| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* $Id: locks.S,v 1.16 2000/02/26 11:02:47 anton Exp $ |
| 2 | * locks.S: SMP low-level lock primitives on Sparc. |
| 3 | * |
| 4 | * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) |
| 5 | * Copyright (C) 1998 Anton Blanchard (anton@progsoc.uts.edu.au) |
| 6 | * Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz) |
| 7 | */ |
| 8 | |
| 9 | #include <asm/ptrace.h> |
| 10 | #include <asm/psr.h> |
| 11 | #include <asm/smp.h> |
| 12 | #include <asm/spinlock.h> |
| 13 | |
| 14 | .text |
| 15 | .align 4 |
| 16 | |
| 17 | /* Read/writer locks, as usual this is overly clever to make it |
| 18 | * as fast as possible. |
| 19 | */ |
| 20 | |
| 21 | /* caches... */ |
| 22 | ___rw_read_enter_spin_on_wlock: |
| 23 | orcc %g2, 0x0, %g0 |
| 24 | be,a ___rw_read_enter |
| 25 | ldstub [%g1 + 3], %g2 |
| 26 | b ___rw_read_enter_spin_on_wlock |
| 27 | ldub [%g1 + 3], %g2 |
| Al Viro | 7a39f52 | 2006-10-08 14:32:15 +0100 | [diff] [blame] | 28 | ___rw_read_try_spin_on_wlock: |
| 29 | andcc %g2, 0xff, %g0 |
| 30 | be,a ___rw_read_try |
| 31 | ldstub [%g1 + 3], %g2 |
| 32 | xnorcc %g2, 0x0, %o0 /* if g2 is ~0, set o0 to 0 and bugger off */ |
| 33 | bne,a ___rw_read_enter_spin_on_wlock |
| 34 | ld [%g1], %g2 |
| 35 | retl |
| 36 | mov %g4, %o7 |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | ___rw_read_exit_spin_on_wlock: |
| 38 | orcc %g2, 0x0, %g0 |
| 39 | be,a ___rw_read_exit |
| 40 | ldstub [%g1 + 3], %g2 |
| 41 | b ___rw_read_exit_spin_on_wlock |
| 42 | ldub [%g1 + 3], %g2 |
| 43 | ___rw_write_enter_spin_on_wlock: |
| 44 | orcc %g2, 0x0, %g0 |
| 45 | be,a ___rw_write_enter |
| 46 | ldstub [%g1 + 3], %g2 |
| 47 | b ___rw_write_enter_spin_on_wlock |
| 48 | ld [%g1], %g2 |
| 49 | |
| 50 | .globl ___rw_read_enter |
| 51 | ___rw_read_enter: |
| 52 | orcc %g2, 0x0, %g0 |
| 53 | bne,a ___rw_read_enter_spin_on_wlock |
| 54 | ldub [%g1 + 3], %g2 |
| 55 | ld [%g1], %g2 |
| 56 | add %g2, 1, %g2 |
| 57 | st %g2, [%g1] |
| 58 | retl |
| 59 | mov %g4, %o7 |
| 60 | |
| 61 | .globl ___rw_read_exit |
| 62 | ___rw_read_exit: |
| 63 | orcc %g2, 0x0, %g0 |
| 64 | bne,a ___rw_read_exit_spin_on_wlock |
| 65 | ldub [%g1 + 3], %g2 |
| 66 | ld [%g1], %g2 |
| 67 | sub %g2, 0x1ff, %g2 |
| 68 | st %g2, [%g1] |
| 69 | retl |
| 70 | mov %g4, %o7 |
| 71 | |
| Al Viro | 7a39f52 | 2006-10-08 14:32:15 +0100 | [diff] [blame] | 72 | .globl ___rw_read_try |
| 73 | ___rw_read_try: |
| 74 | orcc %g2, 0x0, %g0 |
| 75 | bne ___rw_read_try_spin_on_wlock |
| 76 | ld [%g1], %g2 |
| 77 | add %g2, 1, %g2 |
| 78 | st %g2, [%g1] |
| 79 | set 1, %o1 |
| 80 | retl |
| 81 | mov %g4, %o7 |
| 82 | |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | .globl ___rw_write_enter |
| 84 | ___rw_write_enter: |
| 85 | orcc %g2, 0x0, %g0 |
| 86 | bne ___rw_write_enter_spin_on_wlock |
| 87 | ld [%g1], %g2 |
| 88 | andncc %g2, 0xff, %g0 |
| 89 | bne,a ___rw_write_enter_spin_on_wlock |
| 90 | stb %g0, [%g1 + 3] |
| 91 | retl |
| 92 | mov %g4, %o7 |