/* $Id: atomic.S,v 1.4 2001/11/18 00:12:56 davem Exp $
* atomic.S: These things are too big to do inline.
*
* Copyright (C) 1999 David S. Miller (davem@redhat.com)
*/
#include <asm/asi.h>
.text
/* Two versions of the atomic routines, one that
* does not return a value and does not perform
* memory barriers, and a second which returns
* a value and does the barriers.
*/
.globl atomic_add
.type atomic_add,#function
atomic_add: /* %o0 = increment, %o1 = atomic_ptr */
1: lduw [%o1], %g1
add %g1, %o0, %g7
cas [%o1], %g1, %g7
cmp %g1, %g7
bne,pn %icc, 1b
nop
retl
nop
.size atomic_add, .-atomic_add
.globl atomic_sub
.type atomic_sub,#function
atomic_sub: /* %o0 = decrement, %o1 = atomic_ptr */
1: lduw [%o1], %g1
sub %g1, %o0, %g7
cas [%o1], %g1, %g7
cmp %g1, %g7
bne,pn %icc, 1b
nop
retl
nop
.size atomic_sub, .-atomic_sub
/* On SMP we need to use memory barriers to ensure
* correct memory operation ordering, nop these out
* for uniprocessor.
*/
#ifdef CONFIG_SMP
#define ATOMIC_PRE_BARRIER membar #StoreLoad | #LoadLoad;
#define ATOMIC_POST_BARRIER \
ba,pt %xcc, 80b; \
membar #StoreLoad | #StoreStore
80: retl
nop
#else
#define ATOMIC_PRE_BARRIER
#define ATOMIC_POST_BARRIER
#endif
.globl atomic_add_ret
.type atomic_add_ret,#function
atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
ATOMIC_PRE_BARRIER
1: lduw [%o1], %g1
add %g1, %o0, %g7
cas [%o1], %g1, %g7
cmp %g1, %g7
bne,pn %icc, 1b
add %g7, %o0, %g7
sra %g7, 0, %o0
ATOMIC_POST_BARRIER
retl
nop
.size atomic_add_ret, .-atomic_add_ret
.globl atomic_sub_ret
.type atomic_sub_ret,#function
atomic_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
ATOMIC_PRE_BARRIER
1: lduw [%o1], %g1
sub %g1, %o0, %g7
cas [%o1], %g1, %g7
cmp %g1, %g7
bne,pn %icc, 1b
sub %g7, %o0, %g7
sra %g7, 0, %o0
ATOMIC_POST_BARRIER
retl
nop
.size atomic_sub_ret, .-atomic_sub_ret
.globl atomic64_add
.type atomic64_add,#function
atomic64_add: /* %o0 = increment, %o1 = atomic_ptr */
1: ldx [%o1], %g1
add %g1, %o0, %g7
casx [%o1], %g1, %g7
cmp %g1, %g7
bne,pn %xcc, 1b
nop
retl
nop
.size atomic64_add, .-atomic64_add
.globl atomic64_sub
.type atomic64_sub,#function
atomic64_sub: /* %o0 = decrement, %o1 = atomic_ptr */
1: ldx [%o1], %g1
sub %g1, %o0, %g7
casx [%o1], %g1, %g7
cmp %g1, %g7
bne,pn %xcc, 1b
nop
retl
nop
.size atomic64_sub, .-atomic64_sub
.globl atomic64_add_ret
.type atomic64_add_ret,#function
atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
ATOMIC_PRE_BARRIER
1: ldx [%o1], %g1
add %g1, %o0, %g7
casx [%o1], %g1, %g7
cmp %g1, %g7
bne,pn %xcc, 1b
add %g7, %o0, %g7
mov %g7, %o0
ATOMIC_POST_BARRIER
retl
nop
.size atomic64_add_ret, .-atomic64_add_ret
.globl atomic64_sub_ret
.type atomic64_sub_ret,#function
atomic64_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
ATOMIC_PRE_BARRIER
1: ldx [%o1], %g1
sub %g1, %o0, %g7
casx [%o1], %g1, %g7
cmp %g1, %g7
bne,pn %xcc, 1b
sub %g7, %o0, %g7
mov %g7, %o0
ATOMIC_POST_BARRIER
retl
nop
.size atomic64_sub_ret, .-atomic64_sub_ret
