| /* |
| * locks.S: SMP low-level lock primitives on Sparc. |
| * |
| * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) |
| * Copyright (C) 1998 Anton Blanchard (anton@progsoc.uts.edu.au) |
| * Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz) |
| */ |
| |
| #include <asm/ptrace.h> |
| #include <asm/psr.h> |
| #include <asm/smp.h> |
| #include <asm/spinlock.h> |
| |
| .text |
| .align 4 |
| |
| /* Read/writer locks, as usual this is overly clever to make it |
| * as fast as possible. |
| */ |
| |
| /* caches... */ |
| ___rw_read_enter_spin_on_wlock: |
| orcc %g2, 0x0, %g0 |
| be,a ___rw_read_enter |
| ldstub [%g1 + 3], %g2 |
| b ___rw_read_enter_spin_on_wlock |
| ldub [%g1 + 3], %g2 |
| ___rw_read_try_spin_on_wlock: |
| andcc %g2, 0xff, %g0 |
| be,a ___rw_read_try |
| ldstub [%g1 + 3], %g2 |
| xnorcc %g2, 0x0, %o0 /* if g2 is ~0, set o0 to 0 and bugger off */ |
| bne,a ___rw_read_enter_spin_on_wlock |
| ld [%g1], %g2 |
| retl |
| mov %g4, %o7 |
| ___rw_read_exit_spin_on_wlock: |
| orcc %g2, 0x0, %g0 |
| be,a ___rw_read_exit |
| ldstub [%g1 + 3], %g2 |
| b ___rw_read_exit_spin_on_wlock |
| ldub [%g1 + 3], %g2 |
| ___rw_write_enter_spin_on_wlock: |
| orcc %g2, 0x0, %g0 |
| be,a ___rw_write_enter |
| ldstub [%g1 + 3], %g2 |
| b ___rw_write_enter_spin_on_wlock |
| ld [%g1], %g2 |
| |
| .globl ___rw_read_enter |
| ___rw_read_enter: |
| orcc %g2, 0x0, %g0 |
| bne,a ___rw_read_enter_spin_on_wlock |
| ldub [%g1 + 3], %g2 |
| ld [%g1], %g2 |
| add %g2, 1, %g2 |
| st %g2, [%g1] |
| retl |
| mov %g4, %o7 |
| |
| .globl ___rw_read_exit |
| ___rw_read_exit: |
| orcc %g2, 0x0, %g0 |
| bne,a ___rw_read_exit_spin_on_wlock |
| ldub [%g1 + 3], %g2 |
| ld [%g1], %g2 |
| sub %g2, 0x1ff, %g2 |
| st %g2, [%g1] |
| retl |
| mov %g4, %o7 |
| |
| .globl ___rw_read_try |
| ___rw_read_try: |
| orcc %g2, 0x0, %g0 |
| bne ___rw_read_try_spin_on_wlock |
| ld [%g1], %g2 |
| add %g2, 1, %g2 |
| st %g2, [%g1] |
| set 1, %o1 |
| retl |
| mov %g4, %o7 |
| |
| .globl ___rw_write_enter |
| ___rw_write_enter: |
| orcc %g2, 0x0, %g0 |
| bne ___rw_write_enter_spin_on_wlock |
| ld [%g1], %g2 |
| andncc %g2, 0xff, %g0 |
| bne,a ___rw_write_enter_spin_on_wlock |
| stb %g0, [%g1 + 3] |
| retl |
| mov %g4, %o7 |