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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 | /* * 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 "../kernel/ppc_asm.tmpl" .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: cmpi 0,r4,2 blt+ 4f lhz r5,4(r3) addi r3,r3,2 subi r4,r4,2 adde r0,r0,r5 4: cmpi 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: 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: cmpi 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: cmpi 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_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 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: cmpi 0,r7,0 beq 1f li r6,-EFAULT stw r6,0(r7) 1: addze r3,r0 blr dst_error: cmpi 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 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 |