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/* $Id: rwsem.S,v 1.2 2000/01/05 01:00:38 davem Exp $
 * Assembly part of rw semaphores.
 *
 * Copyright (C) 1999 Jakub Jelinek (jakub@redhat.com)
 */

#include <asm/ptrace.h>
#include <asm/psr.h>

	.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 __SMP__
1:	ldstub		[%g1 + 4], %g7
	tst		%g7
	bne		1b
	 ld		[%g1], %g7
	subcc		%g7, 1, %g7
	st		%g7, [%g1]
	stb		%g0, [%g1 + 4]
#else
	ld		[%g1], %g7
	subcc		%g7, 1, %g7
	st		%g7, [%g1]
#endif
	wr		%g3, 0, %psr
	nop
	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 __SMP__
1:	ldstub		[%g1 + 4], %g7
	tst		%g7
	bne		1b
	 ld		[%g1], %g7
	subcc		%g7, %g2, %g7
	st		%g7, [%g1]
	stb		%g0, [%g1 + 4]
#else
	ld		[%g1], %g7
	subcc		%g7, %g2, %g7
	st		%g7, [%g1]
#endif
	wr		%g3, 0, %psr
	nop
	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

	.globl		___up_read
___up_read:
	rd		%psr, %g3
	nop
	nop
	nop
	or		%g3, PSR_PIL, %g7
	wr		%g7, 0, %psr
	nop
	nop
	nop
#ifdef __SMP__
1:	ldstub		[%g1 + 4], %g7
	tst		%g7
	bne		1b
	 ld		[%g1], %g7
	addcc		%g7, 1, %g7
	st		%g7, [%g1]
	stb		%g0, [%g1 + 4]
#else
	ld		[%g1], %g7
	addcc		%g7, 1, %g7
	st		%g7, [%g1]
#endif
	wr		%g3, 0, %psr
	nop
	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 __SMP__
1:	ldstub		[%g1 + 4], %g7
	tst		%g7
	bne		1b
	 ld		[%g1], %g7
	addcc		%g7, %g2, %g7
	st		%g7, [%g1]
	stb		%g0, [%g1 + 4]
#else
	ld		[%g1], %g7
	addcc		%g7, %g2, %g7
	st		%g7, [%g1]
#endif
	wr		%g3, 0, %psr
	nop
	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