| Bernd Schmidt | 7adfb58 | 2007-06-21 11:34:16 +0800 | [diff] [blame] | 1 | /* |
| 2 | * This file contains sequences of code that will be copied to a |
| 3 | * fixed location, defined in <asm/atomic_seq.h>. The interrupt |
| 4 | * handlers ensure that these sequences appear to be atomic when |
| 5 | * executed from userspace. |
| 6 | * These are aligned to 16 bytes, so that we have some space to replace |
| 7 | * these sequences with something else (e.g. kernel traps if we ever do |
| 8 | * BF561 SMP). |
| 9 | */ |
| 10 | #include <linux/linkage.h> |
| Mike Frysinger | 1f83b8f | 2007-07-12 22:58:21 +0800 | [diff] [blame] | 11 | #include <linux/unistd.h> |
| Bernd Schmidt | 7adfb58 | 2007-06-21 11:34:16 +0800 | [diff] [blame] | 12 | #include <asm/entry.h> |
| Bernd Schmidt | 7adfb58 | 2007-06-21 11:34:16 +0800 | [diff] [blame] | 13 | |
| 14 | .text |
| 15 | ENTRY(_fixed_code_start) |
| 16 | |
| 17 | .align 16 |
| 18 | ENTRY(_sigreturn_stub) |
| 19 | P0 = __NR_rt_sigreturn; |
| 20 | EXCPT 0; |
| 21 | /* Speculative execution paranoia. */ |
| 22 | 0: JUMP.S 0b; |
| 23 | ENDPROC (_sigreturn_stub) |
| 24 | |
| 25 | .align 16 |
| 26 | /* |
| 27 | * Atomic swap, 8 bit. |
| 28 | * Inputs: P0: memory address to use |
| 29 | * R1: value to store |
| 30 | * Output: R0: old contents of the memory address, zero extended. |
| 31 | */ |
| 32 | ENTRY(_atomic_xchg32) |
| 33 | R0 = [P0]; |
| 34 | [P0] = R1; |
| 35 | rts; |
| 36 | ENDPROC (_atomic_xchg32) |
| 37 | |
| 38 | .align 16 |
| 39 | /* |
| 40 | * Compare and swap, 32 bit. |
| 41 | * Inputs: P0: memory address to use |
| 42 | * R1: compare value |
| 43 | * R2: new value to store |
| 44 | * The new value is stored if the contents of the memory |
| 45 | * address is equal to the compare value. |
| 46 | * Output: R0: old contents of the memory address. |
| 47 | */ |
| 48 | ENTRY(_atomic_cas32) |
| 49 | R0 = [P0]; |
| 50 | CC = R0 == R1; |
| 51 | IF !CC JUMP 1f; |
| 52 | [P0] = R2; |
| 53 | 1: |
| 54 | rts; |
| 55 | ENDPROC (_atomic_cas32) |
| 56 | |
| 57 | .align 16 |
| 58 | /* |
| 59 | * Atomic add, 32 bit. |
| 60 | * Inputs: P0: memory address to use |
| 61 | * R0: value to add |
| 62 | * Outputs: R0: new contents of the memory address. |
| 63 | * R1: previous contents of the memory address. |
| 64 | */ |
| 65 | ENTRY(_atomic_add32) |
| 66 | R1 = [P0]; |
| 67 | R0 = R1 + R0; |
| 68 | [P0] = R0; |
| 69 | rts; |
| 70 | ENDPROC (_atomic_add32) |
| 71 | |
| 72 | .align 16 |
| 73 | /* |
| 74 | * Atomic sub, 32 bit. |
| 75 | * Inputs: P0: memory address to use |
| 76 | * R0: value to subtract |
| 77 | * Outputs: R0: new contents of the memory address. |
| 78 | * R1: previous contents of the memory address. |
| 79 | */ |
| 80 | ENTRY(_atomic_sub32) |
| 81 | R1 = [P0]; |
| 82 | R0 = R1 - R0; |
| 83 | [P0] = R0; |
| 84 | rts; |
| 85 | ENDPROC (_atomic_sub32) |
| 86 | |
| 87 | .align 16 |
| 88 | /* |
| 89 | * Atomic ior, 32 bit. |
| 90 | * Inputs: P0: memory address to use |
| 91 | * R0: value to ior |
| 92 | * Outputs: R0: new contents of the memory address. |
| 93 | * R1: previous contents of the memory address. |
| 94 | */ |
| 95 | ENTRY(_atomic_ior32) |
| 96 | R1 = [P0]; |
| 97 | R0 = R1 | R0; |
| 98 | [P0] = R0; |
| 99 | rts; |
| 100 | ENDPROC (_atomic_ior32) |
| 101 | |
| 102 | .align 16 |
| 103 | /* |
| 104 | * Atomic ior, 32 bit. |
| 105 | * Inputs: P0: memory address to use |
| 106 | * R0: value to ior |
| 107 | * Outputs: R0: new contents of the memory address. |
| 108 | * R1: previous contents of the memory address. |
| 109 | */ |
| 110 | ENTRY(_atomic_and32) |
| 111 | R1 = [P0]; |
| 112 | R0 = R1 & R0; |
| 113 | [P0] = R0; |
| 114 | rts; |
| 115 | ENDPROC (_atomic_ior32) |
| 116 | |
| 117 | .align 16 |
| 118 | /* |
| 119 | * Atomic ior, 32 bit. |
| 120 | * Inputs: P0: memory address to use |
| 121 | * R0: value to ior |
| 122 | * Outputs: R0: new contents of the memory address. |
| 123 | * R1: previous contents of the memory address. |
| 124 | */ |
| 125 | ENTRY(_atomic_xor32) |
| 126 | R1 = [P0]; |
| 127 | R0 = R1 ^ R0; |
| 128 | [P0] = R0; |
| 129 | rts; |
| 130 | ENDPROC (_atomic_ior32) |
| 131 | |
| 132 | ENTRY(_fixed_code_end) |