mirror of
https://github.com/torvalds/linux.git
synced 2024-12-15 07:33:56 +00:00
70d64ceaa1
This doesn't change any code, just renames things so we consistently have foo_32.c and foo_64.c where we have separate 32- and 64-bit versions. Signed-off-by: Paul Mackerras <paulus@samba.org>
230 lines
6.0 KiB
ArmAsm
230 lines
6.0 KiB
ArmAsm
/*
|
|
* This file contains assembly-language implementations
|
|
* of IP-style 1's complement checksum routines.
|
|
*
|
|
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
|
|
*
|
|
* 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.
|
|
*
|
|
* Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au).
|
|
*/
|
|
|
|
#include <linux/sys.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/ppc_asm.h>
|
|
|
|
/*
|
|
* ip_fast_csum(r3=buf, r4=len) -- Optimized for IP header
|
|
* len is in words and is always >= 5.
|
|
*
|
|
* In practice len == 5, but this is not guaranteed. So this code does not
|
|
* attempt to use doubleword instructions.
|
|
*/
|
|
_GLOBAL(ip_fast_csum)
|
|
lwz r0,0(r3)
|
|
lwzu r5,4(r3)
|
|
addic. r4,r4,-2
|
|
addc r0,r0,r5
|
|
mtctr r4
|
|
blelr-
|
|
1: lwzu r4,4(r3)
|
|
adde r0,r0,r4
|
|
bdnz 1b
|
|
addze r0,r0 /* add in final carry */
|
|
rldicl r4,r0,32,0 /* fold two 32-bit halves together */
|
|
add r0,r0,r4
|
|
srdi r0,r0,32
|
|
rlwinm r3,r0,16,0,31 /* fold two halves together */
|
|
add r3,r0,r3
|
|
not r3,r3
|
|
srwi r3,r3,16
|
|
blr
|
|
|
|
/*
|
|
* Compute checksum of TCP or UDP pseudo-header:
|
|
* csum_tcpudp_magic(r3=saddr, r4=daddr, r5=len, r6=proto, r7=sum)
|
|
* No real gain trying to do this specially for 64 bit, but
|
|
* the 32 bit addition may spill into the upper bits of
|
|
* the doubleword so we still must fold it down from 64.
|
|
*/
|
|
_GLOBAL(csum_tcpudp_magic)
|
|
rlwimi r5,r6,16,0,15 /* put proto in upper half of len */
|
|
addc r0,r3,r4 /* add 4 32-bit words together */
|
|
adde r0,r0,r5
|
|
adde r0,r0,r7
|
|
rldicl r4,r0,32,0 /* fold 64 bit value */
|
|
add r0,r4,r0
|
|
srdi r0,r0,32
|
|
rlwinm r3,r0,16,0,31 /* fold two halves together */
|
|
add r3,r0,r3
|
|
not r3,r3
|
|
srwi r3,r3,16
|
|
blr
|
|
|
|
/*
|
|
* Computes the checksum of a memory block at buff, length len,
|
|
* and adds in "sum" (32-bit).
|
|
*
|
|
* This code assumes at least halfword alignment, though the length
|
|
* can be any number of bytes. The sum is accumulated in r5.
|
|
*
|
|
* csum_partial(r3=buff, r4=len, r5=sum)
|
|
*/
|
|
_GLOBAL(csum_partial)
|
|
subi r3,r3,8 /* we'll offset by 8 for the loads */
|
|
srdi. r6,r4,3 /* divide by 8 for doubleword count */
|
|
addic r5,r5,0 /* clear carry */
|
|
beq 3f /* if we're doing < 8 bytes */
|
|
andi. r0,r3,2 /* aligned on a word boundary already? */
|
|
beq+ 1f
|
|
lhz r6,8(r3) /* do 2 bytes to get aligned */
|
|
addi r3,r3,2
|
|
subi r4,r4,2
|
|
addc r5,r5,r6
|
|
srdi. r6,r4,3 /* recompute number of doublewords */
|
|
beq 3f /* any left? */
|
|
1: mtctr r6
|
|
2: ldu r6,8(r3) /* main sum loop */
|
|
adde r5,r5,r6
|
|
bdnz 2b
|
|
andi. r4,r4,7 /* compute bytes left to sum after doublewords */
|
|
3: cmpwi 0,r4,4 /* is at least a full word left? */
|
|
blt 4f
|
|
lwz r6,8(r3) /* sum this word */
|
|
addi r3,r3,4
|
|
subi r4,r4,4
|
|
adde r5,r5,r6
|
|
4: cmpwi 0,r4,2 /* is at least a halfword left? */
|
|
blt+ 5f
|
|
lhz r6,8(r3) /* sum this halfword */
|
|
addi r3,r3,2
|
|
subi r4,r4,2
|
|
adde r5,r5,r6
|
|
5: cmpwi 0,r4,1 /* is at least a byte left? */
|
|
bne+ 6f
|
|
lbz r6,8(r3) /* sum this byte */
|
|
slwi r6,r6,8 /* this byte is assumed to be the upper byte of a halfword */
|
|
adde r5,r5,r6
|
|
6: addze r5,r5 /* add in final carry */
|
|
rldicl r4,r5,32,0 /* fold two 32-bit halves together */
|
|
add r3,r4,r5
|
|
srdi r3,r3,32
|
|
blr
|
|
|
|
/*
|
|
* Computes the checksum of a memory block at src, length len,
|
|
* and adds in "sum" (32-bit), while copying the block to dst.
|
|
* If an access exception occurs on src or dst, it stores -EFAULT
|
|
* to *src_err or *dst_err respectively, and (for an error on
|
|
* src) zeroes the rest of dst.
|
|
*
|
|
* This code needs to be reworked to take advantage of 64 bit sum+copy.
|
|
* However, due to tokenring halfword alignment problems this will be very
|
|
* tricky. For now we'll leave it until we instrument it somehow.
|
|
*
|
|
* csum_partial_copy_generic(r3=src, r4=dst, r5=len, r6=sum, r7=src_err, r8=dst_err)
|
|
*/
|
|
_GLOBAL(csum_partial_copy_generic)
|
|
addic r0,r6,0
|
|
subi r3,r3,4
|
|
subi r4,r4,4
|
|
srwi. r6,r5,2
|
|
beq 3f /* if we're doing < 4 bytes */
|
|
andi. r9,r4,2 /* Align dst to longword boundary */
|
|
beq+ 1f
|
|
81: lhz r6,4(r3) /* do 2 bytes to get aligned */
|
|
addi r3,r3,2
|
|
subi r5,r5,2
|
|
91: sth r6,4(r4)
|
|
addi r4,r4,2
|
|
addc r0,r0,r6
|
|
srwi. r6,r5,2 /* # words to do */
|
|
beq 3f
|
|
1: mtctr r6
|
|
82: lwzu r6,4(r3) /* the bdnz has zero overhead, so it should */
|
|
92: stwu r6,4(r4) /* be unnecessary to unroll this loop */
|
|
adde r0,r0,r6
|
|
bdnz 82b
|
|
andi. r5,r5,3
|
|
3: cmpwi 0,r5,2
|
|
blt+ 4f
|
|
83: lhz r6,4(r3)
|
|
addi r3,r3,2
|
|
subi r5,r5,2
|
|
93: sth r6,4(r4)
|
|
addi r4,r4,2
|
|
adde r0,r0,r6
|
|
4: cmpwi 0,r5,1
|
|
bne+ 5f
|
|
84: lbz r6,4(r3)
|
|
94: stb r6,4(r4)
|
|
slwi r6,r6,8 /* Upper byte of word */
|
|
adde r0,r0,r6
|
|
5: addze r3,r0 /* add in final carry (unlikely with 64-bit regs) */
|
|
rldicl r4,r3,32,0 /* fold 64 bit value */
|
|
add r3,r4,r3
|
|
srdi r3,r3,32
|
|
blr
|
|
|
|
/* These shouldn't go in the fixup section, since that would
|
|
cause the ex_table addresses to get out of order. */
|
|
|
|
.globl src_error_1
|
|
src_error_1:
|
|
li r6,0
|
|
subi r5,r5,2
|
|
95: sth r6,4(r4)
|
|
addi r4,r4,2
|
|
srwi. r6,r5,2
|
|
beq 3f
|
|
mtctr r6
|
|
.globl src_error_2
|
|
src_error_2:
|
|
li r6,0
|
|
96: stwu r6,4(r4)
|
|
bdnz 96b
|
|
3: andi. r5,r5,3
|
|
beq src_error
|
|
.globl src_error_3
|
|
src_error_3:
|
|
li r6,0
|
|
mtctr r5
|
|
addi r4,r4,3
|
|
97: stbu r6,1(r4)
|
|
bdnz 97b
|
|
.globl src_error
|
|
src_error:
|
|
cmpdi 0,r7,0
|
|
beq 1f
|
|
li r6,-EFAULT
|
|
stw r6,0(r7)
|
|
1: addze r3,r0
|
|
blr
|
|
|
|
.globl dst_error
|
|
dst_error:
|
|
cmpdi 0,r8,0
|
|
beq 1f
|
|
li r6,-EFAULT
|
|
stw r6,0(r8)
|
|
1: addze r3,r0
|
|
blr
|
|
|
|
.section __ex_table,"a"
|
|
.align 3
|
|
.llong 81b,src_error_1
|
|
.llong 91b,dst_error
|
|
.llong 82b,src_error_2
|
|
.llong 92b,dst_error
|
|
.llong 83b,src_error_3
|
|
.llong 93b,dst_error
|
|
.llong 84b,src_error_3
|
|
.llong 94b,dst_error
|
|
.llong 95b,dst_error
|
|
.llong 96b,dst_error
|
|
.llong 97b,dst_error
|