include/asm/atomic64_32.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_X86_ATOMIC64_32_H
0003 #define _ASM_X86_ATOMIC64_32_H
0004
0005 #include <linux/compiler.h>
0006 #include <linux/types.h>
0007 //#include <asm/cmpxchg.h>
0008
0009 /* An 64bit atomic type */
0010
0011 typedef struct {
0012     s64 __aligned(8) counter;
0013 } atomic64_t;
0014
0015 #define ATOMIC64_INIT(val)  { (val) }
0016
0017 #define __ATOMIC64_DECL(sym) void atomic64_##sym(atomic64_t *, ...)
0018 #ifndef ATOMIC64_EXPORT
0019 #define ATOMIC64_DECL_ONE __ATOMIC64_DECL
0020 #else
0021 #define ATOMIC64_DECL_ONE(sym) __ATOMIC64_DECL(sym); \
0022     ATOMIC64_EXPORT(atomic64_##sym)
0023 #endif
0024
0025 #ifdef CONFIG_X86_CMPXCHG64
0026 #define __alternative_atomic64(f, g, out, in...) \
0027     asm volatile("call %P[func]" \
0028              : out : [func] "i" (atomic64_##g##_cx8), ## in)
0029
0030 #define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
0031 #else
0032 #define __alternative_atomic64(f, g, out, in...) \
0033     alternative_call(atomic64_##f##_386, atomic64_##g##_cx8, \
0034              X86_FEATURE_CX8, ASM_OUTPUT2(out), ## in)
0035
0036 #define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8); \
0037     ATOMIC64_DECL_ONE(sym##_386)
0038
0039 ATOMIC64_DECL_ONE(add_386);
0040 ATOMIC64_DECL_ONE(sub_386);
0041 ATOMIC64_DECL_ONE(inc_386);
0042 ATOMIC64_DECL_ONE(dec_386);
0043 #endif
0044
0045 #define alternative_atomic64(f, out, in...) \
0046     __alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)
0047
0048 ATOMIC64_DECL(read);
0049 ATOMIC64_DECL(set);
0050 ATOMIC64_DECL(xchg);
0051 ATOMIC64_DECL(add_return);
0052 ATOMIC64_DECL(sub_return);
0053 ATOMIC64_DECL(inc_return);
0054 ATOMIC64_DECL(dec_return);
0055 ATOMIC64_DECL(dec_if_positive);
0056 ATOMIC64_DECL(inc_not_zero);
0057 ATOMIC64_DECL(add_unless);
0058
0059 #undef ATOMIC64_DECL
0060 #undef ATOMIC64_DECL_ONE
0061 #undef __ATOMIC64_DECL
0062 #undef ATOMIC64_EXPORT
0063
0064 /**
0065  * arch_atomic64_cmpxchg - cmpxchg atomic64 variable
0066  * @v: pointer to type atomic64_t
0067  * @o: expected value
0068  * @n: new value
0069  *
0070  * Atomically sets @v to @n if it was equal to @o and returns
0071  * the old value.
0072  */
0073
0074 static inline s64 arch_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
0075 {
0076     return arch_cmpxchg64(&v->counter, o, n);
0077 }
0078 #define arch_atomic64_cmpxchg arch_atomic64_cmpxchg
0079
0080 /**
0081  * arch_atomic64_xchg - xchg atomic64 variable
0082  * @v: pointer to type atomic64_t
0083  * @n: value to assign
0084  *
0085  * Atomically xchgs the value of @v to @n and returns
0086  * the old value.
0087  */
0088 static inline s64 arch_atomic64_xchg(atomic64_t *v, s64 n)
0089 {
0090     s64 o;
0091     unsigned high = (unsigned)(n >> 32);
0092     unsigned low = (unsigned)n;
0093     alternative_atomic64(xchg, "=&A" (o),
0094                  "S" (v), "b" (low), "c" (high)
0095                  : "memory");
0096     return o;
0097 }
0098 #define arch_atomic64_xchg arch_atomic64_xchg
0099
0100 /**
0101  * arch_atomic64_set - set atomic64 variable
0102  * @v: pointer to type atomic64_t
0103  * @i: value to assign
0104  *
0105  * Atomically sets the value of @v to @n.
0106  */
0107 static inline void arch_atomic64_set(atomic64_t *v, s64 i)
0108 {
0109     unsigned high = (unsigned)(i >> 32);
0110     unsigned low = (unsigned)i;
0111     alternative_atomic64(set, /* no output */,
0112                  "S" (v), "b" (low), "c" (high)
0113                  : "eax", "edx", "memory");
0114 }
0115
0116 /**
0117  * arch_atomic64_read - read atomic64 variable
0118  * @v: pointer to type atomic64_t
0119  *
0120  * Atomically reads the value of @v and returns it.
0121  */
0122 static inline s64 arch_atomic64_read(const atomic64_t *v)
0123 {
0124     s64 r;
0125     alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
0126     return r;
0127 }
0128
0129 /**
0130  * arch_atomic64_add_return - add and return
0131  * @i: integer value to add
0132  * @v: pointer to type atomic64_t
0133  *
0134  * Atomically adds @i to @v and returns @i + *@v
0135  */
0136 static inline s64 arch_atomic64_add_return(s64 i, atomic64_t *v)
0137 {
0138     alternative_atomic64(add_return,
0139                  ASM_OUTPUT2("+A" (i), "+c" (v)),
0140                  ASM_NO_INPUT_CLOBBER("memory"));
0141     return i;
0142 }
0143 #define arch_atomic64_add_return arch_atomic64_add_return
0144
0145 /*
0146  * Other variants with different arithmetic operators:
0147  */
0148 static inline s64 arch_atomic64_sub_return(s64 i, atomic64_t *v)
0149 {
0150     alternative_atomic64(sub_return,
0151                  ASM_OUTPUT2("+A" (i), "+c" (v)),
0152                  ASM_NO_INPUT_CLOBBER("memory"));
0153     return i;
0154 }
0155 #define arch_atomic64_sub_return arch_atomic64_sub_return
0156
0157 static inline s64 arch_atomic64_inc_return(atomic64_t *v)
0158 {
0159     s64 a;
0160     alternative_atomic64(inc_return, "=&A" (a),
0161                  "S" (v) : "memory", "ecx");
0162     return a;
0163 }
0164 #define arch_atomic64_inc_return arch_atomic64_inc_return
0165
0166 static inline s64 arch_atomic64_dec_return(atomic64_t *v)
0167 {
0168     s64 a;
0169     alternative_atomic64(dec_return, "=&A" (a),
0170                  "S" (v) : "memory", "ecx");
0171     return a;
0172 }
0173 #define arch_atomic64_dec_return arch_atomic64_dec_return
0174
0175 /**
0176  * arch_atomic64_add - add integer to atomic64 variable
0177  * @i: integer value to add
0178  * @v: pointer to type atomic64_t
0179  *
0180  * Atomically adds @i to @v.
0181  */
0182 static inline s64 arch_atomic64_add(s64 i, atomic64_t *v)
0183 {
0184     __alternative_atomic64(add, add_return,
0185                    ASM_OUTPUT2("+A" (i), "+c" (v)),
0186                    ASM_NO_INPUT_CLOBBER("memory"));
0187     return i;
0188 }
0189
0190 /**
0191  * arch_atomic64_sub - subtract the atomic64 variable
0192  * @i: integer value to subtract
0193  * @v: pointer to type atomic64_t
0194  *
0195  * Atomically subtracts @i from @v.
0196  */
0197 static inline s64 arch_atomic64_sub(s64 i, atomic64_t *v)
0198 {
0199     __alternative_atomic64(sub, sub_return,
0200                    ASM_OUTPUT2("+A" (i), "+c" (v)),
0201                    ASM_NO_INPUT_CLOBBER("memory"));
0202     return i;
0203 }
0204
0205 /**
0206  * arch_atomic64_inc - increment atomic64 variable
0207  * @v: pointer to type atomic64_t
0208  *
0209  * Atomically increments @v by 1.
0210  */
0211 static inline void arch_atomic64_inc(atomic64_t *v)
0212 {
0213     __alternative_atomic64(inc, inc_return, /* no output */,
0214                    "S" (v) : "memory", "eax", "ecx", "edx");
0215 }
0216 #define arch_atomic64_inc arch_atomic64_inc
0217
0218 /**
0219  * arch_atomic64_dec - decrement atomic64 variable
0220  * @v: pointer to type atomic64_t
0221  *
0222  * Atomically decrements @v by 1.
0223  */
0224 static inline void arch_atomic64_dec(atomic64_t *v)
0225 {
0226     __alternative_atomic64(dec, dec_return, /* no output */,
0227                    "S" (v) : "memory", "eax", "ecx", "edx");
0228 }
0229 #define arch_atomic64_dec arch_atomic64_dec
0230
0231 /**
0232  * arch_atomic64_add_unless - add unless the number is a given value
0233  * @v: pointer of type atomic64_t
0234  * @a: the amount to add to v...
0235  * @u: ...unless v is equal to u.
0236  *
0237  * Atomically adds @a to @v, so long as it was not @u.
0238  * Returns non-zero if the add was done, zero otherwise.
0239  */
0240 static inline int arch_atomic64_add_unless(atomic64_t *v, s64 a, s64 u)
0241 {
0242     unsigned low = (unsigned)u;
0243     unsigned high = (unsigned)(u >> 32);
0244     alternative_atomic64(add_unless,
0245                  ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
0246                  "S" (v) : "memory");
0247     return (int)a;
0248 }
0249 #define arch_atomic64_add_unless arch_atomic64_add_unless
0250
0251 static inline int arch_atomic64_inc_not_zero(atomic64_t *v)
0252 {
0253     int r;
0254     alternative_atomic64(inc_not_zero, "=&a" (r),
0255                  "S" (v) : "ecx", "edx", "memory");
0256     return r;
0257 }
0258 #define arch_atomic64_inc_not_zero arch_atomic64_inc_not_zero
0259
0260 static inline s64 arch_atomic64_dec_if_positive(atomic64_t *v)
0261 {
0262     s64 r;
0263     alternative_atomic64(dec_if_positive, "=&A" (r),
0264                  "S" (v) : "ecx", "memory");
0265     return r;
0266 }
0267 #define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive
0268
0269 #undef alternative_atomic64
0270 #undef __alternative_atomic64
0271
0272 static inline void arch_atomic64_and(s64 i, atomic64_t *v)
0273 {
0274     s64 old, c = 0;
0275
0276     while ((old = arch_atomic64_cmpxchg(v, c, c & i)) != c)
0277         c = old;
0278 }
0279
0280 static inline s64 arch_atomic64_fetch_and(s64 i, atomic64_t *v)
0281 {
0282     s64 old, c = 0;
0283
0284     while ((old = arch_atomic64_cmpxchg(v, c, c & i)) != c)
0285         c = old;
0286
0287     return old;
0288 }
0289 #define arch_atomic64_fetch_and arch_atomic64_fetch_and
0290
0291 static inline void arch_atomic64_or(s64 i, atomic64_t *v)
0292 {
0293     s64 old, c = 0;
0294
0295     while ((old = arch_atomic64_cmpxchg(v, c, c | i)) != c)
0296         c = old;
0297 }
0298
0299 static inline s64 arch_atomic64_fetch_or(s64 i, atomic64_t *v)
0300 {
0301     s64 old, c = 0;
0302
0303     while ((old = arch_atomic64_cmpxchg(v, c, c | i)) != c)
0304         c = old;
0305
0306     return old;
0307 }
0308 #define arch_atomic64_fetch_or arch_atomic64_fetch_or
0309
0310 static inline void arch_atomic64_xor(s64 i, atomic64_t *v)
0311 {
0312     s64 old, c = 0;
0313
0314     while ((old = arch_atomic64_cmpxchg(v, c, c ^ i)) != c)
0315         c = old;
0316 }
0317
0318 static inline s64 arch_atomic64_fetch_xor(s64 i, atomic64_t *v)
0319 {
0320     s64 old, c = 0;
0321
0322     while ((old = arch_atomic64_cmpxchg(v, c, c ^ i)) != c)
0323         c = old;
0324
0325     return old;
0326 }
0327 #define arch_atomic64_fetch_xor arch_atomic64_fetch_xor
0328
0329 static inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
0330 {
0331     s64 old, c = 0;
0332
0333     while ((old = arch_atomic64_cmpxchg(v, c, c + i)) != c)
0334         c = old;
0335
0336     return old;
0337 }
0338 #define arch_atomic64_fetch_add arch_atomic64_fetch_add
0339
0340 #define arch_atomic64_fetch_sub(i, v)   arch_atomic64_fetch_add(-(i), (v))
0341
0342 #endif /* _ASM_X86_ATOMIC64_32_H */