X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=include%2Fasm-sh%2Fspinlock.h;h=e793181d64da33395ee432189d112fd6b821c0cc;hb=1bf99477226963d84b182b3995e355d3091199be;hp=54458fd2498150ce964e159748faac8339c1f235;hpb=59458f40e25915a355d8b1d701425fe9f4f9ea23;p=linux-2.6-omap-h63xx.git diff --git a/include/asm-sh/spinlock.h b/include/asm-sh/spinlock.h index 54458fd2498..e793181d64d 100644 --- a/include/asm-sh/spinlock.h +++ b/include/asm-sh/spinlock.h @@ -2,6 +2,7 @@ * include/asm-sh/spinlock.h * * Copyright (C) 2002, 2003 Paul Mundt + * Copyright (C) 2006, 2007 Akio Idehara * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive @@ -10,16 +11,22 @@ #ifndef __ASM_SH_SPINLOCK_H #define __ASM_SH_SPINLOCK_H -#include +/* + * The only locking implemented here uses SH-4A opcodes. For others, + * split this out as per atomic-*.h. + */ +#ifndef CONFIG_CPU_SH4A +#error "Need movli.l/movco.l for spinlocks" +#endif /* * Your basic SMP spinlocks, allowing only a single CPU anywhere */ -#define __raw_spin_is_locked(x) ((x)->lock != 0) +#define __raw_spin_is_locked(x) ((x)->lock <= 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)) + do { cpu_relax(); } while ((x)->lock) /* * Simple spin lock operations. There are two variants, one clears IRQ's @@ -29,12 +36,19 @@ */ static inline void __raw_spin_lock(raw_spinlock_t *lock) { + unsigned long tmp; + unsigned long oldval; + __asm__ __volatile__ ( - "1:\n\t" - "tas.b @%0\n\t" - "bf/s 1b\n\t" - "nop\n\t" - : "=r" (lock->lock) + "1: \n\t" + "movli.l @%2, %0 ! __raw_spin_lock \n\t" + "mov %0, %1 \n\t" + "mov #0, %0 \n\t" + "movco.l %0, @%2 \n\t" + "bf 1b \n\t" + "cmp/pl %1 \n\t" + "bf 1b \n\t" + : "=&z" (tmp), "=&r" (oldval) : "r" (&lock->lock) : "t", "memory" ); @@ -42,12 +56,36 @@ static inline void __raw_spin_lock(raw_spinlock_t *lock) static inline void __raw_spin_unlock(raw_spinlock_t *lock) { - assert_spin_locked(lock); + unsigned long tmp; - lock->lock = 0; + __asm__ __volatile__ ( + "mov #1, %0 ! __raw_spin_unlock \n\t" + "mov.l %0, @%1 \n\t" + : "=&z" (tmp) + : "r" (&lock->lock) + : "t", "memory" + ); } -#define __raw_spin_trylock(x) (!test_and_set_bit(0, &(x)->lock)) +static inline int __raw_spin_trylock(raw_spinlock_t *lock) +{ + unsigned long tmp, oldval; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%2, %0 ! __raw_spin_trylock \n\t" + "mov %0, %1 \n\t" + "mov #0, %0 \n\t" + "movco.l %0, @%2 \n\t" + "bf 1b \n\t" + "synco \n\t" + : "=&z" (tmp), "=&r" (oldval) + : "r" (&lock->lock) + : "t", "memory" + ); + + return oldval; +} /* * Read-write spinlocks, allowing multiple readers but only one writer. @@ -58,46 +96,124 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock) * read-locks. */ +/** + * read_can_lock - would read_trylock() succeed? + * @lock: the rwlock in question. + */ +#define __raw_read_can_lock(x) ((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) { - __raw_spin_lock(&rw->lock); - - atomic_inc(&rw->counter); + unsigned long tmp; - __raw_spin_unlock(&rw->lock); + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%1, %0 ! __raw_read_lock \n\t" + "cmp/pl %0 \n\t" + "bf 1b \n\t" + "add #-1, %0 \n\t" + "movco.l %0, @%1 \n\t" + "bf 1b \n\t" + : "=&z" (tmp) + : "r" (&rw->lock) + : "t", "memory" + ); } static inline void __raw_read_unlock(raw_rwlock_t *rw) { - __raw_spin_lock(&rw->lock); + unsigned long tmp; - atomic_dec(&rw->counter); - - __raw_spin_unlock(&rw->lock); + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%1, %0 ! __raw_read_unlock \n\t" + "add #1, %0 \n\t" + "movco.l %0, @%1 \n\t" + "bf 1b \n\t" + : "=&z" (tmp) + : "r" (&rw->lock) + : "t", "memory" + ); } static inline void __raw_write_lock(raw_rwlock_t *rw) { - __raw_spin_lock(&rw->lock); - atomic_set(&rw->counter, -1); + unsigned long tmp; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%1, %0 ! __raw_write_lock \n\t" + "cmp/hs %2, %0 \n\t" + "bf 1b \n\t" + "sub %2, %0 \n\t" + "movco.l %0, @%1 \n\t" + "bf 1b \n\t" + : "=&z" (tmp) + : "r" (&rw->lock), "r" (RW_LOCK_BIAS) + : "t", "memory" + ); } static inline void __raw_write_unlock(raw_rwlock_t *rw) { - atomic_set(&rw->counter, 0); - __raw_spin_unlock(&rw->lock); + __asm__ __volatile__ ( + "mov.l %1, @%0 ! __raw_write_unlock \n\t" + : + : "r" (&rw->lock), "r" (RW_LOCK_BIAS) + : "t", "memory" + ); } -#define __raw_read_trylock(lock) generic__raw_read_trylock(lock) +static inline int __raw_read_trylock(raw_rwlock_t *rw) +{ + unsigned long tmp, oldval; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%2, %0 ! __raw_read_trylock \n\t" + "mov %0, %1 \n\t" + "cmp/pl %0 \n\t" + "bf 2f \n\t" + "add #-1, %0 \n\t" + "movco.l %0, @%2 \n\t" + "bf 1b \n\t" + "2: \n\t" + "synco \n\t" + : "=&z" (tmp), "=&r" (oldval) + : "r" (&rw->lock) + : "t", "memory" + ); + + return (oldval > 0); +} static inline int __raw_write_trylock(raw_rwlock_t *rw) { - if (atomic_sub_and_test(RW_LOCK_BIAS, &rw->counter)) - return 1; - - atomic_add(RW_LOCK_BIAS, &rw->counter); + unsigned long tmp, oldval; + + __asm__ __volatile__ ( + "1: \n\t" + "movli.l @%2, %0 ! __raw_write_trylock \n\t" + "mov %0, %1 \n\t" + "cmp/hs %3, %0 \n\t" + "bf 2f \n\t" + "sub %3, %0 \n\t" + "2: \n\t" + "movco.l %0, @%2 \n\t" + "bf 1b \n\t" + "synco \n\t" + : "=&z" (tmp), "=&r" (oldval) + : "r" (&rw->lock), "r" (RW_LOCK_BIAS) + : "t", "memory" + ); - return 0; + return (oldval > (RW_LOCK_BIAS - 1)); } #define _raw_spin_relax(lock) cpu_relax()