linux/arch/mn10300/lib/memset.S
David Howells b920de1b77 mn10300: add the MN10300/AM33 architecture to the kernel
Add architecture support for the MN10300/AM33 CPUs produced by MEI to the
kernel.

This patch also adds board support for the ASB2303 with the ASB2308 daughter
board, and the ASB2305.  The only processor supported is the MN103E010, which
is an AM33v2 core plus on-chip devices.

[akpm@linux-foundation.org: nuke cvs control strings]
Signed-off-by: Masakazu Urade <urade.masakazu@jp.panasonic.com>
Signed-off-by: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:30 -08:00

122 lines
2.3 KiB
ArmAsm

/* Optimised simple memory fill
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <asm/cache.h>
.section .text
.balign L1_CACHE_BYTES
###############################################################################
#
# void *memset(void *dst, int c, size_t n)
#
###############################################################################
.globl memset
.type memset,@function
memset:
movm [d2,d3],(sp)
mov d0,(12,sp)
mov d1,(16,sp)
mov (20,sp),d2 # count
mov d0,a0 # dst
mov d0,e3 # the return value
cmp +0,d2
beq memset_done # return if zero-length fill
# see if the region parameters are four-byte aligned
or d0,d2,d3
and +3,d3
bne memset_1 # jump if not
extbu d1
mov_asl d1,d3,8,d1
or_asl d1,d3,8,d1
or_asl d1,d3,8,d1
or d3,d1
# we want to transfer as much as we can in chunks of 32 bytes
cmp +31,d2
bls memset_4_remainder # 4-byte aligned remainder
add -32,d2
mov +32,d3
memset_4_loop:
mov d1,(a0+)
mov d1,(a0+)
mov d1,(a0+)
mov d1,(a0+)
mov d1,(a0+)
mov d1,(a0+)
mov d1,(a0+)
mov d1,(a0+)
sub d3,d2
bcc memset_4_loop
add d3,d2
beq memset_4_no_remainder
memset_4_remainder:
# cut 4-7 words down to 0-3
cmp +16,d2
bcs memset_4_three_or_fewer_words
mov d1,(a0+)
mov d1,(a0+)
mov d1,(a0+)
mov d1,(a0+)
add -16,d2
beq memset_4_no_remainder
# copy the remaining 1, 2 or 3 words
memset_4_three_or_fewer_words:
cmp +8,d2
bcs memset_4_one_word
beq memset_4_two_words
mov d1,(a0+)
memset_4_two_words:
mov d1,(a0+)
memset_4_one_word:
mov d1,(a0+)
memset_4_no_remainder:
# check we set the correct amount
# TODO: REMOVE CHECK
sub e3,a0,d2
mov (20,sp),d1
cmp d2,d1
beq memset_done
break
break
break
memset_done:
mov e3,a0
ret [d2,d3],8
# handle misaligned copying
memset_1:
add -1,d2
mov +1,d3
setlb # setlb requires the next insns
# to occupy exactly 4 bytes
sub d3,d2
movbu d1,(a0)
inc a0
lcc
mov e3,a0
ret [d2,d3],8
memset_end:
.size memset, memset_end-memset