You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
243 lines
4.1 KiB
243 lines
4.1 KiB
20 years ago
|
/*
|
||
|
* This file is subject to the terms and conditions of the GNU General Public
|
||
|
* License. See the file "COPYING" in the main directory of this archive
|
||
|
* for more details.
|
||
|
*
|
||
|
* Quick'n'dirty IP checksum ...
|
||
|
*
|
||
|
* Copyright (C) 1998, 1999 Ralf Baechle
|
||
|
* Copyright (C) 1999 Silicon Graphics, Inc.
|
||
|
*/
|
||
|
#include <asm/asm.h>
|
||
|
#include <asm/regdef.h>
|
||
|
|
||
|
#define ADDC(sum,reg) \
|
||
|
addu sum, reg; \
|
||
|
sltu v1, sum, reg; \
|
||
|
addu sum, v1
|
||
|
|
||
|
#define CSUM_BIGCHUNK(src, offset, sum, t0, t1, t2, t3) \
|
||
|
lw t0, (offset + 0x00)(src); \
|
||
|
lw t1, (offset + 0x04)(src); \
|
||
|
lw t2, (offset + 0x08)(src); \
|
||
|
lw t3, (offset + 0x0c)(src); \
|
||
|
ADDC(sum, t0); \
|
||
|
ADDC(sum, t1); \
|
||
|
ADDC(sum, t2); \
|
||
|
ADDC(sum, t3); \
|
||
|
lw t0, (offset + 0x10)(src); \
|
||
|
lw t1, (offset + 0x14)(src); \
|
||
|
lw t2, (offset + 0x18)(src); \
|
||
|
lw t3, (offset + 0x1c)(src); \
|
||
|
ADDC(sum, t0); \
|
||
|
ADDC(sum, t1); \
|
||
|
ADDC(sum, t2); \
|
||
|
ADDC(sum, t3); \
|
||
|
|
||
|
/*
|
||
|
* a0: source address
|
||
|
* a1: length of the area to checksum
|
||
|
* a2: partial checksum
|
||
|
*/
|
||
|
|
||
|
#define src a0
|
||
|
#define sum v0
|
||
|
|
||
|
.text
|
||
|
.set noreorder
|
||
|
|
||
|
/* unknown src alignment and < 8 bytes to go */
|
||
|
small_csumcpy:
|
||
|
move a1, ta2
|
||
|
|
||
|
andi ta0, a1, 4
|
||
|
beqz ta0, 1f
|
||
|
andi ta0, a1, 2
|
||
|
|
||
|
/* Still a full word to go */
|
||
|
ulw ta1, (src)
|
||
|
daddiu src, 4
|
||
|
ADDC(sum, ta1)
|
||
|
|
||
|
1: move ta1, zero
|
||
|
beqz ta0, 1f
|
||
|
andi ta0, a1, 1
|
||
|
|
||
|
/* Still a halfword to go */
|
||
|
ulhu ta1, (src)
|
||
|
daddiu src, 2
|
||
|
|
||
|
1: beqz ta0, 1f
|
||
|
sll ta1, ta1, 16
|
||
|
|
||
|
lbu ta2, (src)
|
||
|
nop
|
||
|
|
||
|
#ifdef __MIPSEB__
|
||
|
sll ta2, ta2, 8
|
||
|
#endif
|
||
|
or ta1, ta2
|
||
|
|
||
|
1: ADDC(sum, ta1)
|
||
|
|
||
|
/* fold checksum */
|
||
|
sll v1, sum, 16
|
||
|
addu sum, v1
|
||
|
sltu v1, sum, v1
|
||
|
srl sum, sum, 16
|
||
|
addu sum, v1
|
||
|
|
||
|
/* odd buffer alignment? */
|
||
|
beqz t3, 1f
|
||
|
nop
|
||
|
sll v1, sum, 8
|
||
|
srl sum, sum, 8
|
||
|
or sum, v1
|
||
|
andi sum, 0xffff
|
||
|
1:
|
||
|
.set reorder
|
||
|
/* Add the passed partial csum. */
|
||
|
ADDC(sum, a2)
|
||
|
jr ra
|
||
|
.set noreorder
|
||
|
|
||
|
/* ------------------------------------------------------------------------- */
|
||
|
|
||
|
.align 5
|
||
|
LEAF(csum_partial)
|
||
|
move sum, zero
|
||
|
move t3, zero
|
||
|
|
||
|
sltiu t8, a1, 0x8
|
||
|
bnez t8, small_csumcpy /* < 8 bytes to copy */
|
||
|
move ta2, a1
|
||
|
|
||
|
beqz a1, out
|
||
|
andi t3, src, 0x1 /* odd buffer? */
|
||
|
|
||
|
hword_align:
|
||
|
beqz t3, word_align
|
||
|
andi t8, src, 0x2
|
||
|
|
||
|
lbu ta0, (src)
|
||
|
dsubu a1, a1, 0x1
|
||
|
#ifdef __MIPSEL__
|
||
|
sll ta0, ta0, 8
|
||
|
#endif
|
||
|
ADDC(sum, ta0)
|
||
|
daddu src, src, 0x1
|
||
|
andi t8, src, 0x2
|
||
|
|
||
|
word_align:
|
||
|
beqz t8, dword_align
|
||
|
sltiu t8, a1, 56
|
||
|
|
||
|
lhu ta0, (src)
|
||
|
dsubu a1, a1, 0x2
|
||
|
ADDC(sum, ta0)
|
||
|
sltiu t8, a1, 56
|
||
|
daddu src, src, 0x2
|
||
|
|
||
|
dword_align:
|
||
|
bnez t8, do_end_words
|
||
|
move t8, a1
|
||
|
|
||
|
andi t8, src, 0x4
|
||
|
beqz t8, qword_align
|
||
|
andi t8, src, 0x8
|
||
|
|
||
|
lw ta0, 0x00(src)
|
||
|
dsubu a1, a1, 0x4
|
||
|
ADDC(sum, ta0)
|
||
|
daddu src, src, 0x4
|
||
|
andi t8, src, 0x8
|
||
|
|
||
|
qword_align:
|
||
|
beqz t8, oword_align
|
||
|
andi t8, src, 0x10
|
||
|
|
||
|
lw ta0, 0x00(src)
|
||
|
lw ta1, 0x04(src)
|
||
|
dsubu a1, a1, 0x8
|
||
|
ADDC(sum, ta0)
|
||
|
ADDC(sum, ta1)
|
||
|
daddu src, src, 0x8
|
||
|
andi t8, src, 0x10
|
||
|
|
||
|
oword_align:
|
||
|
beqz t8, begin_movement
|
||
|
dsrl t8, a1, 0x7
|
||
|
|
||
|
lw ta3, 0x08(src)
|
||
|
lw t0, 0x0c(src)
|
||
|
lw ta0, 0x00(src)
|
||
|
lw ta1, 0x04(src)
|
||
|
ADDC(sum, ta3)
|
||
|
ADDC(sum, t0)
|
||
|
ADDC(sum, ta0)
|
||
|
ADDC(sum, ta1)
|
||
|
dsubu a1, a1, 0x10
|
||
|
daddu src, src, 0x10
|
||
|
dsrl t8, a1, 0x7
|
||
|
|
||
|
begin_movement:
|
||
|
beqz t8, 1f
|
||
|
andi ta2, a1, 0x40
|
||
|
|
||
|
move_128bytes:
|
||
|
CSUM_BIGCHUNK(src, 0x00, sum, ta0, ta1, ta3, t0)
|
||
|
CSUM_BIGCHUNK(src, 0x20, sum, ta0, ta1, ta3, t0)
|
||
|
CSUM_BIGCHUNK(src, 0x40, sum, ta0, ta1, ta3, t0)
|
||
|
CSUM_BIGCHUNK(src, 0x60, sum, ta0, ta1, ta3, t0)
|
||
|
dsubu t8, t8, 0x01
|
||
|
bnez t8, move_128bytes
|
||
|
daddu src, src, 0x80
|
||
|
|
||
|
1:
|
||
|
beqz ta2, 1f
|
||
|
andi ta2, a1, 0x20
|
||
|
|
||
|
move_64bytes:
|
||
|
CSUM_BIGCHUNK(src, 0x00, sum, ta0, ta1, ta3, t0)
|
||
|
CSUM_BIGCHUNK(src, 0x20, sum, ta0, ta1, ta3, t0)
|
||
|
daddu src, src, 0x40
|
||
|
|
||
|
1:
|
||
|
beqz ta2, do_end_words
|
||
|
andi t8, a1, 0x1c
|
||
|
|
||
|
move_32bytes:
|
||
|
CSUM_BIGCHUNK(src, 0x00, sum, ta0, ta1, ta3, t0)
|
||
|
andi t8, a1, 0x1c
|
||
|
daddu src, src, 0x20
|
||
|
|
||
|
do_end_words:
|
||
|
beqz t8, maybe_end_cruft
|
||
|
dsrl t8, t8, 0x2
|
||
|
|
||
|
end_words:
|
||
|
lw ta0, (src)
|
||
|
dsubu t8, t8, 0x1
|
||
|
ADDC(sum, ta0)
|
||
|
bnez t8, end_words
|
||
|
daddu src, src, 0x4
|
||
|
|
||
|
maybe_end_cruft:
|
||
|
andi ta2, a1, 0x3
|
||
|
|
||
|
small_memcpy:
|
||
|
j small_csumcpy; move a1, ta2 /* XXX ??? */
|
||
|
beqz t2, out
|
||
|
move a1, ta2
|
||
|
|
||
|
end_bytes:
|
||
|
lb ta0, (src)
|
||
|
dsubu a1, a1, 0x1
|
||
|
bnez a2, end_bytes
|
||
|
daddu src, src, 0x1
|
||
|
|
||
|
out:
|
||
|
jr ra
|
||
|
move v0, sum
|
||
|
END(csum_partial)
|