+++ /dev/null
-/*
- * 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
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