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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __ARCH_X86_64_ATOMIC__
2#define __ARCH_X86_64_ATOMIC__
3
Gerd Hoffmannd167a512006-06-26 13:56:16 +02004#include <asm/alternative.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005
6/* atomic_t should be 32 bit signed type */
7
8/*
9 * Atomic operations that C can't guarantee us. Useful for
10 * resource counting etc..
11 */
12
13#ifdef CONFIG_SMP
14#define LOCK "lock ; "
15#else
16#define LOCK ""
17#endif
18
19/*
20 * Make sure gcc doesn't try to be clever and move things around
21 * on us. We need to use _exactly_ the address the user gave us,
22 * not some alias that contains the same information.
23 */
Linus Torvaldsf9e9dcb2006-12-06 14:42:57 -080024typedef struct { int counter; } atomic_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26#define ATOMIC_INIT(i) { (i) }
27
28/**
29 * atomic_read - read atomic variable
30 * @v: pointer of type atomic_t
31 *
32 * Atomically reads the value of @v.
33 */
34#define atomic_read(v) ((v)->counter)
35
36/**
37 * atomic_set - set atomic variable
38 * @v: pointer of type atomic_t
39 * @i: required value
40 *
41 * Atomically sets the value of @v to @i.
42 */
43#define atomic_set(v,i) (((v)->counter) = (i))
44
45/**
46 * atomic_add - add integer to atomic variable
47 * @i: integer value to add
48 * @v: pointer of type atomic_t
49 *
50 * Atomically adds @i to @v.
51 */
52static __inline__ void atomic_add(int i, atomic_t *v)
53{
54 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +020055 LOCK_PREFIX "addl %1,%0"
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 :"=m" (v->counter)
57 :"ir" (i), "m" (v->counter));
58}
59
60/**
61 * atomic_sub - subtract the atomic variable
62 * @i: integer value to subtract
63 * @v: pointer of type atomic_t
64 *
65 * Atomically subtracts @i from @v.
66 */
67static __inline__ void atomic_sub(int i, atomic_t *v)
68{
69 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +020070 LOCK_PREFIX "subl %1,%0"
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 :"=m" (v->counter)
72 :"ir" (i), "m" (v->counter));
73}
74
75/**
76 * atomic_sub_and_test - subtract value from variable and test result
77 * @i: integer value to subtract
78 * @v: pointer of type atomic_t
79 *
80 * Atomically subtracts @i from @v and returns
81 * true if the result is zero, or false for all
82 * other cases.
83 */
84static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
85{
86 unsigned char c;
87
88 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +020089 LOCK_PREFIX "subl %2,%0; sete %1"
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 :"=m" (v->counter), "=qm" (c)
91 :"ir" (i), "m" (v->counter) : "memory");
92 return c;
93}
94
95/**
96 * atomic_inc - increment atomic variable
97 * @v: pointer of type atomic_t
98 *
99 * Atomically increments @v by 1.
100 */
101static __inline__ void atomic_inc(atomic_t *v)
102{
103 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200104 LOCK_PREFIX "incl %0"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 :"=m" (v->counter)
106 :"m" (v->counter));
107}
108
109/**
110 * atomic_dec - decrement atomic variable
111 * @v: pointer of type atomic_t
112 *
113 * Atomically decrements @v by 1.
114 */
115static __inline__ void atomic_dec(atomic_t *v)
116{
117 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200118 LOCK_PREFIX "decl %0"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 :"=m" (v->counter)
120 :"m" (v->counter));
121}
122
123/**
124 * atomic_dec_and_test - decrement and test
125 * @v: pointer of type atomic_t
126 *
127 * Atomically decrements @v by 1 and
128 * returns true if the result is 0, or false for all other
129 * cases.
130 */
131static __inline__ int atomic_dec_and_test(atomic_t *v)
132{
133 unsigned char c;
134
135 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200136 LOCK_PREFIX "decl %0; sete %1"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 :"=m" (v->counter), "=qm" (c)
138 :"m" (v->counter) : "memory");
139 return c != 0;
140}
141
142/**
143 * atomic_inc_and_test - increment and test
144 * @v: pointer of type atomic_t
145 *
146 * Atomically increments @v by 1
147 * and returns true if the result is zero, or false for all
148 * other cases.
149 */
150static __inline__ int atomic_inc_and_test(atomic_t *v)
151{
152 unsigned char c;
153
154 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200155 LOCK_PREFIX "incl %0; sete %1"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 :"=m" (v->counter), "=qm" (c)
157 :"m" (v->counter) : "memory");
158 return c != 0;
159}
160
161/**
162 * atomic_add_negative - add and test if negative
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 * @i: integer value to add
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800164 * @v: pointer of type atomic_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 *
166 * Atomically adds @i to @v and returns true
167 * if the result is negative, or false when
168 * result is greater than or equal to zero.
169 */
170static __inline__ int atomic_add_negative(int i, atomic_t *v)
171{
172 unsigned char c;
173
174 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200175 LOCK_PREFIX "addl %2,%0; sets %1"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 :"=m" (v->counter), "=qm" (c)
177 :"ir" (i), "m" (v->counter) : "memory");
178 return c;
179}
180
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800181/**
182 * atomic_add_return - add and return
183 * @i: integer value to add
184 * @v: pointer of type atomic_t
185 *
186 * Atomically adds @i to @v and returns @i + @v
187 */
188static __inline__ int atomic_add_return(int i, atomic_t *v)
189{
190 int __i = i;
191 __asm__ __volatile__(
Andi Kleen9dc452b2006-12-07 02:14:13 +0100192 LOCK_PREFIX "xaddl %0, %1"
193 :"+r" (i), "+m" (v->counter)
194 : : "memory");
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800195 return i + __i;
196}
197
198static __inline__ int atomic_sub_return(int i, atomic_t *v)
199{
200 return atomic_add_return(-i,v);
201}
202
203#define atomic_inc_return(v) (atomic_add_return(1,v))
204#define atomic_dec_return(v) (atomic_sub_return(1,v))
205
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206/* An 64bit atomic type */
207
208typedef struct { volatile long counter; } atomic64_t;
209
210#define ATOMIC64_INIT(i) { (i) }
211
212/**
213 * atomic64_read - read atomic64 variable
214 * @v: pointer of type atomic64_t
215 *
216 * Atomically reads the value of @v.
217 * Doesn't imply a read memory barrier.
218 */
219#define atomic64_read(v) ((v)->counter)
220
221/**
222 * atomic64_set - set atomic64 variable
223 * @v: pointer to type atomic64_t
224 * @i: required value
225 *
226 * Atomically sets the value of @v to @i.
227 */
228#define atomic64_set(v,i) (((v)->counter) = (i))
229
230/**
231 * atomic64_add - add integer to atomic64 variable
232 * @i: integer value to add
233 * @v: pointer to type atomic64_t
234 *
235 * Atomically adds @i to @v.
236 */
237static __inline__ void atomic64_add(long i, atomic64_t *v)
238{
239 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200240 LOCK_PREFIX "addq %1,%0"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 :"=m" (v->counter)
242 :"ir" (i), "m" (v->counter));
243}
244
245/**
246 * atomic64_sub - subtract the atomic64 variable
247 * @i: integer value to subtract
248 * @v: pointer to type atomic64_t
249 *
250 * Atomically subtracts @i from @v.
251 */
252static __inline__ void atomic64_sub(long i, atomic64_t *v)
253{
254 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200255 LOCK_PREFIX "subq %1,%0"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 :"=m" (v->counter)
257 :"ir" (i), "m" (v->counter));
258}
259
260/**
261 * atomic64_sub_and_test - subtract value from variable and test result
262 * @i: integer value to subtract
263 * @v: pointer to type atomic64_t
264 *
265 * Atomically subtracts @i from @v and returns
266 * true if the result is zero, or false for all
267 * other cases.
268 */
269static __inline__ int atomic64_sub_and_test(long i, atomic64_t *v)
270{
271 unsigned char c;
272
273 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200274 LOCK_PREFIX "subq %2,%0; sete %1"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 :"=m" (v->counter), "=qm" (c)
276 :"ir" (i), "m" (v->counter) : "memory");
277 return c;
278}
279
280/**
281 * atomic64_inc - increment atomic64 variable
282 * @v: pointer to type atomic64_t
283 *
284 * Atomically increments @v by 1.
285 */
286static __inline__ void atomic64_inc(atomic64_t *v)
287{
288 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200289 LOCK_PREFIX "incq %0"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 :"=m" (v->counter)
291 :"m" (v->counter));
292}
293
294/**
295 * atomic64_dec - decrement atomic64 variable
296 * @v: pointer to type atomic64_t
297 *
298 * Atomically decrements @v by 1.
299 */
300static __inline__ void atomic64_dec(atomic64_t *v)
301{
302 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200303 LOCK_PREFIX "decq %0"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 :"=m" (v->counter)
305 :"m" (v->counter));
306}
307
308/**
309 * atomic64_dec_and_test - decrement and test
310 * @v: pointer to type atomic64_t
311 *
312 * Atomically decrements @v by 1 and
313 * returns true if the result is 0, or false for all other
314 * cases.
315 */
316static __inline__ int atomic64_dec_and_test(atomic64_t *v)
317{
318 unsigned char c;
319
320 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200321 LOCK_PREFIX "decq %0; sete %1"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 :"=m" (v->counter), "=qm" (c)
323 :"m" (v->counter) : "memory");
324 return c != 0;
325}
326
327/**
328 * atomic64_inc_and_test - increment and test
329 * @v: pointer to type atomic64_t
330 *
331 * Atomically increments @v by 1
332 * and returns true if the result is zero, or false for all
333 * other cases.
334 */
335static __inline__ int atomic64_inc_and_test(atomic64_t *v)
336{
337 unsigned char c;
338
339 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200340 LOCK_PREFIX "incq %0; sete %1"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 :"=m" (v->counter), "=qm" (c)
342 :"m" (v->counter) : "memory");
343 return c != 0;
344}
345
346/**
347 * atomic64_add_negative - add and test if negative
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 * @i: integer value to add
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800349 * @v: pointer to type atomic64_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 *
351 * Atomically adds @i to @v and returns true
352 * if the result is negative, or false when
353 * result is greater than or equal to zero.
354 */
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800355static __inline__ int atomic64_add_negative(long i, atomic64_t *v)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356{
357 unsigned char c;
358
359 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200360 LOCK_PREFIX "addq %2,%0; sets %1"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 :"=m" (v->counter), "=qm" (c)
362 :"ir" (i), "m" (v->counter) : "memory");
363 return c;
364}
365
366/**
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800367 * atomic64_add_return - add and return
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 * @i: integer value to add
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800369 * @v: pointer to type atomic64_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 *
371 * Atomically adds @i to @v and returns @i + @v
372 */
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800373static __inline__ long atomic64_add_return(long i, atomic64_t *v)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374{
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800375 long __i = i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 __asm__ __volatile__(
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200377 LOCK_PREFIX "xaddq %0, %1;"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 :"=r"(i)
379 :"m"(v->counter), "0"(i));
380 return i + __i;
381}
382
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800383static __inline__ long atomic64_sub_return(long i, atomic64_t *v)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384{
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800385 return atomic64_add_return(-i,v);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386}
387
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800388#define atomic64_inc_return(v) (atomic64_add_return(1,v))
389#define atomic64_dec_return(v) (atomic64_sub_return(1,v))
390
Nick Piggin4a6dae62005-11-13 16:07:24 -0800391#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
Ingo Molnarffbf6702006-01-09 15:59:17 -0800392#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
Nick Piggin4a6dae62005-11-13 16:07:24 -0800393
Nick Piggin8426e1f2005-11-13 16:07:25 -0800394/**
395 * atomic_add_unless - add unless the number is a given value
396 * @v: pointer of type atomic_t
397 * @a: the amount to add to v...
398 * @u: ...unless v is equal to u.
399 *
400 * Atomically adds @a to @v, so long as it was not @u.
401 * Returns non-zero if @v was not @u, and zero otherwise.
402 */
403#define atomic_add_unless(v, a, u) \
404({ \
405 int c, old; \
406 c = atomic_read(v); \
Nick Piggin0b2fcfd2006-03-23 03:01:02 -0800407 for (;;) { \
408 if (unlikely(c == (u))) \
409 break; \
410 old = atomic_cmpxchg((v), c, c + (a)); \
411 if (likely(old == c)) \
412 break; \
Nick Piggin8426e1f2005-11-13 16:07:25 -0800413 c = old; \
Nick Piggin0b2fcfd2006-03-23 03:01:02 -0800414 } \
Nick Piggin8426e1f2005-11-13 16:07:25 -0800415 c != (u); \
416})
417#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
418
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419/* These are x86-specific, used by some header files */
420#define atomic_clear_mask(mask, addr) \
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200421__asm__ __volatile__(LOCK_PREFIX "andl %0,%1" \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422: : "r" (~(mask)),"m" (*addr) : "memory")
423
424#define atomic_set_mask(mask, addr) \
Gerd Hoffmannd167a512006-06-26 13:56:16 +0200425__asm__ __volatile__(LOCK_PREFIX "orl %0,%1" \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426: : "r" ((unsigned)mask),"m" (*(addr)) : "memory")
427
428/* Atomic operations are already serializing on x86 */
429#define smp_mb__before_atomic_dec() barrier()
430#define smp_mb__after_atomic_dec() barrier()
431#define smp_mb__before_atomic_inc() barrier()
432#define smp_mb__after_atomic_inc() barrier()
433
Christoph Lameterd3cb4872006-01-06 00:11:20 -0800434#include <asm-generic/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435#endif