arch/x86/include/asm/atomic64_32.h

   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         u64 __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  * 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 long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
  75 {
  76         return cmpxchg64(&v->counter, o, n);
  77 }
  78
  79 /**
  80  * atomic64_xchg - xchg atomic64 variable
  81  * @v: pointer to type atomic64_t
  82  * @n: value to assign
  83  *
  84  * Atomically xchgs the value of @v to @n and returns
  85  * the old value.
  86  */
  87 static inline long long atomic64_xchg(atomic64_t *v, long long n)
  88 {
  89         long long o;
  90         unsigned high = (unsigned)(n >> 32);
  91         unsigned low = (unsigned)n;
  92         alternative_atomic64(xchg, "=&A" (o),
  93                              "S" (v), "b" (low), "c" (high)
  94                              : "memory");
  95         return o;
  96 }
  97
  98 /**
  99  * atomic64_set - set atomic64 variable
 100  * @v: pointer to type atomic64_t
 101  * @i: value to assign
 102  *
 103  * Atomically sets the value of @v to @n.
 104  */
 105 static inline void atomic64_set(atomic64_t *v, long long i)
 106 {
 107         unsigned high = (unsigned)(i >> 32);
 108         unsigned low = (unsigned)i;
 109         alternative_atomic64(set, /* no output */,
 110                              "S" (v), "b" (low), "c" (high)
 111                              : "eax", "edx", "memory");
 112 }
 113
 114 /**
 115  * atomic64_read - read atomic64 variable
 116  * @v: pointer to type atomic64_t
 117  *
 118  * Atomically reads the value of @v and returns it.
 119  */
 120 static inline long long atomic64_read(const atomic64_t *v)
 121 {
 122         long long r;
 123         alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
 124         return r;
 125  }
 126
 127 /**
 128  * atomic64_add_return - add and return
 129  * @i: integer value to add
 130  * @v: pointer to type atomic64_t
 131  *
 132  * Atomically adds @i to @v and returns @i + *@v
 133  */
 134 static inline long long atomic64_add_return(long long i, atomic64_t *v)
 135 {
 136         alternative_atomic64(add_return,
 137                              ASM_OUTPUT2("+A" (i), "+c" (v)),
 138                              ASM_NO_INPUT_CLOBBER("memory"));
 139         return i;
 140 }
 141
 142 /*
 143  * Other variants with different arithmetic operators:
 144  */
 145 static inline long long atomic64_sub_return(long long i, atomic64_t *v)
 146 {
 147         alternative_atomic64(sub_return,
 148                              ASM_OUTPUT2("+A" (i), "+c" (v)),
 149                              ASM_NO_INPUT_CLOBBER("memory"));
 150         return i;
 151 }
 152
 153 static inline long long atomic64_inc_return(atomic64_t *v)
 154 {
 155         long long a;
 156         alternative_atomic64(inc_return, "=&A" (a),
 157                              "S" (v) : "memory", "ecx");
 158         return a;
 159 }
 160
 161 static inline long long atomic64_dec_return(atomic64_t *v)
 162 {
 163         long long a;
 164         alternative_atomic64(dec_return, "=&A" (a),
 165                              "S" (v) : "memory", "ecx");
 166         return a;
 167 }
 168
 169 /**
 170  * atomic64_add - add integer to atomic64 variable
 171  * @i: integer value to add
 172  * @v: pointer to type atomic64_t
 173  *
 174  * Atomically adds @i to @v.
 175  */
 176 static inline long long atomic64_add(long long i, atomic64_t *v)
 177 {
 178         __alternative_atomic64(add, add_return,
 179                                ASM_OUTPUT2("+A" (i), "+c" (v)),
 180                                ASM_NO_INPUT_CLOBBER("memory"));
 181         return i;
 182 }
 183
 184 /**
 185  * atomic64_sub - subtract the atomic64 variable
 186  * @i: integer value to subtract
 187  * @v: pointer to type atomic64_t
 188  *
 189  * Atomically subtracts @i from @v.
 190  */
 191 static inline long long atomic64_sub(long long i, atomic64_t *v)
 192 {
 193         __alternative_atomic64(sub, sub_return,
 194                                ASM_OUTPUT2("+A" (i), "+c" (v)),
 195                                ASM_NO_INPUT_CLOBBER("memory"));
 196         return i;
 197 }
 198
 199 /**
 200  * atomic64_sub_and_test - subtract value from variable and test result
 201  * @i: integer value to subtract
 202  * @v: pointer to type atomic64_t
 203  *
 204  * Atomically subtracts @i from @v and returns
 205  * true if the result is zero, or false for all
 206  * other cases.
 207  */
 208 static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
 209 {
 210         return atomic64_sub_return(i, v) == 0;
 211 }
 212
 213 /**
 214  * atomic64_inc - increment atomic64 variable
 215  * @v: pointer to type atomic64_t
 216  *
 217  * Atomically increments @v by 1.
 218  */
 219 static inline void atomic64_inc(atomic64_t *v)
 220 {
 221         __alternative_atomic64(inc, inc_return, /* no output */,
 222                                "S" (v) : "memory", "eax", "ecx", "edx");
 223 }
 224
 225 /**
 226  * atomic64_dec - decrement atomic64 variable
 227  * @v: pointer to type atomic64_t
 228  *
 229  * Atomically decrements @v by 1.
 230  */
 231 static inline void atomic64_dec(atomic64_t *v)
 232 {
 233         __alternative_atomic64(dec, dec_return, /* no output */,
 234                                "S" (v) : "memory", "eax", "ecx", "edx");
 235 }
 236
 237 /**
 238  * atomic64_dec_and_test - decrement and test
 239  * @v: pointer to type atomic64_t
 240  *
 241  * Atomically decrements @v by 1 and
 242  * returns true if the result is 0, or false for all other
 243  * cases.
 244  */
 245 static inline int atomic64_dec_and_test(atomic64_t *v)
 246 {
 247         return atomic64_dec_return(v) == 0;
 248 }
 249
 250 /**
 251  * atomic64_inc_and_test - increment and test
 252  * @v: pointer to type atomic64_t
 253  *
 254  * Atomically increments @v by 1
 255  * and returns true if the result is zero, or false for all
 256  * other cases.
 257  */
 258 static inline int atomic64_inc_and_test(atomic64_t *v)
 259 {
 260         return atomic64_inc_return(v) == 0;
 261 }
 262
 263 /**
 264  * atomic64_add_negative - add and test if negative
 265  * @i: integer value to add
 266  * @v: pointer to type atomic64_t
 267  *
 268  * Atomically adds @i to @v and returns true
 269  * if the result is negative, or false when
 270  * result is greater than or equal to zero.
 271  */
 272 static inline int atomic64_add_negative(long long i, atomic64_t *v)
 273 {
 274         return atomic64_add_return(i, v) < 0;
 275 }
 276
 277 /**
 278  * atomic64_add_unless - add unless the number is a given value
 279  * @v: pointer of type atomic64_t
 280  * @a: the amount to add to v...
 281  * @u: ...unless v is equal to u.
 282  *
 283  * Atomically adds @a to @v, so long as it was not @u.
 284  * Returns non-zero if the add was done, zero otherwise.
 285  */
 286 static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
 287 {
 288         unsigned low = (unsigned)u;
 289         unsigned high = (unsigned)(u >> 32);
 290         alternative_atomic64(add_unless,
 291                              ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
 292                              "S" (v) : "memory");
 293         return (int)a;
 294 }
 295
 296
 297 static inline int atomic64_inc_not_zero(atomic64_t *v)
 298 {
 299         int r;
 300         alternative_atomic64(inc_not_zero, "=&a" (r),
 301                              "S" (v) : "ecx", "edx", "memory");
 302         return r;
 303 }
 304
 305 static inline long long atomic64_dec_if_positive(atomic64_t *v)
 306 {
 307         long long r;
 308         alternative_atomic64(dec_if_positive, "=&A" (r),
 309                              "S" (v) : "ecx", "memory");
 310         return r;
 311 }
 312
 313 #undef alternative_atomic64
 314 #undef __alternative_atomic64
 315
 316 static inline void atomic64_and(long long i, atomic64_t *v)
 317 {
 318         long long old, c = 0;
 319
 320         while ((old = atomic64_cmpxchg(v, c, c & i)) != c)
 321                 c = old;
 322 }
 323
 324 static inline long long atomic64_fetch_and(long long i, atomic64_t *v)
 325 {
 326         long long old, c = 0;
 327
 328         while ((old = atomic64_cmpxchg(v, c, c & i)) != c)
 329                 c = old;
 330
 331         return old;
 332 }
 333
 334 static inline void atomic64_or(long long i, atomic64_t *v)
 335 {
 336         long long old, c = 0;
 337
 338         while ((old = atomic64_cmpxchg(v, c, c | i)) != c)
 339                 c = old;
 340 }
 341
 342 static inline long long atomic64_fetch_or(long long i, atomic64_t *v)
 343 {
 344         long long old, c = 0;
 345
 346         while ((old = atomic64_cmpxchg(v, c, c | i)) != c)
 347                 c = old;
 348
 349         return old;
 350 }
 351
 352 static inline void atomic64_xor(long long i, atomic64_t *v)
 353 {
 354         long long old, c = 0;
 355
 356         while ((old = atomic64_cmpxchg(v, c, c ^ i)) != c)
 357                 c = old;
 358 }
 359
 360 static inline long long atomic64_fetch_xor(long long i, atomic64_t *v)
 361 {
 362         long long old, c = 0;
 363
 364         while ((old = atomic64_cmpxchg(v, c, c ^ i)) != c)
 365                 c = old;
 366
 367         return old;
 368 }
 369
 370 static inline long long atomic64_fetch_add(long long i, atomic64_t *v)
 371 {
 372         long long old, c = 0;
 373
 374         while ((old = atomic64_cmpxchg(v, c, c + i)) != c)
 375                 c = old;
 376
 377         return old;
 378 }
 379
 380 #define atomic64_fetch_sub(i, v)        atomic64_fetch_add(-(i), (v))
 381
 382 #endif /* _ASM_X86_ATOMIC64_32_H */