Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * IP/TCP/UDP checksumming routines | |
7 | * | |
8 | * Authors: Jorge Cwik, <jorge@laser.satlink.net> | |
9 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> | |
10 | * Tom May, <ftom@netcom.com> | |
11 | * Pentium Pro/II routines: | |
12 | * Alexander Kjeldaas <astor@guardian.no> | |
13 | * Finn Arne Gangstad <finnag@guardian.no> | |
14 | * Lots of code moved from tcp.c and ip.c; see those files | |
15 | * for more names. | |
16 | * | |
17 | * Changes: Ingo Molnar, converted csum_partial_copy() to 2.1 exception | |
18 | * handling. | |
19 | * Andi Kleen, add zeroing on error | |
20 | * converted to pure assembler | |
21 | * | |
22 | * This program is free software; you can redistribute it and/or | |
23 | * modify it under the terms of the GNU General Public License | |
24 | * as published by the Free Software Foundation; either version | |
25 | * 2 of the License, or (at your option) any later version. | |
26 | */ | |
27 | ||
00e065ea JB |
28 | #include <linux/linkage.h> |
29 | #include <asm/dwarf2.h> | |
1da177e4 | 30 | #include <asm/errno.h> |
5f2e8a84 | 31 | #include <asm/asm.h> |
1da177e4 LT |
32 | |
33 | /* | |
34 | * computes a partial checksum, e.g. for TCP/UDP fragments | |
35 | */ | |
36 | ||
37 | /* | |
38 | unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum) | |
39 | */ | |
40 | ||
41 | .text | |
1da177e4 LT |
42 | |
43 | #ifndef CONFIG_X86_USE_PPRO_CHECKSUM | |
44 | ||
45 | /* | |
46 | * Experiments with Ethernet and SLIP connections show that buff | |
47 | * is aligned on either a 2-byte or 4-byte boundary. We get at | |
48 | * least a twofold speedup on 486 and Pentium if it is 4-byte aligned. | |
49 | * Fortunately, it is easy to convert 2-byte alignment to 4-byte | |
50 | * alignment for the unrolled loop. | |
51 | */ | |
00e065ea JB |
52 | ENTRY(csum_partial) |
53 | CFI_STARTPROC | |
49db46a6 DV |
54 | pushl_cfi_reg esi |
55 | pushl_cfi_reg ebx | |
1da177e4 LT |
56 | movl 20(%esp),%eax # Function arg: unsigned int sum |
57 | movl 16(%esp),%ecx # Function arg: int len | |
58 | movl 12(%esp),%esi # Function arg: unsigned char *buff | |
59 | testl $3, %esi # Check alignment. | |
60 | jz 2f # Jump if alignment is ok. | |
61 | testl $1, %esi # Check alignment. | |
d50ba368 | 62 | jz 10f # Jump if alignment is boundary of 2 bytes. |
1da177e4 LT |
63 | |
64 | # buf is odd | |
65 | dec %ecx | |
66 | jl 8f | |
67 | movzbl (%esi), %ebx | |
68 | adcl %ebx, %eax | |
69 | roll $8, %eax | |
70 | inc %esi | |
71 | testl $2, %esi | |
72 | jz 2f | |
73 | 10: | |
74 | subl $2, %ecx # Alignment uses up two bytes. | |
75 | jae 1f # Jump if we had at least two bytes. | |
76 | addl $2, %ecx # ecx was < 2. Deal with it. | |
77 | jmp 4f | |
78 | 1: movw (%esi), %bx | |
79 | addl $2, %esi | |
80 | addw %bx, %ax | |
81 | adcl $0, %eax | |
82 | 2: | |
83 | movl %ecx, %edx | |
84 | shrl $5, %ecx | |
85 | jz 2f | |
86 | testl %esi, %esi | |
87 | 1: movl (%esi), %ebx | |
88 | adcl %ebx, %eax | |
89 | movl 4(%esi), %ebx | |
90 | adcl %ebx, %eax | |
91 | movl 8(%esi), %ebx | |
92 | adcl %ebx, %eax | |
93 | movl 12(%esi), %ebx | |
94 | adcl %ebx, %eax | |
95 | movl 16(%esi), %ebx | |
96 | adcl %ebx, %eax | |
97 | movl 20(%esi), %ebx | |
98 | adcl %ebx, %eax | |
99 | movl 24(%esi), %ebx | |
100 | adcl %ebx, %eax | |
101 | movl 28(%esi), %ebx | |
102 | adcl %ebx, %eax | |
103 | lea 32(%esi), %esi | |
104 | dec %ecx | |
105 | jne 1b | |
106 | adcl $0, %eax | |
107 | 2: movl %edx, %ecx | |
108 | andl $0x1c, %edx | |
109 | je 4f | |
110 | shrl $2, %edx # This clears CF | |
111 | 3: adcl (%esi), %eax | |
112 | lea 4(%esi), %esi | |
113 | dec %edx | |
114 | jne 3b | |
115 | adcl $0, %eax | |
116 | 4: andl $3, %ecx | |
117 | jz 7f | |
118 | cmpl $2, %ecx | |
119 | jb 5f | |
120 | movw (%esi),%cx | |
121 | leal 2(%esi),%esi | |
122 | je 6f | |
123 | shll $16,%ecx | |
124 | 5: movb (%esi),%cl | |
125 | 6: addl %ecx,%eax | |
126 | adcl $0, %eax | |
127 | 7: | |
3e1aa7cb | 128 | testb $1, 12(%esp) |
1da177e4 LT |
129 | jz 8f |
130 | roll $8, %eax | |
131 | 8: | |
49db46a6 DV |
132 | popl_cfi_reg ebx |
133 | popl_cfi_reg esi | |
1da177e4 | 134 | ret |
00e065ea JB |
135 | CFI_ENDPROC |
136 | ENDPROC(csum_partial) | |
1da177e4 LT |
137 | |
138 | #else | |
139 | ||
140 | /* Version for PentiumII/PPro */ | |
141 | ||
00e065ea JB |
142 | ENTRY(csum_partial) |
143 | CFI_STARTPROC | |
49db46a6 DV |
144 | pushl_cfi_reg esi |
145 | pushl_cfi_reg ebx | |
1da177e4 LT |
146 | movl 20(%esp),%eax # Function arg: unsigned int sum |
147 | movl 16(%esp),%ecx # Function arg: int len | |
148 | movl 12(%esp),%esi # Function arg: const unsigned char *buf | |
149 | ||
150 | testl $3, %esi | |
151 | jnz 25f | |
152 | 10: | |
153 | movl %ecx, %edx | |
154 | movl %ecx, %ebx | |
155 | andl $0x7c, %ebx | |
156 | shrl $7, %ecx | |
157 | addl %ebx,%esi | |
158 | shrl $2, %ebx | |
159 | negl %ebx | |
160 | lea 45f(%ebx,%ebx,2), %ebx | |
161 | testl %esi, %esi | |
162 | jmp *%ebx | |
163 | ||
164 | # Handle 2-byte-aligned regions | |
165 | 20: addw (%esi), %ax | |
166 | lea 2(%esi), %esi | |
167 | adcl $0, %eax | |
168 | jmp 10b | |
169 | 25: | |
170 | testl $1, %esi | |
171 | jz 30f | |
172 | # buf is odd | |
173 | dec %ecx | |
174 | jl 90f | |
175 | movzbl (%esi), %ebx | |
176 | addl %ebx, %eax | |
177 | adcl $0, %eax | |
178 | roll $8, %eax | |
179 | inc %esi | |
180 | testl $2, %esi | |
181 | jz 10b | |
182 | ||
183 | 30: subl $2, %ecx | |
184 | ja 20b | |
185 | je 32f | |
186 | addl $2, %ecx | |
187 | jz 80f | |
188 | movzbl (%esi),%ebx # csumming 1 byte, 2-aligned | |
189 | addl %ebx, %eax | |
190 | adcl $0, %eax | |
191 | jmp 80f | |
192 | 32: | |
193 | addw (%esi), %ax # csumming 2 bytes, 2-aligned | |
194 | adcl $0, %eax | |
195 | jmp 80f | |
196 | ||
197 | 40: | |
198 | addl -128(%esi), %eax | |
199 | adcl -124(%esi), %eax | |
200 | adcl -120(%esi), %eax | |
201 | adcl -116(%esi), %eax | |
202 | adcl -112(%esi), %eax | |
203 | adcl -108(%esi), %eax | |
204 | adcl -104(%esi), %eax | |
205 | adcl -100(%esi), %eax | |
206 | adcl -96(%esi), %eax | |
207 | adcl -92(%esi), %eax | |
208 | adcl -88(%esi), %eax | |
209 | adcl -84(%esi), %eax | |
210 | adcl -80(%esi), %eax | |
211 | adcl -76(%esi), %eax | |
212 | adcl -72(%esi), %eax | |
213 | adcl -68(%esi), %eax | |
214 | adcl -64(%esi), %eax | |
215 | adcl -60(%esi), %eax | |
216 | adcl -56(%esi), %eax | |
217 | adcl -52(%esi), %eax | |
218 | adcl -48(%esi), %eax | |
219 | adcl -44(%esi), %eax | |
220 | adcl -40(%esi), %eax | |
221 | adcl -36(%esi), %eax | |
222 | adcl -32(%esi), %eax | |
223 | adcl -28(%esi), %eax | |
224 | adcl -24(%esi), %eax | |
225 | adcl -20(%esi), %eax | |
226 | adcl -16(%esi), %eax | |
227 | adcl -12(%esi), %eax | |
228 | adcl -8(%esi), %eax | |
229 | adcl -4(%esi), %eax | |
230 | 45: | |
231 | lea 128(%esi), %esi | |
232 | adcl $0, %eax | |
233 | dec %ecx | |
234 | jge 40b | |
235 | movl %edx, %ecx | |
236 | 50: andl $3, %ecx | |
237 | jz 80f | |
238 | ||
239 | # Handle the last 1-3 bytes without jumping | |
240 | notl %ecx # 1->2, 2->1, 3->0, higher bits are masked | |
241 | movl $0xffffff,%ebx # by the shll and shrl instructions | |
242 | shll $3,%ecx | |
243 | shrl %cl,%ebx | |
244 | andl -128(%esi),%ebx # esi is 4-aligned so should be ok | |
245 | addl %ebx,%eax | |
246 | adcl $0,%eax | |
247 | 80: | |
3e1aa7cb | 248 | testb $1, 12(%esp) |
1da177e4 LT |
249 | jz 90f |
250 | roll $8, %eax | |
251 | 90: | |
49db46a6 DV |
252 | popl_cfi_reg ebx |
253 | popl_cfi_reg esi | |
1da177e4 | 254 | ret |
00e065ea JB |
255 | CFI_ENDPROC |
256 | ENDPROC(csum_partial) | |
1da177e4 LT |
257 | |
258 | #endif | |
259 | ||
260 | /* | |
261 | unsigned int csum_partial_copy_generic (const char *src, char *dst, | |
262 | int len, int sum, int *src_err_ptr, int *dst_err_ptr) | |
263 | */ | |
264 | ||
265 | /* | |
266 | * Copy from ds while checksumming, otherwise like csum_partial | |
267 | * | |
268 | * The macros SRC and DST specify the type of access for the instruction. | |
269 | * thus we can call a custom exception handler for all access types. | |
270 | * | |
271 | * FIXME: could someone double-check whether I haven't mixed up some SRC and | |
272 | * DST definitions? It's damn hard to trigger all cases. I hope I got | |
273 | * them all but there's no guarantee. | |
274 | */ | |
275 | ||
276 | #define SRC(y...) \ | |
277 | 9999: y; \ | |
5f2e8a84 | 278 | _ASM_EXTABLE(9999b, 6001f) |
1da177e4 LT |
279 | |
280 | #define DST(y...) \ | |
281 | 9999: y; \ | |
5f2e8a84 | 282 | _ASM_EXTABLE(9999b, 6002f) |
1da177e4 | 283 | |
1da177e4 LT |
284 | #ifndef CONFIG_X86_USE_PPRO_CHECKSUM |
285 | ||
286 | #define ARGBASE 16 | |
287 | #define FP 12 | |
288 | ||
00e065ea JB |
289 | ENTRY(csum_partial_copy_generic) |
290 | CFI_STARTPROC | |
1da177e4 | 291 | subl $4,%esp |
00e065ea | 292 | CFI_ADJUST_CFA_OFFSET 4 |
49db46a6 DV |
293 | pushl_cfi_reg edi |
294 | pushl_cfi_reg esi | |
295 | pushl_cfi_reg ebx | |
1da177e4 LT |
296 | movl ARGBASE+16(%esp),%eax # sum |
297 | movl ARGBASE+12(%esp),%ecx # len | |
298 | movl ARGBASE+4(%esp),%esi # src | |
299 | movl ARGBASE+8(%esp),%edi # dst | |
300 | ||
301 | testl $2, %edi # Check alignment. | |
302 | jz 2f # Jump if alignment is ok. | |
303 | subl $2, %ecx # Alignment uses up two bytes. | |
304 | jae 1f # Jump if we had at least two bytes. | |
305 | addl $2, %ecx # ecx was < 2. Deal with it. | |
306 | jmp 4f | |
307 | SRC(1: movw (%esi), %bx ) | |
308 | addl $2, %esi | |
309 | DST( movw %bx, (%edi) ) | |
310 | addl $2, %edi | |
311 | addw %bx, %ax | |
312 | adcl $0, %eax | |
313 | 2: | |
314 | movl %ecx, FP(%esp) | |
315 | shrl $5, %ecx | |
316 | jz 2f | |
317 | testl %esi, %esi | |
318 | SRC(1: movl (%esi), %ebx ) | |
319 | SRC( movl 4(%esi), %edx ) | |
320 | adcl %ebx, %eax | |
321 | DST( movl %ebx, (%edi) ) | |
322 | adcl %edx, %eax | |
323 | DST( movl %edx, 4(%edi) ) | |
324 | ||
325 | SRC( movl 8(%esi), %ebx ) | |
326 | SRC( movl 12(%esi), %edx ) | |
327 | adcl %ebx, %eax | |
328 | DST( movl %ebx, 8(%edi) ) | |
329 | adcl %edx, %eax | |
330 | DST( movl %edx, 12(%edi) ) | |
331 | ||
332 | SRC( movl 16(%esi), %ebx ) | |
333 | SRC( movl 20(%esi), %edx ) | |
334 | adcl %ebx, %eax | |
335 | DST( movl %ebx, 16(%edi) ) | |
336 | adcl %edx, %eax | |
337 | DST( movl %edx, 20(%edi) ) | |
338 | ||
339 | SRC( movl 24(%esi), %ebx ) | |
340 | SRC( movl 28(%esi), %edx ) | |
341 | adcl %ebx, %eax | |
342 | DST( movl %ebx, 24(%edi) ) | |
343 | adcl %edx, %eax | |
344 | DST( movl %edx, 28(%edi) ) | |
345 | ||
346 | lea 32(%esi), %esi | |
347 | lea 32(%edi), %edi | |
348 | dec %ecx | |
349 | jne 1b | |
350 | adcl $0, %eax | |
351 | 2: movl FP(%esp), %edx | |
352 | movl %edx, %ecx | |
353 | andl $0x1c, %edx | |
354 | je 4f | |
355 | shrl $2, %edx # This clears CF | |
356 | SRC(3: movl (%esi), %ebx ) | |
357 | adcl %ebx, %eax | |
358 | DST( movl %ebx, (%edi) ) | |
359 | lea 4(%esi), %esi | |
360 | lea 4(%edi), %edi | |
361 | dec %edx | |
362 | jne 3b | |
363 | adcl $0, %eax | |
364 | 4: andl $3, %ecx | |
365 | jz 7f | |
366 | cmpl $2, %ecx | |
367 | jb 5f | |
368 | SRC( movw (%esi), %cx ) | |
369 | leal 2(%esi), %esi | |
370 | DST( movw %cx, (%edi) ) | |
371 | leal 2(%edi), %edi | |
372 | je 6f | |
373 | shll $16,%ecx | |
374 | SRC(5: movb (%esi), %cl ) | |
375 | DST( movb %cl, (%edi) ) | |
376 | 6: addl %ecx, %eax | |
377 | adcl $0, %eax | |
378 | 7: | |
379 | 5000: | |
380 | ||
381 | # Exception handler: | |
382 | .section .fixup, "ax" | |
383 | ||
384 | 6001: | |
385 | movl ARGBASE+20(%esp), %ebx # src_err_ptr | |
386 | movl $-EFAULT, (%ebx) | |
387 | ||
388 | # zero the complete destination - computing the rest | |
389 | # is too much work | |
390 | movl ARGBASE+8(%esp), %edi # dst | |
391 | movl ARGBASE+12(%esp), %ecx # len | |
392 | xorl %eax,%eax | |
393 | rep ; stosb | |
394 | ||
395 | jmp 5000b | |
396 | ||
397 | 6002: | |
398 | movl ARGBASE+24(%esp), %ebx # dst_err_ptr | |
399 | movl $-EFAULT,(%ebx) | |
400 | jmp 5000b | |
401 | ||
402 | .previous | |
403 | ||
49db46a6 DV |
404 | popl_cfi_reg ebx |
405 | popl_cfi_reg esi | |
406 | popl_cfi_reg edi | |
60cf637a | 407 | popl_cfi %ecx # equivalent to addl $4,%esp |
1da177e4 | 408 | ret |
00e065ea JB |
409 | CFI_ENDPROC |
410 | ENDPROC(csum_partial_copy_generic) | |
1da177e4 LT |
411 | |
412 | #else | |
413 | ||
414 | /* Version for PentiumII/PPro */ | |
415 | ||
416 | #define ROUND1(x) \ | |
417 | SRC(movl x(%esi), %ebx ) ; \ | |
418 | addl %ebx, %eax ; \ | |
419 | DST(movl %ebx, x(%edi) ) ; | |
420 | ||
421 | #define ROUND(x) \ | |
422 | SRC(movl x(%esi), %ebx ) ; \ | |
423 | adcl %ebx, %eax ; \ | |
424 | DST(movl %ebx, x(%edi) ) ; | |
425 | ||
426 | #define ARGBASE 12 | |
427 | ||
00e065ea JB |
428 | ENTRY(csum_partial_copy_generic) |
429 | CFI_STARTPROC | |
49db46a6 DV |
430 | pushl_cfi_reg ebx |
431 | pushl_cfi_reg edi | |
432 | pushl_cfi_reg esi | |
1da177e4 LT |
433 | movl ARGBASE+4(%esp),%esi #src |
434 | movl ARGBASE+8(%esp),%edi #dst | |
435 | movl ARGBASE+12(%esp),%ecx #len | |
436 | movl ARGBASE+16(%esp),%eax #sum | |
437 | # movl %ecx, %edx | |
438 | movl %ecx, %ebx | |
439 | movl %esi, %edx | |
440 | shrl $6, %ecx | |
441 | andl $0x3c, %ebx | |
442 | negl %ebx | |
443 | subl %ebx, %esi | |
444 | subl %ebx, %edi | |
445 | lea -1(%esi),%edx | |
446 | andl $-32,%edx | |
447 | lea 3f(%ebx,%ebx), %ebx | |
448 | testl %esi, %esi | |
449 | jmp *%ebx | |
450 | 1: addl $64,%esi | |
451 | addl $64,%edi | |
452 | SRC(movb -32(%edx),%bl) ; SRC(movb (%edx),%bl) | |
453 | ROUND1(-64) ROUND(-60) ROUND(-56) ROUND(-52) | |
454 | ROUND (-48) ROUND(-44) ROUND(-40) ROUND(-36) | |
455 | ROUND (-32) ROUND(-28) ROUND(-24) ROUND(-20) | |
456 | ROUND (-16) ROUND(-12) ROUND(-8) ROUND(-4) | |
457 | 3: adcl $0,%eax | |
458 | addl $64, %edx | |
459 | dec %ecx | |
460 | jge 1b | |
461 | 4: movl ARGBASE+12(%esp),%edx #len | |
462 | andl $3, %edx | |
463 | jz 7f | |
464 | cmpl $2, %edx | |
465 | jb 5f | |
466 | SRC( movw (%esi), %dx ) | |
467 | leal 2(%esi), %esi | |
468 | DST( movw %dx, (%edi) ) | |
469 | leal 2(%edi), %edi | |
470 | je 6f | |
471 | shll $16,%edx | |
472 | 5: | |
473 | SRC( movb (%esi), %dl ) | |
474 | DST( movb %dl, (%edi) ) | |
475 | 6: addl %edx, %eax | |
476 | adcl $0, %eax | |
477 | 7: | |
478 | .section .fixup, "ax" | |
479 | 6001: movl ARGBASE+20(%esp), %ebx # src_err_ptr | |
480 | movl $-EFAULT, (%ebx) | |
481 | # zero the complete destination (computing the rest is too much work) | |
482 | movl ARGBASE+8(%esp),%edi # dst | |
483 | movl ARGBASE+12(%esp),%ecx # len | |
484 | xorl %eax,%eax | |
485 | rep; stosb | |
486 | jmp 7b | |
487 | 6002: movl ARGBASE+24(%esp), %ebx # dst_err_ptr | |
488 | movl $-EFAULT, (%ebx) | |
489 | jmp 7b | |
490 | .previous | |
491 | ||
49db46a6 DV |
492 | popl_cfi_reg esi |
493 | popl_cfi_reg edi | |
494 | popl_cfi_reg ebx | |
1da177e4 | 495 | ret |
00e065ea JB |
496 | CFI_ENDPROC |
497 | ENDPROC(csum_partial_copy_generic) | |
1da177e4 LT |
498 | |
499 | #undef ROUND | |
500 | #undef ROUND1 | |
501 | ||
502 | #endif |