linux/arch/sparc/lib/rwsem.S
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

206 lines
2.9 KiB
ArmAsm

/* $Id: rwsem.S,v 1.5 2000/05/09 17:40:13 davem Exp $
* Assembly part of rw semaphores.
*
* Copyright (C) 1999 Jakub Jelinek (jakub@redhat.com)
*/
#include <linux/config.h>
#include <asm/ptrace.h>
#include <asm/psr.h>
.section .sched.text
.align 4
.globl ___down_read
___down_read:
rd %psr, %g3
nop
nop
nop
or %g3, PSR_PIL, %g7
wr %g7, 0, %psr
nop
nop
nop
#ifdef CONFIG_SMP
1: ldstub [%g1 + 4], %g7
tst %g7
bne 1b
ld [%g1], %g7
sub %g7, 1, %g7
st %g7, [%g1]
stb %g0, [%g1 + 4]
#else
ld [%g1], %g7
sub %g7, 1, %g7
st %g7, [%g1]
#endif
wr %g3, 0, %psr
add %g7, 1, %g7
nop
nop
subcc %g7, 1, %g7
bneg 3f
nop
2: jmpl %o7, %g0
mov %g4, %o7
3: save %sp, -64, %sp
mov %g1, %l1
mov %g4, %l4
bcs 4f
mov %g5, %l5
call down_read_failed
mov %l1, %o0
mov %l1, %g1
mov %l4, %g4
ba ___down_read
restore %l5, %g0, %g5
4: call down_read_failed_biased
mov %l1, %o0
mov %l1, %g1
mov %l4, %g4
ba 2b
restore %l5, %g0, %g5
.globl ___down_write
___down_write:
rd %psr, %g3
nop
nop
nop
or %g3, PSR_PIL, %g7
wr %g7, 0, %psr
sethi %hi(0x01000000), %g2
nop
nop
#ifdef CONFIG_SMP
1: ldstub [%g1 + 4], %g7
tst %g7
bne 1b
ld [%g1], %g7
sub %g7, %g2, %g7
st %g7, [%g1]
stb %g0, [%g1 + 4]
#else
ld [%g1], %g7
sub %g7, %g2, %g7
st %g7, [%g1]
#endif
wr %g3, 0, %psr
add %g7, %g2, %g7
nop
nop
subcc %g7, %g2, %g7
bne 3f
nop
2: jmpl %o7, %g0
mov %g4, %o7
3: save %sp, -64, %sp
mov %g1, %l1
mov %g4, %l4
bcs 4f
mov %g5, %l5
call down_write_failed
mov %l1, %o0
mov %l1, %g1
mov %l4, %g4
ba ___down_write
restore %l5, %g0, %g5
4: call down_write_failed_biased
mov %l1, %o0
mov %l1, %g1
mov %l4, %g4
ba 2b
restore %l5, %g0, %g5
.text
.globl ___up_read
___up_read:
rd %psr, %g3
nop
nop
nop
or %g3, PSR_PIL, %g7
wr %g7, 0, %psr
nop
nop
nop
#ifdef CONFIG_SMP
1: ldstub [%g1 + 4], %g7
tst %g7
bne 1b
ld [%g1], %g7
add %g7, 1, %g7
st %g7, [%g1]
stb %g0, [%g1 + 4]
#else
ld [%g1], %g7
add %g7, 1, %g7
st %g7, [%g1]
#endif
wr %g3, 0, %psr
nop
nop
nop
cmp %g7, 0
be 3f
nop
2: jmpl %o7, %g0
mov %g4, %o7
3: save %sp, -64, %sp
mov %g1, %l1
mov %g4, %l4
mov %g5, %l5
clr %o1
call __rwsem_wake
mov %l1, %o0
mov %l1, %g1
mov %l4, %g4
ba 2b
restore %l5, %g0, %g5
.globl ___up_write
___up_write:
rd %psr, %g3
nop
nop
nop
or %g3, PSR_PIL, %g7
wr %g7, 0, %psr
sethi %hi(0x01000000), %g2
nop
nop
#ifdef CONFIG_SMP
1: ldstub [%g1 + 4], %g7
tst %g7
bne 1b
ld [%g1], %g7
add %g7, %g2, %g7
st %g7, [%g1]
stb %g0, [%g1 + 4]
#else
ld [%g1], %g7
add %g7, %g2, %g7
st %g7, [%g1]
#endif
wr %g3, 0, %psr
sub %g7, %g2, %g7
nop
nop
addcc %g7, %g2, %g7
bcs 3f
nop
2: jmpl %o7, %g0
mov %g4, %o7
3: save %sp, -64, %sp
mov %g1, %l1
mov %g4, %l4
mov %g5, %l5
mov %g7, %o1
call __rwsem_wake
mov %l1, %o0
mov %l1, %g1
mov %l4, %g4
ba 2b
restore %l5, %g0, %g5