| Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| Adrian Bunk | 88278ca | 2008-05-19 16:53:02 -0700 | [diff] [blame] | 2 | /* |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * locks.S: SMP low-level lock primitives on Sparc. |
| 4 | * |
| 5 | * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) |
| 6 | * Copyright (C) 1998 Anton Blanchard (anton@progsoc.uts.edu.au) |
| 7 | * Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz) |
| 8 | */ |
| 9 | |
| 10 | #include <asm/ptrace.h> |
| 11 | #include <asm/psr.h> |
| 12 | #include <asm/smp.h> |
| 13 | #include <asm/spinlock.h> |
| Al Viro | d3867f04 | 2016-01-16 21:39:30 -0500 | [diff] [blame] | 14 | #include <asm/export.h> |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | |
| 16 | .text |
| 17 | .align 4 |
| 18 | |
| 19 | /* Read/writer locks, as usual this is overly clever to make it |
| 20 | * as fast as possible. |
| 21 | */ |
| 22 | |
| 23 | /* caches... */ |
| 24 | ___rw_read_enter_spin_on_wlock: |
| 25 | orcc %g2, 0x0, %g0 |
| 26 | be,a ___rw_read_enter |
| 27 | ldstub [%g1 + 3], %g2 |
| 28 | b ___rw_read_enter_spin_on_wlock |
| 29 | ldub [%g1 + 3], %g2 |
| Al Viro | 7a39f52 | 2006-10-08 14:32:15 +0100 | [diff] [blame] | 30 | ___rw_read_try_spin_on_wlock: |
| 31 | andcc %g2, 0xff, %g0 |
| 32 | be,a ___rw_read_try |
| 33 | ldstub [%g1 + 3], %g2 |
| 34 | xnorcc %g2, 0x0, %o0 /* if g2 is ~0, set o0 to 0 and bugger off */ |
| 35 | bne,a ___rw_read_enter_spin_on_wlock |
| 36 | ld [%g1], %g2 |
| 37 | retl |
| 38 | mov %g4, %o7 |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | ___rw_read_exit_spin_on_wlock: |
| 40 | orcc %g2, 0x0, %g0 |
| 41 | be,a ___rw_read_exit |
| 42 | ldstub [%g1 + 3], %g2 |
| 43 | b ___rw_read_exit_spin_on_wlock |
| 44 | ldub [%g1 + 3], %g2 |
| 45 | ___rw_write_enter_spin_on_wlock: |
| 46 | orcc %g2, 0x0, %g0 |
| 47 | be,a ___rw_write_enter |
| 48 | ldstub [%g1 + 3], %g2 |
| 49 | b ___rw_write_enter_spin_on_wlock |
| 50 | ld [%g1], %g2 |
| 51 | |
| 52 | .globl ___rw_read_enter |
| Al Viro | d3867f04 | 2016-01-16 21:39:30 -0500 | [diff] [blame] | 53 | EXPORT_SYMBOL(___rw_read_enter) |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | ___rw_read_enter: |
| 55 | orcc %g2, 0x0, %g0 |
| 56 | bne,a ___rw_read_enter_spin_on_wlock |
| 57 | ldub [%g1 + 3], %g2 |
| 58 | ld [%g1], %g2 |
| 59 | add %g2, 1, %g2 |
| 60 | st %g2, [%g1] |
| 61 | retl |
| 62 | mov %g4, %o7 |
| 63 | |
| 64 | .globl ___rw_read_exit |
| Al Viro | d3867f04 | 2016-01-16 21:39:30 -0500 | [diff] [blame] | 65 | EXPORT_SYMBOL(___rw_read_exit) |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | ___rw_read_exit: |
| 67 | orcc %g2, 0x0, %g0 |
| 68 | bne,a ___rw_read_exit_spin_on_wlock |
| 69 | ldub [%g1 + 3], %g2 |
| 70 | ld [%g1], %g2 |
| 71 | sub %g2, 0x1ff, %g2 |
| 72 | st %g2, [%g1] |
| 73 | retl |
| 74 | mov %g4, %o7 |
| 75 | |
| Al Viro | 7a39f52 | 2006-10-08 14:32:15 +0100 | [diff] [blame] | 76 | .globl ___rw_read_try |
| Al Viro | d3867f04 | 2016-01-16 21:39:30 -0500 | [diff] [blame] | 77 | EXPORT_SYMBOL(___rw_read_try) |
| Al Viro | 7a39f52 | 2006-10-08 14:32:15 +0100 | [diff] [blame] | 78 | ___rw_read_try: |
| 79 | orcc %g2, 0x0, %g0 |
| 80 | bne ___rw_read_try_spin_on_wlock |
| 81 | ld [%g1], %g2 |
| 82 | add %g2, 1, %g2 |
| 83 | st %g2, [%g1] |
| 84 | set 1, %o1 |
| 85 | retl |
| 86 | mov %g4, %o7 |
| 87 | |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | .globl ___rw_write_enter |
| Al Viro | d3867f04 | 2016-01-16 21:39:30 -0500 | [diff] [blame] | 89 | EXPORT_SYMBOL(___rw_write_enter) |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | ___rw_write_enter: |
| 91 | orcc %g2, 0x0, %g0 |
| 92 | bne ___rw_write_enter_spin_on_wlock |
| 93 | ld [%g1], %g2 |
| 94 | andncc %g2, 0xff, %g0 |
| 95 | bne,a ___rw_write_enter_spin_on_wlock |
| 96 | stb %g0, [%g1 + 3] |
| 97 | retl |
| 98 | mov %g4, %o7 |