linux/arch/sparc/lib/bitops.S
David S. Miller 0f58189d4a sparc64: Make lock backoff really a NOP on UP builds.
As noticed by Mikulas Patocka, the backoff macros don't
completely nop out for UP builds, we still get a
branch always and a delay slot nop.

Fix this by making the branch to the backoff spin loop
selective, then we can nop out the spin loop completely.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-18 22:53:26 -07:00

142 lines
2.7 KiB
ArmAsm

/* bitops.S: Sparc64 atomic bit operations.
*
* Copyright (C) 2000, 2007 David S. Miller (davem@davemloft.net)
*/
#include <asm/asi.h>
#include <asm/backoff.h>
.text
.globl test_and_set_bit
.type test_and_set_bit,#function
test_and_set_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
and %o0, 63, %g2
sllx %o2, %g2, %o2
add %o1, %g3, %o1
1: ldx [%o1], %g7
or %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
.size test_and_set_bit, .-test_and_set_bit
.globl test_and_clear_bit
.type test_and_clear_bit,#function
test_and_clear_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
and %o0, 63, %g2
sllx %o2, %g2, %o2
add %o1, %g3, %o1
1: ldx [%o1], %g7
andn %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
.size test_and_clear_bit, .-test_and_clear_bit
.globl test_and_change_bit
.type test_and_change_bit,#function
test_and_change_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
and %o0, 63, %g2
sllx %o2, %g2, %o2
add %o1, %g3, %o1
1: ldx [%o1], %g7
xor %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
.size test_and_change_bit, .-test_and_change_bit
.globl set_bit
.type set_bit,#function
set_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
and %o0, 63, %g2
sllx %o2, %g2, %o2
add %o1, %g3, %o1
1: ldx [%o1], %g7
or %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
.size set_bit, .-set_bit
.globl clear_bit
.type clear_bit,#function
clear_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
and %o0, 63, %g2
sllx %o2, %g2, %o2
add %o1, %g3, %o1
1: ldx [%o1], %g7
andn %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
.size clear_bit, .-clear_bit
.globl change_bit
.type change_bit,#function
change_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
and %o0, 63, %g2
sllx %o2, %g2, %o2
add %o1, %g3, %o1
1: ldx [%o1], %g7
xor %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
.size change_bit, .-change_bit