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1#ifndef _ASM_X86_ATOMIC64_32_H
2#define _ASM_X86_ATOMIC64_32_H
3
4#include <linux/compiler.h>
5#include <linux/types.h>
6#include <asm/processor.h>
7//#include <asm/cmpxchg.h>
8
9/* An 64bit atomic type */
10
11typedef struct {
12 u64 __aligned(8) counter;
13} atomic64_t;
14
15#define ATOMIC64_INIT(val) { (val) }
16
17#ifdef CONFIG_X86_CMPXCHG64
18#define ATOMIC64_ALTERNATIVE_(f, g) "call atomic64_" #g "_cx8"
19#else
20#define ATOMIC64_ALTERNATIVE_(f, g) ALTERNATIVE("call atomic64_" #f "_386", "call atomic64_" #g "_cx8", X86_FEATURE_CX8)
21#endif
22
23#define ATOMIC64_ALTERNATIVE(f) ATOMIC64_ALTERNATIVE_(f, f)
24
25/**
26 * atomic64_cmpxchg - cmpxchg atomic64 variable
27 * @p: pointer to type atomic64_t
28 * @o: expected value
29 * @n: new value
30 *
31 * Atomically sets @v to @n if it was equal to @o and returns
32 * the old value.
33 */
34
35static inline long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
36{
37 return cmpxchg64(&v->counter, o, n);
38}
39
40/**
41 * atomic64_xchg - xchg atomic64 variable
42 * @v: pointer to type atomic64_t
43 * @n: value to assign
44 *
45 * Atomically xchgs the value of @v to @n and returns
46 * the old value.
47 */
48static inline long long atomic64_xchg(atomic64_t *v, long long n)
49{
50 long long o;
51 unsigned high = (unsigned)(n >> 32);
52 unsigned low = (unsigned)n;
53 asm volatile(ATOMIC64_ALTERNATIVE(xchg)
54 : "=A" (o), "+b" (low), "+c" (high)
55 : "S" (v)
56 : "memory"
57 );
58 return o;
59}
60
61/**
62 * atomic64_set - set atomic64 variable
63 * @v: pointer to type atomic64_t
64 * @n: value to assign
65 *
66 * Atomically sets the value of @v to @n.
67 */
68static inline void atomic64_set(atomic64_t *v, long long i)
69{
70 unsigned high = (unsigned)(i >> 32);
71 unsigned low = (unsigned)i;
72 asm volatile(ATOMIC64_ALTERNATIVE(set)
73 : "+b" (low), "+c" (high)
74 : "S" (v)
75 : "eax", "edx", "memory"
76 );
77}
78
79/**
80 * atomic64_read - read atomic64 variable
81 * @v: pointer to type atomic64_t
82 *
83 * Atomically reads the value of @v and returns it.
84 */
85static inline long long atomic64_read(atomic64_t *v)
86{
87 long long r;
88 asm volatile(ATOMIC64_ALTERNATIVE(read)
89 : "=A" (r), "+c" (v)
90 : : "memory"
91 );
92 return r;
93 }
94
95/**
96 * atomic64_add_return - add and return
97 * @i: integer value to add
98 * @v: pointer to type atomic64_t
99 *
100 * Atomically adds @i to @v and returns @i + *@v
101 */
102static inline long long atomic64_add_return(long long i, atomic64_t *v)
103{
104 asm volatile(ATOMIC64_ALTERNATIVE(add_return)
105 : "+A" (i), "+c" (v)
106 : : "memory"
107 );
108 return i;
109}
110
111/*
112 * Other variants with different arithmetic operators:
113 */
114static inline long long atomic64_sub_return(long long i, atomic64_t *v)
115{
116 asm volatile(ATOMIC64_ALTERNATIVE(sub_return)
117 : "+A" (i), "+c" (v)
118 : : "memory"
119 );
120 return i;
121}
122
123static inline long long atomic64_inc_return(atomic64_t *v)
124{
125 long long a;
126 asm volatile(ATOMIC64_ALTERNATIVE(inc_return)
127 : "=A" (a)
128 : "S" (v)
129 : "memory", "ecx"
130 );
131 return a;
132}
133
134static inline long long atomic64_dec_return(atomic64_t *v)
135{
136 long long a;
137 asm volatile(ATOMIC64_ALTERNATIVE(dec_return)
138 : "=A" (a)
139 : "S" (v)
140 : "memory", "ecx"
141 );
142 return a;
143}
144
145/**
146 * atomic64_add - add integer to atomic64 variable
147 * @i: integer value to add
148 * @v: pointer to type atomic64_t
149 *
150 * Atomically adds @i to @v.
151 */
152static inline long long atomic64_add(long long i, atomic64_t *v)
153{
154 asm volatile(ATOMIC64_ALTERNATIVE_(add, add_return)
155 : "+A" (i), "+c" (v)
156 : : "memory"
157 );
158 return i;
159}
160
161/**
162 * atomic64_sub - subtract the atomic64 variable
163 * @i: integer value to subtract
164 * @v: pointer to type atomic64_t
165 *
166 * Atomically subtracts @i from @v.
167 */
168static inline long long atomic64_sub(long long i, atomic64_t *v)
169{
170 asm volatile(ATOMIC64_ALTERNATIVE_(sub, sub_return)
171 : "+A" (i), "+c" (v)
172 : : "memory"
173 );
174 return i;
175}
176
177/**
178 * atomic64_sub_and_test - subtract value from variable and test result
179 * @i: integer value to subtract
180 * @v: pointer to type atomic64_t
181 *
182 * Atomically subtracts @i from @v and returns
183 * true if the result is zero, or false for all
184 * other cases.
185 */
186static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
187{
188 return atomic64_sub_return(i, v) == 0;
189}
190
191/**
192 * atomic64_inc - increment atomic64 variable
193 * @v: pointer to type atomic64_t
194 *
195 * Atomically increments @v by 1.
196 */
197static inline void atomic64_inc(atomic64_t *v)
198{
199 asm volatile(ATOMIC64_ALTERNATIVE_(inc, inc_return)
200 : : "S" (v)
201 : "memory", "eax", "ecx", "edx"
202 );
203}
204
205/**
206 * atomic64_dec - decrement atomic64 variable
207 * @ptr: pointer to type atomic64_t
208 *
209 * Atomically decrements @ptr by 1.
210 */
211static inline void atomic64_dec(atomic64_t *v)
212{
213 asm volatile(ATOMIC64_ALTERNATIVE_(dec, dec_return)
214 : : "S" (v)
215 : "memory", "eax", "ecx", "edx"
216 );
217}
218
219/**
220 * atomic64_dec_and_test - decrement and test
221 * @v: pointer to type atomic64_t
222 *
223 * Atomically decrements @v by 1 and
224 * returns true if the result is 0, or false for all other
225 * cases.
226 */
227static inline int atomic64_dec_and_test(atomic64_t *v)
228{
229 return atomic64_dec_return(v) == 0;
230}
231
232/**
233 * atomic64_inc_and_test - increment and test
234 * @v: pointer to type atomic64_t
235 *
236 * Atomically increments @v by 1
237 * and returns true if the result is zero, or false for all
238 * other cases.
239 */
240static inline int atomic64_inc_and_test(atomic64_t *v)
241{
242 return atomic64_inc_return(v) == 0;
243}
244
245/**
246 * atomic64_add_negative - add and test if negative
247 * @i: integer value to add
248 * @v: pointer to type atomic64_t
249 *
250 * Atomically adds @i to @v and returns true
251 * if the result is negative, or false when
252 * result is greater than or equal to zero.
253 */
254static inline int atomic64_add_negative(long long i, atomic64_t *v)
255{
256 return atomic64_add_return(i, v) < 0;
257}
258
259/**
260 * atomic64_add_unless - add unless the number is a given value
261 * @v: pointer of type atomic64_t
262 * @a: the amount to add to v...
263 * @u: ...unless v is equal to u.
264 *
265 * Atomically adds @a to @v, so long as it was not @u.
266 * Returns the old value of @v.
267 */
268static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
269{
270 unsigned low = (unsigned)u;
271 unsigned high = (unsigned)(u >> 32);
272 asm volatile(ATOMIC64_ALTERNATIVE(add_unless) "\n\t"
273 : "+A" (a), "+c" (v), "+S" (low), "+D" (high)
274 : : "memory");
275 return (int)a;
276}
277
278
279static inline int atomic64_inc_not_zero(atomic64_t *v)
280{
281 int r;
282 asm volatile(ATOMIC64_ALTERNATIVE(inc_not_zero)
283 : "=a" (r)
284 : "S" (v)
285 : "ecx", "edx", "memory"
286 );
287 return r;
288}
289
290static inline long long atomic64_dec_if_positive(atomic64_t *v)
291{
292 long long r;
293 asm volatile(ATOMIC64_ALTERNATIVE(dec_if_positive)
294 : "=A" (r)
295 : "S" (v)
296 : "ecx", "memory"
297 );
298 return r;
299}
300
301#undef ATOMIC64_ALTERNATIVE
302#undef ATOMIC64_ALTERNATIVE_
303
304#endif /* _ASM_X86_ATOMIC64_32_H */