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/* rwsem.S: RW semaphore assembler.
*
* Written by David S. Miller (davem@redhat.com), 2001.
* Derived from asm-i386/rwsem.h
*/
#include <asm/rwsem-const.h>
.section .sched.text
.globl __down_read
__down_read:
1: lduw [%o0], %g1
add %g1, 1, %g7
cas [%o0], %g1, %g7
cmp %g1, %g7
bne,pn %icc, 1b
add %g7, 1, %g7
cmp %g7, 0
bl,pn %icc, 3f
membar #StoreLoad | #StoreStore
2:
retl
nop
3:
save %sp, -192, %sp
call rwsem_down_read_failed
mov %i0, %o0
ret
restore
.size __down_read, .-__down_read
.globl __down_read_trylock
__down_read_trylock:
1: lduw [%o0], %g1
add %g1, 1, %g7
cmp %g7, 0
bl,pn %icc, 2f
mov 0, %o1
cas [%o0], %g1, %g7
cmp %g1, %g7
bne,pn %icc, 1b
mov 1, %o1
membar #StoreLoad | #StoreStore
2: retl
mov %o1, %o0
.size __down_read_trylock, .-__down_read_trylock
.globl __down_write
__down_write:
sethi %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1
or %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1
1:
lduw [%o0], %g3
add %g3, %g1, %g7
cas [%o0], %g3, %g7
cmp %g3, %g7
bne,pn %icc, 1b
cmp %g7, 0
bne,pn %icc, 3f
membar #StoreLoad | #StoreStore
2: retl
nop
3:
save %sp, -192, %sp
call rwsem_down_write_failed
mov %i0, %o0
ret
restore
.size __down_write, .-__down_write
.globl __down_write_trylock
__down_write_trylock:
sethi %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1
or %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1
1:
lduw [%o0], %g3
cmp %g3, 0
bne,pn %icc, 2f
mov 0, %o1
add %g3, %g1, %g7
cas [%o0], %g3, %g7
cmp %g3, %g7
bne,pn %icc, 1b
mov 1, %o1
membar #StoreLoad | #StoreStore
2: retl
mov %o1, %o0
.size __down_write_trylock, .-__down_write_trylock
.globl __up_read
__up_read:
1:
lduw [%o0], %g1
sub %g1, 1, %g7
cas [%o0], %g1, %g7
cmp %g1, %g7
bne,pn %icc, 1b
cmp %g7, 0
bl,pn %icc, 3f
membar #StoreLoad | #StoreStore
2: retl
nop
3: sethi %hi(RWSEM_ACTIVE_MASK), %g1
sub %g7, 1, %g7
or %g1, %lo(RWSEM_ACTIVE_MASK), %g1
andcc %g7, %g1, %g0
bne,pn %icc, 2b
nop
save %sp, -192, %sp
call rwsem_wake
mov %i0, %o0
ret
restore
.size __up_read, .-__up_read
.globl __up_write
__up_write:
sethi %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1
or %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1
1:
lduw [%o0], %g3
sub %g3, %g1, %g7
cas [%o0], %g3, %g7
cmp %g3, %g7
bne,pn %icc, 1b
sub %g7, %g1, %g7
cmp %g7, 0
bl,pn %icc, 3f
membar #StoreLoad | #StoreStore
2:
retl
nop
3:
save %sp, -192, %sp
call rwsem_wake
mov %i0, %o0
ret
restore
.size __up_write, .-__up_write
.globl __downgrade_write
__downgrade_write:
sethi %hi(RWSEM_WAITING_BIAS), %g1
or %g1, %lo(RWSEM_WAITING_BIAS), %g1
1:
lduw [%o0], %g3
sub %g3, %g1, %g7
cas [%o0], %g3, %g7
cmp %g3, %g7
bne,pn %icc, 1b
sub %g7, %g1, %g7
cmp %g7, 0
bl,pn %icc, 3f
membar #StoreLoad | #StoreStore
2:
retl
nop
3:
save %sp, -192, %sp
call rwsem_downgrade_wake
mov %i0, %o0
ret
restore
.size __downgrade_write, .-__downgrade_write
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