xref: /linux/arch/x86/include/asm/atomic64_32.h (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
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 
11 typedef struct {
12 	u64 __aligned(8) counter;
13 } atomic64_t;
14 
15 #define ATOMIC64_INIT(val)	{ (val) }
16 
17 #define __ATOMIC64_DECL(sym) void atomic64_##sym(atomic64_t *, ...)
18 #ifndef ATOMIC64_EXPORT
19 #define ATOMIC64_DECL_ONE __ATOMIC64_DECL
20 #else
21 #define ATOMIC64_DECL_ONE(sym) __ATOMIC64_DECL(sym); \
22 	ATOMIC64_EXPORT(atomic64_##sym)
23 #endif
24 
25 #ifdef CONFIG_X86_CMPXCHG64
26 #define __alternative_atomic64(f, g, out, in...) \
27 	asm volatile("call %P[func]" \
28 		     : out : [func] "i" (atomic64_##g##_cx8), ## in)
29 
30 #define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
31 #else
32 #define __alternative_atomic64(f, g, out, in...) \
33 	alternative_call(atomic64_##f##_386, atomic64_##g##_cx8, \
34 			 X86_FEATURE_CX8, ASM_OUTPUT2(out), ## in)
35 
36 #define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8); \
37 	ATOMIC64_DECL_ONE(sym##_386)
38 
39 ATOMIC64_DECL_ONE(add_386);
40 ATOMIC64_DECL_ONE(sub_386);
41 ATOMIC64_DECL_ONE(inc_386);
42 ATOMIC64_DECL_ONE(dec_386);
43 #endif
44 
45 #define alternative_atomic64(f, out, in...) \
46 	__alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)
47 
48 ATOMIC64_DECL(read);
49 ATOMIC64_DECL(set);
50 ATOMIC64_DECL(xchg);
51 ATOMIC64_DECL(add_return);
52 ATOMIC64_DECL(sub_return);
53 ATOMIC64_DECL(inc_return);
54 ATOMIC64_DECL(dec_return);
55 ATOMIC64_DECL(dec_if_positive);
56 ATOMIC64_DECL(inc_not_zero);
57 ATOMIC64_DECL(add_unless);
58 
59 #undef ATOMIC64_DECL
60 #undef ATOMIC64_DECL_ONE
61 #undef __ATOMIC64_DECL
62 #undef ATOMIC64_EXPORT
63 
64 /**
65  * atomic64_cmpxchg - cmpxchg atomic64 variable
66  * @v: pointer to type atomic64_t
67  * @o: expected value
68  * @n: new value
69  *
70  * Atomically sets @v to @n if it was equal to @o and returns
71  * the old value.
72  */
73 
74 static inline long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
75 {
76 	return cmpxchg64(&v->counter, o, n);
77 }
78 
79 /**
80  * atomic64_xchg - xchg atomic64 variable
81  * @v: pointer to type atomic64_t
82  * @n: value to assign
83  *
84  * Atomically xchgs the value of @v to @n and returns
85  * the old value.
86  */
87 static inline long long atomic64_xchg(atomic64_t *v, long long n)
88 {
89 	long long o;
90 	unsigned high = (unsigned)(n >> 32);
91 	unsigned low = (unsigned)n;
92 	alternative_atomic64(xchg, "=&A" (o),
93 			     "S" (v), "b" (low), "c" (high)
94 			     : "memory");
95 	return o;
96 }
97 
98 /**
99  * atomic64_set - set atomic64 variable
100  * @v: pointer to type atomic64_t
101  * @i: value to assign
102  *
103  * Atomically sets the value of @v to @n.
104  */
105 static inline void atomic64_set(atomic64_t *v, long long i)
106 {
107 	unsigned high = (unsigned)(i >> 32);
108 	unsigned low = (unsigned)i;
109 	alternative_atomic64(set, /* no output */,
110 			     "S" (v), "b" (low), "c" (high)
111 			     : "eax", "edx", "memory");
112 }
113 
114 /**
115  * atomic64_read - read atomic64 variable
116  * @v: pointer to type atomic64_t
117  *
118  * Atomically reads the value of @v and returns it.
119  */
120 static inline long long atomic64_read(const atomic64_t *v)
121 {
122 	long long r;
123 	alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
124 	return r;
125  }
126 
127 /**
128  * atomic64_add_return - add and return
129  * @i: integer value to add
130  * @v: pointer to type atomic64_t
131  *
132  * Atomically adds @i to @v and returns @i + *@v
133  */
134 static inline long long atomic64_add_return(long long i, atomic64_t *v)
135 {
136 	alternative_atomic64(add_return,
137 			     ASM_OUTPUT2("+A" (i), "+c" (v)),
138 			     ASM_NO_INPUT_CLOBBER("memory"));
139 	return i;
140 }
141 
142 /*
143  * Other variants with different arithmetic operators:
144  */
145 static inline long long atomic64_sub_return(long long i, atomic64_t *v)
146 {
147 	alternative_atomic64(sub_return,
148 			     ASM_OUTPUT2("+A" (i), "+c" (v)),
149 			     ASM_NO_INPUT_CLOBBER("memory"));
150 	return i;
151 }
152 
153 static inline long long atomic64_inc_return(atomic64_t *v)
154 {
155 	long long a;
156 	alternative_atomic64(inc_return, "=&A" (a),
157 			     "S" (v) : "memory", "ecx");
158 	return a;
159 }
160 
161 static inline long long atomic64_dec_return(atomic64_t *v)
162 {
163 	long long a;
164 	alternative_atomic64(dec_return, "=&A" (a),
165 			     "S" (v) : "memory", "ecx");
166 	return a;
167 }
168 
169 /**
170  * atomic64_add - add integer to atomic64 variable
171  * @i: integer value to add
172  * @v: pointer to type atomic64_t
173  *
174  * Atomically adds @i to @v.
175  */
176 static inline long long atomic64_add(long long i, atomic64_t *v)
177 {
178 	__alternative_atomic64(add, add_return,
179 			       ASM_OUTPUT2("+A" (i), "+c" (v)),
180 			       ASM_NO_INPUT_CLOBBER("memory"));
181 	return i;
182 }
183 
184 /**
185  * atomic64_sub - subtract the atomic64 variable
186  * @i: integer value to subtract
187  * @v: pointer to type atomic64_t
188  *
189  * Atomically subtracts @i from @v.
190  */
191 static inline long long atomic64_sub(long long i, atomic64_t *v)
192 {
193 	__alternative_atomic64(sub, sub_return,
194 			       ASM_OUTPUT2("+A" (i), "+c" (v)),
195 			       ASM_NO_INPUT_CLOBBER("memory"));
196 	return i;
197 }
198 
199 /**
200  * atomic64_sub_and_test - subtract value from variable and test result
201  * @i: integer value to subtract
202  * @v: pointer to type atomic64_t
203  *
204  * Atomically subtracts @i from @v and returns
205  * true if the result is zero, or false for all
206  * other cases.
207  */
208 static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
209 {
210 	return atomic64_sub_return(i, v) == 0;
211 }
212 
213 /**
214  * atomic64_inc - increment atomic64 variable
215  * @v: pointer to type atomic64_t
216  *
217  * Atomically increments @v by 1.
218  */
219 static inline void atomic64_inc(atomic64_t *v)
220 {
221 	__alternative_atomic64(inc, inc_return, /* no output */,
222 			       "S" (v) : "memory", "eax", "ecx", "edx");
223 }
224 
225 /**
226  * atomic64_dec - decrement atomic64 variable
227  * @v: pointer to type atomic64_t
228  *
229  * Atomically decrements @v by 1.
230  */
231 static inline void atomic64_dec(atomic64_t *v)
232 {
233 	__alternative_atomic64(dec, dec_return, /* no output */,
234 			       "S" (v) : "memory", "eax", "ecx", "edx");
235 }
236 
237 /**
238  * atomic64_dec_and_test - decrement and test
239  * @v: pointer to type atomic64_t
240  *
241  * Atomically decrements @v by 1 and
242  * returns true if the result is 0, or false for all other
243  * cases.
244  */
245 static inline int atomic64_dec_and_test(atomic64_t *v)
246 {
247 	return atomic64_dec_return(v) == 0;
248 }
249 
250 /**
251  * atomic64_inc_and_test - increment and test
252  * @v: pointer to type atomic64_t
253  *
254  * Atomically increments @v by 1
255  * and returns true if the result is zero, or false for all
256  * other cases.
257  */
258 static inline int atomic64_inc_and_test(atomic64_t *v)
259 {
260 	return atomic64_inc_return(v) == 0;
261 }
262 
263 /**
264  * atomic64_add_negative - add and test if negative
265  * @i: integer value to add
266  * @v: pointer to type atomic64_t
267  *
268  * Atomically adds @i to @v and returns true
269  * if the result is negative, or false when
270  * result is greater than or equal to zero.
271  */
272 static inline int atomic64_add_negative(long long i, atomic64_t *v)
273 {
274 	return atomic64_add_return(i, v) < 0;
275 }
276 
277 /**
278  * atomic64_add_unless - add unless the number is a given value
279  * @v: pointer of type atomic64_t
280  * @a: the amount to add to v...
281  * @u: ...unless v is equal to u.
282  *
283  * Atomically adds @a to @v, so long as it was not @u.
284  * Returns non-zero if the add was done, zero otherwise.
285  */
286 static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
287 {
288 	unsigned low = (unsigned)u;
289 	unsigned high = (unsigned)(u >> 32);
290 	alternative_atomic64(add_unless,
291 			     ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
292 			     "S" (v) : "memory");
293 	return (int)a;
294 }
295 
296 
297 static inline int atomic64_inc_not_zero(atomic64_t *v)
298 {
299 	int r;
300 	alternative_atomic64(inc_not_zero, "=&a" (r),
301 			     "S" (v) : "ecx", "edx", "memory");
302 	return r;
303 }
304 
305 static inline long long atomic64_dec_if_positive(atomic64_t *v)
306 {
307 	long long r;
308 	alternative_atomic64(dec_if_positive, "=&A" (r),
309 			     "S" (v) : "ecx", "memory");
310 	return r;
311 }
312 
313 #undef alternative_atomic64
314 #undef __alternative_atomic64
315 
316 #endif /* _ASM_X86_ATOMIC64_32_H */
317