diff options
Diffstat (limited to 'arch/powerpc/lib/checksum_32.S')
| -rw-r--r-- | arch/powerpc/lib/checksum_32.S | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S new file mode 100644 index 000000000..4541e8e29 --- /dev/null +++ b/arch/powerpc/lib/checksum_32.S @@ -0,0 +1,309 @@ +/* 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 (gdt@linuxppc.org) + * + * Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au). + */ + +#include <linux/sys.h> +#include <asm/processor.h> +#include <asm/cache.h> +#include <asm/errno.h> +#include <asm/ppc_asm.h> +#include <asm/export.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) |