diff options
Diffstat (limited to 'include/asm-i386/spinlock.h')
| -rw-r--r-- | include/asm-i386/spinlock.h | 200 |
1 files changed, 70 insertions, 130 deletions
diff --git a/include/asm-i386/spinlock.h b/include/asm-i386/spinlock.h index f9ff31f40036..23604350cdf4 100644 --- a/include/asm-i386/spinlock.h +++ b/include/asm-i386/spinlock.h | |||
| @@ -7,46 +7,21 @@ | |||
| 7 | #include <linux/config.h> | 7 | #include <linux/config.h> |
| 8 | #include <linux/compiler.h> | 8 | #include <linux/compiler.h> |
| 9 | 9 | ||
| 10 | asmlinkage int printk(const char * fmt, ...) | ||
| 11 | __attribute__ ((format (printf, 1, 2))); | ||
| 12 | |||
| 13 | /* | 10 | /* |
| 14 | * Your basic SMP spinlocks, allowing only a single CPU anywhere | 11 | * Your basic SMP spinlocks, allowing only a single CPU anywhere |
| 15 | */ | 12 | * |
| 16 | |||
| 17 | typedef struct { | ||
| 18 | volatile unsigned int slock; | ||
| 19 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 20 | unsigned magic; | ||
| 21 | #endif | ||
| 22 | #ifdef CONFIG_PREEMPT | ||
| 23 | unsigned int break_lock; | ||
| 24 | #endif | ||
| 25 | } spinlock_t; | ||
| 26 | |||
| 27 | #define SPINLOCK_MAGIC 0xdead4ead | ||
| 28 | |||
| 29 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 30 | #define SPINLOCK_MAGIC_INIT , SPINLOCK_MAGIC | ||
| 31 | #else | ||
| 32 | #define SPINLOCK_MAGIC_INIT /* */ | ||
| 33 | #endif | ||
| 34 | |||
| 35 | #define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 SPINLOCK_MAGIC_INIT } | ||
| 36 | |||
| 37 | #define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0) | ||
| 38 | |||
| 39 | /* | ||
| 40 | * Simple spin lock operations. There are two variants, one clears IRQ's | 13 | * Simple spin lock operations. There are two variants, one clears IRQ's |
| 41 | * on the local processor, one does not. | 14 | * on the local processor, one does not. |
| 42 | * | 15 | * |
| 43 | * We make no fairness assumptions. They have a cost. | 16 | * We make no fairness assumptions. They have a cost. |
| 17 | * | ||
| 18 | * (the type definitions are in asm/spinlock_types.h) | ||
| 44 | */ | 19 | */ |
| 45 | 20 | ||
| 46 | #define spin_is_locked(x) (*(volatile signed char *)(&(x)->slock) <= 0) | 21 | #define __raw_spin_is_locked(x) \ |
| 47 | #define spin_unlock_wait(x) do { barrier(); } while(spin_is_locked(x)) | 22 | (*(volatile signed char *)(&(x)->slock) <= 0) |
| 48 | 23 | ||
| 49 | #define spin_lock_string \ | 24 | #define __raw_spin_lock_string \ |
| 50 | "\n1:\t" \ | 25 | "\n1:\t" \ |
| 51 | "lock ; decb %0\n\t" \ | 26 | "lock ; decb %0\n\t" \ |
| 52 | "jns 3f\n" \ | 27 | "jns 3f\n" \ |
| @@ -57,7 +32,7 @@ typedef struct { | |||
| 57 | "jmp 1b\n" \ | 32 | "jmp 1b\n" \ |
| 58 | "3:\n\t" | 33 | "3:\n\t" |
| 59 | 34 | ||
| 60 | #define spin_lock_string_flags \ | 35 | #define __raw_spin_lock_string_flags \ |
| 61 | "\n1:\t" \ | 36 | "\n1:\t" \ |
| 62 | "lock ; decb %0\n\t" \ | 37 | "lock ; decb %0\n\t" \ |
| 63 | "jns 4f\n\t" \ | 38 | "jns 4f\n\t" \ |
| @@ -73,86 +48,71 @@ typedef struct { | |||
| 73 | "jmp 1b\n" \ | 48 | "jmp 1b\n" \ |
| 74 | "4:\n\t" | 49 | "4:\n\t" |
| 75 | 50 | ||
| 51 | static inline void __raw_spin_lock(raw_spinlock_t *lock) | ||
| 52 | { | ||
| 53 | __asm__ __volatile__( | ||
| 54 | __raw_spin_lock_string | ||
| 55 | :"=m" (lock->slock) : : "memory"); | ||
| 56 | } | ||
| 57 | |||
| 58 | static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags) | ||
| 59 | { | ||
| 60 | __asm__ __volatile__( | ||
| 61 | __raw_spin_lock_string_flags | ||
| 62 | :"=m" (lock->slock) : "r" (flags) : "memory"); | ||
| 63 | } | ||
| 64 | |||
| 65 | static inline int __raw_spin_trylock(raw_spinlock_t *lock) | ||
| 66 | { | ||
| 67 | char oldval; | ||
| 68 | __asm__ __volatile__( | ||
| 69 | "xchgb %b0,%1" | ||
| 70 | :"=q" (oldval), "=m" (lock->slock) | ||
| 71 | :"0" (0) : "memory"); | ||
| 72 | return oldval > 0; | ||
| 73 | } | ||
| 74 | |||
| 76 | /* | 75 | /* |
| 77 | * This works. Despite all the confusion. | 76 | * __raw_spin_unlock based on writing $1 to the low byte. |
| 78 | * (except on PPro SMP or if we are using OOSTORE) | 77 | * This method works. Despite all the confusion. |
| 78 | * (except on PPro SMP or if we are using OOSTORE, so we use xchgb there) | ||
| 79 | * (PPro errata 66, 92) | 79 | * (PPro errata 66, 92) |
| 80 | */ | 80 | */ |
| 81 | 81 | ||
| 82 | #if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE) | 82 | #if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE) |
| 83 | 83 | ||
| 84 | #define spin_unlock_string \ | 84 | #define __raw_spin_unlock_string \ |
| 85 | "movb $1,%0" \ | 85 | "movb $1,%0" \ |
| 86 | :"=m" (lock->slock) : : "memory" | 86 | :"=m" (lock->slock) : : "memory" |
| 87 | 87 | ||
| 88 | 88 | ||
| 89 | static inline void _raw_spin_unlock(spinlock_t *lock) | 89 | static inline void __raw_spin_unlock(raw_spinlock_t *lock) |
| 90 | { | 90 | { |
| 91 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 92 | BUG_ON(lock->magic != SPINLOCK_MAGIC); | ||
| 93 | BUG_ON(!spin_is_locked(lock)); | ||
| 94 | #endif | ||
| 95 | __asm__ __volatile__( | 91 | __asm__ __volatile__( |
| 96 | spin_unlock_string | 92 | __raw_spin_unlock_string |
| 97 | ); | 93 | ); |
| 98 | } | 94 | } |
| 99 | 95 | ||
| 100 | #else | 96 | #else |
| 101 | 97 | ||
| 102 | #define spin_unlock_string \ | 98 | #define __raw_spin_unlock_string \ |
| 103 | "xchgb %b0, %1" \ | 99 | "xchgb %b0, %1" \ |
| 104 | :"=q" (oldval), "=m" (lock->slock) \ | 100 | :"=q" (oldval), "=m" (lock->slock) \ |
| 105 | :"0" (oldval) : "memory" | 101 | :"0" (oldval) : "memory" |
| 106 | 102 | ||
| 107 | static inline void _raw_spin_unlock(spinlock_t *lock) | 103 | static inline void __raw_spin_unlock(raw_spinlock_t *lock) |
| 108 | { | 104 | { |
| 109 | char oldval = 1; | 105 | char oldval = 1; |
| 110 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 111 | BUG_ON(lock->magic != SPINLOCK_MAGIC); | ||
| 112 | BUG_ON(!spin_is_locked(lock)); | ||
| 113 | #endif | ||
| 114 | __asm__ __volatile__( | ||
| 115 | spin_unlock_string | ||
| 116 | ); | ||
| 117 | } | ||
| 118 | 106 | ||
| 119 | #endif | ||
| 120 | |||
| 121 | static inline int _raw_spin_trylock(spinlock_t *lock) | ||
| 122 | { | ||
| 123 | char oldval; | ||
| 124 | __asm__ __volatile__( | 107 | __asm__ __volatile__( |
| 125 | "xchgb %b0,%1" | 108 | __raw_spin_unlock_string |
| 126 | :"=q" (oldval), "=m" (lock->slock) | 109 | ); |
| 127 | :"0" (0) : "memory"); | ||
| 128 | return oldval > 0; | ||
| 129 | } | 110 | } |
| 130 | 111 | ||
| 131 | static inline void _raw_spin_lock(spinlock_t *lock) | ||
| 132 | { | ||
| 133 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 134 | if (unlikely(lock->magic != SPINLOCK_MAGIC)) { | ||
| 135 | printk("eip: %p\n", __builtin_return_address(0)); | ||
| 136 | BUG(); | ||
| 137 | } | ||
| 138 | #endif | 112 | #endif |
| 139 | __asm__ __volatile__( | ||
| 140 | spin_lock_string | ||
| 141 | :"=m" (lock->slock) : : "memory"); | ||
| 142 | } | ||
| 143 | 113 | ||
| 144 | static inline void _raw_spin_lock_flags (spinlock_t *lock, unsigned long flags) | 114 | #define __raw_spin_unlock_wait(lock) \ |
| 145 | { | 115 | do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0) |
| 146 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 147 | if (unlikely(lock->magic != SPINLOCK_MAGIC)) { | ||
| 148 | printk("eip: %p\n", __builtin_return_address(0)); | ||
| 149 | BUG(); | ||
| 150 | } | ||
| 151 | #endif | ||
| 152 | __asm__ __volatile__( | ||
| 153 | spin_lock_string_flags | ||
| 154 | :"=m" (lock->slock) : "r" (flags) : "memory"); | ||
| 155 | } | ||
| 156 | 116 | ||
| 157 | /* | 117 | /* |
| 158 | * Read-write spinlocks, allowing multiple readers | 118 | * Read-write spinlocks, allowing multiple readers |
| @@ -163,72 +123,41 @@ static inline void _raw_spin_lock_flags (spinlock_t *lock, unsigned long flags) | |||
| 163 | * can "mix" irq-safe locks - any writer needs to get a | 123 | * can "mix" irq-safe locks - any writer needs to get a |
| 164 | * irq-safe write-lock, but readers can get non-irqsafe | 124 | * irq-safe write-lock, but readers can get non-irqsafe |
| 165 | * read-locks. | 125 | * read-locks. |
| 126 | * | ||
| 127 | * On x86, we implement read-write locks as a 32-bit counter | ||
| 128 | * with the high bit (sign) being the "contended" bit. | ||
| 129 | * | ||
| 130 | * The inline assembly is non-obvious. Think about it. | ||
| 131 | * | ||
| 132 | * Changed to use the same technique as rw semaphores. See | ||
| 133 | * semaphore.h for details. -ben | ||
| 134 | * | ||
| 135 | * the helpers are in arch/i386/kernel/semaphore.c | ||
| 166 | */ | 136 | */ |
| 167 | typedef struct { | ||
| 168 | volatile unsigned int lock; | ||
| 169 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 170 | unsigned magic; | ||
| 171 | #endif | ||
| 172 | #ifdef CONFIG_PREEMPT | ||
| 173 | unsigned int break_lock; | ||
| 174 | #endif | ||
| 175 | } rwlock_t; | ||
| 176 | |||
| 177 | #define RWLOCK_MAGIC 0xdeaf1eed | ||
| 178 | |||
| 179 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 180 | #define RWLOCK_MAGIC_INIT , RWLOCK_MAGIC | ||
| 181 | #else | ||
| 182 | #define RWLOCK_MAGIC_INIT /* */ | ||
| 183 | #endif | ||
| 184 | |||
| 185 | #define RW_LOCK_UNLOCKED (rwlock_t) { RW_LOCK_BIAS RWLOCK_MAGIC_INIT } | ||
| 186 | |||
| 187 | #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) | ||
| 188 | 137 | ||
| 189 | /** | 138 | /** |
| 190 | * read_can_lock - would read_trylock() succeed? | 139 | * read_can_lock - would read_trylock() succeed? |
| 191 | * @lock: the rwlock in question. | 140 | * @lock: the rwlock in question. |
| 192 | */ | 141 | */ |
| 193 | #define read_can_lock(x) ((int)(x)->lock > 0) | 142 | #define __raw_read_can_lock(x) ((int)(x)->lock > 0) |
| 194 | 143 | ||
| 195 | /** | 144 | /** |
| 196 | * write_can_lock - would write_trylock() succeed? | 145 | * write_can_lock - would write_trylock() succeed? |
| 197 | * @lock: the rwlock in question. | 146 | * @lock: the rwlock in question. |
| 198 | */ | 147 | */ |
| 199 | #define write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) | 148 | #define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) |
| 200 | 149 | ||
| 201 | /* | 150 | static inline void __raw_read_lock(raw_rwlock_t *rw) |
| 202 | * On x86, we implement read-write locks as a 32-bit counter | ||
| 203 | * with the high bit (sign) being the "contended" bit. | ||
| 204 | * | ||
| 205 | * The inline assembly is non-obvious. Think about it. | ||
| 206 | * | ||
| 207 | * Changed to use the same technique as rw semaphores. See | ||
| 208 | * semaphore.h for details. -ben | ||
| 209 | */ | ||
| 210 | /* the spinlock helpers are in arch/i386/kernel/semaphore.c */ | ||
| 211 | |||
| 212 | static inline void _raw_read_lock(rwlock_t *rw) | ||
| 213 | { | 151 | { |
| 214 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 215 | BUG_ON(rw->magic != RWLOCK_MAGIC); | ||
| 216 | #endif | ||
| 217 | __build_read_lock(rw, "__read_lock_failed"); | 152 | __build_read_lock(rw, "__read_lock_failed"); |
| 218 | } | 153 | } |
| 219 | 154 | ||
| 220 | static inline void _raw_write_lock(rwlock_t *rw) | 155 | static inline void __raw_write_lock(raw_rwlock_t *rw) |
| 221 | { | 156 | { |
| 222 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
| 223 | BUG_ON(rw->magic != RWLOCK_MAGIC); | ||
| 224 | #endif | ||
| 225 | __build_write_lock(rw, "__write_lock_failed"); | 157 | __build_write_lock(rw, "__write_lock_failed"); |
| 226 | } | 158 | } |
| 227 | 159 | ||
| 228 | #define _raw_read_unlock(rw) asm volatile("lock ; incl %0" :"=m" ((rw)->lock) : : "memory") | 160 | static inline int __raw_read_trylock(raw_rwlock_t *lock) |
| 229 | #define _raw_write_unlock(rw) asm volatile("lock ; addl $" RW_LOCK_BIAS_STR ",%0":"=m" ((rw)->lock) : : "memory") | ||
| 230 | |||
| 231 | static inline int _raw_read_trylock(rwlock_t *lock) | ||
| 232 | { | 161 | { |
| 233 | atomic_t *count = (atomic_t *)lock; | 162 | atomic_t *count = (atomic_t *)lock; |
| 234 | atomic_dec(count); | 163 | atomic_dec(count); |
| @@ -238,7 +167,7 @@ static inline int _raw_read_trylock(rwlock_t *lock) | |||
| 238 | return 0; | 167 | return 0; |
| 239 | } | 168 | } |
| 240 | 169 | ||
| 241 | static inline int _raw_write_trylock(rwlock_t *lock) | 170 | static inline int __raw_write_trylock(raw_rwlock_t *lock) |
| 242 | { | 171 | { |
| 243 | atomic_t *count = (atomic_t *)lock; | 172 | atomic_t *count = (atomic_t *)lock; |
| 244 | if (atomic_sub_and_test(RW_LOCK_BIAS, count)) | 173 | if (atomic_sub_and_test(RW_LOCK_BIAS, count)) |
| @@ -247,4 +176,15 @@ static inline int _raw_write_trylock(rwlock_t *lock) | |||
| 247 | return 0; | 176 | return 0; |
| 248 | } | 177 | } |
| 249 | 178 | ||
| 179 | static inline void __raw_read_unlock(raw_rwlock_t *rw) | ||
| 180 | { | ||
| 181 | asm volatile("lock ; incl %0" :"=m" (rw->lock) : : "memory"); | ||
| 182 | } | ||
| 183 | |||
| 184 | static inline void __raw_write_unlock(raw_rwlock_t *rw) | ||
| 185 | { | ||
| 186 | asm volatile("lock ; addl $" RW_LOCK_BIAS_STR ", %0" | ||
| 187 | : "=m" (rw->lock) : : "memory"); | ||
| 188 | } | ||
| 189 | |||
| 250 | #endif /* __ASM_SPINLOCK_H */ | 190 | #endif /* __ASM_SPINLOCK_H */ |
