linux/arch/score/lib/checksum.S

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/*
* arch/score/lib/csum_partial.S
*
* Score Processor version.
*
* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
* Lennox Wu <lennox.wu@sunplusct.com>
* Chen Liqin <liqin.chen@sunplusct.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/linkage.h>
#define ADDC(sum,reg) \
add sum, sum, reg; \
cmp.c reg, sum; \
bleu 9f; \
addi sum, 0x1; \
9:
#define CSUM_BIGCHUNK(src, offset, sum) \
lw r8, [src, offset + 0x00]; \
lw r9, [src, offset + 0x04]; \
lw r10, [src, offset + 0x08]; \
lw r11, [src, offset + 0x0c]; \
ADDC(sum, r8); \
ADDC(sum, r9); \
ADDC(sum, r10); \
ADDC(sum, r11); \
lw r8, [src, offset + 0x10]; \
lw r9, [src, offset + 0x14]; \
lw r10, [src, offset + 0x18]; \
lw r11, [src, offset + 0x1c]; \
ADDC(sum, r8); \
ADDC(sum, r9); \
ADDC(sum, r10); \
ADDC(sum, r11); \
#define src r4
#define dest r5
#define sum r27
.text
/* unknown src alignment and < 8 bytes to go */
small_csumcpy:
mv r5, r10
ldi r9, 0x0
cmpi.c r25, 0x1
beq pass_small_set_t7 /*already set, jump to pass_small_set_t7*/
andri.c r25,r4 , 0x1 /*Is src 2 bytes aligned?*/
pass_small_set_t7:
beq aligned
cmpi.c r5, 0x0
beq fold
lbu r9, [src]
slli r9,r9, 0x8 /*Little endian*/
ADDC(sum, r9)
addi src, 0x1
subi.c r5, 0x1
/*len still a full word */
aligned:
andri.c r8, r5, 0x4 /*Len >= 4?*/
beq len_less_4bytes
/* Still a full word (4byte) to go,and the src is word aligned.*/
andri.c r8, src, 0x3 /*src is 4bytes aligned, so use LW!!*/
beq four_byte_aligned
lhu r9, [src]
addi src, 2
ADDC(sum, r9)
lhu r9, [src]
addi src, 2
ADDC(sum, r9)
b len_less_4bytes
four_byte_aligned: /* Len >=4 and four byte aligned */
lw r9, [src]
addi src, 4
ADDC(sum, r9)
len_less_4bytes: /* 2 byte aligned aligned and length<4B */
andri.c r8, r5, 0x2
beq len_less_2bytes
lhu r9, [src]
addi src, 0x2 /* src+=2 */
ADDC(sum, r9)
len_less_2bytes: /* len = 1 */
andri.c r8, r5, 0x1
beq fold /* less than 2 and not equal 1--> len=0 -> fold */
lbu r9, [src]
fold_ADDC:
ADDC(sum, r9)
fold:
/* fold checksum */
slli r26, sum, 16
add sum, sum, r26
cmp.c r26, sum
srli sum, sum, 16
bleu 1f /* if r26<=sum */
addi sum, 0x1 /* r26>sum */
1:
/* odd buffer alignment? r25 was set in csum_partial */
cmpi.c r25, 0x0
beq 1f
slli r26, sum, 8
srli sum, sum, 8
or sum, sum, r26
andi sum, 0xffff
1:
.set optimize
/* Add the passed partial csum. */
ADDC(sum, r6)
mv r4, sum
br r3
.set volatile
.align 5
ENTRY(csum_partial)
ldi sum, 0
ldi r25, 0
mv r10, r5
cmpi.c r5, 0x8
blt small_csumcpy /* < 8(signed) bytes to copy */
cmpi.c r5, 0x0
beq out
andri.c r25, src, 0x1 /* odd buffer? */
beq word_align
hword_align: /* 1 byte */
lbu r8, [src]
subi r5, 0x1
slli r8, r8, 8
ADDC(sum, r8)
addi src, 0x1
word_align: /* 2 bytes */
andri.c r8, src, 0x2 /* 4bytes(dword)_aligned? */
beq dword_align /* not, maybe dword_align */
lhu r8, [src]
subi r5, 0x2
ADDC(sum, r8)
addi src, 0x2
dword_align: /* 4bytes */
mv r26, r5 /* maybe useless when len >=56 */
ldi r8, 56
cmp.c r8, r5
bgtu do_end_words /* if a1(len)<t0(56) ,unsigned */
andri.c r26, src, 0x4
beq qword_align
lw r8, [src]
subi r5, 0x4
ADDC(sum, r8)
addi src, 0x4
qword_align: /* 8 bytes */
andri.c r26, src, 0x8
beq oword_align
lw r8, [src, 0x0]
lw r9, [src, 0x4]
subi r5, 0x8 /* len-=0x8 */
ADDC(sum, r8)
ADDC(sum, r9)
addi src, 0x8
oword_align: /* 16bytes */
andri.c r26, src, 0x10
beq begin_movement
lw r10, [src, 0x08]
lw r11, [src, 0x0c]
lw r8, [src, 0x00]
lw r9, [src, 0x04]
ADDC(sum, r10)
ADDC(sum, r11)
ADDC(sum, r8)
ADDC(sum, r9)
subi r5, 0x10
addi src, 0x10
begin_movement:
srli.c r26, r5, 0x7 /* len>=128? */
beq 1f /* len<128 */
/* r26 is the result that computed in oword_align */
move_128bytes:
CSUM_BIGCHUNK(src, 0x00, sum)
CSUM_BIGCHUNK(src, 0x20, sum)
CSUM_BIGCHUNK(src, 0x40, sum)
CSUM_BIGCHUNK(src, 0x60, sum)
subi.c r26, 0x01 /* r26 equals len/128 */
addi src, 0x80
bne move_128bytes
1: /* len<128,we process 64byte here */
andri.c r10, r5, 0x40
beq 1f
move_64bytes:
CSUM_BIGCHUNK(src, 0x00, sum)
CSUM_BIGCHUNK(src, 0x20, sum)
addi src, 0x40
1: /* len<64 */
andri r26, r5, 0x1c /* 0x1c=28 */
andri.c r10, r5, 0x20
beq do_end_words /* decided by andri */
move_32bytes:
CSUM_BIGCHUNK(src, 0x00, sum)
andri r26, r5, 0x1c
addri src, src, 0x20
do_end_words: /* len<32 */
/* r26 was set already in dword_align */
cmpi.c r26, 0x0
beq maybe_end_cruft /* len<28 or len<56 */
srli r26, r26, 0x2
end_words:
lw r8, [src]
subi.c r26, 0x1 /* unit is 4 byte */
ADDC(sum, r8)
addi src, 0x4
cmpi.c r26, 0x0
bne end_words /* r26!=0 */
maybe_end_cruft: /* len<4 */
andri r10, r5, 0x3
small_memcpy:
mv r5, r10
j small_csumcpy
out:
mv r4, sum
br r3
END(csum_partial)