "2: \n\t" + "ld %0, @%2; \n\t" + "bgtz %0, 1b; \n\t" + "bra 2b; \n\t" + LOCK_SECTION_END + : "=&r" (tmp0), "=&r" (tmp1) + : "r" (&lock->slock) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r6" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); +} + +static inline void __raw_spin_unlock(raw_spinlock_t *lock) +{ + mb(); + lock->slock = 1; +} + +/* + * Read-write spinlocks, allowing multiple readers + * but only one writer. + * + * NOTE! it is quite common to have readers in interrupts + * but no interrupt writers. For those circumstances we + * can "mix" irq-safe locks - any writer needs to get a + * irq-safe write-lock, but readers can get non-irqsafe + * read-locks. + * + * On x86, we implement read-write locks as a 32-bit counter + * with the high bit (sign) being the "contended" bit. + * + * The inline assembly is non-obvious. Think about it. + * + * Changed to use the same technique as rw semaphores. See + * semaphore.h for details. -ben + */ + +/** + * read_can_lock - would read_trylock() succeed? + * @lock: the rwlock in question. + */ +#define __raw_read_can_lock(x) ((int)(x)->lock > 0) + +/** + * write_can_lock - would write_trylock() succeed? + * @lock: the rwlock in question. + */ +#define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) + +static inline void __raw_read_lock(raw_rwlock_t *rw) +{ + unsigned long tmp0, tmp1; + + /* + * rw->lock : >0 : unlock + * : <=0 : lock + * + * for ( ; ; ) { + * rw->lock -= 1; <-- need atomic operation + * if (rw->lock >= 0) break; + * rw->lock += 1; <-- need atomic operation + * for ( ; rw->lock <= 0 ; ); + * } + */ + __asm__ __volatile__ ( + "# read_lock \n\t" + ".fillinsn \n" + "1: \n\t" + "mvfc %1, psw; \n\t" + "clrpsw #0x40 -> nop; \n\t" + DCACHE_CLEAR("%0", "r6", "%2") + "lock %0, @%2; \n\t" + "addi %0, #-1; \n\t" + "unlock %0, @%2; \n\t" + "mvtc %1, psw; \n\t" + "bltz %0, 2f; \n\t" + LOCK_SECTION_START(".balign 4 \n\t") + ".fillinsn \n" + "2: \n\t" + "clrpsw #0x40 -> nop; \n\t" + DCACHE_CLEAR("%0", "r6", "%2") + "lock %0, @%2; \n\t" + "addi %0, #1; \n\t" + "unlock %0, @%2; \n\t" + "mvtc %1, psw; \n\t" + ".fillinsn \n" + "3: \n\t" + "ld %0, @%2; \n\t" + "bgtz %0, 1b; \n\t" + "bra 3b; \n\t" + LOCK_SECTION_END + : "=&r" (tmp0), "=&r" (tmp1) + : "r" (&rw->lock) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r6" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); +} + +static inline void __raw_write_lock(raw_rwlock_t *rw) +{ + unsigned long tmp0, tmp1, tmp2; + + /* + * rw->lock : =RW_LOCK_BIAS_STR : unlock + * : !=RW_LOCK_BIAS_STR : lock + * + * for ( ; ; ) { + * rw->lock -= RW_LOCK_BIAS_STR; <-- need atomic operation + * if (rw->lock == 0) break; + * rw->lock += RW_LOCK_BIAS_STR; <-- need atomic operation + * for ( ; rw->lock != RW_LOCK_BIAS_STR ; ) ; + * } + */ + __asm__ __volatile__ ( + "# write_lock \n\t" + "seth %1, #high(" RW_LOCK_BIAS_STR "); \n\t" + "or3 %1, %1, #low(" RW_LOCK_BIAS_STR "); \n\t" + ".fillinsn \n" + "1: \n\t" + "mvfc %2, psw; \n\t" + "clrpsw #0x40 -> nop; \n\t" + DCACHE_CLEAR("%0", "r7", "%3") + "lock %0, @%3; \n\t" + "sub %0, %1; \n\t" + "unlock %0, @%3; \n\t" + "mvtc %2, psw; \n\t" + "bnez %0, 2f; \n\t" + LOCK_SECTION_START(".balign 4 \n\t") + ".fillinsn \n" + "2: \n\t" + "clrpsw #0x40 -> nop; \n\t" + DCACHE_CLEAR("%0", "r7", "%3") + "lock %0, @%3; \n\t" + "add %0, %1; \n\t" + "unlock %0, @%3; \n\t" + "mvtc %2, psw; \n\t" + ".fillinsn \n" + "3: \n\t" + "ld %0, @%3; \n\t" + "beq %0, %1, 1b; \n\t" + "bra 3b; \n\t" + LOCK_SECTION_END + : "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2) + : "r" (&rw->lock) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r7" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); +} + +static inline void __raw_read_unlock(raw_rwlock_t *rw) +{ + unsigned long tmp0, tmp1; + + __asm__ __volatile__ ( + "# read_unlock \n\t" + "mvfc %1, psw; \n\t" + "clrpsw #0x40 -> nop; \n\t" + DCACHE_CLEAR("%0", "r6", "%2") + "lock %0, @%2; \n\t" + "addi %0, #1; \n\t" + "unlock %0, @%2; \n\t" + "mvtc %1, psw; \n\t" + : "=&r" (tmp0), "=&r" (tmp1) + : "r" (&rw->lock) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r6" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); +} + +static inline void __raw_write_unlock(raw_rwlock_t *rw) +{ + unsigned long tmp0, tmp1, tmp2; + + __asm__ __volatile__ ( + "# write_unlock \n\t" + "seth %1, #high(" RW_LOCK_BIAS_STR "); \n\t" + "or3 %1, %1, #low(" RW_LOCK_BIAS_STR "); \n\t" + "mvfc %2, psw; \n\t" + "clrpsw #0x40 -> nop; \n\t" + DCACHE_CLEAR("%0", "r7", "%3") + "lock %0, @%3; \n\t" + "add %0, %1; \n\t" + "unlock %0, @%3; \n\t" + "mvtc %2, psw; \n\t" + : "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2) + : "r" (&rw->lock) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r7" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); +} + +static inline int __raw_read_trylock(raw_rwlock_t *lock) +{ + atomic_t *count = (atomic_t*)lock; + if (atomic_dec_return(count) >= 0) + return 1; + atomic_inc(count); + return 0; +} + +static inline int __raw_write_trylock(raw_rwlock_t *lock) +{ + atomic_t *count = (atomic_t *)lock; + if (atomic_sub_and_test(RW_LOCK_BIAS, count)) + return 1; + atomic_add(RW_LOCK_BIAS, count); + return 0; +} + +#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock) +#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock) + +#define _raw_spin_relax(lock) cpu_relax() +#define _raw_read_relax(lock) cpu_relax() +#define _raw_write_relax(lock) cpu_relax() + +#endif /* _ASM_M32R_SPINLOCK_H */ |