arch/x86/include/asm/atomic64_32.h

   1 #ifndef _ASM_X86_ATOMIC64_32_H
   2 #define _ASM_X86_ATOMIC64_32_H
   3
   4 #include <linux/compiler.h>
   5 #include <linux/types.h>
   6 //#include <asm/cmpxchg.h>
   7
   8 /* An 64bit atomic type */
   9
  10 typedef struct {
  11         u64 __aligned(8) counter;
  12 } atomic64_t;
  13
  14 #define ATOMIC64_INIT(val)      { (val) }
  15
  16 #define __ATOMIC64_DECL(sym) void atomic64_##sym(atomic64_t *, ...)
  17 #ifndef ATOMIC64_EXPORT
  18 #define ATOMIC64_DECL_ONE __ATOMIC64_DECL
  19 #else
  20 #define ATOMIC64_DECL_ONE(sym) __ATOMIC64_DECL(sym); \
  21         ATOMIC64_EXPORT(atomic64_##sym)
  22 #endif
  23
  24 #ifdef CONFIG_X86_CMPXCHG64
  25 #define __alternative_atomic64(f, g, out, in...) \
  26         asm volatile("call %P[func]" \
  27                      : out : [func] "i" (atomic64_##g##_cx8), ## in)
  28
  29 #define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
  30 #else
  31 #define __alternative_atomic64(f, g, out, in...) \
  32         alternative_call(atomic64_##f##_386, atomic64_##g##_cx8, \
  33                          X86_FEATURE_CX8, ASM_OUTPUT2(out), ## in)
  34
  35 #define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8); \
  36         ATOMIC64_DECL_ONE(sym##_386)
  37
  38 ATOMIC64_DECL_ONE(add_386);
  39 ATOMIC64_DECL_ONE(sub_386);
  40 ATOMIC64_DECL_ONE(inc_386);
  41 ATOMIC64_DECL_ONE(dec_386);
  42 #endif
  43
  44 #define alternative_atomic64(f, out, in...) \
  45         __alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)
  46
  47 ATOMIC64_DECL(read);
  48 ATOMIC64_DECL(set);
  49 ATOMIC64_DECL(xchg);
  50 ATOMIC64_DECL(add_return);
  51 ATOMIC64_DECL(sub_return);
  52 ATOMIC64_DECL(inc_return);
  53 ATOMIC64_DECL(dec_return);
  54 ATOMIC64_DECL(dec_if_positive);
  55 ATOMIC64_DECL(inc_not_zero);
  56 ATOMIC64_DECL(add_unless);
  57
  58 #undef ATOMIC64_DECL
  59 #undef ATOMIC64_DECL_ONE
  60 #undef __ATOMIC64_DECL
  61 #undef ATOMIC64_EXPORT
  62
  63 /**
  64  * atomic64_cmpxchg - cmpxchg atomic64 variable
  65  * @v: pointer to type atomic64_t
  66  * @o: expected value
  67  * @n: new value
  68  *
  69  * Atomically sets @v to @n if it was equal to @o and returns
  70  * the old value.
  71  */
  72
  73 static inline long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
  74 {
  75         return cmpxchg64(&v->counter, o, n);
  76 }
  77
  78 /**
  79  * atomic64_xchg - xchg atomic64 variable
  80  * @v: pointer to type atomic64_t
  81  * @n: value to assign
  82  *
  83  * Atomically xchgs the value of @v to @n and returns
  84  * the old value.
  85  */
  86 static inline long long atomic64_xchg(atomic64_t *v, long long n)
  87 {
  88         long long o;
  89         unsigned high = (unsigned)(n >> 32);
  90         unsigned low = (unsigned)n;
  91         alternative_atomic64(xchg, "=&A" (o),
  92                              "S" (v), "b" (low), "c" (high)
  93                              : "memory");
  94         return o;
  95 }
  96
  97 /**
  98  * atomic64_set - set atomic64 variable
  99  * @v: pointer to type atomic64_t
 100  * @i: value to assign
 101  *
 102  * Atomically sets the value of @v to @n.
 103  */
 104 static inline void atomic64_set(atomic64_t *v, long long i)
 105 {
 106         unsigned high = (unsigned)(i >> 32);
 107         unsigned low = (unsigned)i;
 108         alternative_atomic64(set, /* no output */,
 109                              "S" (v), "b" (low), "c" (high)
 110                              : "eax", "edx", "memory");
 111 }
 112
 113 /**
 114  * atomic64_read - read atomic64 variable
 115  * @v: pointer to type atomic64_t
 116  *
 117  * Atomically reads the value of @v and returns it.
 118  */
 119 static inline long long atomic64_read(const atomic64_t *v)
 120 {
 121         long long r;
 122         alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
 123         return r;
 124  }
 125
 126 /**
 127  * atomic64_add_return - add and return
 128  * @i: integer value to add
 129  * @v: pointer to type atomic64_t
 130  *
 131  * Atomically adds @i to @v and returns @i + *@v
 132  */
 133 static inline long long atomic64_add_return(long long i, atomic64_t *v)
 134 {
 135         alternative_atomic64(add_return,
 136                              ASM_OUTPUT2("+A" (i), "+c" (v)),
 137                              ASM_NO_INPUT_CLOBBER("memory"));
 138         return i;
 139 }
 140
 141 /*
 142  * Other variants with different arithmetic operators:
 143  */
 144 static inline long long atomic64_sub_return(long long i, atomic64_t *v)
 145 {
 146         alternative_atomic64(sub_return,
 147                              ASM_OUTPUT2("+A" (i), "+c" (v)),
 148                              ASM_NO_INPUT_CLOBBER("memory"));
 149         return i;
 150 }
 151
 152 static inline long long atomic64_inc_return(atomic64_t *v)
 153 {
 154         long long a;
 155         alternative_atomic64(inc_return, "=&A" (a),
 156                              "S" (v) : "memory", "ecx");
 157         return a;
 158 }
 159
 160 static inline long long atomic64_dec_return(atomic64_t *v)
 161 {
 162         long long a;
 163         alternative_atomic64(dec_return, "=&A" (a),
 164                              "S" (v) : "memory", "ecx");
 165         return a;
 166 }
 167
 168 /**
 169  * atomic64_add - add integer to atomic64 variable
 170  * @i: integer value to add
 171  * @v: pointer to type atomic64_t
 172  *
 173  * Atomically adds @i to @v.
 174  */
 175 static inline long long atomic64_add(long long i, atomic64_t *v)
 176 {
 177         __alternative_atomic64(add, add_return,
 178                                ASM_OUTPUT2("+A" (i), "+c" (v)),
 179                                ASM_NO_INPUT_CLOBBER("memory"));
 180         return i;
 181 }
 182
 183 /**
 184  * atomic64_sub - subtract the atomic64 variable
 185  * @i: integer value to subtract
 186  * @v: pointer to type atomic64_t
 187  *
 188  * Atomically subtracts @i from @v.
 189  */
 190 static inline long long atomic64_sub(long long i, atomic64_t *v)
 191 {
 192         __alternative_atomic64(sub, sub_return,
 193                                ASM_OUTPUT2("+A" (i), "+c" (v)),
 194                                ASM_NO_INPUT_CLOBBER("memory"));
 195         return i;
 196 }
 197
 198 /**
 199  * atomic64_sub_and_test - subtract value from variable and test result
 200  * @i: integer value to subtract
 201  * @v: pointer to type atomic64_t
 202  *
 203  * Atomically subtracts @i from @v and returns
 204  * true if the result is zero, or false for all
 205  * other cases.
 206  */
 207 static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
 208 {
 209         return atomic64_sub_return(i, v) == 0;
 210 }
 211
 212 /**
 213  * atomic64_inc - increment atomic64 variable
 214  * @v: pointer to type atomic64_t
 215  *
 216  * Atomically increments @v by 1.
 217  */
 218 static inline void atomic64_inc(atomic64_t *v)
 219 {
 220         __alternative_atomic64(inc, inc_return, /* no output */,
 221                                "S" (v) : "memory", "eax", "ecx", "edx");
 222 }
 223
 224 /**
 225  * atomic64_dec - decrement atomic64 variable
 226  * @v: pointer to type atomic64_t
 227  *
 228  * Atomically decrements @v by 1.
 229  */
 230 static inline void atomic64_dec(atomic64_t *v)
 231 {
 232         __alternative_atomic64(dec, dec_return, /* no output */,
 233                                "S" (v) : "memory", "eax", "ecx", "edx");
 234 }
 235
 236 /**
 237  * atomic64_dec_and_test - decrement and test
 238  * @v: pointer to type atomic64_t
 239  *
 240  * Atomically decrements @v by 1 and
 241  * returns true if the result is 0, or false for all other
 242  * cases.
 243  */
 244 static inline int atomic64_dec_and_test(atomic64_t *v)
 245 {
 246         return atomic64_dec_return(v) == 0;
 247 }
 248
 249 /**
 250  * atomic64_inc_and_test - increment and test
 251  * @v: pointer to type atomic64_t
 252  *
 253  * Atomically increments @v by 1
 254  * and returns true if the result is zero, or false for all
 255  * other cases.
 256  */
 257 static inline int atomic64_inc_and_test(atomic64_t *v)
 258 {
 259         return atomic64_inc_return(v) == 0;
 260 }
 261
 262 /**
 263  * atomic64_add_negative - add and test if negative
 264  * @i: integer value to add
 265  * @v: pointer to type atomic64_t
 266  *
 267  * Atomically adds @i to @v and returns true
 268  * if the result is negative, or false when
 269  * result is greater than or equal to zero.
 270  */
 271 static inline int atomic64_add_negative(long long i, atomic64_t *v)
 272 {
 273         return atomic64_add_return(i, v) < 0;
 274 }
 275
 276 /**
 277  * atomic64_add_unless - add unless the number is a given value
 278  * @v: pointer of type atomic64_t
 279  * @a: the amount to add to v...
 280  * @u: ...unless v is equal to u.
 281  *
 282  * Atomically adds @a to @v, so long as it was not @u.
 283  * Returns non-zero if the add was done, zero otherwise.
 284  */
 285 static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
 286 {
 287         unsigned low = (unsigned)u;
 288         unsigned high = (unsigned)(u >> 32);
 289         alternative_atomic64(add_unless,
 290                              ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
 291                              "S" (v) : "memory");
 292         return (int)a;
 293 }
 294
 295
 296 static inline int atomic64_inc_not_zero(atomic64_t *v)
 297 {
 298         int r;
 299         alternative_atomic64(inc_not_zero, "=&a" (r),
 300                              "S" (v) : "ecx", "edx", "memory");
 301         return r;
 302 }
 303
 304 static inline long long atomic64_dec_if_positive(atomic64_t *v)
 305 {
 306         long long r;
 307         alternative_atomic64(dec_if_positive, "=&A" (r),
 308                              "S" (v) : "ecx", "memory");
 309         return r;
 310 }
 311
 312 #undef alternative_atomic64
 313 #undef __alternative_atomic64
 314
 315 #define ATOMIC64_OP(op, c_op)                                           \
 316 static inline void atomic64_##op(long long i, atomic64_t *v)            \
 317 {                                                                       \
 318         long long old, c = 0;                                           \
 319         while ((old = atomic64_cmpxchg(v, c, c c_op i)) != c)           \
 320                 c = old;                                                \
 321 }
 322
 323 ATOMIC64_OP(and, &)
 324 ATOMIC64_OP(or, |)
 325 ATOMIC64_OP(xor, ^)
 326
 327 #undef ATOMIC64_OP
 328
 329 #endif /* _ASM_X86_ATOMIC64_32_H */