aboutsummaryrefslogtreecommitdiffstats
path: root/arch/um/sys-i386/checksum.S
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/um/sys-i386/checksum.S
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/um/sys-i386/checksum.S')
-rw-r--r--arch/um/sys-i386/checksum.S460
1 files changed, 460 insertions, 0 deletions
diff --git a/arch/um/sys-i386/checksum.S b/arch/um/sys-i386/checksum.S
new file mode 100644
index 000000000000..a11171fb6223
--- /dev/null
+++ b/arch/um/sys-i386/checksum.S
@@ -0,0 +1,460 @@
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
28#include <linux/config.h>
29#include <asm/errno.h>
30
31/*
32 * computes a partial checksum, e.g. for TCP/UDP fragments
33 */
34
35/*
36unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum)
37 */
38
39.text
40.align 4
41.globl arch_csum_partial
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 */
52arch_csum_partial:
53 pushl %esi
54 pushl %ebx
55 movl 20(%esp),%eax # Function arg: unsigned int sum
56 movl 16(%esp),%ecx # Function arg: int len
57 movl 12(%esp),%esi # Function arg: unsigned char *buff
58 testl $2, %esi # Check alignment.
59 jz 2f # Jump if alignment is ok.
60 subl $2, %ecx # Alignment uses up two bytes.
61 jae 1f # Jump if we had at least two bytes.
62 addl $2, %ecx # ecx was < 2. Deal with it.
63 jmp 4f
641: movw (%esi), %bx
65 addl $2, %esi
66 addw %bx, %ax
67 adcl $0, %eax
682:
69 movl %ecx, %edx
70 shrl $5, %ecx
71 jz 2f
72 testl %esi, %esi
731: movl (%esi), %ebx
74 adcl %ebx, %eax
75 movl 4(%esi), %ebx
76 adcl %ebx, %eax
77 movl 8(%esi), %ebx
78 adcl %ebx, %eax
79 movl 12(%esi), %ebx
80 adcl %ebx, %eax
81 movl 16(%esi), %ebx
82 adcl %ebx, %eax
83 movl 20(%esi), %ebx
84 adcl %ebx, %eax
85 movl 24(%esi), %ebx
86 adcl %ebx, %eax
87 movl 28(%esi), %ebx
88 adcl %ebx, %eax
89 lea 32(%esi), %esi
90 dec %ecx
91 jne 1b
92 adcl $0, %eax
932: movl %edx, %ecx
94 andl $0x1c, %edx
95 je 4f
96 shrl $2, %edx # This clears CF
973: adcl (%esi), %eax
98 lea 4(%esi), %esi
99 dec %edx
100 jne 3b
101 adcl $0, %eax
1024: andl $3, %ecx
103 jz 7f
104 cmpl $2, %ecx
105 jb 5f
106 movw (%esi),%cx
107 leal 2(%esi),%esi
108 je 6f
109 shll $16,%ecx
1105: movb (%esi),%cl
1116: addl %ecx,%eax
112 adcl $0, %eax
1137:
114 popl %ebx
115 popl %esi
116 ret
117
118#else
119
120/* Version for PentiumII/PPro */
121
122arch_csum_partial:
123 pushl %esi
124 pushl %ebx
125 movl 20(%esp),%eax # Function arg: unsigned int sum
126 movl 16(%esp),%ecx # Function arg: int len
127 movl 12(%esp),%esi # Function arg: const unsigned char *buf
128
129 testl $2, %esi
130 jnz 30f
13110:
132 movl %ecx, %edx
133 movl %ecx, %ebx
134 andl $0x7c, %ebx
135 shrl $7, %ecx
136 addl %ebx,%esi
137 shrl $2, %ebx
138 negl %ebx
139 lea 45f(%ebx,%ebx,2), %ebx
140 testl %esi, %esi
141 jmp *%ebx
142
143 # Handle 2-byte-aligned regions
14420: addw (%esi), %ax
145 lea 2(%esi), %esi
146 adcl $0, %eax
147 jmp 10b
148
14930: subl $2, %ecx
150 ja 20b
151 je 32f
152 movzbl (%esi),%ebx # csumming 1 byte, 2-aligned
153 addl %ebx, %eax
154 adcl $0, %eax
155 jmp 80f
15632:
157 addw (%esi), %ax # csumming 2 bytes, 2-aligned
158 adcl $0, %eax
159 jmp 80f
160
16140:
162 addl -128(%esi), %eax
163 adcl -124(%esi), %eax
164 adcl -120(%esi), %eax
165 adcl -116(%esi), %eax
166 adcl -112(%esi), %eax
167 adcl -108(%esi), %eax
168 adcl -104(%esi), %eax
169 adcl -100(%esi), %eax
170 adcl -96(%esi), %eax
171 adcl -92(%esi), %eax
172 adcl -88(%esi), %eax
173 adcl -84(%esi), %eax
174 adcl -80(%esi), %eax
175 adcl -76(%esi), %eax
176 adcl -72(%esi), %eax
177 adcl -68(%esi), %eax
178 adcl -64(%esi), %eax
179 adcl -60(%esi), %eax
180 adcl -56(%esi), %eax
181 adcl -52(%esi), %eax
182 adcl -48(%esi), %eax
183 adcl -44(%esi), %eax
184 adcl -40(%esi), %eax
185 adcl -36(%esi), %eax
186 adcl -32(%esi), %eax
187 adcl -28(%esi), %eax
188 adcl -24(%esi), %eax
189 adcl -20(%esi), %eax
190 adcl -16(%esi), %eax
191 adcl -12(%esi), %eax
192 adcl -8(%esi), %eax
193 adcl -4(%esi), %eax
19445:
195 lea 128(%esi), %esi
196 adcl $0, %eax
197 dec %ecx
198 jge 40b
199 movl %edx, %ecx
20050: andl $3, %ecx
201 jz 80f
202
203 # Handle the last 1-3 bytes without jumping
204 notl %ecx # 1->2, 2->1, 3->0, higher bits are masked
205 movl $0xffffff,%ebx # by the shll and shrl instructions
206 shll $3,%ecx
207 shrl %cl,%ebx
208 andl -128(%esi),%ebx # esi is 4-aligned so should be ok
209 addl %ebx,%eax
210 adcl $0,%eax
21180:
212 popl %ebx
213 popl %esi
214 ret
215
216#endif
217
218/*
219unsigned int csum_partial_copy_generic (const char *src, char *dst,
220 int len, int sum, int *src_err_ptr, int *dst_err_ptr)
221 */
222
223/*
224 * Copy from ds while checksumming, otherwise like csum_partial
225 *
226 * The macros SRC and DST specify the type of access for the instruction.
227 * thus we can call a custom exception handler for all access types.
228 *
229 * FIXME: could someone double-check whether I haven't mixed up some SRC and
230 * DST definitions? It's damn hard to trigger all cases. I hope I got
231 * them all but there's no guarantee.
232 */
233
234#define SRC(y...) \
235 9999: y; \
236 .section __ex_table, "a"; \
237 .long 9999b, 6001f ; \
238 .previous
239
240#define DST(y...) \
241 9999: y; \
242 .section __ex_table, "a"; \
243 .long 9999b, 6002f ; \
244 .previous
245
246.align 4
247.globl csum_partial_copy_generic_i386
248
249#ifndef CONFIG_X86_USE_PPRO_CHECKSUM
250
251#define ARGBASE 16
252#define FP 12
253
254csum_partial_copy_generic_i386:
255 subl $4,%esp
256 pushl %edi
257 pushl %esi
258 pushl %ebx
259 movl ARGBASE+16(%esp),%eax # sum
260 movl ARGBASE+12(%esp),%ecx # len
261 movl ARGBASE+4(%esp),%esi # src
262 movl ARGBASE+8(%esp),%edi # dst
263
264 testl $2, %edi # Check alignment.
265 jz 2f # Jump if alignment is ok.
266 subl $2, %ecx # Alignment uses up two bytes.
267 jae 1f # Jump if we had at least two bytes.
268 addl $2, %ecx # ecx was < 2. Deal with it.
269 jmp 4f
270SRC(1: movw (%esi), %bx )
271 addl $2, %esi
272DST( movw %bx, (%edi) )
273 addl $2, %edi
274 addw %bx, %ax
275 adcl $0, %eax
2762:
277 movl %ecx, FP(%esp)
278 shrl $5, %ecx
279 jz 2f
280 testl %esi, %esi
281SRC(1: movl (%esi), %ebx )
282SRC( movl 4(%esi), %edx )
283 adcl %ebx, %eax
284DST( movl %ebx, (%edi) )
285 adcl %edx, %eax
286DST( movl %edx, 4(%edi) )
287
288SRC( movl 8(%esi), %ebx )
289SRC( movl 12(%esi), %edx )
290 adcl %ebx, %eax
291DST( movl %ebx, 8(%edi) )
292 adcl %edx, %eax
293DST( movl %edx, 12(%edi) )
294
295SRC( movl 16(%esi), %ebx )
296SRC( movl 20(%esi), %edx )
297 adcl %ebx, %eax
298DST( movl %ebx, 16(%edi) )
299 adcl %edx, %eax
300DST( movl %edx, 20(%edi) )
301
302SRC( movl 24(%esi), %ebx )
303SRC( movl 28(%esi), %edx )
304 adcl %ebx, %eax
305DST( movl %ebx, 24(%edi) )
306 adcl %edx, %eax
307DST( movl %edx, 28(%edi) )
308
309 lea 32(%esi), %esi
310 lea 32(%edi), %edi
311 dec %ecx
312 jne 1b
313 adcl $0, %eax
3142: movl FP(%esp), %edx
315 movl %edx, %ecx
316 andl $0x1c, %edx
317 je 4f
318 shrl $2, %edx # This clears CF
319SRC(3: movl (%esi), %ebx )
320 adcl %ebx, %eax
321DST( movl %ebx, (%edi) )
322 lea 4(%esi), %esi
323 lea 4(%edi), %edi
324 dec %edx
325 jne 3b
326 adcl $0, %eax
3274: andl $3, %ecx
328 jz 7f
329 cmpl $2, %ecx
330 jb 5f
331SRC( movw (%esi), %cx )
332 leal 2(%esi), %esi
333DST( movw %cx, (%edi) )
334 leal 2(%edi), %edi
335 je 6f
336 shll $16,%ecx
337SRC(5: movb (%esi), %cl )
338DST( movb %cl, (%edi) )
3396: addl %ecx, %eax
340 adcl $0, %eax
3417:
3425000:
343
344# Exception handler:
345.section .fixup, "ax"
346
3476001:
348 movl ARGBASE+20(%esp), %ebx # src_err_ptr
349 movl $-EFAULT, (%ebx)
350
351 # zero the complete destination - computing the rest
352 # is too much work
353 movl ARGBASE+8(%esp), %edi # dst
354 movl ARGBASE+12(%esp), %ecx # len
355 xorl %eax,%eax
356 rep ; stosb
357
358 jmp 5000b
359
3606002:
361 movl ARGBASE+24(%esp), %ebx # dst_err_ptr
362 movl $-EFAULT,(%ebx)
363 jmp 5000b
364
365.previous
366
367 popl %ebx
368 popl %esi
369 popl %edi
370 popl %ecx # equivalent to addl $4,%esp
371 ret
372
373#else
374
375/* Version for PentiumII/PPro */
376
377#define ROUND1(x) \
378 SRC(movl x(%esi), %ebx ) ; \
379 addl %ebx, %eax ; \
380 DST(movl %ebx, x(%edi) ) ;
381
382#define ROUND(x) \
383 SRC(movl x(%esi), %ebx ) ; \
384 adcl %ebx, %eax ; \
385 DST(movl %ebx, x(%edi) ) ;
386
387#define ARGBASE 12
388
389csum_partial_copy_generic_i386:
390 pushl %ebx
391 pushl %edi
392 pushl %esi
393 movl ARGBASE+4(%esp),%esi #src
394 movl ARGBASE+8(%esp),%edi #dst
395 movl ARGBASE+12(%esp),%ecx #len
396 movl ARGBASE+16(%esp),%eax #sum
397# movl %ecx, %edx
398 movl %ecx, %ebx
399 movl %esi, %edx
400 shrl $6, %ecx
401 andl $0x3c, %ebx
402 negl %ebx
403 subl %ebx, %esi
404 subl %ebx, %edi
405 lea -1(%esi),%edx
406 andl $-32,%edx
407 lea 3f(%ebx,%ebx), %ebx
408 testl %esi, %esi
409 jmp *%ebx
4101: addl $64,%esi
411 addl $64,%edi
412 SRC(movb -32(%edx),%bl) ; SRC(movb (%edx),%bl)
413 ROUND1(-64) ROUND(-60) ROUND(-56) ROUND(-52)
414 ROUND (-48) ROUND(-44) ROUND(-40) ROUND(-36)
415 ROUND (-32) ROUND(-28) ROUND(-24) ROUND(-20)
416 ROUND (-16) ROUND(-12) ROUND(-8) ROUND(-4)
4173: adcl $0,%eax
418 addl $64, %edx
419 dec %ecx
420 jge 1b
4214: movl ARGBASE+12(%esp),%edx #len
422 andl $3, %edx
423 jz 7f
424 cmpl $2, %edx
425 jb 5f
426SRC( movw (%esi), %dx )
427 leal 2(%esi), %esi
428DST( movw %dx, (%edi) )
429 leal 2(%edi), %edi
430 je 6f
431 shll $16,%edx
4325:
433SRC( movb (%esi), %dl )
434DST( movb %dl, (%edi) )
4356: addl %edx, %eax
436 adcl $0, %eax
4377:
438.section .fixup, "ax"
4396001: movl ARGBASE+20(%esp), %ebx # src_err_ptr
440 movl $-EFAULT, (%ebx)
441 # zero the complete destination (computing the rest is too much work)
442 movl ARGBASE+8(%esp),%edi # dst
443 movl ARGBASE+12(%esp),%ecx # len
444 xorl %eax,%eax
445 rep; stosb
446 jmp 7b
4476002: movl ARGBASE+24(%esp), %ebx # dst_err_ptr
448 movl $-EFAULT, (%ebx)
449 jmp 7b
450.previous
451
452 popl %esi
453 popl %edi
454 popl %ebx
455 ret
456
457#undef ROUND
458#undef ROUND1
459
460#endif