Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Based on arch/arm/include/asm/cmpxchg.h |
| 3 | * |
| 4 | * Copyright (C) 2012 ARM Ltd. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | #ifndef __ASM_CMPXCHG_H |
| 19 | #define __ASM_CMPXCHG_H |
| 20 | |
| 21 | #include <linux/bug.h> |
| 22 | |
| 23 | #include <asm/barrier.h> |
| 24 | |
| 25 | static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size) |
| 26 | { |
| 27 | unsigned long ret, tmp; |
| 28 | |
| 29 | switch (size) { |
| 30 | case 1: |
| 31 | asm volatile("// __xchg1\n" |
Will Deacon | 8e86f0b | 2014-02-04 12:29:12 +0000 | [diff] [blame] | 32 | "1: ldxrb %w0, %2\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 33 | " stlxrb %w1, %w3, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 34 | " cbnz %w1, 1b\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 35 | : "=&r" (ret), "=&r" (tmp), "+Q" (*(u8 *)ptr) |
| 36 | : "r" (x) |
Will Deacon | 95c4189 | 2014-02-04 12:29:13 +0000 | [diff] [blame] | 37 | : "memory"); |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 38 | break; |
| 39 | case 2: |
| 40 | asm volatile("// __xchg2\n" |
Will Deacon | 8e86f0b | 2014-02-04 12:29:12 +0000 | [diff] [blame] | 41 | "1: ldxrh %w0, %2\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 42 | " stlxrh %w1, %w3, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 43 | " cbnz %w1, 1b\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 44 | : "=&r" (ret), "=&r" (tmp), "+Q" (*(u16 *)ptr) |
| 45 | : "r" (x) |
Will Deacon | 95c4189 | 2014-02-04 12:29:13 +0000 | [diff] [blame] | 46 | : "memory"); |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 47 | break; |
| 48 | case 4: |
| 49 | asm volatile("// __xchg4\n" |
Will Deacon | 8e86f0b | 2014-02-04 12:29:12 +0000 | [diff] [blame] | 50 | "1: ldxr %w0, %2\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 51 | " stlxr %w1, %w3, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 52 | " cbnz %w1, 1b\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 53 | : "=&r" (ret), "=&r" (tmp), "+Q" (*(u32 *)ptr) |
| 54 | : "r" (x) |
Will Deacon | 95c4189 | 2014-02-04 12:29:13 +0000 | [diff] [blame] | 55 | : "memory"); |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 56 | break; |
| 57 | case 8: |
| 58 | asm volatile("// __xchg8\n" |
Will Deacon | 8e86f0b | 2014-02-04 12:29:12 +0000 | [diff] [blame] | 59 | "1: ldxr %0, %2\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 60 | " stlxr %w1, %3, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 61 | " cbnz %w1, 1b\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 62 | : "=&r" (ret), "=&r" (tmp), "+Q" (*(u64 *)ptr) |
| 63 | : "r" (x) |
Will Deacon | 95c4189 | 2014-02-04 12:29:13 +0000 | [diff] [blame] | 64 | : "memory"); |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 65 | break; |
| 66 | default: |
| 67 | BUILD_BUG(); |
| 68 | } |
| 69 | |
Will Deacon | 8e86f0b | 2014-02-04 12:29:12 +0000 | [diff] [blame] | 70 | smp_mb(); |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 71 | return ret; |
| 72 | } |
| 73 | |
| 74 | #define xchg(ptr,x) \ |
| 75 | ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) |
| 76 | |
| 77 | static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, |
| 78 | unsigned long new, int size) |
| 79 | { |
| 80 | unsigned long oldval = 0, res; |
| 81 | |
| 82 | switch (size) { |
| 83 | case 1: |
| 84 | do { |
| 85 | asm volatile("// __cmpxchg1\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 86 | " ldxrb %w1, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 87 | " mov %w0, #0\n" |
| 88 | " cmp %w1, %w3\n" |
| 89 | " b.ne 1f\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 90 | " stxrb %w0, %w4, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 91 | "1:\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 92 | : "=&r" (res), "=&r" (oldval), "+Q" (*(u8 *)ptr) |
| 93 | : "Ir" (old), "r" (new) |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 94 | : "cc"); |
| 95 | } while (res); |
| 96 | break; |
| 97 | |
| 98 | case 2: |
| 99 | do { |
| 100 | asm volatile("// __cmpxchg2\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 101 | " ldxrh %w1, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 102 | " mov %w0, #0\n" |
| 103 | " cmp %w1, %w3\n" |
| 104 | " b.ne 1f\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 105 | " stxrh %w0, %w4, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 106 | "1:\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 107 | : "=&r" (res), "=&r" (oldval), "+Q" (*(u16 *)ptr) |
| 108 | : "Ir" (old), "r" (new) |
| 109 | : "cc"); |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 110 | } while (res); |
| 111 | break; |
| 112 | |
| 113 | case 4: |
| 114 | do { |
| 115 | asm volatile("// __cmpxchg4\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 116 | " ldxr %w1, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 117 | " mov %w0, #0\n" |
| 118 | " cmp %w1, %w3\n" |
| 119 | " b.ne 1f\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 120 | " stxr %w0, %w4, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 121 | "1:\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 122 | : "=&r" (res), "=&r" (oldval), "+Q" (*(u32 *)ptr) |
| 123 | : "Ir" (old), "r" (new) |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 124 | : "cc"); |
| 125 | } while (res); |
| 126 | break; |
| 127 | |
| 128 | case 8: |
| 129 | do { |
| 130 | asm volatile("// __cmpxchg8\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 131 | " ldxr %1, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 132 | " mov %w0, #0\n" |
| 133 | " cmp %1, %3\n" |
| 134 | " b.ne 1f\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 135 | " stxr %w0, %4, %2\n" |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 136 | "1:\n" |
Will Deacon | 3a0310e | 2013-02-04 12:12:33 +0000 | [diff] [blame] | 137 | : "=&r" (res), "=&r" (oldval), "+Q" (*(u64 *)ptr) |
| 138 | : "Ir" (old), "r" (new) |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 139 | : "cc"); |
| 140 | } while (res); |
| 141 | break; |
| 142 | |
| 143 | default: |
| 144 | BUILD_BUG(); |
| 145 | } |
| 146 | |
| 147 | return oldval; |
| 148 | } |
| 149 | |
| 150 | static inline unsigned long __cmpxchg_mb(volatile void *ptr, unsigned long old, |
| 151 | unsigned long new, int size) |
| 152 | { |
| 153 | unsigned long ret; |
| 154 | |
| 155 | smp_mb(); |
| 156 | ret = __cmpxchg(ptr, old, new, size); |
| 157 | smp_mb(); |
| 158 | |
| 159 | return ret; |
| 160 | } |
| 161 | |
Mark Hambleton | 60010e5 | 2013-12-03 19:19:12 +0000 | [diff] [blame] | 162 | #define cmpxchg(ptr, o, n) \ |
| 163 | ({ \ |
| 164 | __typeof__(*(ptr)) __ret; \ |
| 165 | __ret = (__typeof__(*(ptr))) \ |
| 166 | __cmpxchg_mb((ptr), (unsigned long)(o), (unsigned long)(n), \ |
| 167 | sizeof(*(ptr))); \ |
| 168 | __ret; \ |
| 169 | }) |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 170 | |
Mark Hambleton | 60010e5 | 2013-12-03 19:19:12 +0000 | [diff] [blame] | 171 | #define cmpxchg_local(ptr, o, n) \ |
| 172 | ({ \ |
| 173 | __typeof__(*(ptr)) __ret; \ |
| 174 | __ret = (__typeof__(*(ptr))) \ |
| 175 | __cmpxchg((ptr), (unsigned long)(o), \ |
| 176 | (unsigned long)(n), sizeof(*(ptr))); \ |
| 177 | __ret; \ |
| 178 | }) |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 179 | |
Chen Gang | a84b086 | 2013-04-22 06:08:41 +0100 | [diff] [blame] | 180 | #define cmpxchg64(ptr,o,n) cmpxchg((ptr),(o),(n)) |
| 181 | #define cmpxchg64_local(ptr,o,n) cmpxchg_local((ptr),(o),(n)) |
| 182 | |
Will Deacon | cf10b79 | 2013-10-09 15:54:28 +0100 | [diff] [blame] | 183 | #define cmpxchg64_relaxed(ptr,o,n) cmpxchg_local((ptr),(o),(n)) |
| 184 | |
Catalin Marinas | 10b663a | 2012-03-05 11:49:34 +0000 | [diff] [blame] | 185 | #endif /* __ASM_CMPXCHG_H */ |