Vineet Gupta | 14e968b | 2013-01-18 15:12:16 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | */ |
| 8 | |
| 9 | #ifndef _ASM_ARC_ATOMIC_H |
| 10 | #define _ASM_ARC_ATOMIC_H |
| 11 | |
| 12 | #ifdef __KERNEL__ |
| 13 | |
| 14 | #ifndef __ASSEMBLY__ |
| 15 | |
| 16 | #include <linux/types.h> |
| 17 | #include <linux/compiler.h> |
| 18 | #include <asm/cmpxchg.h> |
| 19 | #include <asm/barrier.h> |
| 20 | #include <asm/smp.h> |
| 21 | |
| 22 | #define atomic_read(v) ((v)->counter) |
| 23 | |
| 24 | #ifdef CONFIG_ARC_HAS_LLSC |
| 25 | |
| 26 | #define atomic_set(v, i) (((v)->counter) = (i)) |
| 27 | |
Peter Zijlstra | f7d11e9 | 2014-03-23 16:29:31 +0100 | [diff] [blame] | 28 | #define ATOMIC_OP(op, c_op, asm_op) \ |
| 29 | static inline void atomic_##op(int i, atomic_t *v) \ |
| 30 | { \ |
| 31 | unsigned int temp; \ |
| 32 | \ |
| 33 | __asm__ __volatile__( \ |
| 34 | "1: llock %0, [%1] \n" \ |
| 35 | " " #asm_op " %0, %0, %2 \n" \ |
| 36 | " scond %0, [%1] \n" \ |
| 37 | " bnz 1b \n" \ |
| 38 | : "=&r"(temp) /* Early clobber, to prevent reg reuse */ \ |
| 39 | : "r"(&v->counter), "ir"(i) \ |
| 40 | : "cc"); \ |
| 41 | } \ |
Vineet Gupta | 14e968b | 2013-01-18 15:12:16 +0530 | [diff] [blame] | 42 | |
Peter Zijlstra | f7d11e9 | 2014-03-23 16:29:31 +0100 | [diff] [blame] | 43 | #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ |
| 44 | static inline int atomic_##op##_return(int i, atomic_t *v) \ |
| 45 | { \ |
| 46 | unsigned int temp; \ |
| 47 | \ |
| 48 | __asm__ __volatile__( \ |
| 49 | "1: llock %0, [%1] \n" \ |
| 50 | " " #asm_op " %0, %0, %2 \n" \ |
| 51 | " scond %0, [%1] \n" \ |
| 52 | " bnz 1b \n" \ |
| 53 | : "=&r"(temp) \ |
| 54 | : "r"(&v->counter), "ir"(i) \ |
| 55 | : "cc"); \ |
| 56 | \ |
| 57 | return temp; \ |
Vineet Gupta | 14e968b | 2013-01-18 15:12:16 +0530 | [diff] [blame] | 58 | } |
| 59 | |
| 60 | #else /* !CONFIG_ARC_HAS_LLSC */ |
| 61 | |
| 62 | #ifndef CONFIG_SMP |
| 63 | |
| 64 | /* violating atomic_xxx API locking protocol in UP for optimization sake */ |
| 65 | #define atomic_set(v, i) (((v)->counter) = (i)) |
| 66 | |
| 67 | #else |
| 68 | |
| 69 | static inline void atomic_set(atomic_t *v, int i) |
| 70 | { |
| 71 | /* |
| 72 | * Independent of hardware support, all of the atomic_xxx() APIs need |
| 73 | * to follow the same locking rules to make sure that a "hardware" |
| 74 | * atomic insn (e.g. LD) doesn't clobber an "emulated" atomic insn |
| 75 | * sequence |
| 76 | * |
| 77 | * Thus atomic_set() despite being 1 insn (and seemingly atomic) |
| 78 | * requires the locking. |
| 79 | */ |
| 80 | unsigned long flags; |
| 81 | |
| 82 | atomic_ops_lock(flags); |
| 83 | v->counter = i; |
| 84 | atomic_ops_unlock(flags); |
| 85 | } |
Peter Zijlstra | f7d11e9 | 2014-03-23 16:29:31 +0100 | [diff] [blame] | 86 | |
Vineet Gupta | 14e968b | 2013-01-18 15:12:16 +0530 | [diff] [blame] | 87 | #endif |
| 88 | |
| 89 | /* |
| 90 | * Non hardware assisted Atomic-R-M-W |
| 91 | * Locking would change to irq-disabling only (UP) and spinlocks (SMP) |
| 92 | */ |
| 93 | |
Peter Zijlstra | f7d11e9 | 2014-03-23 16:29:31 +0100 | [diff] [blame] | 94 | #define ATOMIC_OP(op, c_op, asm_op) \ |
| 95 | static inline void atomic_##op(int i, atomic_t *v) \ |
| 96 | { \ |
| 97 | unsigned long flags; \ |
| 98 | \ |
| 99 | atomic_ops_lock(flags); \ |
| 100 | v->counter c_op i; \ |
| 101 | atomic_ops_unlock(flags); \ |
Vineet Gupta | 14e968b | 2013-01-18 15:12:16 +0530 | [diff] [blame] | 102 | } |
| 103 | |
Peter Zijlstra | f7d11e9 | 2014-03-23 16:29:31 +0100 | [diff] [blame] | 104 | #define ATOMIC_OP_RETURN(op, c_op) \ |
| 105 | static inline int atomic_##op##_return(int i, atomic_t *v) \ |
| 106 | { \ |
| 107 | unsigned long flags; \ |
| 108 | unsigned long temp; \ |
| 109 | \ |
| 110 | atomic_ops_lock(flags); \ |
| 111 | temp = v->counter; \ |
| 112 | temp c_op i; \ |
| 113 | v->counter = temp; \ |
| 114 | atomic_ops_unlock(flags); \ |
| 115 | \ |
| 116 | return temp; \ |
Vineet Gupta | 14e968b | 2013-01-18 15:12:16 +0530 | [diff] [blame] | 117 | } |
| 118 | |
| 119 | #endif /* !CONFIG_ARC_HAS_LLSC */ |
| 120 | |
Peter Zijlstra | f7d11e9 | 2014-03-23 16:29:31 +0100 | [diff] [blame] | 121 | #define ATOMIC_OPS(op, c_op, asm_op) \ |
| 122 | ATOMIC_OP(op, c_op, asm_op) \ |
| 123 | ATOMIC_OP_RETURN(op, c_op, asm_op) |
| 124 | |
| 125 | ATOMIC_OPS(add, +=, add) |
| 126 | ATOMIC_OPS(sub, -=, sub) |
| 127 | ATOMIC_OP(and, &=, and) |
| 128 | |
| 129 | #define atomic_clear_mask(mask, v) atomic_and(~(mask), (v)) |
| 130 | |
| 131 | #undef ATOMIC_OPS |
| 132 | #undef ATOMIC_OP_RETURN |
| 133 | #undef ATOMIC_OP |
| 134 | |
Vineet Gupta | 14e968b | 2013-01-18 15:12:16 +0530 | [diff] [blame] | 135 | /** |
| 136 | * __atomic_add_unless - add unless the number is a given value |
| 137 | * @v: pointer of type atomic_t |
| 138 | * @a: the amount to add to v... |
| 139 | * @u: ...unless v is equal to u. |
| 140 | * |
| 141 | * Atomically adds @a to @v, so long as it was not @u. |
| 142 | * Returns the old value of @v |
| 143 | */ |
| 144 | #define __atomic_add_unless(v, a, u) \ |
| 145 | ({ \ |
| 146 | int c, old; \ |
| 147 | c = atomic_read(v); \ |
| 148 | while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c)\ |
| 149 | c = old; \ |
| 150 | c; \ |
| 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_inc_return(v) atomic_add_return(1, (v)) |
| 161 | #define atomic_dec_return(v) atomic_sub_return(1, (v)) |
| 162 | #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) |
| 163 | |
| 164 | #define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0) |
| 165 | |
| 166 | #define ATOMIC_INIT(i) { (i) } |
| 167 | |
| 168 | #include <asm-generic/atomic64.h> |
| 169 | |
| 170 | #endif |
| 171 | |
| 172 | #endif |
| 173 | |
| 174 | #endif |