H. Peter Anvin | 1965aae | 2008-10-22 22:26:29 -0700 | [diff] [blame] | 1 | #ifndef _ASM_X86_LOCAL_H |
| 2 | #define _ASM_X86_LOCAL_H |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 3 | |
| 4 | #include <linux/percpu.h> |
| 5 | |
Arun Sharma | 60063497 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 6 | #include <linux/atomic.h> |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 7 | #include <asm/asm.h> |
| 8 | |
Harvey Harrison | 01c57fb | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 9 | typedef struct { |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 10 | atomic_long_t a; |
| 11 | } local_t; |
| 12 | |
| 13 | #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } |
| 14 | |
| 15 | #define local_read(l) atomic_long_read(&(l)->a) |
Harvey Harrison | 01c57fb | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 16 | #define local_set(l, i) atomic_long_set(&(l)->a, (i)) |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 17 | |
| 18 | static inline void local_inc(local_t *l) |
| 19 | { |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 20 | asm volatile(_ASM_INC "%0" |
| 21 | : "+m" (l->a.counter)); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 22 | } |
| 23 | |
| 24 | static inline void local_dec(local_t *l) |
| 25 | { |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 26 | asm volatile(_ASM_DEC "%0" |
| 27 | : "+m" (l->a.counter)); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 28 | } |
| 29 | |
| 30 | static inline void local_add(long i, local_t *l) |
| 31 | { |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 32 | asm volatile(_ASM_ADD "%1,%0" |
| 33 | : "+m" (l->a.counter) |
| 34 | : "ir" (i)); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 35 | } |
| 36 | |
| 37 | static inline void local_sub(long i, local_t *l) |
| 38 | { |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 39 | asm volatile(_ASM_SUB "%1,%0" |
| 40 | : "+m" (l->a.counter) |
| 41 | : "ir" (i)); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 42 | } |
| 43 | |
| 44 | /** |
| 45 | * local_sub_and_test - subtract value from variable and test result |
| 46 | * @i: integer value to subtract |
| 47 | * @l: pointer to type local_t |
| 48 | * |
| 49 | * Atomically subtracts @i from @l and returns |
| 50 | * true if the result is zero, or false for all |
| 51 | * other cases. |
| 52 | */ |
| 53 | static inline int local_sub_and_test(long i, local_t *l) |
| 54 | { |
| 55 | unsigned char c; |
| 56 | |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 57 | asm volatile(_ASM_SUB "%2,%0; sete %1" |
| 58 | : "+m" (l->a.counter), "=qm" (c) |
| 59 | : "ir" (i) : "memory"); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 60 | return c; |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * local_dec_and_test - decrement and test |
| 65 | * @l: pointer to type local_t |
| 66 | * |
| 67 | * Atomically decrements @l by 1 and |
| 68 | * returns true if the result is 0, or false for all other |
| 69 | * cases. |
| 70 | */ |
| 71 | static inline int local_dec_and_test(local_t *l) |
| 72 | { |
| 73 | unsigned char c; |
| 74 | |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 75 | asm volatile(_ASM_DEC "%0; sete %1" |
| 76 | : "+m" (l->a.counter), "=qm" (c) |
| 77 | : : "memory"); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 78 | return c != 0; |
| 79 | } |
| 80 | |
| 81 | /** |
| 82 | * local_inc_and_test - increment and test |
| 83 | * @l: pointer to type local_t |
| 84 | * |
| 85 | * Atomically increments @l by 1 |
| 86 | * and returns true if the result is zero, or false for all |
| 87 | * other cases. |
| 88 | */ |
| 89 | static inline int local_inc_and_test(local_t *l) |
| 90 | { |
| 91 | unsigned char c; |
| 92 | |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 93 | asm volatile(_ASM_INC "%0; sete %1" |
| 94 | : "+m" (l->a.counter), "=qm" (c) |
| 95 | : : "memory"); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 96 | return c != 0; |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * local_add_negative - add and test if negative |
| 101 | * @i: integer value to add |
| 102 | * @l: pointer to type local_t |
| 103 | * |
| 104 | * Atomically adds @i to @l and returns true |
| 105 | * if the result is negative, or false when |
| 106 | * result is greater than or equal to zero. |
| 107 | */ |
| 108 | static inline int local_add_negative(long i, local_t *l) |
| 109 | { |
| 110 | unsigned char c; |
| 111 | |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 112 | asm volatile(_ASM_ADD "%2,%0; sets %1" |
| 113 | : "+m" (l->a.counter), "=qm" (c) |
| 114 | : "ir" (i) : "memory"); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 115 | return c; |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * local_add_return - add and return |
| 120 | * @i: integer value to add |
| 121 | * @l: pointer to type local_t |
| 122 | * |
| 123 | * Atomically adds @i to @l and returns @i + @l |
| 124 | */ |
| 125 | static inline long local_add_return(long i, local_t *l) |
| 126 | { |
| 127 | long __i; |
| 128 | #ifdef CONFIG_M386 |
| 129 | unsigned long flags; |
Harvey Harrison | 01c57fb | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 130 | if (unlikely(boot_cpu_data.x86 <= 3)) |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 131 | goto no_xadd; |
Thomas Gleixner | 96a388d | 2007-10-11 11:20:03 +0200 | [diff] [blame] | 132 | #endif |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 133 | /* Modern 486+ processor */ |
| 134 | __i = i; |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 135 | asm volatile(_ASM_XADD "%0, %1;" |
| 136 | : "+r" (i), "+m" (l->a.counter) |
| 137 | : : "memory"); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 138 | return i + __i; |
| 139 | |
| 140 | #ifdef CONFIG_M386 |
| 141 | no_xadd: /* Legacy 386 processor */ |
| 142 | local_irq_save(flags); |
| 143 | __i = local_read(l); |
| 144 | local_set(l, i + __i); |
| 145 | local_irq_restore(flags); |
| 146 | return i + __i; |
| 147 | #endif |
| 148 | } |
| 149 | |
| 150 | static inline long local_sub_return(long i, local_t *l) |
| 151 | { |
Harvey Harrison | 01c57fb | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 152 | return local_add_return(-i, l); |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 153 | } |
| 154 | |
Harvey Harrison | 01c57fb | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 155 | #define local_inc_return(l) (local_add_return(1, l)) |
| 156 | #define local_dec_return(l) (local_sub_return(1, l)) |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 157 | |
| 158 | #define local_cmpxchg(l, o, n) \ |
| 159 | (cmpxchg_local(&((l)->a.counter), (o), (n))) |
| 160 | /* Always has a lock prefix */ |
| 161 | #define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) |
| 162 | |
| 163 | /** |
| 164 | * local_add_unless - add unless the number is a given value |
| 165 | * @l: pointer of type local_t |
| 166 | * @a: the amount to add to l... |
| 167 | * @u: ...unless l is equal to u. |
| 168 | * |
| 169 | * Atomically adds @a to @l, so long as it was not @u. |
| 170 | * Returns non-zero if @l was not @u, and zero otherwise. |
| 171 | */ |
| 172 | #define local_add_unless(l, a, u) \ |
| 173 | ({ \ |
| 174 | long c, old; \ |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 175 | c = local_read((l)); \ |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 176 | for (;;) { \ |
| 177 | if (unlikely(c == (u))) \ |
| 178 | break; \ |
Joe Perches | 69cde65 | 2008-03-23 01:02:39 -0700 | [diff] [blame] | 179 | old = local_cmpxchg((l), c, c + (a)); \ |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 180 | if (likely(old == c)) \ |
| 181 | break; \ |
| 182 | c = old; \ |
| 183 | } \ |
| 184 | c != (u); \ |
| 185 | }) |
| 186 | #define local_inc_not_zero(l) local_add_unless((l), 1, 0) |
| 187 | |
| 188 | /* On x86_32, these are no better than the atomic variants. |
| 189 | * On x86-64 these are better than the atomic variants on SMP kernels |
| 190 | * because they dont use a lock prefix. |
| 191 | */ |
| 192 | #define __local_inc(l) local_inc(l) |
| 193 | #define __local_dec(l) local_dec(l) |
Harvey Harrison | 01c57fb | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 194 | #define __local_add(i, l) local_add((i), (l)) |
| 195 | #define __local_sub(i, l) local_sub((i), (l)) |
Harvey Harrison | 5638f99 | 2008-01-30 13:31:26 +0100 | [diff] [blame] | 196 | |
H. Peter Anvin | 1965aae | 2008-10-22 22:26:29 -0700 | [diff] [blame] | 197 | #endif /* _ASM_X86_LOCAL_H */ |