Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Atomic operations that C can't guarantee us. Useful for |
| 3 | * resource counting etc. |
| 4 | * |
| 5 | * But use these as seldom as possible since they are slower than |
| 6 | * regular operations. |
| 7 | * |
| 8 | * Copyright (C) 2004-2006 Atmel Corporation |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License version 2 as |
| 12 | * published by the Free Software Foundation. |
| 13 | */ |
| 14 | #ifndef __ASM_AVR32_ATOMIC_H |
| 15 | #define __ASM_AVR32_ATOMIC_H |
| 16 | |
Matthew Wilcox | ea435467 | 2009-01-06 14:40:39 -0800 | [diff] [blame] | 17 | #include <linux/types.h> |
David Howells | ae47394 | 2012-03-28 18:30:01 +0100 | [diff] [blame] | 18 | #include <asm/cmpxchg.h> |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 19 | |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 20 | #define ATOMIC_INIT(i) { (i) } |
| 21 | |
Anton Blanchard | f3d46f9 | 2010-05-17 14:33:53 +1000 | [diff] [blame] | 22 | #define atomic_read(v) (*(volatile int *)&(v)->counter) |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 23 | #define atomic_set(v, i) (((v)->counter) = i) |
| 24 | |
| 25 | /* |
| 26 | * atomic_sub_return - subtract the atomic variable |
| 27 | * @i: integer value to subtract |
| 28 | * @v: pointer of type atomic_t |
| 29 | * |
| 30 | * Atomically subtracts @i from @v. Returns the resulting value. |
| 31 | */ |
| 32 | static inline int atomic_sub_return(int i, atomic_t *v) |
| 33 | { |
| 34 | int result; |
| 35 | |
| 36 | asm volatile( |
| 37 | "/* atomic_sub_return */\n" |
| 38 | "1: ssrf 5\n" |
| 39 | " ld.w %0, %2\n" |
| 40 | " sub %0, %3\n" |
| 41 | " stcond %1, %0\n" |
| 42 | " brne 1b" |
| 43 | : "=&r"(result), "=o"(v->counter) |
Haavard Skinnemoen | fa35224 | 2006-10-24 10:12:42 +0200 | [diff] [blame] | 44 | : "m"(v->counter), "rKs21"(i) |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 45 | : "cc"); |
| 46 | |
| 47 | return result; |
| 48 | } |
| 49 | |
| 50 | /* |
| 51 | * atomic_add_return - add integer to atomic variable |
| 52 | * @i: integer value to add |
| 53 | * @v: pointer of type atomic_t |
| 54 | * |
| 55 | * Atomically adds @i to @v. Returns the resulting value. |
| 56 | */ |
| 57 | static inline int atomic_add_return(int i, atomic_t *v) |
| 58 | { |
| 59 | int result; |
| 60 | |
Haavard Skinnemoen | fa35224 | 2006-10-24 10:12:42 +0200 | [diff] [blame] | 61 | if (__builtin_constant_p(i) && (i >= -1048575) && (i <= 1048576)) |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 62 | result = atomic_sub_return(-i, v); |
| 63 | else |
| 64 | asm volatile( |
| 65 | "/* atomic_add_return */\n" |
| 66 | "1: ssrf 5\n" |
| 67 | " ld.w %0, %1\n" |
| 68 | " add %0, %3\n" |
| 69 | " stcond %2, %0\n" |
| 70 | " brne 1b" |
| 71 | : "=&r"(result), "=o"(v->counter) |
| 72 | : "m"(v->counter), "r"(i) |
| 73 | : "cc", "memory"); |
| 74 | |
| 75 | return result; |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * atomic_sub_unless - sub unless the number is a given value |
| 80 | * @v: pointer of type atomic_t |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 81 | * @a: the amount to subtract from v... |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 82 | * @u: ...unless v is equal to u. |
| 83 | * |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 84 | * Atomically subtract @a from @v, so long as it was not @u. |
| 85 | * Returns the old value of @v. |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 86 | */ |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 87 | static inline void atomic_sub_unless(atomic_t *v, int a, int u) |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 88 | { |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 89 | int tmp; |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 90 | |
| 91 | asm volatile( |
| 92 | "/* atomic_sub_unless */\n" |
| 93 | "1: ssrf 5\n" |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 94 | " ld.w %0, %2\n" |
| 95 | " cp.w %0, %4\n" |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 96 | " breq 1f\n" |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 97 | " sub %0, %3\n" |
| 98 | " stcond %1, %0\n" |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 99 | " brne 1b\n" |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 100 | "1:" |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 101 | : "=&r"(tmp), "=o"(v->counter) |
| 102 | : "m"(v->counter), "rKs21"(a), "rKs21"(u) |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 103 | : "cc", "memory"); |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 104 | } |
| 105 | |
| 106 | /* |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 107 | * __atomic_add_unless - add unless the number is a given value |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 108 | * @v: pointer of type atomic_t |
| 109 | * @a: the amount to add to v... |
| 110 | * @u: ...unless v is equal to u. |
| 111 | * |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 112 | * Atomically adds @a to @v, so long as it was not @u. |
| 113 | * Returns the old value of @v. |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 114 | */ |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 115 | static inline int __atomic_add_unless(atomic_t *v, int a, int u) |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 116 | { |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 117 | int tmp, old = atomic_read(v); |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 118 | |
Haavard Skinnemoen | fa35224 | 2006-10-24 10:12:42 +0200 | [diff] [blame] | 119 | if (__builtin_constant_p(a) && (a >= -1048575) && (a <= 1048576)) |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 120 | atomic_sub_unless(v, -a, u); |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 121 | else { |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 122 | asm volatile( |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 123 | "/* __atomic_add_unless */\n" |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 124 | "1: ssrf 5\n" |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 125 | " ld.w %0, %2\n" |
| 126 | " cp.w %0, %4\n" |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 127 | " breq 1f\n" |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 128 | " add %0, %3\n" |
| 129 | " stcond %1, %0\n" |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 130 | " brne 1b\n" |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 131 | "1:" |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 132 | : "=&r"(tmp), "=o"(v->counter) |
| 133 | : "m"(v->counter), "r"(a), "ir"(u) |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 134 | : "cc", "memory"); |
| 135 | } |
| 136 | |
Arun Sharma | f24219b | 2011-07-26 16:09:07 -0700 | [diff] [blame] | 137 | return old; |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 138 | } |
| 139 | |
| 140 | /* |
| 141 | * atomic_sub_if_positive - conditionally subtract integer from atomic variable |
| 142 | * @i: integer value to subtract |
| 143 | * @v: pointer of type atomic_t |
| 144 | * |
| 145 | * Atomically test @v and subtract @i if @v is greater or equal than @i. |
| 146 | * The function returns the old value of @v minus @i. |
| 147 | */ |
| 148 | static inline int atomic_sub_if_positive(int i, atomic_t *v) |
| 149 | { |
| 150 | int result; |
| 151 | |
| 152 | asm volatile( |
| 153 | "/* atomic_sub_if_positive */\n" |
| 154 | "1: ssrf 5\n" |
| 155 | " ld.w %0, %2\n" |
| 156 | " sub %0, %3\n" |
| 157 | " brlt 1f\n" |
| 158 | " stcond %1, %0\n" |
| 159 | " brne 1b\n" |
| 160 | "1:" |
| 161 | : "=&r"(result), "=o"(v->counter) |
| 162 | : "m"(v->counter), "ir"(i) |
| 163 | : "cc", "memory"); |
| 164 | |
| 165 | return result; |
| 166 | } |
| 167 | |
| 168 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) |
Mathieu Desnoyers | a4022b0 | 2007-04-10 18:23:09 -0400 | [diff] [blame] | 169 | #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 170 | |
| 171 | #define atomic_sub(i, v) (void)atomic_sub_return(i, v) |
| 172 | #define atomic_add(i, v) (void)atomic_add_return(i, v) |
| 173 | #define atomic_dec(v) atomic_sub(1, (v)) |
| 174 | #define atomic_inc(v) atomic_add(1, (v)) |
| 175 | |
| 176 | #define atomic_dec_return(v) atomic_sub_return(1, v) |
| 177 | #define atomic_inc_return(v) atomic_add_return(1, v) |
| 178 | |
| 179 | #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) |
| 180 | #define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0) |
| 181 | #define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) |
| 182 | #define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0) |
| 183 | |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 184 | #define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v) |
| 185 | |
| 186 | #define smp_mb__before_atomic_dec() barrier() |
| 187 | #define smp_mb__after_atomic_dec() barrier() |
| 188 | #define smp_mb__before_atomic_inc() barrier() |
| 189 | #define smp_mb__after_atomic_inc() barrier() |
| 190 | |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 191 | #endif /* __ASM_AVR32_ATOMIC_H */ |