diff options
Diffstat (limited to 'include/asm-x86_64/spinlock.h')
-rw-r--r-- | include/asm-x86_64/spinlock.h | 164 |
1 files changed, 42 insertions, 122 deletions
diff --git a/include/asm-x86_64/spinlock.h b/include/asm-x86_64/spinlock.h index 5aeb57a3baad..69636831ad2f 100644 --- a/include/asm-x86_64/spinlock.h +++ b/include/asm-x86_64/spinlock.h | |||
@@ -6,47 +6,21 @@ | |||
6 | #include <asm/page.h> | 6 | #include <asm/page.h> |
7 | #include <linux/config.h> | 7 | #include <linux/config.h> |
8 | 8 | ||
9 | extern int printk(const char * fmt, ...) | ||
10 | __attribute__ ((format (printf, 1, 2))); | ||
11 | |||
12 | /* | 9 | /* |
13 | * Your basic SMP spinlocks, allowing only a single CPU anywhere | 10 | * Your basic SMP spinlocks, allowing only a single CPU anywhere |
14 | */ | 11 | * |
15 | |||
16 | typedef struct { | ||
17 | volatile unsigned int lock; | ||
18 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
19 | unsigned magic; | ||
20 | #endif | ||
21 | #ifdef CONFIG_PREEMPT | ||
22 | unsigned int break_lock; | ||
23 | #endif | ||
24 | } spinlock_t; | ||
25 | |||
26 | #define SPINLOCK_MAGIC 0xdead4ead | ||
27 | |||
28 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
29 | #define SPINLOCK_MAGIC_INIT , SPINLOCK_MAGIC | ||
30 | #else | ||
31 | #define SPINLOCK_MAGIC_INIT /* */ | ||
32 | #endif | ||
33 | |||
34 | #define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 SPINLOCK_MAGIC_INIT } | ||
35 | |||
36 | #define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0) | ||
37 | |||
38 | /* | ||
39 | * Simple spin lock operations. There are two variants, one clears IRQ's | 12 | * Simple spin lock operations. There are two variants, one clears IRQ's |
40 | * on the local processor, one does not. | 13 | * on the local processor, one does not. |
41 | * | 14 | * |
42 | * We make no fairness assumptions. They have a cost. | 15 | * We make no fairness assumptions. They have a cost. |
16 | * | ||
17 | * (the type definitions are in asm/spinlock_types.h) | ||
43 | */ | 18 | */ |
44 | 19 | ||
45 | #define spin_is_locked(x) (*(volatile signed char *)(&(x)->lock) <= 0) | 20 | #define __raw_spin_is_locked(x) \ |
46 | #define spin_unlock_wait(x) do { barrier(); } while(spin_is_locked(x)) | 21 | (*(volatile signed char *)(&(x)->slock) <= 0) |
47 | #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) | ||
48 | 22 | ||
49 | #define spin_lock_string \ | 23 | #define __raw_spin_lock_string \ |
50 | "\n1:\t" \ | 24 | "\n1:\t" \ |
51 | "lock ; decb %0\n\t" \ | 25 | "lock ; decb %0\n\t" \ |
52 | "js 2f\n" \ | 26 | "js 2f\n" \ |
@@ -58,74 +32,40 @@ typedef struct { | |||
58 | "jmp 1b\n" \ | 32 | "jmp 1b\n" \ |
59 | LOCK_SECTION_END | 33 | LOCK_SECTION_END |
60 | 34 | ||
61 | /* | 35 | #define __raw_spin_unlock_string \ |
62 | * This works. Despite all the confusion. | ||
63 | * (except on PPro SMP or if we are using OOSTORE) | ||
64 | * (PPro errata 66, 92) | ||
65 | */ | ||
66 | |||
67 | #if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE) | ||
68 | |||
69 | #define spin_unlock_string \ | ||
70 | "movb $1,%0" \ | 36 | "movb $1,%0" \ |
71 | :"=m" (lock->lock) : : "memory" | 37 | :"=m" (lock->slock) : : "memory" |
72 | |||
73 | |||
74 | static inline void _raw_spin_unlock(spinlock_t *lock) | ||
75 | { | ||
76 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
77 | BUG_ON(lock->magic != SPINLOCK_MAGIC); | ||
78 | assert_spin_locked(lock); | ||
79 | #endif | ||
80 | __asm__ __volatile__( | ||
81 | spin_unlock_string | ||
82 | ); | ||
83 | } | ||
84 | |||
85 | #else | ||
86 | |||
87 | #define spin_unlock_string \ | ||
88 | "xchgb %b0, %1" \ | ||
89 | :"=q" (oldval), "=m" (lock->lock) \ | ||
90 | :"0" (oldval) : "memory" | ||
91 | 38 | ||
92 | static inline void _raw_spin_unlock(spinlock_t *lock) | 39 | static inline void __raw_spin_lock(raw_spinlock_t *lock) |
93 | { | 40 | { |
94 | char oldval = 1; | ||
95 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
96 | BUG_ON(lock->magic != SPINLOCK_MAGIC); | ||
97 | assert_spin_locked(lock); | ||
98 | #endif | ||
99 | __asm__ __volatile__( | 41 | __asm__ __volatile__( |
100 | spin_unlock_string | 42 | __raw_spin_lock_string |
101 | ); | 43 | :"=m" (lock->slock) : : "memory"); |
102 | } | 44 | } |
103 | 45 | ||
104 | #endif | 46 | #define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) |
105 | 47 | ||
106 | static inline int _raw_spin_trylock(spinlock_t *lock) | 48 | static inline int __raw_spin_trylock(raw_spinlock_t *lock) |
107 | { | 49 | { |
108 | char oldval; | 50 | char oldval; |
51 | |||
109 | __asm__ __volatile__( | 52 | __asm__ __volatile__( |
110 | "xchgb %b0,%1" | 53 | "xchgb %b0,%1" |
111 | :"=q" (oldval), "=m" (lock->lock) | 54 | :"=q" (oldval), "=m" (lock->slock) |
112 | :"0" (0) : "memory"); | 55 | :"0" (0) : "memory"); |
56 | |||
113 | return oldval > 0; | 57 | return oldval > 0; |
114 | } | 58 | } |
115 | 59 | ||
116 | static inline void _raw_spin_lock(spinlock_t *lock) | 60 | static inline void __raw_spin_unlock(raw_spinlock_t *lock) |
117 | { | 61 | { |
118 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
119 | if (lock->magic != SPINLOCK_MAGIC) { | ||
120 | printk("eip: %p\n", __builtin_return_address(0)); | ||
121 | BUG(); | ||
122 | } | ||
123 | #endif | ||
124 | __asm__ __volatile__( | 62 | __asm__ __volatile__( |
125 | spin_lock_string | 63 | __raw_spin_unlock_string |
126 | :"=m" (lock->lock) : : "memory"); | 64 | ); |
127 | } | 65 | } |
128 | 66 | ||
67 | #define __raw_spin_unlock_wait(lock) \ | ||
68 | do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0) | ||
129 | 69 | ||
130 | /* | 70 | /* |
131 | * Read-write spinlocks, allowing multiple readers | 71 | * Read-write spinlocks, allowing multiple readers |
@@ -136,33 +76,7 @@ static inline void _raw_spin_lock(spinlock_t *lock) | |||
136 | * can "mix" irq-safe locks - any writer needs to get a | 76 | * can "mix" irq-safe locks - any writer needs to get a |
137 | * irq-safe write-lock, but readers can get non-irqsafe | 77 | * irq-safe write-lock, but readers can get non-irqsafe |
138 | * read-locks. | 78 | * read-locks. |
139 | */ | 79 | * |
140 | typedef struct { | ||
141 | volatile unsigned int lock; | ||
142 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
143 | unsigned magic; | ||
144 | #endif | ||
145 | #ifdef CONFIG_PREEMPT | ||
146 | unsigned int break_lock; | ||
147 | #endif | ||
148 | } rwlock_t; | ||
149 | |||
150 | #define RWLOCK_MAGIC 0xdeaf1eed | ||
151 | |||
152 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
153 | #define RWLOCK_MAGIC_INIT , RWLOCK_MAGIC | ||
154 | #else | ||
155 | #define RWLOCK_MAGIC_INIT /* */ | ||
156 | #endif | ||
157 | |||
158 | #define RW_LOCK_UNLOCKED (rwlock_t) { RW_LOCK_BIAS RWLOCK_MAGIC_INIT } | ||
159 | |||
160 | #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) | ||
161 | |||
162 | #define read_can_lock(x) ((int)(x)->lock > 0) | ||
163 | #define write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) | ||
164 | |||
165 | /* | ||
166 | * On x86, we implement read-write locks as a 32-bit counter | 80 | * On x86, we implement read-write locks as a 32-bit counter |
167 | * with the high bit (sign) being the "contended" bit. | 81 | * with the high bit (sign) being the "contended" bit. |
168 | * | 82 | * |
@@ -170,29 +84,24 @@ typedef struct { | |||
170 | * | 84 | * |
171 | * Changed to use the same technique as rw semaphores. See | 85 | * Changed to use the same technique as rw semaphores. See |
172 | * semaphore.h for details. -ben | 86 | * semaphore.h for details. -ben |
87 | * | ||
88 | * the helpers are in arch/i386/kernel/semaphore.c | ||
173 | */ | 89 | */ |
174 | /* the spinlock helpers are in arch/i386/kernel/semaphore.c */ | ||
175 | 90 | ||
176 | static inline void _raw_read_lock(rwlock_t *rw) | 91 | #define __raw_read_can_lock(x) ((int)(x)->lock > 0) |
92 | #define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) | ||
93 | |||
94 | static inline void __raw_read_lock(raw_rwlock_t *rw) | ||
177 | { | 95 | { |
178 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
179 | BUG_ON(rw->magic != RWLOCK_MAGIC); | ||
180 | #endif | ||
181 | __build_read_lock(rw, "__read_lock_failed"); | 96 | __build_read_lock(rw, "__read_lock_failed"); |
182 | } | 97 | } |
183 | 98 | ||
184 | static inline void _raw_write_lock(rwlock_t *rw) | 99 | static inline void __raw_write_lock(raw_rwlock_t *rw) |
185 | { | 100 | { |
186 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
187 | BUG_ON(rw->magic != RWLOCK_MAGIC); | ||
188 | #endif | ||
189 | __build_write_lock(rw, "__write_lock_failed"); | 101 | __build_write_lock(rw, "__write_lock_failed"); |
190 | } | 102 | } |
191 | 103 | ||
192 | #define _raw_read_unlock(rw) asm volatile("lock ; incl %0" :"=m" ((rw)->lock) : : "memory") | 104 | static inline int __raw_read_trylock(raw_rwlock_t *lock) |
193 | #define _raw_write_unlock(rw) asm volatile("lock ; addl $" RW_LOCK_BIAS_STR ",%0":"=m" ((rw)->lock) : : "memory") | ||
194 | |||
195 | static inline int _raw_read_trylock(rwlock_t *lock) | ||
196 | { | 105 | { |
197 | atomic_t *count = (atomic_t *)lock; | 106 | atomic_t *count = (atomic_t *)lock; |
198 | atomic_dec(count); | 107 | atomic_dec(count); |
@@ -202,7 +111,7 @@ static inline int _raw_read_trylock(rwlock_t *lock) | |||
202 | return 0; | 111 | return 0; |
203 | } | 112 | } |
204 | 113 | ||
205 | static inline int _raw_write_trylock(rwlock_t *lock) | 114 | static inline int __raw_write_trylock(raw_rwlock_t *lock) |
206 | { | 115 | { |
207 | atomic_t *count = (atomic_t *)lock; | 116 | atomic_t *count = (atomic_t *)lock; |
208 | if (atomic_sub_and_test(RW_LOCK_BIAS, count)) | 117 | if (atomic_sub_and_test(RW_LOCK_BIAS, count)) |
@@ -211,4 +120,15 @@ static inline int _raw_write_trylock(rwlock_t *lock) | |||
211 | return 0; | 120 | return 0; |
212 | } | 121 | } |
213 | 122 | ||
123 | static inline void __raw_read_unlock(raw_rwlock_t *rw) | ||
124 | { | ||
125 | asm volatile("lock ; incl %0" :"=m" (rw->lock) : : "memory"); | ||
126 | } | ||
127 | |||
128 | static inline void __raw_write_unlock(raw_rwlock_t *rw) | ||
129 | { | ||
130 | asm volatile("lock ; addl $" RW_LOCK_BIAS_STR ",%0" | ||
131 | : "=m" (rw->lock) : : "memory"); | ||
132 | } | ||
133 | |||
214 | #endif /* __ASM_SPINLOCK_H */ | 134 | #endif /* __ASM_SPINLOCK_H */ |