diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2007-10-11 05:20:03 -0400 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2007-10-11 05:20:03 -0400 |
commit | 96a388de5dc53a8b234b3fd41f3ae2cedc9ffd42 (patch) | |
tree | d947a467aa2da3140279617bc4b9b101640d7bf4 /include/asm-x86/semaphore_32.h | |
parent | 27bd0c955648646abf2a353a8371d28c37bcd982 (diff) |
i386/x86_64: move headers to include/asm-x86
Move the headers to include/asm-x86 and fixup the
header install make rules
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/asm-x86/semaphore_32.h')
-rw-r--r-- | include/asm-x86/semaphore_32.h | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/include/asm-x86/semaphore_32.h b/include/asm-x86/semaphore_32.h new file mode 100644 index 000000000000..4e34a468c383 --- /dev/null +++ b/include/asm-x86/semaphore_32.h | |||
@@ -0,0 +1,176 @@ | |||
1 | #ifndef _I386_SEMAPHORE_H | ||
2 | #define _I386_SEMAPHORE_H | ||
3 | |||
4 | #include <linux/linkage.h> | ||
5 | |||
6 | #ifdef __KERNEL__ | ||
7 | |||
8 | /* | ||
9 | * SMP- and interrupt-safe semaphores.. | ||
10 | * | ||
11 | * (C) Copyright 1996 Linus Torvalds | ||
12 | * | ||
13 | * Modified 1996-12-23 by Dave Grothe <dave@gcom.com> to fix bugs in | ||
14 | * the original code and to make semaphore waits | ||
15 | * interruptible so that processes waiting on | ||
16 | * semaphores can be killed. | ||
17 | * Modified 1999-02-14 by Andrea Arcangeli, split the sched.c helper | ||
18 | * functions in asm/sempahore-helper.h while fixing a | ||
19 | * potential and subtle race discovered by Ulrich Schmid | ||
20 | * in down_interruptible(). Since I started to play here I | ||
21 | * also implemented the `trylock' semaphore operation. | ||
22 | * 1999-07-02 Artur Skawina <skawina@geocities.com> | ||
23 | * Optimized "0(ecx)" -> "(ecx)" (the assembler does not | ||
24 | * do this). Changed calling sequences from push/jmp to | ||
25 | * traditional call/ret. | ||
26 | * Modified 2001-01-01 Andreas Franck <afranck@gmx.de> | ||
27 | * Some hacks to ensure compatibility with recent | ||
28 | * GCC snapshots, to avoid stack corruption when compiling | ||
29 | * with -fomit-frame-pointer. It's not sure if this will | ||
30 | * be fixed in GCC, as our previous implementation was a | ||
31 | * bit dubious. | ||
32 | * | ||
33 | * If you would like to see an analysis of this implementation, please | ||
34 | * ftp to gcom.com and download the file | ||
35 | * /pub/linux/src/semaphore/semaphore-2.0.24.tar.gz. | ||
36 | * | ||
37 | */ | ||
38 | |||
39 | #include <asm/system.h> | ||
40 | #include <asm/atomic.h> | ||
41 | #include <linux/wait.h> | ||
42 | #include <linux/rwsem.h> | ||
43 | |||
44 | struct semaphore { | ||
45 | atomic_t count; | ||
46 | int sleepers; | ||
47 | wait_queue_head_t wait; | ||
48 | }; | ||
49 | |||
50 | |||
51 | #define __SEMAPHORE_INITIALIZER(name, n) \ | ||
52 | { \ | ||
53 | .count = ATOMIC_INIT(n), \ | ||
54 | .sleepers = 0, \ | ||
55 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | ||
56 | } | ||
57 | |||
58 | #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ | ||
59 | struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) | ||
60 | |||
61 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) | ||
62 | #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) | ||
63 | |||
64 | static inline void sema_init (struct semaphore *sem, int val) | ||
65 | { | ||
66 | /* | ||
67 | * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); | ||
68 | * | ||
69 | * i'd rather use the more flexible initialization above, but sadly | ||
70 | * GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well. | ||
71 | */ | ||
72 | atomic_set(&sem->count, val); | ||
73 | sem->sleepers = 0; | ||
74 | init_waitqueue_head(&sem->wait); | ||
75 | } | ||
76 | |||
77 | static inline void init_MUTEX (struct semaphore *sem) | ||
78 | { | ||
79 | sema_init(sem, 1); | ||
80 | } | ||
81 | |||
82 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | ||
83 | { | ||
84 | sema_init(sem, 0); | ||
85 | } | ||
86 | |||
87 | fastcall void __down_failed(void /* special register calling convention */); | ||
88 | fastcall int __down_failed_interruptible(void /* params in registers */); | ||
89 | fastcall int __down_failed_trylock(void /* params in registers */); | ||
90 | fastcall void __up_wakeup(void /* special register calling convention */); | ||
91 | |||
92 | /* | ||
93 | * This is ugly, but we want the default case to fall through. | ||
94 | * "__down_failed" is a special asm handler that calls the C | ||
95 | * routine that actually waits. See arch/i386/kernel/semaphore.c | ||
96 | */ | ||
97 | static inline void down(struct semaphore * sem) | ||
98 | { | ||
99 | might_sleep(); | ||
100 | __asm__ __volatile__( | ||
101 | "# atomic down operation\n\t" | ||
102 | LOCK_PREFIX "decl %0\n\t" /* --sem->count */ | ||
103 | "jns 2f\n" | ||
104 | "\tlea %0,%%eax\n\t" | ||
105 | "call __down_failed\n" | ||
106 | "2:" | ||
107 | :"+m" (sem->count) | ||
108 | : | ||
109 | :"memory","ax"); | ||
110 | } | ||
111 | |||
112 | /* | ||
113 | * Interruptible try to acquire a semaphore. If we obtained | ||
114 | * it, return zero. If we were interrupted, returns -EINTR | ||
115 | */ | ||
116 | static inline int down_interruptible(struct semaphore * sem) | ||
117 | { | ||
118 | int result; | ||
119 | |||
120 | might_sleep(); | ||
121 | __asm__ __volatile__( | ||
122 | "# atomic interruptible down operation\n\t" | ||
123 | "xorl %0,%0\n\t" | ||
124 | LOCK_PREFIX "decl %1\n\t" /* --sem->count */ | ||
125 | "jns 2f\n\t" | ||
126 | "lea %1,%%eax\n\t" | ||
127 | "call __down_failed_interruptible\n" | ||
128 | "2:" | ||
129 | :"=&a" (result), "+m" (sem->count) | ||
130 | : | ||
131 | :"memory"); | ||
132 | return result; | ||
133 | } | ||
134 | |||
135 | /* | ||
136 | * Non-blockingly attempt to down() a semaphore. | ||
137 | * Returns zero if we acquired it | ||
138 | */ | ||
139 | static inline int down_trylock(struct semaphore * sem) | ||
140 | { | ||
141 | int result; | ||
142 | |||
143 | __asm__ __volatile__( | ||
144 | "# atomic interruptible down operation\n\t" | ||
145 | "xorl %0,%0\n\t" | ||
146 | LOCK_PREFIX "decl %1\n\t" /* --sem->count */ | ||
147 | "jns 2f\n\t" | ||
148 | "lea %1,%%eax\n\t" | ||
149 | "call __down_failed_trylock\n\t" | ||
150 | "2:\n" | ||
151 | :"=&a" (result), "+m" (sem->count) | ||
152 | : | ||
153 | :"memory"); | ||
154 | return result; | ||
155 | } | ||
156 | |||
157 | /* | ||
158 | * Note! This is subtle. We jump to wake people up only if | ||
159 | * the semaphore was negative (== somebody was waiting on it). | ||
160 | */ | ||
161 | static inline void up(struct semaphore * sem) | ||
162 | { | ||
163 | __asm__ __volatile__( | ||
164 | "# atomic up operation\n\t" | ||
165 | LOCK_PREFIX "incl %0\n\t" /* ++sem->count */ | ||
166 | "jg 1f\n\t" | ||
167 | "lea %0,%%eax\n\t" | ||
168 | "call __up_wakeup\n" | ||
169 | "1:" | ||
170 | :"+m" (sem->count) | ||
171 | : | ||
172 | :"memory","ax"); | ||
173 | } | ||
174 | |||
175 | #endif | ||
176 | #endif | ||