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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 | #ifndef _ASM_X86_ATOMIC_H
#define _ASM_X86_ATOMIC_H
#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/processor.h>
#include <asm/alternative.h>
#include <asm/cmpxchg.h>
#include <asm/rmwcc.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*/
#define ATOMIC_INIT(i) { (i) }
/**
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
static inline int atomic_read(const atomic_t *v)
{
return (*(volatile int *)&(v)->counter);
}
/**
* atomic_set - set atomic variable
* @v: pointer of type atomic_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
static inline void atomic_set(atomic_t *v, int i)
{
v->counter = i;
}
/**
* atomic_add - add integer to atomic variable
* @i: integer value to add
* @v: pointer of type atomic_t
*
* Atomically adds @i to @v.
*/
static inline void atomic_add(int i, atomic_t *v)
{
asm volatile(LOCK_PREFIX "addl %1,%0"
: "+m" (v->counter)
: "ir" (i));
}
/**
* atomic_sub - subtract integer from atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v.
*/
static inline void atomic_sub(int i, atomic_t *v)
{
asm volatile(LOCK_PREFIX "subl %1,%0"
: "+m" (v->counter)
: "ir" (i));
}
/**
* atomic_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
static inline int atomic_sub_and_test(int i, atomic_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, "er", i, "%0", "e");
}
/**
* atomic_inc - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1.
*/
static inline void atomic_inc(atomic_t *v)
{
asm volatile(LOCK_PREFIX "incl %0"
: "+m" (v->counter));
}
/**
* atomic_dec - decrement atomic variable
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1.
*/
static inline void atomic_dec(atomic_t *v)
{
asm volatile(LOCK_PREFIX "decl %0"
: "+m" (v->counter));
}
/**
* atomic_dec_and_test - decrement and test
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
static inline int atomic_dec_and_test(atomic_t *v)
{
GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e");
}
/**
* atomic_inc_and_test - increment and test
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
static inline int atomic_inc_and_test(atomic_t *v)
{
GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, "%0", "e");
}
/**
* atomic_add_negative - add and test if negative
* @i: integer value to add
* @v: pointer of type atomic_t
*
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
static inline int atomic_add_negative(int i, atomic_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, "er", i, "%0", "s");
}
/**
* atomic_add_return - add integer and return
* @i: integer value to add
* @v: pointer of type atomic_t
*
* Atomically adds @i to @v and returns @i + @v
*/
static inline int atomic_add_return(int i, atomic_t *v)
{
return i + xadd(&v->counter, i);
}
/**
* atomic_sub_return - subtract integer and return
* @v: pointer of type atomic_t
* @i: integer value to subtract
*
* Atomically subtracts @i from @v and returns @v - @i
*/
static inline int atomic_sub_return(int i, atomic_t *v)
{
return atomic_add_return(-i, v);
}
#define atomic_inc_return(v) (atomic_add_return(1, v))
#define atomic_dec_return(v) (atomic_sub_return(1, v))
static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
{
return cmpxchg(&v->counter, old, new);
}
static inline int atomic_xchg(atomic_t *v, int new)
{
return xchg(&v->counter, new);
}
/**
* __atomic_add_unless - add unless the number is already a given value
* @v: pointer of type atomic_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as @v was not already @u.
* Returns the old value of @v.
*/
static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c;
}
/**
* atomic_inc_short - increment of a short integer
* @v: pointer to type int
*
* Atomically adds 1 to @v
* Returns the new value of @u
*/
static inline short int atomic_inc_short(short int *v)
{
asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v));
return *v;
}
#ifdef CONFIG_X86_64
/**
* atomic_or_long - OR of two long integers
* @v1: pointer to type unsigned long
* @v2: pointer to type unsigned long
*
* Atomically ORs @v1 and @v2
* Returns the result of the OR
*/
static inline void atomic_or_long(unsigned long *v1, unsigned long v2)
{
asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2));
}
#endif
/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr) \
asm volatile(LOCK_PREFIX "andl %0,%1" \
: : "r" (~(mask)), "m" (*(addr)) : "memory")
#define atomic_set_mask(mask, addr) \
asm volatile(LOCK_PREFIX "orl %0,%1" \
: : "r" ((unsigned)(mask)), "m" (*(addr)) \
: "memory")
/* Atomic operations are already serializing on x86 */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()
#define smp_mb__before_atomic_inc() barrier()
#define smp_mb__after_atomic_inc() barrier()
#ifdef CONFIG_X86_32
# include <asm/atomic64_32.h>
#else
# include <asm/atomic64_64.h>
#endif
#endif /* _ASM_X86_ATOMIC_H */
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