diff options
Diffstat (limited to 'include/asm-s390/spinlock.h')
| -rw-r--r-- | include/asm-s390/spinlock.h | 252 |
1 files changed, 78 insertions, 174 deletions
diff --git a/include/asm-s390/spinlock.h b/include/asm-s390/spinlock.h index 53cc736b9820..8ff10300f7ee 100644 --- a/include/asm-s390/spinlock.h +++ b/include/asm-s390/spinlock.h @@ -11,21 +11,16 @@ #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 <asm/lowcore.h> -#define __DIAG44_INSN "ex" -#define __DIAG44_OPERAND __LC_DIAG44_OPCODE -#else -#define __DIAG44_INSN "#" -#define __DIAG44_OPERAND 0 -#endif -#endif /* __s390x__ */ +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; +} /* * Simple spin lock operations. There are two variants, one clears IRQ's @@ -41,58 +36,35 @@ typedef struct { #endif } __attribute__ ((aligned (4))) spinlock_t; -#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } -#define spin_lock_init(lp) do { (lp)->lock = 0; } 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 spin_is_locked(x) ((x)->lock != 0) #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) -extern inline void _raw_spin_lock(spinlock_t *lp) +extern void _raw_spin_lock_wait(spinlock_t *lp, unsigned int pc); +extern int _raw_spin_trylock_retry(spinlock_t *lp, unsigned int pc); + +static inline void _raw_spin_lock(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 = (unsigned long) __builtin_return_address(0); + + if (unlikely(_raw_compare_and_swap(&lp->lock, 0, pc) != 0)) + _raw_spin_lock_wait(lp, pc); } -extern inline int _raw_spin_trylock(spinlock_t *lp) +static inline int _raw_spin_trylock(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 = (unsigned long) __builtin_return_address(0); + + if (likely(_raw_compare_and_swap(&lp->lock, 0, pc) == 0)) + return 1; + return _raw_spin_trylock_retry(lp, pc); } -extern inline void _raw_spin_unlock(spinlock_t *lp) +static inline void _raw_spin_unlock(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" ); + _raw_compare_and_swap(&lp->lock, lp->lock, 0); } /* @@ -106,7 +78,7 @@ extern inline void _raw_spin_unlock(spinlock_t *lp) * read-locks. */ typedef struct { - volatile unsigned long lock; + volatile unsigned int lock; volatile unsigned long owner_pc; #ifdef CONFIG_PREEMPT unsigned int break_lock; @@ -129,123 +101,55 @@ typedef struct { */ #define write_can_lock(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__ */ - -#define _raw_read_trylock(lock) generic_raw_read_trylock(lock) - -extern inline int _raw_write_trylock(rwlock_t *rw) +extern void _raw_read_lock_wait(rwlock_t *lp); +extern int _raw_read_trylock_retry(rwlock_t *lp); +extern void _raw_write_lock_wait(rwlock_t *lp); +extern int _raw_write_trylock_retry(rwlock_t *lp); + +static inline void _raw_read_lock(rwlock_t *rw) +{ + 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(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(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(rwlock_t *rw) +{ + _raw_compare_and_swap(&rw->lock, 0x80000000, 0); +} + +static inline int _raw_read_trylock(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(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; + if (likely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)) + return 1; + return _raw_write_trylock_retry(rw); } #endif /* __ASM_SPINLOCK_H */ |