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
11typedef 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
39ATOMIC64_DECL_ONE(add_386);
40ATOMIC64_DECL_ONE(sub_386);
41ATOMIC64_DECL_ONE(inc_386);
42ATOMIC64_DECL_ONE(dec_386);
43#endif
44
45#define alternative_atomic64(f, out, in...) \
46	__alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)
47
48ATOMIC64_DECL(read);
49ATOMIC64_DECL(set);
50ATOMIC64_DECL(xchg);
51ATOMIC64_DECL(add_return);
52ATOMIC64_DECL(sub_return);
53ATOMIC64_DECL(inc_return);
54ATOMIC64_DECL(dec_return);
55ATOMIC64_DECL(dec_if_positive);
56ATOMIC64_DECL(inc_not_zero);
57ATOMIC64_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
74static 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 */
88static 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 */
107static 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 */
122static 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 */
136static 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 */
148static 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
157static 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
166static 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 */
182static 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 */
197static 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 */
211static 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 */
224static 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 */
240static 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
251static 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
260static 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
272static 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
280static 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
291static 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
299static 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
310static 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
318static 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
329static 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