Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Atomic operations for the Hexagon architecture |
| 3 | * |
Richard Kuo | 7c6a5df | 2013-03-28 20:45:40 -0500 | [diff] [blame] | 4 | * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 5 | * |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 and |
| 9 | * only version 2 as published by the Free Software Foundation. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 19 | * 02110-1301, USA. |
| 20 | */ |
| 21 | |
| 22 | #ifndef _ASM_ATOMIC_H |
| 23 | #define _ASM_ATOMIC_H |
| 24 | |
| 25 | #include <linux/types.h> |
David Howells | 8335896 | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 26 | #include <asm/cmpxchg.h> |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 27 | |
| 28 | #define ATOMIC_INIT(i) { (i) } |
| 29 | #define atomic_set(v, i) ((v)->counter = (i)) |
| 30 | |
| 31 | /** |
| 32 | * atomic_read - reads a word, atomically |
| 33 | * @v: pointer to atomic value |
| 34 | * |
| 35 | * Assumes all word reads on our architecture are atomic. |
| 36 | */ |
| 37 | #define atomic_read(v) ((v)->counter) |
| 38 | |
| 39 | /** |
| 40 | * atomic_xchg - atomic |
| 41 | * @v: pointer to memory to change |
| 42 | * @new: new value (technically passed in a register -- see xchg) |
| 43 | */ |
| 44 | #define atomic_xchg(v, new) (xchg(&((v)->counter), (new))) |
| 45 | |
| 46 | |
| 47 | /** |
| 48 | * atomic_cmpxchg - atomic compare-and-exchange values |
| 49 | * @v: pointer to value to change |
| 50 | * @old: desired old value to match |
| 51 | * @new: new value to put in |
| 52 | * |
| 53 | * Parameters are then pointer, value-in-register, value-in-register, |
| 54 | * and the output is the old value. |
| 55 | * |
| 56 | * Apparently this is complicated for archs that don't support |
| 57 | * the memw_locked like we do (or it's broken or whatever). |
| 58 | * |
| 59 | * Kind of the lynchpin of the rest of the generically defined routines. |
| 60 | * Remember V2 had that bug with dotnew predicate set by memw_locked. |
| 61 | * |
| 62 | * "old" is "expected" old val, __oldval is actual old value |
| 63 | */ |
| 64 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
| 65 | { |
| 66 | int __oldval; |
| 67 | |
| 68 | asm volatile( |
| 69 | "1: %0 = memw_locked(%1);\n" |
| 70 | " { P0 = cmp.eq(%0,%2);\n" |
| 71 | " if (!P0.new) jump:nt 2f; }\n" |
| 72 | " memw_locked(%1,P0) = %3;\n" |
| 73 | " if (!P0) jump 1b;\n" |
| 74 | "2:\n" |
| 75 | : "=&r" (__oldval) |
| 76 | : "r" (&v->counter), "r" (old), "r" (new) |
| 77 | : "memory", "p0" |
| 78 | ); |
| 79 | |
| 80 | return __oldval; |
| 81 | } |
| 82 | |
| 83 | static inline int atomic_add_return(int i, atomic_t *v) |
| 84 | { |
| 85 | int output; |
| 86 | |
| 87 | __asm__ __volatile__ ( |
| 88 | "1: %0 = memw_locked(%1);\n" |
| 89 | " %0 = add(%0,%2);\n" |
| 90 | " memw_locked(%1,P3)=%0;\n" |
| 91 | " if !P3 jump 1b;\n" |
| 92 | : "=&r" (output) |
| 93 | : "r" (&v->counter), "r" (i) |
| 94 | : "memory", "p3" |
| 95 | ); |
| 96 | return output; |
| 97 | |
| 98 | } |
| 99 | |
| 100 | #define atomic_add(i, v) atomic_add_return(i, (v)) |
| 101 | |
| 102 | static inline int atomic_sub_return(int i, atomic_t *v) |
| 103 | { |
| 104 | int output; |
| 105 | __asm__ __volatile__ ( |
| 106 | "1: %0 = memw_locked(%1);\n" |
| 107 | " %0 = sub(%0,%2);\n" |
| 108 | " memw_locked(%1,P3)=%0\n" |
| 109 | " if !P3 jump 1b;\n" |
| 110 | : "=&r" (output) |
| 111 | : "r" (&v->counter), "r" (i) |
| 112 | : "memory", "p3" |
| 113 | ); |
| 114 | return output; |
| 115 | } |
| 116 | |
| 117 | #define atomic_sub(i, v) atomic_sub_return(i, (v)) |
| 118 | |
| 119 | /** |
Richard Kuo | e0025a7 | 2013-03-21 18:24:19 -0500 | [diff] [blame] | 120 | * __atomic_add_unless - add unless the number is a given value |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 121 | * @v: pointer to value |
| 122 | * @a: amount to add |
| 123 | * @u: unless value is equal to u |
| 124 | * |
Richard Kuo | e0025a7 | 2013-03-21 18:24:19 -0500 | [diff] [blame] | 125 | * Returns old value. |
| 126 | * |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 127 | */ |
Richard Kuo | e0025a7 | 2013-03-21 18:24:19 -0500 | [diff] [blame] | 128 | |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 129 | static inline int __atomic_add_unless(atomic_t *v, int a, int u) |
| 130 | { |
Richard Kuo | e0025a7 | 2013-03-21 18:24:19 -0500 | [diff] [blame] | 131 | int __oldval; |
| 132 | register int tmp; |
| 133 | |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 134 | asm volatile( |
| 135 | "1: %0 = memw_locked(%2);" |
| 136 | " {" |
| 137 | " p3 = cmp.eq(%0, %4);" |
| 138 | " if (p3.new) jump:nt 2f;" |
Richard Kuo | e0025a7 | 2013-03-21 18:24:19 -0500 | [diff] [blame] | 139 | " %1 = add(%0, %3);" |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 140 | " }" |
Richard Kuo | e0025a7 | 2013-03-21 18:24:19 -0500 | [diff] [blame] | 141 | " memw_locked(%2, p3) = %1;" |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 142 | " {" |
| 143 | " if !p3 jump 1b;" |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 144 | " }" |
| 145 | "2:" |
Richard Kuo | e0025a7 | 2013-03-21 18:24:19 -0500 | [diff] [blame] | 146 | : "=&r" (__oldval), "=&r" (tmp) |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 147 | : "r" (v), "r" (a), "r" (u) |
| 148 | : "memory", "p3" |
| 149 | ); |
Richard Kuo | e0025a7 | 2013-03-21 18:24:19 -0500 | [diff] [blame] | 150 | return __oldval; |
Richard Kuo | 7508501 | 2011-10-31 18:28:13 -0500 | [diff] [blame] | 151 | } |
| 152 | |
| 153 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) |
| 154 | |
| 155 | #define atomic_inc(v) atomic_add(1, (v)) |
| 156 | #define atomic_dec(v) atomic_sub(1, (v)) |
| 157 | |
| 158 | #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) |
| 159 | #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) |
| 160 | #define atomic_sub_and_test(i, v) (atomic_sub_return(i, (v)) == 0) |
| 161 | #define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0) |
| 162 | |
| 163 | |
| 164 | #define atomic_inc_return(v) (atomic_add_return(1, v)) |
| 165 | #define atomic_dec_return(v) (atomic_sub_return(1, v)) |
| 166 | |
| 167 | #endif |