xref: /linux/arch/x86/include/asm/atomic64_32.h (revision fbce3befd60d40639bf3c6b60f7477b2f988f92d)
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/cmpxchg.h>
7 
8 /* An 64bit atomic type */
9 
10 typedef struct {
11 	u64 __aligned(8) counter;
12 } atomic64_t;
13 
14 #define ATOMIC64_INIT(val)	{ (val) }
15 
16 #define __ATOMIC64_DECL(sym) void atomic64_##sym(atomic64_t *, ...)
17 #ifndef ATOMIC64_EXPORT
18 #define ATOMIC64_DECL_ONE __ATOMIC64_DECL
19 #else
20 #define ATOMIC64_DECL_ONE(sym) __ATOMIC64_DECL(sym); \
21 	ATOMIC64_EXPORT(atomic64_##sym)
22 #endif
23 
24 #ifdef CONFIG_X86_CMPXCHG64
25 #define __alternative_atomic64(f, g, out, in...) \
26 	asm volatile("call %P[func]" \
27 		     : out : [func] "i" (atomic64_##g##_cx8), ## in)
28 
29 #define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
30 #else
31 #define __alternative_atomic64(f, g, out, in...) \
32 	alternative_call(atomic64_##f##_386, atomic64_##g##_cx8, \
33 			 X86_FEATURE_CX8, ASM_OUTPUT2(out), ## in)
34 
35 #define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8); \
36 	ATOMIC64_DECL_ONE(sym##_386)
37 
38 ATOMIC64_DECL_ONE(add_386);
39 ATOMIC64_DECL_ONE(sub_386);
40 ATOMIC64_DECL_ONE(inc_386);
41 ATOMIC64_DECL_ONE(dec_386);
42 #endif
43 
44 #define alternative_atomic64(f, out, in...) \
45 	__alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)
46 
47 ATOMIC64_DECL(read);
48 ATOMIC64_DECL(set);
49 ATOMIC64_DECL(xchg);
50 ATOMIC64_DECL(add_return);
51 ATOMIC64_DECL(sub_return);
52 ATOMIC64_DECL(inc_return);
53 ATOMIC64_DECL(dec_return);
54 ATOMIC64_DECL(dec_if_positive);
55 ATOMIC64_DECL(inc_not_zero);
56 ATOMIC64_DECL(add_unless);
57 
58 #undef ATOMIC64_DECL
59 #undef ATOMIC64_DECL_ONE
60 #undef __ATOMIC64_DECL
61 #undef ATOMIC64_EXPORT
62 
63 /**
64  * atomic64_cmpxchg - cmpxchg atomic64 variable
65  * @v: pointer to type atomic64_t
66  * @o: expected value
67  * @n: new value
68  *
69  * Atomically sets @v to @n if it was equal to @o and returns
70  * the old value.
71  */
72 
73 static inline long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
74 {
75 	return cmpxchg64(&v->counter, o, n);
76 }
77 
78 /**
79  * atomic64_xchg - xchg atomic64 variable
80  * @v: pointer to type atomic64_t
81  * @n: value to assign
82  *
83  * Atomically xchgs the value of @v to @n and returns
84  * the old value.
85  */
86 static inline long long atomic64_xchg(atomic64_t *v, long long n)
87 {
88 	long long o;
89 	unsigned high = (unsigned)(n >> 32);
90 	unsigned low = (unsigned)n;
91 	alternative_atomic64(xchg, "=&A" (o),
92 			     "S" (v), "b" (low), "c" (high)
93 			     : "memory");
94 	return o;
95 }
96 
97 /**
98  * atomic64_set - set atomic64 variable
99  * @v: pointer to type atomic64_t
100  * @i: value to assign
101  *
102  * Atomically sets the value of @v to @n.
103  */
104 static inline void atomic64_set(atomic64_t *v, long long i)
105 {
106 	unsigned high = (unsigned)(i >> 32);
107 	unsigned low = (unsigned)i;
108 	alternative_atomic64(set, /* no output */,
109 			     "S" (v), "b" (low), "c" (high)
110 			     : "eax", "edx", "memory");
111 }
112 
113 /**
114  * atomic64_read - read atomic64 variable
115  * @v: pointer to type atomic64_t
116  *
117  * Atomically reads the value of @v and returns it.
118  */
119 static inline long long atomic64_read(const atomic64_t *v)
120 {
121 	long long r;
122 	alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
123 	return r;
124  }
125 
126 /**
127  * atomic64_add_return - add and return
128  * @i: integer value to add
129  * @v: pointer to type atomic64_t
130  *
131  * Atomically adds @i to @v and returns @i + *@v
132  */
133 static inline long long atomic64_add_return(long long i, atomic64_t *v)
134 {
135 	alternative_atomic64(add_return,
136 			     ASM_OUTPUT2("+A" (i), "+c" (v)),
137 			     ASM_NO_INPUT_CLOBBER("memory"));
138 	return i;
139 }
140 
141 /*
142  * Other variants with different arithmetic operators:
143  */
144 static inline long long atomic64_sub_return(long long i, atomic64_t *v)
145 {
146 	alternative_atomic64(sub_return,
147 			     ASM_OUTPUT2("+A" (i), "+c" (v)),
148 			     ASM_NO_INPUT_CLOBBER("memory"));
149 	return i;
150 }
151 
152 static inline long long atomic64_inc_return(atomic64_t *v)
153 {
154 	long long a;
155 	alternative_atomic64(inc_return, "=&A" (a),
156 			     "S" (v) : "memory", "ecx");
157 	return a;
158 }
159 
160 static inline long long atomic64_dec_return(atomic64_t *v)
161 {
162 	long long a;
163 	alternative_atomic64(dec_return, "=&A" (a),
164 			     "S" (v) : "memory", "ecx");
165 	return a;
166 }
167 
168 /**
169  * atomic64_add - add integer to atomic64 variable
170  * @i: integer value to add
171  * @v: pointer to type atomic64_t
172  *
173  * Atomically adds @i to @v.
174  */
175 static inline long long atomic64_add(long long i, atomic64_t *v)
176 {
177 	__alternative_atomic64(add, add_return,
178 			       ASM_OUTPUT2("+A" (i), "+c" (v)),
179 			       ASM_NO_INPUT_CLOBBER("memory"));
180 	return i;
181 }
182 
183 /**
184  * atomic64_sub - subtract the atomic64 variable
185  * @i: integer value to subtract
186  * @v: pointer to type atomic64_t
187  *
188  * Atomically subtracts @i from @v.
189  */
190 static inline long long atomic64_sub(long long i, atomic64_t *v)
191 {
192 	__alternative_atomic64(sub, sub_return,
193 			       ASM_OUTPUT2("+A" (i), "+c" (v)),
194 			       ASM_NO_INPUT_CLOBBER("memory"));
195 	return i;
196 }
197 
198 /**
199  * atomic64_sub_and_test - subtract value from variable and test result
200  * @i: integer value to subtract
201  * @v: pointer to type atomic64_t
202  *
203  * Atomically subtracts @i from @v and returns
204  * true if the result is zero, or false for all
205  * other cases.
206  */
207 static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
208 {
209 	return atomic64_sub_return(i, v) == 0;
210 }
211 
212 /**
213  * atomic64_inc - increment atomic64 variable
214  * @v: pointer to type atomic64_t
215  *
216  * Atomically increments @v by 1.
217  */
218 static inline void atomic64_inc(atomic64_t *v)
219 {
220 	__alternative_atomic64(inc, inc_return, /* no output */,
221 			       "S" (v) : "memory", "eax", "ecx", "edx");
222 }
223 
224 /**
225  * atomic64_dec - decrement atomic64 variable
226  * @v: pointer to type atomic64_t
227  *
228  * Atomically decrements @v by 1.
229  */
230 static inline void atomic64_dec(atomic64_t *v)
231 {
232 	__alternative_atomic64(dec, dec_return, /* no output */,
233 			       "S" (v) : "memory", "eax", "ecx", "edx");
234 }
235 
236 /**
237  * atomic64_dec_and_test - decrement and test
238  * @v: pointer to type atomic64_t
239  *
240  * Atomically decrements @v by 1 and
241  * returns true if the result is 0, or false for all other
242  * cases.
243  */
244 static inline int atomic64_dec_and_test(atomic64_t *v)
245 {
246 	return atomic64_dec_return(v) == 0;
247 }
248 
249 /**
250  * atomic64_inc_and_test - increment and test
251  * @v: pointer to type atomic64_t
252  *
253  * Atomically increments @v by 1
254  * and returns true if the result is zero, or false for all
255  * other cases.
256  */
257 static inline int atomic64_inc_and_test(atomic64_t *v)
258 {
259 	return atomic64_inc_return(v) == 0;
260 }
261 
262 /**
263  * atomic64_add_negative - add and test if negative
264  * @i: integer value to add
265  * @v: pointer to type atomic64_t
266  *
267  * Atomically adds @i to @v and returns true
268  * if the result is negative, or false when
269  * result is greater than or equal to zero.
270  */
271 static inline int atomic64_add_negative(long long i, atomic64_t *v)
272 {
273 	return atomic64_add_return(i, v) < 0;
274 }
275 
276 /**
277  * atomic64_add_unless - add unless the number is a given value
278  * @v: pointer of type atomic64_t
279  * @a: the amount to add to v...
280  * @u: ...unless v is equal to u.
281  *
282  * Atomically adds @a to @v, so long as it was not @u.
283  * Returns non-zero if the add was done, zero otherwise.
284  */
285 static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
286 {
287 	unsigned low = (unsigned)u;
288 	unsigned high = (unsigned)(u >> 32);
289 	alternative_atomic64(add_unless,
290 			     ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
291 			     "S" (v) : "memory");
292 	return (int)a;
293 }
294 
295 
296 static inline int atomic64_inc_not_zero(atomic64_t *v)
297 {
298 	int r;
299 	alternative_atomic64(inc_not_zero, "=&a" (r),
300 			     "S" (v) : "ecx", "edx", "memory");
301 	return r;
302 }
303 
304 static inline long long atomic64_dec_if_positive(atomic64_t *v)
305 {
306 	long long r;
307 	alternative_atomic64(dec_if_positive, "=&A" (r),
308 			     "S" (v) : "ecx", "memory");
309 	return r;
310 }
311 
312 #undef alternative_atomic64
313 #undef __alternative_atomic64
314 
315 #define ATOMIC64_OP(op, c_op)						\
316 static inline void atomic64_##op(long long i, atomic64_t *v)		\
317 {									\
318 	long long old, c = 0;						\
319 	while ((old = atomic64_cmpxchg(v, c, c c_op i)) != c)		\
320 		c = old;						\
321 }
322 
323 ATOMIC64_OP(and, &)
324 ATOMIC64_OP(or, |)
325 ATOMIC64_OP(xor, ^)
326 
327 #undef ATOMIC64_OP
328 
329 #endif /* _ASM_X86_ATOMIC64_32_H */
330