| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* $Id: atomic.S,v 1.4 2001/11/18 00:12:56 davem Exp $ |
| 2 | * atomic.S: These things are too big to do inline. |
| 3 | * |
| 4 | * Copyright (C) 1999 David S. Miller (davem@redhat.com) |
| 5 | */ |
| 6 | |
| 7 | #include <linux/config.h> |
| 8 | #include <asm/asi.h> |
| 9 | |
| 10 | /* On SMP we need to use memory barriers to ensure |
| 11 | * correct memory operation ordering, nop these out |
| 12 | * for uniprocessor. |
| 13 | */ |
| 14 | #ifdef CONFIG_SMP |
| 15 | #define ATOMIC_PRE_BARRIER membar #StoreLoad | #LoadLoad |
| 16 | #define ATOMIC_POST_BARRIER membar #StoreLoad | #StoreStore |
| 17 | #else |
| 18 | #define ATOMIC_PRE_BARRIER nop |
| 19 | #define ATOMIC_POST_BARRIER nop |
| 20 | #endif |
| 21 | |
| 22 | .text |
| 23 | |
| 24 | /* Two versions of the atomic routines, one that |
| 25 | * does not return a value and does not perform |
| 26 | * memory barriers, and a second which returns |
| 27 | * a value and does the barriers. |
| 28 | */ |
| 29 | .globl atomic_add |
| 30 | .type atomic_add,#function |
| 31 | atomic_add: /* %o0 = increment, %o1 = atomic_ptr */ |
| 32 | 1: lduw [%o1], %g1 |
| 33 | add %g1, %o0, %g7 |
| 34 | cas [%o1], %g1, %g7 |
| 35 | cmp %g1, %g7 |
| 36 | bne,pn %icc, 1b |
| 37 | nop |
| 38 | retl |
| 39 | nop |
| 40 | .size atomic_add, .-atomic_add |
| 41 | |
| 42 | .globl atomic_sub |
| 43 | .type atomic_sub,#function |
| 44 | atomic_sub: /* %o0 = decrement, %o1 = atomic_ptr */ |
| 45 | 1: lduw [%o1], %g1 |
| 46 | sub %g1, %o0, %g7 |
| 47 | cas [%o1], %g1, %g7 |
| 48 | cmp %g1, %g7 |
| 49 | bne,pn %icc, 1b |
| 50 | nop |
| 51 | retl |
| 52 | nop |
| 53 | .size atomic_sub, .-atomic_sub |
| 54 | |
| 55 | .globl atomic_add_ret |
| 56 | .type atomic_add_ret,#function |
| 57 | atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */ |
| 58 | ATOMIC_PRE_BARRIER |
| 59 | 1: lduw [%o1], %g1 |
| 60 | add %g1, %o0, %g7 |
| 61 | cas [%o1], %g1, %g7 |
| 62 | cmp %g1, %g7 |
| 63 | bne,pn %icc, 1b |
| 64 | add %g7, %o0, %g7 |
| 65 | ATOMIC_POST_BARRIER |
| 66 | retl |
| 67 | sra %g7, 0, %o0 |
| 68 | .size atomic_add_ret, .-atomic_add_ret |
| 69 | |
| 70 | .globl atomic_sub_ret |
| 71 | .type atomic_sub_ret,#function |
| 72 | atomic_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */ |
| 73 | ATOMIC_PRE_BARRIER |
| 74 | 1: lduw [%o1], %g1 |
| 75 | sub %g1, %o0, %g7 |
| 76 | cas [%o1], %g1, %g7 |
| 77 | cmp %g1, %g7 |
| 78 | bne,pn %icc, 1b |
| 79 | sub %g7, %o0, %g7 |
| 80 | ATOMIC_POST_BARRIER |
| 81 | retl |
| 82 | sra %g7, 0, %o0 |
| 83 | .size atomic_sub_ret, .-atomic_sub_ret |
| 84 | |
| 85 | .globl atomic64_add |
| 86 | .type atomic64_add,#function |
| 87 | atomic64_add: /* %o0 = increment, %o1 = atomic_ptr */ |
| 88 | 1: ldx [%o1], %g1 |
| 89 | add %g1, %o0, %g7 |
| 90 | casx [%o1], %g1, %g7 |
| 91 | cmp %g1, %g7 |
| 92 | bne,pn %xcc, 1b |
| 93 | nop |
| 94 | retl |
| 95 | nop |
| 96 | .size atomic64_add, .-atomic64_add |
| 97 | |
| 98 | .globl atomic64_sub |
| 99 | .type atomic64_sub,#function |
| 100 | atomic64_sub: /* %o0 = decrement, %o1 = atomic_ptr */ |
| 101 | 1: ldx [%o1], %g1 |
| 102 | sub %g1, %o0, %g7 |
| 103 | casx [%o1], %g1, %g7 |
| 104 | cmp %g1, %g7 |
| 105 | bne,pn %xcc, 1b |
| 106 | nop |
| 107 | retl |
| 108 | nop |
| 109 | .size atomic64_sub, .-atomic64_sub |
| 110 | |
| 111 | .globl atomic64_add_ret |
| 112 | .type atomic64_add_ret,#function |
| 113 | atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */ |
| 114 | ATOMIC_PRE_BARRIER |
| 115 | 1: ldx [%o1], %g1 |
| 116 | add %g1, %o0, %g7 |
| 117 | casx [%o1], %g1, %g7 |
| 118 | cmp %g1, %g7 |
| 119 | bne,pn %xcc, 1b |
| 120 | add %g7, %o0, %g7 |
| 121 | ATOMIC_POST_BARRIER |
| 122 | retl |
| 123 | mov %g7, %o0 |
| 124 | .size atomic64_add_ret, .-atomic64_add_ret |
| 125 | |
| 126 | .globl atomic64_sub_ret |
| 127 | .type atomic64_sub_ret,#function |
| 128 | atomic64_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */ |
| 129 | ATOMIC_PRE_BARRIER |
| 130 | 1: ldx [%o1], %g1 |
| 131 | sub %g1, %o0, %g7 |
| 132 | casx [%o1], %g1, %g7 |
| 133 | cmp %g1, %g7 |
| 134 | bne,pn %xcc, 1b |
| 135 | sub %g7, %o0, %g7 |
| 136 | ATOMIC_POST_BARRIER |
| 137 | retl |
| 138 | mov %g7, %o0 |
| 139 | .size atomic64_sub_ret, .-atomic64_sub_ret |