1
linux/arch/blackfin/lib/outs.S
Mike Frysinger bb7b11290a Blackfin: outs[lwb]: make sure count is greater than 0
Some devices will use the outs* funcs with a length of zero, so make sure
we do not write any data in that case.

Reported-by: Gilbert Inho <gneny@edevice.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2011-03-04 01:26:55 -05:00

69 lines
1.3 KiB
ArmAsm

/*
* Implementation of outs{bwl} for BlackFin processors using zero overhead loops.
*
* Copyright 2005-2009 Analog Devices Inc.
* 2005 BuyWays BV
* Bas Vermeulen <bas@buyways.nl>
*
* Licensed under the GPL-2.
*/
#include <linux/linkage.h>
.align 2
ENTRY(_outsl)
CC = R2 == 0;
IF CC JUMP 1f;
P0 = R0; /* P0 = port */
P1 = R1; /* P1 = address */
P2 = R2; /* P2 = count */
LSETUP( .Llong_loop_s, .Llong_loop_e) LC0 = P2;
.Llong_loop_s: R0 = [P1++];
.Llong_loop_e: [P0] = R0;
1: RTS;
ENDPROC(_outsl)
ENTRY(_outsw)
CC = R2 == 0;
IF CC JUMP 1f;
P0 = R0; /* P0 = port */
P1 = R1; /* P1 = address */
P2 = R2; /* P2 = count */
LSETUP( .Lword_loop_s, .Lword_loop_e) LC0 = P2;
.Lword_loop_s: R0 = W[P1++];
.Lword_loop_e: W[P0] = R0;
1: RTS;
ENDPROC(_outsw)
ENTRY(_outsb)
CC = R2 == 0;
IF CC JUMP 1f;
P0 = R0; /* P0 = port */
P1 = R1; /* P1 = address */
P2 = R2; /* P2 = count */
LSETUP( .Lbyte_loop_s, .Lbyte_loop_e) LC0 = P2;
.Lbyte_loop_s: R0 = B[P1++];
.Lbyte_loop_e: B[P0] = R0;
1: RTS;
ENDPROC(_outsb)
ENTRY(_outsw_8)
CC = R2 == 0;
IF CC JUMP 1f;
P0 = R0; /* P0 = port */
P1 = R1; /* P1 = address */
P2 = R2; /* P2 = count */
LSETUP( .Lword8_loop_s, .Lword8_loop_e) LC0 = P2;
.Lword8_loop_s: R1 = B[P1++];
R0 = B[P1++];
R0 = R0 << 8;
R0 = R0 + R1;
.Lword8_loop_e: W[P0] = R0;
1: RTS;
ENDPROC(_outsw_8)