Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _ASM_X86_ATOMIC_H
3 : #define _ASM_X86_ATOMIC_H
4 :
5 : #include <linux/compiler.h>
6 : #include <linux/types.h>
7 : #include <asm/alternative.h>
8 : #include <asm/cmpxchg.h>
9 : #include <asm/rmwcc.h>
10 : #include <asm/barrier.h>
11 :
12 : /*
13 : * Atomic operations that C can't guarantee us. Useful for
14 : * resource counting etc..
15 : */
16 :
17 : /**
18 : * arch_atomic_read - read atomic variable
19 : * @v: pointer of type atomic_t
20 : *
21 : * Atomically reads the value of @v.
22 : */
23 : static __always_inline int arch_atomic_read(const atomic_t *v)
24 : {
25 : /*
26 : * Note for KASAN: we deliberately don't use READ_ONCE_NOCHECK() here,
27 : * it's non-inlined function that increases binary size and stack usage.
28 : */
29 871182 : return __READ_ONCE((v)->counter);
30 : }
31 :
32 : /**
33 : * arch_atomic_set - set atomic variable
34 : * @v: pointer of type atomic_t
35 : * @i: required value
36 : *
37 : * Atomically sets the value of @v to @i.
38 : */
39 : static __always_inline void arch_atomic_set(atomic_t *v, int i)
40 : {
41 : __WRITE_ONCE(v->counter, i);
42 : }
43 :
44 : /**
45 : * arch_atomic_add - add integer to atomic variable
46 : * @i: integer value to add
47 : * @v: pointer of type atomic_t
48 : *
49 : * Atomically adds @i to @v.
50 : */
51 : static __always_inline void arch_atomic_add(int i, atomic_t *v)
52 : {
53 524 : asm volatile(LOCK_PREFIX "addl %1,%0"
54 : : "+m" (v->counter)
55 : : "ir" (i) : "memory");
56 : }
57 :
58 : /**
59 : * arch_atomic_sub - subtract integer from atomic variable
60 : * @i: integer value to subtract
61 : * @v: pointer of type atomic_t
62 : *
63 : * Atomically subtracts @i from @v.
64 : */
65 : static __always_inline void arch_atomic_sub(int i, atomic_t *v)
66 : {
67 8760 : asm volatile(LOCK_PREFIX "subl %1,%0"
68 : : "+m" (v->counter)
69 : : "ir" (i) : "memory");
70 : }
71 :
72 : /**
73 : * arch_atomic_sub_and_test - subtract value from variable and test result
74 : * @i: integer value to subtract
75 : * @v: pointer of type atomic_t
76 : *
77 : * Atomically subtracts @i from @v and returns
78 : * true if the result is zero, or false for all
79 : * other cases.
80 : */
81 : static __always_inline bool arch_atomic_sub_and_test(int i, atomic_t *v)
82 : {
83 0 : return GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, e, "er", i);
84 : }
85 : #define arch_atomic_sub_and_test arch_atomic_sub_and_test
86 :
87 : /**
88 : * arch_atomic_inc - increment atomic variable
89 : * @v: pointer of type atomic_t
90 : *
91 : * Atomically increments @v by 1.
92 : */
93 : static __always_inline void arch_atomic_inc(atomic_t *v)
94 : {
95 18235 : asm volatile(LOCK_PREFIX "incl %0"
96 : : "+m" (v->counter) :: "memory");
97 : }
98 : #define arch_atomic_inc arch_atomic_inc
99 :
100 : /**
101 : * arch_atomic_dec - decrement atomic variable
102 : * @v: pointer of type atomic_t
103 : *
104 : * Atomically decrements @v by 1.
105 : */
106 : static __always_inline void arch_atomic_dec(atomic_t *v)
107 : {
108 23 : asm volatile(LOCK_PREFIX "decl %0"
109 : : "+m" (v->counter) :: "memory");
110 : }
111 : #define arch_atomic_dec arch_atomic_dec
112 :
113 : /**
114 : * arch_atomic_dec_and_test - decrement and test
115 : * @v: pointer of type atomic_t
116 : *
117 : * Atomically decrements @v by 1 and
118 : * returns true if the result is 0, or false for all other
119 : * cases.
120 : */
121 : static __always_inline bool arch_atomic_dec_and_test(atomic_t *v)
122 : {
123 51885 : return GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, e);
124 : }
125 : #define arch_atomic_dec_and_test arch_atomic_dec_and_test
126 :
127 : /**
128 : * arch_atomic_inc_and_test - increment and test
129 : * @v: pointer of type atomic_t
130 : *
131 : * Atomically increments @v by 1
132 : * and returns true if the result is zero, or false for all
133 : * other cases.
134 : */
135 : static __always_inline bool arch_atomic_inc_and_test(atomic_t *v)
136 : {
137 0 : return GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, e);
138 : }
139 : #define arch_atomic_inc_and_test arch_atomic_inc_and_test
140 :
141 : /**
142 : * arch_atomic_add_negative - add and test if negative
143 : * @i: integer value to add
144 : * @v: pointer of type atomic_t
145 : *
146 : * Atomically adds @i to @v and returns true
147 : * if the result is negative, or false when
148 : * result is greater than or equal to zero.
149 : */
150 : static __always_inline bool arch_atomic_add_negative(int i, atomic_t *v)
151 : {
152 382 : return GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, s, "er", i);
153 : }
154 : #define arch_atomic_add_negative arch_atomic_add_negative
155 :
156 : /**
157 : * arch_atomic_add_return - add integer and return
158 : * @i: integer value to add
159 : * @v: pointer of type atomic_t
160 : *
161 : * Atomically adds @i to @v and returns @i + @v
162 : */
163 : static __always_inline int arch_atomic_add_return(int i, atomic_t *v)
164 : {
165 71 : return i + xadd(&v->counter, i);
166 : }
167 : #define arch_atomic_add_return arch_atomic_add_return
168 :
169 : /**
170 : * arch_atomic_sub_return - subtract integer and return
171 : * @v: pointer of type atomic_t
172 : * @i: integer value to subtract
173 : *
174 : * Atomically subtracts @i from @v and returns @v - @i
175 : */
176 : static __always_inline int arch_atomic_sub_return(int i, atomic_t *v)
177 : {
178 132 : return arch_atomic_add_return(-i, v);
179 : }
180 : #define arch_atomic_sub_return arch_atomic_sub_return
181 :
182 : static __always_inline int arch_atomic_fetch_add(int i, atomic_t *v)
183 : {
184 7063 : return xadd(&v->counter, i);
185 : }
186 : #define arch_atomic_fetch_add arch_atomic_fetch_add
187 :
188 : static __always_inline int arch_atomic_fetch_sub(int i, atomic_t *v)
189 : {
190 7030 : return xadd(&v->counter, -i);
191 : }
192 : #define arch_atomic_fetch_sub arch_atomic_fetch_sub
193 :
194 : static __always_inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
195 : {
196 0 : return arch_cmpxchg(&v->counter, old, new);
197 : }
198 : #define arch_atomic_cmpxchg arch_atomic_cmpxchg
199 :
200 : static __always_inline bool arch_atomic_try_cmpxchg(atomic_t *v, int *old, int new)
201 : {
202 1352 : return arch_try_cmpxchg(&v->counter, old, new);
203 : }
204 : #define arch_atomic_try_cmpxchg arch_atomic_try_cmpxchg
205 :
206 : static __always_inline int arch_atomic_xchg(atomic_t *v, int new)
207 : {
208 0 : return arch_xchg(&v->counter, new);
209 : }
210 : #define arch_atomic_xchg arch_atomic_xchg
211 :
212 : static __always_inline void arch_atomic_and(int i, atomic_t *v)
213 : {
214 0 : asm volatile(LOCK_PREFIX "andl %1,%0"
215 : : "+m" (v->counter)
216 : : "ir" (i)
217 : : "memory");
218 : }
219 :
220 : static __always_inline int arch_atomic_fetch_and(int i, atomic_t *v)
221 : {
222 : int val = arch_atomic_read(v);
223 :
224 : do { } while (!arch_atomic_try_cmpxchg(v, &val, val & i));
225 :
226 : return val;
227 : }
228 : #define arch_atomic_fetch_and arch_atomic_fetch_and
229 :
230 : static __always_inline void arch_atomic_or(int i, atomic_t *v)
231 : {
232 0 : asm volatile(LOCK_PREFIX "orl %1,%0"
233 : : "+m" (v->counter)
234 : : "ir" (i)
235 : : "memory");
236 : }
237 :
238 : static __always_inline int arch_atomic_fetch_or(int i, atomic_t *v)
239 : {
240 0 : int val = arch_atomic_read(v);
241 :
242 0 : do { } while (!arch_atomic_try_cmpxchg(v, &val, val | i));
243 :
244 : return val;
245 : }
246 : #define arch_atomic_fetch_or arch_atomic_fetch_or
247 :
248 : static __always_inline void arch_atomic_xor(int i, atomic_t *v)
249 : {
250 : asm volatile(LOCK_PREFIX "xorl %1,%0"
251 : : "+m" (v->counter)
252 : : "ir" (i)
253 : : "memory");
254 : }
255 :
256 : static __always_inline int arch_atomic_fetch_xor(int i, atomic_t *v)
257 : {
258 : int val = arch_atomic_read(v);
259 :
260 : do { } while (!arch_atomic_try_cmpxchg(v, &val, val ^ i));
261 :
262 : return val;
263 : }
264 : #define arch_atomic_fetch_xor arch_atomic_fetch_xor
265 :
266 : #ifdef CONFIG_X86_32
267 : # include <asm/atomic64_32.h>
268 : #else
269 : # include <asm/atomic64_64.h>
270 : #endif
271 :
272 : #endif /* _ASM_X86_ATOMIC_H */
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