X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fasm-s390%2Fspinlock.h;h=3fd43826fd0bf864a94bb307b86354b358d280bd;hb=refs%2Fheads%2Fvserver;hp=bc7a8471cd5e4e1738c321f69d0c9c351bdc721a;hpb=9213980e6a70d8473e0ffd4b39ab5b6caaba9ff5;p=linux-2.6.git diff --git a/include/asm-s390/spinlock.h b/include/asm-s390/spinlock.h index bc7a8471c..3fd43826f 100644 --- a/include/asm-s390/spinlock.h +++ b/include/asm-s390/spinlock.h @@ -11,85 +11,87 @@ #ifndef __ASM_SPINLOCK_H #define __ASM_SPINLOCK_H -#ifdef __s390x__ -/* - * Grmph, take care of %&#! user space programs that include - * asm/spinlock.h. The diagnose is only available in kernel - * context. - */ -#ifdef __KERNEL__ -#include -#define __DIAG44_INSN "ex" -#define __DIAG44_OPERAND __LC_DIAG44_OPCODE -#else -#define __DIAG44_INSN "#" -#define __DIAG44_OPERAND 0 -#endif -#endif /* __s390x__ */ +#include + +#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) + +static inline int +_raw_compare_and_swap(volatile unsigned int *lock, + unsigned int old, unsigned int new) +{ + asm volatile( + " cs %0,%3,%1" + : "=d" (old), "=Q" (*lock) + : "0" (old), "d" (new), "Q" (*lock) + : "cc", "memory" ); + return old; +} + +#else /* __GNUC__ */ + +static inline int +_raw_compare_and_swap(volatile unsigned int *lock, + unsigned int old, unsigned int new) +{ + asm volatile( + " cs %0,%3,0(%4)" + : "=d" (old), "=m" (*lock) + : "0" (old), "d" (new), "a" (lock), "m" (*lock) + : "cc", "memory" ); + return old; +} + +#endif /* __GNUC__ */ /* * 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. + * + * (the type definitions are in asm/spinlock_types.h) */ -typedef struct { - volatile unsigned int lock; -} __attribute__ ((aligned (4))) spinlock_t; +#define __raw_spin_is_locked(x) ((x)->owner_cpu != 0) +#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) +#define __raw_spin_unlock_wait(lock) \ + do { while (__raw_spin_is_locked(lock)) \ + _raw_spin_relax(lock); } while (0) -#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } -#define spin_lock_init(lp) do { (lp)->lock = 0; } while(0) -#define spin_unlock_wait(lp) do { barrier(); } while(((volatile spinlock_t *)(lp))->lock) -#define spin_is_locked(x) ((x)->lock != 0) -#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) +extern void _raw_spin_lock_wait(raw_spinlock_t *, unsigned int pc); +extern int _raw_spin_trylock_retry(raw_spinlock_t *, unsigned int pc); +extern void _raw_spin_relax(raw_spinlock_t *lock); -extern inline void _raw_spin_lock(spinlock_t *lp) +static inline void __raw_spin_lock(raw_spinlock_t *lp) { -#ifndef __s390x__ - unsigned int reg1, reg2; - __asm__ __volatile__(" bras %0,1f\n" - "0: diag 0,0,68\n" - "1: slr %1,%1\n" - " cs %1,%0,0(%3)\n" - " jl 0b\n" - : "=&d" (reg1), "=&d" (reg2), "=m" (lp->lock) - : "a" (&lp->lock), "m" (lp->lock) - : "cc", "memory" ); -#else /* __s390x__ */ - unsigned long reg1, reg2; - __asm__ __volatile__(" bras %1,1f\n" - "0: " __DIAG44_INSN " 0,%4\n" - "1: slr %0,%0\n" - " cs %0,%1,0(%3)\n" - " jl 0b\n" - : "=&d" (reg1), "=&d" (reg2), "=m" (lp->lock) - : "a" (&lp->lock), "i" (__DIAG44_OPERAND), - "m" (lp->lock) : "cc", "memory" ); -#endif /* __s390x__ */ + unsigned long pc = 1 | (unsigned long) __builtin_return_address(0); + int old; + + old = _raw_compare_and_swap(&lp->owner_cpu, 0, ~smp_processor_id()); + if (likely(old == 0)) { + lp->owner_pc = pc; + return; + } + _raw_spin_lock_wait(lp, pc); } -extern inline int _raw_spin_trylock(spinlock_t *lp) +static inline int __raw_spin_trylock(raw_spinlock_t *lp) { - unsigned long reg; - unsigned int result; - - __asm__ __volatile__(" basr %1,0\n" - "0: cs %0,%1,0(%3)" - : "=d" (result), "=&d" (reg), "=m" (lp->lock) - : "a" (&lp->lock), "m" (lp->lock), "0" (0) - : "cc", "memory" ); - return !result; + unsigned long pc = 1 | (unsigned long) __builtin_return_address(0); + int old; + + old = _raw_compare_and_swap(&lp->owner_cpu, 0, ~smp_processor_id()); + if (likely(old == 0)) { + lp->owner_pc = pc; + return 1; + } + return _raw_spin_trylock_retry(lp, pc); } -extern inline void _raw_spin_unlock(spinlock_t *lp) +static inline void __raw_spin_unlock(raw_spinlock_t *lp) { - unsigned int old; - - __asm__ __volatile__("cs %0,%3,0(%4)" - : "=d" (old), "=m" (lp->lock) - : "0" (lp->lock), "d" (0), "a" (lp) - : "cc", "memory" ); + lp->owner_pc = 0; + _raw_compare_and_swap(&lp->owner_cpu, lp->owner_cpu, 0); } /* @@ -102,132 +104,71 @@ extern inline void _raw_spin_unlock(spinlock_t *lp) * irq-safe write-lock, but readers can get non-irqsafe * read-locks. */ -typedef struct { - volatile unsigned long lock; - volatile unsigned long owner_pc; -} rwlock_t; - -#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } - -#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) - -#define rwlock_is_locked(x) ((x)->lock != 0) - -#ifndef __s390x__ -#define _raw_read_lock(rw) \ - asm volatile(" l 2,0(%1)\n" \ - " j 1f\n" \ - "0: diag 0,0,68\n" \ - "1: la 2,0(2)\n" /* clear high (=write) bit */ \ - " la 3,1(2)\n" /* one more reader */ \ - " cs 2,3,0(%1)\n" /* try to write new value */ \ - " jl 0b" \ - : "=m" ((rw)->lock) : "a" (&(rw)->lock), \ - "m" ((rw)->lock) : "2", "3", "cc", "memory" ) -#else /* __s390x__ */ -#define _raw_read_lock(rw) \ - asm volatile(" lg 2,0(%1)\n" \ - " j 1f\n" \ - "0: " __DIAG44_INSN " 0,%2\n" \ - "1: nihh 2,0x7fff\n" /* clear high (=write) bit */ \ - " la 3,1(2)\n" /* one more reader */ \ - " csg 2,3,0(%1)\n" /* try to write new value */ \ - " jl 0b" \ - : "=m" ((rw)->lock) \ - : "a" (&(rw)->lock), "i" (__DIAG44_OPERAND), \ - "m" ((rw)->lock) : "2", "3", "cc", "memory" ) -#endif /* __s390x__ */ - -#ifndef __s390x__ -#define _raw_read_unlock(rw) \ - asm volatile(" l 2,0(%1)\n" \ - " j 1f\n" \ - "0: diag 0,0,68\n" \ - "1: lr 3,2\n" \ - " ahi 3,-1\n" /* one less reader */ \ - " cs 2,3,0(%1)\n" \ - " jl 0b" \ - : "=m" ((rw)->lock) : "a" (&(rw)->lock), \ - "m" ((rw)->lock) : "2", "3", "cc", "memory" ) -#else /* __s390x__ */ -#define _raw_read_unlock(rw) \ - asm volatile(" lg 2,0(%1)\n" \ - " j 1f\n" \ - "0: " __DIAG44_INSN " 0,%2\n" \ - "1: lgr 3,2\n" \ - " bctgr 3,0\n" /* one less reader */ \ - " csg 2,3,0(%1)\n" \ - " jl 0b" \ - : "=m" ((rw)->lock) \ - : "a" (&(rw)->lock), "i" (__DIAG44_OPERAND), \ - "m" ((rw)->lock) : "2", "3", "cc", "memory" ) -#endif /* __s390x__ */ - -#ifndef __s390x__ -#define _raw_write_lock(rw) \ - asm volatile(" lhi 3,1\n" \ - " sll 3,31\n" /* new lock value = 0x80000000 */ \ - " j 1f\n" \ - "0: diag 0,0,68\n" \ - "1: slr 2,2\n" /* old lock value must be 0 */ \ - " cs 2,3,0(%1)\n" \ - " jl 0b" \ - : "=m" ((rw)->lock) : "a" (&(rw)->lock), \ - "m" ((rw)->lock) : "2", "3", "cc", "memory" ) -#else /* __s390x__ */ -#define _raw_write_lock(rw) \ - asm volatile(" llihh 3,0x8000\n" /* new lock value = 0x80...0 */ \ - " j 1f\n" \ - "0: " __DIAG44_INSN " 0,%2\n" \ - "1: slgr 2,2\n" /* old lock value must be 0 */ \ - " csg 2,3,0(%1)\n" \ - " jl 0b" \ - : "=m" ((rw)->lock) \ - : "a" (&(rw)->lock), "i" (__DIAG44_OPERAND), \ - "m" ((rw)->lock) : "2", "3", "cc", "memory" ) -#endif /* __s390x__ */ - -#ifndef __s390x__ -#define _raw_write_unlock(rw) \ - asm volatile(" slr 3,3\n" /* new lock value = 0 */ \ - " j 1f\n" \ - "0: diag 0,0,68\n" \ - "1: lhi 2,1\n" \ - " sll 2,31\n" /* old lock value must be 0x80000000 */ \ - " cs 2,3,0(%1)\n" \ - " jl 0b" \ - : "=m" ((rw)->lock) : "a" (&(rw)->lock), \ - "m" ((rw)->lock) : "2", "3", "cc", "memory" ) -#else /* __s390x__ */ -#define _raw_write_unlock(rw) \ - asm volatile(" slgr 3,3\n" /* new lock value = 0 */ \ - " j 1f\n" \ - "0: " __DIAG44_INSN " 0,%2\n" \ - "1: llihh 2,0x8000\n" /* old lock value must be 0x8..0 */\ - " csg 2,3,0(%1)\n" \ - " jl 0b" \ - : "=m" ((rw)->lock) \ - : "a" (&(rw)->lock), "i" (__DIAG44_OPERAND), \ - "m" ((rw)->lock) : "2", "3", "cc", "memory" ) -#endif /* __s390x__ */ - -extern inline int _raw_write_trylock(rwlock_t *rw) + +/** + * 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 == 0) + +extern void _raw_read_lock_wait(raw_rwlock_t *lp); +extern int _raw_read_trylock_retry(raw_rwlock_t *lp); +extern void _raw_write_lock_wait(raw_rwlock_t *lp); +extern int _raw_write_trylock_retry(raw_rwlock_t *lp); + +static inline void __raw_read_lock(raw_rwlock_t *rw) { - unsigned long result, reg; - - __asm__ __volatile__( -#ifndef __s390x__ - " lhi %1,1\n" - " sll %1,31\n" - " cs %0,%1,0(%3)" -#else /* __s390x__ */ - " llihh %1,0x8000\n" - "0: csg %0,%1,0(%3)\n" -#endif /* __s390x__ */ - : "=d" (result), "=&d" (reg), "=m" (rw->lock) - : "a" (&rw->lock), "m" (rw->lock), "0" (0UL) - : "cc", "memory" ); - return result == 0; + unsigned int old; + old = rw->lock & 0x7fffffffU; + if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old) + _raw_read_lock_wait(rw); +} + +static inline void __raw_read_unlock(raw_rwlock_t *rw) +{ + unsigned int old, cmp; + + old = rw->lock; + do { + cmp = old; + old = _raw_compare_and_swap(&rw->lock, old, old - 1); + } while (cmp != old); } +static inline void __raw_write_lock(raw_rwlock_t *rw) +{ + if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0)) + _raw_write_lock_wait(rw); +} + +static inline void __raw_write_unlock(raw_rwlock_t *rw) +{ + _raw_compare_and_swap(&rw->lock, 0x80000000, 0); +} + +static inline int __raw_read_trylock(raw_rwlock_t *rw) +{ + unsigned int old; + old = rw->lock & 0x7fffffffU; + if (likely(_raw_compare_and_swap(&rw->lock, old, old + 1) == old)) + return 1; + return _raw_read_trylock_retry(rw); +} + +static inline int __raw_write_trylock(raw_rwlock_t *rw) +{ + if (likely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)) + return 1; + return _raw_write_trylock_retry(rw); +} + +#define _raw_read_relax(lock) cpu_relax() +#define _raw_write_relax(lock) cpu_relax() + #endif /* __ASM_SPINLOCK_H */