/* | |
* 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 |