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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 | /* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * IP/TCP/UDP checksumming routines * * Authors: Jorge Cwik, <jorge@laser.satlink.net> * Arnt Gulbrandsen, <agulbra@nvg.unit.no> * Tom May, <ftom@netcom.com> * Pentium Pro/II routines: * Alexander Kjeldaas <astor@guardian.no> * Finn Arne Gangstad <finnag@guardian.no> * Lots of code moved from tcp.c and ip.c; see those files * for more names. * * Changes: Ingo Molnar, converted csum_partial_copy() to 2.1 exception * handling. * Andi Kleen, add zeroing on error * converted to pure assembler * Hirokazu Takata,Hiroyuki Kondo rewrite for the m32r architecture. * * 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. */ /* $Id$ */ #include <linux/config.h> #include <linux/linkage.h> #include <asm/assembler.h> #include <asm/errno.h> /* * computes a partial checksum, e.g. for TCP/UDP fragments */ /* unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum) */ #ifdef CONFIG_ISA_DUAL_ISSUE /* * Experiments with Ethernet and SLIP connections show that buff * is aligned on either a 2-byte or 4-byte boundary. We get at * least a twofold speedup on 486 and Pentium if it is 4-byte aligned. * Fortunately, it is easy to convert 2-byte alignment to 4-byte * alignment for the unrolled loop. */ .text ENTRY(csum_partial) ; Function args ; r0: unsigned char *buff ; r1: int len ; r2: unsigned int sum push r2 || ldi r2, #0 and3 r7, r0, #1 ; Check alignment. beqz r7, 1f ; Jump if alignment is ok. ; 1-byte mis aligned ldub r4, @r0 || addi r0, #1 ; clear c-bit || Alignment uses up bytes. cmp r0, r0 || addi r1, #-1 ldi r3, #0 || addx r2, r4 addx r2, r3 .fillinsn 1: and3 r4, r0, #2 ; Check alignment. beqz r4, 2f ; Jump if alignment is ok. ; clear c-bit || Alignment uses up two bytes. cmp r0, r0 || addi r1, #-2 bgtz r1, 1f ; Jump if we had at least two bytes. bra 4f || addi r1, #2 .fillinsn ; len(r1) was < 2. Deal with it. 1: ; 2-byte aligned lduh r4, @r0 || ldi r3, #0 addx r2, r4 || addi r0, #2 addx r2, r3 .fillinsn 2: ; 4-byte aligned cmp r0, r0 ; clear c-bit srl3 r6, r1, #5 beqz r6, 2f .fillinsn 1: ld r3, @r0+ ld r4, @r0+ ; +4 ld r5, @r0+ ; +8 ld r3, @r0+ || addx r2, r3 ; +12 ld r4, @r0+ || addx r2, r4 ; +16 ld r5, @r0+ || addx r2, r5 ; +20 ld r3, @r0+ || addx r2, r3 ; +24 ld r4, @r0+ || addx r2, r4 ; +28 addx r2, r5 || addi r6, #-1 addx r2, r3 addx r2, r4 bnez r6, 1b addx r2, r6 ; r6=0 cmp r0, r0 ; This clears c-bit .fillinsn 2: and3 r6, r1, #0x1c ; withdraw len beqz r6, 4f srli r6, #2 .fillinsn 3: ld r4, @r0+ || addi r6, #-1 addx r2, r4 bnez r6, 3b addx r2, r6 ; r6=0 cmp r0, r0 ; This clears c-bit .fillinsn 4: and3 r1, r1, #3 beqz r1, 7f ; if len == 0 goto end and3 r6, r1, #2 beqz r6, 5f ; if len < 2 goto 5f(1byte) lduh r4, @r0 || addi r0, #2 addi r1, #-2 || slli r4, #16 addx r2, r4 beqz r1, 6f .fillinsn 5: ldub r4, @r0 || ldi r1, #0 #ifndef __LITTLE_ENDIAN__ slli r4, #8 #endif addx r2, r4 .fillinsn 6: addx r2, r1 .fillinsn 7: and3 r0, r2, #0xffff srli r2, #16 add r0, r2 srl3 r2, r0, #16 beqz r2, 1f addi r0, #1 and3 r0, r0, #0xffff .fillinsn 1: beqz r7, 1f ; swap the upper byte for the lower and3 r2, r0, #0xff srl3 r0, r0, #8 slli r2, #8 or r0, r2 .fillinsn 1: pop r2 || cmp r0, r0 addx r0, r2 || ldi r2, #0 addx r0, r2 jmp r14 #else /* not CONFIG_ISA_DUAL_ISSUE */ /* * Experiments with Ethernet and SLIP connections show that buff * is aligned on either a 2-byte or 4-byte boundary. We get at * least a twofold speedup on 486 and Pentium if it is 4-byte aligned. * Fortunately, it is easy to convert 2-byte alignment to 4-byte * alignment for the unrolled loop. */ .text ENTRY(csum_partial) ; Function args ; r0: unsigned char *buff ; r1: int len ; r2: unsigned int sum push r2 ldi r2, #0 and3 r7, r0, #1 ; Check alignment. beqz r7, 1f ; Jump if alignment is ok. ; 1-byte mis aligned ldub r4, @r0 addi r0, #1 addi r1, #-1 ; Alignment uses up bytes. cmp r0, r0 ; clear c-bit ldi r3, #0 addx r2, r4 addx r2, r3 .fillinsn 1: and3 r4, r0, #2 ; Check alignment. beqz r4, 2f ; Jump if alignment is ok. addi r1, #-2 ; Alignment uses up two bytes. cmp r0, r0 ; clear c-bit bgtz r1, 1f ; Jump if we had at least two bytes. addi r1, #2 ; len(r1) was < 2. Deal with it. bra 4f .fillinsn 1: ; 2-byte aligned lduh r4, @r0 addi r0, #2 ldi r3, #0 addx r2, r4 addx r2, r3 .fillinsn 2: ; 4-byte aligned cmp r0, r0 ; clear c-bit srl3 r6, r1, #5 beqz r6, 2f .fillinsn 1: ld r3, @r0+ ld r4, @r0+ ; +4 ld r5, @r0+ ; +8 addx r2, r3 addx r2, r4 addx r2, r5 ld r3, @r0+ ; +12 ld r4, @r0+ ; +16 ld r5, @r0+ ; +20 addx r2, r3 addx r2, r4 addx r2, r5 ld r3, @r0+ ; +24 ld r4, @r0+ ; +28 addi r6, #-1 addx r2, r3 addx r2, r4 bnez r6, 1b addx r2, r6 ; r6=0 cmp r0, r0 ; This clears c-bit .fillinsn 2: and3 r6, r1, #0x1c ; withdraw len beqz r6, 4f srli r6, #2 .fillinsn 3: ld r4, @r0+ addi r6, #-1 addx r2, r4 bnez r6, 3b addx r2, r6 ; r6=0 cmp r0, r0 ; This clears c-bit .fillinsn 4: and3 r1, r1, #3 beqz r1, 7f ; if len == 0 goto end and3 r6, r1, #2 beqz r6, 5f ; if len < 2 goto 5f(1byte) lduh r4, @r0 addi r0, #2 addi r1, #-2 slli r4, #16 addx r2, r4 beqz r1, 6f .fillinsn 5: ldub r4, @r0 #ifndef __LITTLE_ENDIAN__ slli r4, #8 #endif addx r2, r4 .fillinsn 6: ldi r5, #0 addx r2, r5 .fillinsn 7: and3 r0, r2, #0xffff srli r2, #16 add r0, r2 srl3 r2, r0, #16 beqz r2, 1f addi r0, #1 and3 r0, r0, #0xffff .fillinsn 1: beqz r7, 1f mv r2, r0 srl3 r0, r2, #8 and3 r2, r2, #0xff slli r2, #8 or r0, r2 .fillinsn 1: pop r2 cmp r0, r0 addx r0, r2 ldi r2, #0 addx r0, r2 jmp r14 #endif /* not CONFIG_ISA_DUAL_ISSUE */ /* unsigned int csum_partial_copy_generic (const char *src, char *dst, int len, int sum, int *src_err_ptr, int *dst_err_ptr) */ /* * Copy from ds while checksumming, otherwise like csum_partial * * The macros SRC and DST specify the type of access for the instruction. * thus we can call a custom exception handler for all access types. * * FIXME: could someone double-check whether I haven't mixed up some SRC and * DST definitions? It's damn hard to trigger all cases. I hope I got * them all but there's no guarantee. */ ENTRY(csum_partial_copy_generic) nop nop nop nop jmp r14 nop nop nop |