/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* This file contains assembly-language implementations
* of IP-style 1's complement checksum routines.
*
* Copyright (C) 1995-1996 Gary Thomas ([email protected])
*
* Severely hacked about by Paul Mackerras ([email protected]).
*/
#include <linux/export.h>
#include <linux/sys.h>
#include <asm/processor.h>
#include <asm/cache.h>
#include <asm/errno.h>
#include <asm/ppc_asm.h>
.text
/*
* computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit)
*
* __csum_partial(buff, len, sum)
*/
_GLOBAL(__csum_partial)
subi r3,r3,4
srawi. r6,r4,2 /* Divide len by 4 and also clear carry */
beq 3f /* if we're doing < 4 bytes */
andi. r0,r3,2 /* Align buffer to longword boundary */
beq+ 1f
lhz r0,4(r3) /* do 2 bytes to get aligned */
subi r4,r4,2
addi r3,r3,2
srwi. r6,r4,2 /* # words to do */
adde r5,r5,r0
beq 3f
1: andi. r6,r6,3 /* Prepare to handle words 4 by 4 */
beq 21f
mtctr r6
2: lwzu r0,4(r3)
adde r5,r5,r0
bdnz 2b
21: srwi. r6,r4,4 /* # blocks of 4 words to do */
beq 3f
lwz r0,4(r3)
mtctr r6
lwz r6,8(r3)
adde r5,r5,r0
lwz r7,12(r3)
adde r5,r5,r6
lwzu r8,16(r3)
adde r5,r5,r7
bdz 23f
22: lwz r0,4(r3)
adde r5,r5,r8
lwz r6,8(r3)
adde r5,r5,r0
lwz r7,12(r3)
adde r5,r5,r6
lwzu r8,16(r3)
adde r5,r5,r7
bdnz 22b
23: adde r5,r5,r8
3: andi. r0,r4,2
beq+ 4f
lhz r0,4(r3)
addi r3,r3,2
adde r5,r5,r0
4: andi. r0,r4,1
beq+ 5f
lbz r0,4(r3)
slwi r0,r0,8 /* Upper byte of word */
adde r5,r5,r0
5: addze r3,r5 /* add in final carry */
blr
EXPORT_SYMBOL(__csum_partial)
/*
* Computes the checksum of a memory block at src, length len,
* and adds in 0xffffffff, while copying the block to dst.
* If an access exception occurs it returns zero.
*
* csum_partial_copy_generic(src, dst, len)
*/
#define CSUM_COPY_16_BYTES_WITHEX(n) \
8 ## n ## 0: \
lwz r7,4(r4); \
8 ## n ## 1: \
lwz r8,8(r4); \
8 ## n ## 2: \
lwz r9,12(r4); \
8 ## n ## 3: \
lwzu r10,16(r4); \
8 ## n ## 4: \
stw r7,4(r6); \
adde r12,r12,r7; \
8 ## n ## 5: \
stw r8,8(r6); \
adde r12,r12,r8; \
8 ## n ## 6: \
stw r9,12(r6); \
adde r12,r12,r9; \
8 ## n ## 7: \
stwu r10,16(r6); \
adde r12,r12,r10
#define CSUM_COPY_16_BYTES_EXCODE(n) \
EX_TABLE(8 ## n ## 0b, fault); \
EX_TABLE(8 ## n ## 1b, fault); \
EX_TABLE(8 ## n ## 2b, fault); \
EX_TABLE(8 ## n ## 3b, fault); \
EX_TABLE(8 ## n ## 4b, fault); \
EX_TABLE(8 ## n ## 5b, fault); \
EX_TABLE(8 ## n ## 6b, fault); \
EX_TABLE(8 ## n ## 7b, fault);
.text
CACHELINE_BYTES = L1_CACHE_BYTES
LG_CACHELINE_BYTES = L1_CACHE_SHIFT
CACHELINE_MASK = (L1_CACHE_BYTES-1)
_GLOBAL(csum_partial_copy_generic)
li r12,-1
addic r0,r0,0 /* clear carry */
addi r6,r4,-4
neg r0,r4
addi r4,r3,-4
andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */
crset 4*cr7+eq
beq 58f
cmplw 0,r5,r0 /* is this more than total to do? */
blt 63f /* if not much to do */
rlwinm r7,r6,3,0x8
rlwnm r12,r12,r7,0,31 /* odd destination address: rotate one byte */
cmplwi cr7,r7,0 /* is destination address even ? */
andi. r8,r0,3 /* get it word-aligned first */
mtctr r8
beq+ 61f
li r3,0
70: lbz r9,4(r4) /* do some bytes */
addi r4,r4,1
slwi r3,r3,8
rlwimi r3,r9,0,24,31
71: stb r9,4(r6)
addi r6,r6,1
bdnz 70b
adde r12,r12,r3
61: subf r5,r0,r5
srwi. r0,r0,2
mtctr r0
beq 58f
72: lwzu r9,4(r4) /* do some words */
adde r12,r12,r9
73: stwu r9,4(r6)
bdnz 72b
58: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */
clrlwi r5,r5,32-LG_CACHELINE_BYTES
li r11,4
beq 63f
/* Here we decide how far ahead to prefetch the source */
li r3,4
cmpwi r0,1
li r7,0
ble 114f
li r7,1
#if MAX_COPY_PREFETCH > 1
/* Heuristically, for large transfers we prefetch
MAX_COPY_PREFETCH cachelines ahead. For small transfers
we prefetch 1 cacheline ahead. */
cmpwi r0,MAX_COPY_PREFETCH
ble 112f
li r7,MAX_COPY_PREFETCH
112: mtctr r7
111: dcbt r3,r4
addi r3,r3,CACHELINE_BYTES
bdnz 111b
#else
dcbt r3,r4
addi r3,r3,CACHELINE_BYTES
#endif /* MAX_COPY_PREFETCH > 1 */
114: subf r8,r7,r0
mr r0,r7
mtctr r8
53: dcbt r3,r4
54: dcbz r11,r6
/* the main body of the cacheline loop */
CSUM_COPY_16_BYTES_WITHEX(0)
#if L1_CACHE_BYTES >= 32
CSUM_COPY_16_BYTES_WITHEX(1)
#if L1_CACHE_BYTES >= 64
CSUM_COPY_16_BYTES_WITHEX(2)
CSUM_COPY_16_BYTES_WITHEX(3)
#if L1_CACHE_BYTES >= 128
CSUM_COPY_16_BYTES_WITHEX(4)
CSUM_COPY_16_BYTES_WITHEX(5)
CSUM_COPY_16_BYTES_WITHEX(6)
CSUM_COPY_16_BYTES_WITHEX(7)
#endif
#endif
#endif
bdnz 53b
cmpwi r0,0
li r3,4
li r7,0
bne 114b
63: srwi. r0,r5,2
mtctr r0
beq 64f
30: lwzu r0,4(r4)
adde r12,r12,r0
31: stwu r0,4(r6)
bdnz 30b
64: andi. r0,r5,2
beq+ 65f
40: lhz r0,4(r4)
addi r4,r4,2
41: sth r0,4(r6)
adde r12,r12,r0
addi r6,r6,2
65: andi. r0,r5,1
beq+ 66f
50: lbz r0,4(r4)
51: stb r0,4(r6)
slwi r0,r0,8
adde r12,r12,r0
66: addze r3,r12
beqlr+ cr7
rlwinm r3,r3,8,0,31 /* odd destination address: rotate one byte */
blr
fault:
li r3,0
blr
EX_TABLE(70b, fault);
EX_TABLE(71b, fault);
EX_TABLE(72b, fault);
EX_TABLE(73b, fault);
EX_TABLE(54b, fault);
/*
* this stuff handles faults in the cacheline loop and branches to either
* fault (if in read part) or fault (if in write part)
*/
CSUM_COPY_16_BYTES_EXCODE(0)
#if L1_CACHE_BYTES >= 32
CSUM_COPY_16_BYTES_EXCODE(1)
#if L1_CACHE_BYTES >= 64
CSUM_COPY_16_BYTES_EXCODE(2)
CSUM_COPY_16_BYTES_EXCODE(3)
#if L1_CACHE_BYTES >= 128
CSUM_COPY_16_BYTES_EXCODE(4)
CSUM_COPY_16_BYTES_EXCODE(5)
CSUM_COPY_16_BYTES_EXCODE(6)
CSUM_COPY_16_BYTES_EXCODE(7)
#endif
#endif
#endif
EX_TABLE(30b, fault);
EX_TABLE(31b, fault);
EX_TABLE(40b, fault);
EX_TABLE(41b, fault);
EX_TABLE(50b, fault);
EX_TABLE(51b, fault);
EXPORT_SYMBOL(csum_partial_copy_generic)
/*
* __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
* const struct in6_addr *daddr,
* __u32 len, __u8 proto, __wsum sum)
*/
_GLOBAL(csum_ipv6_magic)
lwz r8, 0(r3)
lwz r9, 4(r3)
addc r0, r7, r8
lwz r10, 8(r3)
adde r0, r0, r9
lwz r11, 12(r3)
adde r0, r0, r10
lwz r8, 0(r4)
adde r0, r0, r11
lwz r9, 4(r4)
adde r0, r0, r8
lwz r10, 8(r4)
adde r0, r0, r9
lwz r11, 12(r4)
adde r0, r0, r10
add r5, r5, r6 /* assumption: len + proto doesn't carry */
adde r0, r0, r11
adde r0, r0, r5
addze r0, r0
rotlwi r3, r0, 16
add r3, r0, r3
not r3, r3
rlwinm r3, r3, 16, 16, 31
blr
EXPORT_SYMBOL(csum_ipv6_magic)
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