linux/arch/mn10300/lib/memmove.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

161 lines
3.0 KiB
ArmAsm

/* MN10300 Optimised simple memory to memory copy, with support for overlapping
* regions
*
* 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 *memmove(void *dst, const void *src, size_t n)
#
###############################################################################
.globl memmove
.type memmove,@function
memmove:
# fall back to memcpy if dst < src to work bottom up
cmp d1,d0
bcs memmove_memcpy
# work top down
movm [d2,d3],(sp)
mov d0,(12,sp)
mov d1,(16,sp)
mov (20,sp),d2 # count
add d0,d2,a0 # dst end
add d1,d2,a1 # src end
mov d0,e3 # the return value
cmp +0,d2
beq memmove_done # return if zero-length copy
# see if the three parameters are all four-byte aligned
or d0,d1,d3
or d2,d3
and +3,d3
bne memmove_1 # jump if not
# we want to transfer as much as we can in chunks of 32 bytes
add -4,a1
cmp +31,d2
bls memmove_4_remainder # 4-byte aligned remainder
add -32,d2
mov +32,d3
memmove_4_loop:
mov (a1),d0
sub_sub +4,a1,+4,a0
mov d0,(a0)
mov (a1),d1
sub_sub +4,a1,+4,a0
mov d1,(a0)
mov (a1),d0
sub_sub +4,a1,+4,a0
mov d0,(a0)
mov (a1),d1
sub_sub +4,a1,+4,a0
mov d1,(a0)
mov (a1),d0
sub_sub +4,a1,+4,a0
mov d0,(a0)
mov (a1),d1
sub_sub +4,a1,+4,a0
mov d1,(a0)
mov (a1),d0
sub_sub +4,a1,+4,a0
mov d0,(a0)
mov (a1),d1
sub_sub +4,a1,+4,a0
mov d1,(a0)
sub d3,d2
bcc memmove_4_loop
add d3,d2
beq memmove_4_no_remainder
memmove_4_remainder:
# cut 4-7 words down to 0-3
cmp +16,d2
bcs memmove_4_three_or_fewer_words
mov (a1),d0
sub_sub +4,a1,+4,a0
mov d0,(a0)
mov (a1),d1
sub_sub +4,a1,+4,a0
mov d1,(a0)
mov (a1),e0
sub_sub +4,a1,+4,a0
mov e0,(a0)
mov (a1),e1
sub_sub +4,a1,+4,a0
mov e1,(a0)
add -16,d2
beq memmove_4_no_remainder
# copy the remaining 1, 2 or 3 words
memmove_4_three_or_fewer_words:
cmp +8,d2
bcs memmove_4_one_word
beq memmove_4_two_words
mov (a1),d0
sub_sub +4,a1,+4,a0
mov d0,(a0)
memmove_4_two_words:
mov (a1),d0
sub_sub +4,a1,+4,a0
mov d0,(a0)
memmove_4_one_word:
mov (a1),d0
sub_sub +4,a1,+4,a0
mov d0,(a0)
memmove_4_no_remainder:
# check we copied the correct amount
# TODO: REMOVE CHECK
sub e3,a0,d2
beq memmove_done
break
break
break
memmove_done:
mov e3,a0
ret [d2,d3],8
# handle misaligned copying
memmove_1:
add -1,a1
add -1,d2
mov +1,d3
setlb # setlb requires the next insns
# to occupy exactly 4 bytes
sub d3,d2
movbu (a1),d0
sub_sub d3,a1,d3,a0
movbu d0,(a0)
lcc
mov e3,a0
ret [d2,d3],8
memmove_memcpy:
jmp memcpy
memmove_end:
.size memmove, memmove_end-memmove