xref: /linux/arch/x86/include/asm/atomic64_32.h (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_ATOMIC64_32_H
3 #define _ASM_X86_ATOMIC64_32_H
4 
5 #include <linux/compiler.h>
6 #include <linux/types.h>
7 //#include <asm/cmpxchg.h>
8 
9 /* An 64bit atomic type */
10 
11 typedef struct {
12 	s64 __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  * arch_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 s64 arch_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
75 {
76 	return arch_cmpxchg64(&v->counter, o, n);
77 }
78 #define arch_atomic64_cmpxchg arch_atomic64_cmpxchg
79 
80 /**
81  * arch_atomic64_xchg - xchg atomic64 variable
82  * @v: pointer to type atomic64_t
83  * @n: value to assign
84  *
85  * Atomically xchgs the value of @v to @n and returns
86  * the old value.
87  */
88 static inline s64 arch_atomic64_xchg(atomic64_t *v, s64 n)
89 {
90 	s64 o;
91 	unsigned high = (unsigned)(n >> 32);
92 	unsigned low = (unsigned)n;
93 	alternative_atomic64(xchg, "=&A" (o),
94 			     "S" (v), "b" (low), "c" (high)
95 			     : "memory");
96 	return o;
97 }
98 #define arch_atomic64_xchg arch_atomic64_xchg
99 
100 /**
101  * arch_atomic64_set - set atomic64 variable
102  * @v: pointer to type atomic64_t
103  * @i: value to assign
104  *
105  * Atomically sets the value of @v to @n.
106  */
107 static inline void arch_atomic64_set(atomic64_t *v, s64 i)
108 {
109 	unsigned high = (unsigned)(i >> 32);
110 	unsigned low = (unsigned)i;
111 	alternative_atomic64(set, /* no output */,
112 			     "S" (v), "b" (low), "c" (high)
113 			     : "eax", "edx", "memory");
114 }
115 
116 /**
117  * arch_atomic64_read - read atomic64 variable
118  * @v: pointer to type atomic64_t
119  *
120  * Atomically reads the value of @v and returns it.
121  */
122 static inline s64 arch_atomic64_read(const atomic64_t *v)
123 {
124 	s64 r;
125 	alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
126 	return r;
127 }
128 
129 /**
130  * arch_atomic64_add_return - add and return
131  * @i: integer value to add
132  * @v: pointer to type atomic64_t
133  *
134  * Atomically adds @i to @v and returns @i + *@v
135  */
136 static inline s64 arch_atomic64_add_return(s64 i, atomic64_t *v)
137 {
138 	alternative_atomic64(add_return,
139 			     ASM_OUTPUT2("+A" (i), "+c" (v)),
140 			     ASM_NO_INPUT_CLOBBER("memory"));
141 	return i;
142 }
143 #define arch_atomic64_add_return arch_atomic64_add_return
144 
145 /*
146  * Other variants with different arithmetic operators:
147  */
148 static inline s64 arch_atomic64_sub_return(s64 i, atomic64_t *v)
149 {
150 	alternative_atomic64(sub_return,
151 			     ASM_OUTPUT2("+A" (i), "+c" (v)),
152 			     ASM_NO_INPUT_CLOBBER("memory"));
153 	return i;
154 }
155 #define arch_atomic64_sub_return arch_atomic64_sub_return
156 
157 static inline s64 arch_atomic64_inc_return(atomic64_t *v)
158 {
159 	s64 a;
160 	alternative_atomic64(inc_return, "=&A" (a),
161 			     "S" (v) : "memory", "ecx");
162 	return a;
163 }
164 #define arch_atomic64_inc_return arch_atomic64_inc_return
165 
166 static inline s64 arch_atomic64_dec_return(atomic64_t *v)
167 {
168 	s64 a;
169 	alternative_atomic64(dec_return, "=&A" (a),
170 			     "S" (v) : "memory", "ecx");
171 	return a;
172 }
173 #define arch_atomic64_dec_return arch_atomic64_dec_return
174 
175 /**
176  * arch_atomic64_add - add integer to atomic64 variable
177  * @i: integer value to add
178  * @v: pointer to type atomic64_t
179  *
180  * Atomically adds @i to @v.
181  */
182 static inline s64 arch_atomic64_add(s64 i, atomic64_t *v)
183 {
184 	__alternative_atomic64(add, add_return,
185 			       ASM_OUTPUT2("+A" (i), "+c" (v)),
186 			       ASM_NO_INPUT_CLOBBER("memory"));
187 	return i;
188 }
189 
190 /**
191  * arch_atomic64_sub - subtract the atomic64 variable
192  * @i: integer value to subtract
193  * @v: pointer to type atomic64_t
194  *
195  * Atomically subtracts @i from @v.
196  */
197 static inline s64 arch_atomic64_sub(s64 i, atomic64_t *v)
198 {
199 	__alternative_atomic64(sub, sub_return,
200 			       ASM_OUTPUT2("+A" (i), "+c" (v)),
201 			       ASM_NO_INPUT_CLOBBER("memory"));
202 	return i;
203 }
204 
205 /**
206  * arch_atomic64_inc - increment atomic64 variable
207  * @v: pointer to type atomic64_t
208  *
209  * Atomically increments @v by 1.
210  */
211 static inline void arch_atomic64_inc(atomic64_t *v)
212 {
213 	__alternative_atomic64(inc, inc_return, /* no output */,
214 			       "S" (v) : "memory", "eax", "ecx", "edx");
215 }
216 #define arch_atomic64_inc arch_atomic64_inc
217 
218 /**
219  * arch_atomic64_dec - decrement atomic64 variable
220  * @v: pointer to type atomic64_t
221  *
222  * Atomically decrements @v by 1.
223  */
224 static inline void arch_atomic64_dec(atomic64_t *v)
225 {
226 	__alternative_atomic64(dec, dec_return, /* no output */,
227 			       "S" (v) : "memory", "eax", "ecx", "edx");
228 }
229 #define arch_atomic64_dec arch_atomic64_dec
230 
231 /**
232  * arch_atomic64_add_unless - add unless the number is a given value
233  * @v: pointer of type atomic64_t
234  * @a: the amount to add to v...
235  * @u: ...unless v is equal to u.
236  *
237  * Atomically adds @a to @v, so long as it was not @u.
238  * Returns non-zero if the add was done, zero otherwise.
239  */
240 static inline int arch_atomic64_add_unless(atomic64_t *v, s64 a, s64 u)
241 {
242 	unsigned low = (unsigned)u;
243 	unsigned high = (unsigned)(u >> 32);
244 	alternative_atomic64(add_unless,
245 			     ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
246 			     "S" (v) : "memory");
247 	return (int)a;
248 }
249 #define arch_atomic64_add_unless arch_atomic64_add_unless
250 
251 static inline int arch_atomic64_inc_not_zero(atomic64_t *v)
252 {
253 	int r;
254 	alternative_atomic64(inc_not_zero, "=&a" (r),
255 			     "S" (v) : "ecx", "edx", "memory");
256 	return r;
257 }
258 #define arch_atomic64_inc_not_zero arch_atomic64_inc_not_zero
259 
260 static inline s64 arch_atomic64_dec_if_positive(atomic64_t *v)
261 {
262 	s64 r;
263 	alternative_atomic64(dec_if_positive, "=&A" (r),
264 			     "S" (v) : "ecx", "memory");
265 	return r;
266 }
267 #define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive
268 
269 #undef alternative_atomic64
270 #undef __alternative_atomic64
271 
272 static inline void arch_atomic64_and(s64 i, atomic64_t *v)
273 {
274 	s64 old, c = 0;
275 
276 	while ((old = arch_atomic64_cmpxchg(v, c, c & i)) != c)
277 		c = old;
278 }
279 
280 static inline s64 arch_atomic64_fetch_and(s64 i, atomic64_t *v)
281 {
282 	s64 old, c = 0;
283 
284 	while ((old = arch_atomic64_cmpxchg(v, c, c & i)) != c)
285 		c = old;
286 
287 	return old;
288 }
289 #define arch_atomic64_fetch_and arch_atomic64_fetch_and
290 
291 static inline void arch_atomic64_or(s64 i, atomic64_t *v)
292 {
293 	s64 old, c = 0;
294 
295 	while ((old = arch_atomic64_cmpxchg(v, c, c | i)) != c)
296 		c = old;
297 }
298 
299 static inline s64 arch_atomic64_fetch_or(s64 i, atomic64_t *v)
300 {
301 	s64 old, c = 0;
302 
303 	while ((old = arch_atomic64_cmpxchg(v, c, c | i)) != c)
304 		c = old;
305 
306 	return old;
307 }
308 #define arch_atomic64_fetch_or arch_atomic64_fetch_or
309 
310 static inline void arch_atomic64_xor(s64 i, atomic64_t *v)
311 {
312 	s64 old, c = 0;
313 
314 	while ((old = arch_atomic64_cmpxchg(v, c, c ^ i)) != c)
315 		c = old;
316 }
317 
318 static inline s64 arch_atomic64_fetch_xor(s64 i, atomic64_t *v)
319 {
320 	s64 old, c = 0;
321 
322 	while ((old = arch_atomic64_cmpxchg(v, c, c ^ i)) != c)
323 		c = old;
324 
325 	return old;
326 }
327 #define arch_atomic64_fetch_xor arch_atomic64_fetch_xor
328 
329 static inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
330 {
331 	s64 old, c = 0;
332 
333 	while ((old = arch_atomic64_cmpxchg(v, c, c + i)) != c)
334 		c = old;
335 
336 	return old;
337 }
338 #define arch_atomic64_fetch_add arch_atomic64_fetch_add
339 
340 #define arch_atomic64_fetch_sub(i, v)	arch_atomic64_fetch_add(-(i), (v))
341 
342 #endif /* _ASM_X86_ATOMIC64_32_H */
343