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1 | /* |
2 | * Atomic operations for the Hexagon architecture | |
3 | * | |
7c6a5df4 | 4 | * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. |
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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> | |
8335896b | 26 | #include <asm/cmpxchg.h> |
94cf42f8 | 27 | #include <asm/barrier.h> |
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28 | |
29 | #define ATOMIC_INIT(i) { (i) } | |
b10fa7b6 RK |
30 | |
31 | /* Normal writes in our arch don't clear lock reservations */ | |
32 | ||
33 | static inline void atomic_set(atomic_t *v, int new) | |
34 | { | |
35 | asm volatile( | |
36 | "1: r6 = memw_locked(%0);\n" | |
37 | " memw_locked(%0,p0) = %1;\n" | |
38 | " if (!P0) jump 1b;\n" | |
39 | : | |
40 | : "r" (&v->counter), "r" (new) | |
41 | : "memory", "p0", "r6" | |
42 | ); | |
43 | } | |
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44 | |
45 | /** | |
46 | * atomic_read - reads a word, atomically | |
47 | * @v: pointer to atomic value | |
48 | * | |
49 | * Assumes all word reads on our architecture are atomic. | |
50 | */ | |
62e8a325 | 51 | #define atomic_read(v) READ_ONCE((v)->counter) |
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52 | |
53 | /** | |
54 | * atomic_xchg - atomic | |
55 | * @v: pointer to memory to change | |
56 | * @new: new value (technically passed in a register -- see xchg) | |
57 | */ | |
58 | #define atomic_xchg(v, new) (xchg(&((v)->counter), (new))) | |
59 | ||
60 | ||
61 | /** | |
62 | * atomic_cmpxchg - atomic compare-and-exchange values | |
63 | * @v: pointer to value to change | |
64 | * @old: desired old value to match | |
65 | * @new: new value to put in | |
66 | * | |
67 | * Parameters are then pointer, value-in-register, value-in-register, | |
68 | * and the output is the old value. | |
69 | * | |
70 | * Apparently this is complicated for archs that don't support | |
71 | * the memw_locked like we do (or it's broken or whatever). | |
72 | * | |
73 | * Kind of the lynchpin of the rest of the generically defined routines. | |
74 | * Remember V2 had that bug with dotnew predicate set by memw_locked. | |
75 | * | |
76 | * "old" is "expected" old val, __oldval is actual old value | |
77 | */ | |
78 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) | |
79 | { | |
80 | int __oldval; | |
81 | ||
82 | asm volatile( | |
83 | "1: %0 = memw_locked(%1);\n" | |
84 | " { P0 = cmp.eq(%0,%2);\n" | |
85 | " if (!P0.new) jump:nt 2f; }\n" | |
86 | " memw_locked(%1,P0) = %3;\n" | |
87 | " if (!P0) jump 1b;\n" | |
88 | "2:\n" | |
89 | : "=&r" (__oldval) | |
90 | : "r" (&v->counter), "r" (old), "r" (new) | |
91 | : "memory", "p0" | |
92 | ); | |
93 | ||
94 | return __oldval; | |
95 | } | |
96 | ||
50f853e3 PZ |
97 | #define ATOMIC_OP(op) \ |
98 | static inline void atomic_##op(int i, atomic_t *v) \ | |
99 | { \ | |
100 | int output; \ | |
101 | \ | |
102 | __asm__ __volatile__ ( \ | |
103 | "1: %0 = memw_locked(%1);\n" \ | |
104 | " %0 = "#op "(%0,%2);\n" \ | |
105 | " memw_locked(%1,P3)=%0;\n" \ | |
106 | " if !P3 jump 1b;\n" \ | |
107 | : "=&r" (output) \ | |
108 | : "r" (&v->counter), "r" (i) \ | |
109 | : "memory", "p3" \ | |
110 | ); \ | |
111 | } \ | |
112 | ||
113 | #define ATOMIC_OP_RETURN(op) \ | |
114 | static inline int atomic_##op##_return(int i, atomic_t *v) \ | |
115 | { \ | |
116 | int output; \ | |
117 | \ | |
118 | __asm__ __volatile__ ( \ | |
119 | "1: %0 = memw_locked(%1);\n" \ | |
120 | " %0 = "#op "(%0,%2);\n" \ | |
121 | " memw_locked(%1,P3)=%0;\n" \ | |
122 | " if !P3 jump 1b;\n" \ | |
123 | : "=&r" (output) \ | |
124 | : "r" (&v->counter), "r" (i) \ | |
125 | : "memory", "p3" \ | |
126 | ); \ | |
127 | return output; \ | |
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128 | } |
129 | ||
50f853e3 | 130 | #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) |
75085018 | 131 | |
50f853e3 PZ |
132 | ATOMIC_OPS(add) |
133 | ATOMIC_OPS(sub) | |
75085018 | 134 | |
610f7ba9 PZ |
135 | ATOMIC_OP(and) |
136 | ATOMIC_OP(or) | |
137 | ATOMIC_OP(xor) | |
138 | ||
50f853e3 PZ |
139 | #undef ATOMIC_OPS |
140 | #undef ATOMIC_OP_RETURN | |
141 | #undef ATOMIC_OP | |
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142 | |
143 | /** | |
e0025a72 | 144 | * __atomic_add_unless - add unless the number is a given value |
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145 | * @v: pointer to value |
146 | * @a: amount to add | |
147 | * @u: unless value is equal to u | |
148 | * | |
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149 | * Returns old value. |
150 | * | |
75085018 | 151 | */ |
e0025a72 | 152 | |
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153 | static inline int __atomic_add_unless(atomic_t *v, int a, int u) |
154 | { | |
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155 | int __oldval; |
156 | register int tmp; | |
157 | ||
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158 | asm volatile( |
159 | "1: %0 = memw_locked(%2);" | |
160 | " {" | |
161 | " p3 = cmp.eq(%0, %4);" | |
162 | " if (p3.new) jump:nt 2f;" | |
e0025a72 | 163 | " %1 = add(%0, %3);" |
75085018 | 164 | " }" |
e0025a72 | 165 | " memw_locked(%2, p3) = %1;" |
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166 | " {" |
167 | " if !p3 jump 1b;" | |
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168 | " }" |
169 | "2:" | |
e0025a72 | 170 | : "=&r" (__oldval), "=&r" (tmp) |
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171 | : "r" (v), "r" (a), "r" (u) |
172 | : "memory", "p3" | |
173 | ); | |
e0025a72 | 174 | return __oldval; |
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175 | } |
176 | ||
177 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) | |
178 | ||
179 | #define atomic_inc(v) atomic_add(1, (v)) | |
180 | #define atomic_dec(v) atomic_sub(1, (v)) | |
181 | ||
182 | #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) | |
183 | #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) | |
184 | #define atomic_sub_and_test(i, v) (atomic_sub_return(i, (v)) == 0) | |
185 | #define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0) | |
186 | ||
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187 | #define atomic_inc_return(v) (atomic_add_return(1, v)) |
188 | #define atomic_dec_return(v) (atomic_sub_return(1, v)) | |
189 | ||
190 | #endif |