diff options
Diffstat (limited to 'arch/ppc/lib/checksum.S')
| -rw-r--r-- | arch/ppc/lib/checksum.S | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/arch/ppc/lib/checksum.S b/arch/ppc/lib/checksum.S new file mode 100644 index 00000000000..7874e8a8045 --- /dev/null +++ b/arch/ppc/lib/checksum.S @@ -0,0 +1,225 @@ +/* + * 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> + + .text + +/* + * ip_fast_csum(buf, len) -- Optimized for IP header + * len is in words and is always >= 5. + */ +_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 */ + 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(saddr, daddr, len, proto, sum) + */ +_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 + addze r0,r0 /* add in final carry */ + 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) + * + * csum_partial(buff, len, sum) + */ +_GLOBAL(csum_partial) + addic r0,r5,0 + subi r3,r3,4 + srwi. r6,r4,2 + beq 3f /* if we're doing < 4 bytes */ + andi. r5,r3,2 /* Align buffer to longword boundary */ + beq+ 1f + lhz r5,4(r3) /* do 2 bytes to get aligned */ + addi r3,r3,2 + subi r4,r4,2 + addc r0,r0,r5 + srwi. r6,r4,2 /* # words to do */ + beq 3f +1: mtctr r6 +2: lwzu r5,4(r3) /* the bdnz has zero overhead, so it should */ + adde r0,r0,r5 /* be unnecessary to unroll this loop */ + bdnz 2b + andi. r4,r4,3 +3: cmpwi 0,r4,2 + blt+ 4f + lhz r5,4(r3) + addi r3,r3,2 + subi r4,r4,2 + adde r0,r0,r5 +4: cmpwi 0,r4,1 + bne+ 5f + lbz r5,4(r3) + slwi r5,r5,8 /* Upper byte of word */ + adde r0,r0,r5 +5: addze r3,r0 /* add in final carry */ + 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. + * + * csum_partial_copy_generic(src, dst, len, sum, src_err, 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: srwi. r6,r5,4 /* # groups of 4 words to do */ + beq 10f + mtctr r6 +71: lwz r6,4(r3) +72: lwz r9,8(r3) +73: lwz r10,12(r3) +74: lwzu r11,16(r3) + adde r0,r0,r6 +75: stw r6,4(r4) + adde r0,r0,r9 +76: stw r9,8(r4) + adde r0,r0,r10 +77: stw r10,12(r4) + adde r0,r0,r11 +78: stwu r11,16(r4) + bdnz 71b +10: rlwinm. r6,r5,30,30,31 /* # words left to do */ + beq 13f + mtctr r6 +82: lwzu r9,4(r3) +92: stwu r9,4(r4) + adde r0,r0,r9 + bdnz 82b +13: 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 */ + blr + +/* These shouldn't go in the fixup section, since that would + cause the ex_table addresses to get out of order. */ + +src_error_4: + mfctr r6 /* update # bytes remaining from ctr */ + rlwimi r5,r6,4,0,27 + b 79f +src_error_1: + li r6,0 + subi r5,r5,2 +95: sth r6,4(r4) + addi r4,r4,2 +79: srwi. r6,r5,2 + beq 3f + mtctr r6 +src_error_2: + li r6,0 +96: stwu r6,4(r4) + bdnz 96b +3: andi. r5,r5,3 + beq src_error +src_error_3: + li r6,0 + mtctr r5 + addi r4,r4,3 +97: stbu r6,1(r4) + bdnz 97b +src_error: + cmpwi 0,r7,0 + beq 1f + li r6,-EFAULT + stw r6,0(r7) +1: addze r3,r0 + blr + +dst_error: + cmpwi 0,r8,0 + beq 1f + li r6,-EFAULT + stw r6,0(r8) +1: addze r3,r0 + blr + +.section __ex_table,"a" + .long 81b,src_error_1 + .long 91b,dst_error + .long 71b,src_error_4 + .long 72b,src_error_4 + .long 73b,src_error_4 + .long 74b,src_error_4 + .long 75b,dst_error + .long 76b,dst_error + .long 77b,dst_error + .long 78b,dst_error + .long 82b,src_error_2 + .long 92b,dst_error + .long 83b,src_error_3 + .long 93b,dst_error + .long 84b,src_error_3 + .long 94b,dst_error + .long 95b,dst_error + .long 96b,dst_error + .long 97b,dst_error |