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Diffstat (limited to 'arch/powerpc/lib/checksum_64.S')
| -rw-r--r-- | arch/powerpc/lib/checksum_64.S | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/arch/powerpc/lib/checksum_64.S b/arch/powerpc/lib/checksum_64.S new file mode 100644 index 0000000..ef96c6c --- /dev/null +++ b/arch/powerpc/lib/checksum_64.S @@ -0,0 +1,229 @@ +/* + * 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 |
