| blob | 66eda40fce3602e41a9c5004068b7b600ee78a33 |
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* checksum.S: Sparc optimized checksum code.
3 *
4 * Copyright(C) 1995 Linus Torvalds
5 * Copyright(C) 1995 Miguel de Icaza
6 * Copyright(C) 1996 David S. Miller
7 * Copyright(C) 1997 Jakub Jelinek
8 *
9 * derived from:
10 * Linux/Alpha checksum c-code
11 * Linux/ix86 inline checksum assembly
12 * RFC1071 Computing the Internet Checksum (esp. Jacobsons m68k code)
13 * David Mosberger-Tang for optimized reference c-code
14 * BSD4.4 portable checksum routine
15 */
17 #include <linux/export.h>
18 #include <asm/errno.h>
20 #define CSUM_BIGCHUNK(buf, offset, sum, t0, t1, t2, t3, t4, t5) \
21 ldd [buf + offset + 0x00], t0; \
22 ldd [buf + offset + 0x08], t2; \
23 addxcc t0, sum, sum; \
24 addxcc t1, sum, sum; \
25 ldd [buf + offset + 0x10], t4; \
26 addxcc t2, sum, sum; \
27 addxcc t3, sum, sum; \
28 ldd [buf + offset + 0x18], t0; \
29 addxcc t4, sum, sum; \
30 addxcc t5, sum, sum; \
31 addxcc t0, sum, sum; \
32 addxcc t1, sum, sum;
34 #define CSUM_LASTCHUNK(buf, offset, sum, t0, t1, t2, t3) \
35 ldd [buf - offset - 0x08], t0; \
36 ldd [buf - offset - 0x00], t2; \
37 addxcc t0, sum, sum; \
38 addxcc t1, sum, sum; \
39 addxcc t2, sum, sum; \
40 addxcc t3, sum, sum;
42 /* Do end cruft out of band to get better cache patterns. */
43 csum_partial_end_cruft:
44 be 1f ! caller asks %o1 & 0x8
45 andcc %o1, 4, %g0 ! nope, check for word remaining
46 ldd [%o0], %g2 ! load two
47 addcc %g2, %o2, %o2 ! add first word to sum
48 addxcc %g3, %o2, %o2 ! add second word as well
49 add %o0, 8, %o0 ! advance buf ptr
50 addx %g0, %o2, %o2 ! add in final carry
51 andcc %o1, 4, %g0 ! check again for word remaining
52 1: be 1f ! nope, skip this code
53 andcc %o1, 3, %o1 ! check for trailing bytes
54 ld [%o0], %g2 ! load it
55 addcc %g2, %o2, %o2 ! add to sum
56 add %o0, 4, %o0 ! advance buf ptr
57 addx %g0, %o2, %o2 ! add in final carry
58 andcc %o1, 3, %g0 ! check again for trailing bytes
59 1: be 1f ! no trailing bytes, return
60 addcc %o1, -1, %g0 ! only one byte remains?
61 bne 2f ! at least two bytes more
62 subcc %o1, 2, %o1 ! only two bytes more?
63 b 4f ! only one byte remains
64 or %g0, %g0, %o4 ! clear fake hword value
65 2: lduh [%o0], %o4 ! get hword
66 be 6f ! jmp if only hword remains
67 add %o0, 2, %o0 ! advance buf ptr either way
68 sll %o4, 16, %o4 ! create upper hword
69 4: ldub [%o0], %o5 ! get final byte
70 sll %o5, 8, %o5 ! put into place
71 or %o5, %o4, %o4 ! coalese with hword (if any)
72 6: addcc %o4, %o2, %o2 ! add to sum
73 1: retl ! get outta here
74 addx %g0, %o2, %o0 ! add final carry into retval
76 /* Also do alignment out of band to get better cache patterns. */
77 csum_partial_fix_alignment:
78 cmp %o1, 6
79 bl cpte - 0x4
80 andcc %o0, 0x2, %g0
81 be 1f
82 andcc %o0, 0x4, %g0
83 lduh [%o0 + 0x00], %g2
84 sub %o1, 2, %o1
85 add %o0, 2, %o0
86 sll %g2, 16, %g2
87 addcc %g2, %o2, %o2
88 srl %o2, 16, %g3
89 addx %g0, %g3, %g2
90 sll %o2, 16, %o2
91 sll %g2, 16, %g3
92 srl %o2, 16, %o2
93 andcc %o0, 0x4, %g0
94 or %g3, %o2, %o2
95 1: be cpa
96 andcc %o1, 0xffffff80, %o3
97 ld [%o0 + 0x00], %g2
98 sub %o1, 4, %o1
99 addcc %g2, %o2, %o2
100 add %o0, 4, %o0
101 addx %g0, %o2, %o2
102 b cpa
103 andcc %o1, 0xffffff80, %o3
105 /* The common case is to get called with a nicely aligned
106 * buffer of size 0x20. Follow the code path for that case.
107 */
108 .globl csum_partial
109 EXPORT_SYMBOL(csum_partial)
110 csum_partial: /* %o0=buf, %o1=len, %o2=sum */
111 andcc %o0, 0x7, %g0 ! alignment problems?
112 bne csum_partial_fix_alignment ! yep, handle it
113 sethi %hi(cpte - 8), %g7 ! prepare table jmp ptr
114 andcc %o1, 0xffffff80, %o3 ! num loop iterations
115 cpa: be 3f ! none to do
116 andcc %o1, 0x70, %g1 ! clears carry flag too
117 5: CSUM_BIGCHUNK(%o0, 0x00, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
118 CSUM_BIGCHUNK(%o0, 0x20, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
119 CSUM_BIGCHUNK(%o0, 0x40, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
120 CSUM_BIGCHUNK(%o0, 0x60, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
121 addx %g0, %o2, %o2 ! sink in final carry
122 subcc %o3, 128, %o3 ! detract from loop iters
123 bne 5b ! more to do
124 add %o0, 128, %o0 ! advance buf ptr
125 andcc %o1, 0x70, %g1 ! clears carry flag too
126 3: be cpte ! nope
127 andcc %o1, 0xf, %g0 ! anything left at all?
128 srl %g1, 1, %o4 ! compute offset
129 sub %g7, %g1, %g7 ! adjust jmp ptr
130 sub %g7, %o4, %g7 ! final jmp ptr adjust
131 jmp %g7 + %lo(cpte - 8) ! enter the table
132 add %o0, %g1, %o0 ! advance buf ptr
133 cptbl: CSUM_LASTCHUNK(%o0, 0x68, %o2, %g2, %g3, %g4, %g5)
134 CSUM_LASTCHUNK(%o0, 0x58, %o2, %g2, %g3, %g4, %g5)
135 CSUM_LASTCHUNK(%o0, 0x48, %o2, %g2, %g3, %g4, %g5)
136 CSUM_LASTCHUNK(%o0, 0x38, %o2, %g2, %g3, %g4, %g5)
137 CSUM_LASTCHUNK(%o0, 0x28, %o2, %g2, %g3, %g4, %g5)
138 CSUM_LASTCHUNK(%o0, 0x18, %o2, %g2, %g3, %g4, %g5)
139 CSUM_LASTCHUNK(%o0, 0x08, %o2, %g2, %g3, %g4, %g5)
140 addx %g0, %o2, %o2 ! fetch final carry
141 andcc %o1, 0xf, %g0 ! anything left at all?
142 cpte: bne csum_partial_end_cruft ! yep, handle it
143 andcc %o1, 8, %g0 ! check how much
144 cpout: retl ! get outta here
145 mov %o2, %o0 ! return computed csum
147 /* Work around cpp -rob */
148 #define ALLOC #alloc
149 #define EXECINSTR #execinstr
150 #define EX(x,y) \
151 98: x,y; \
152 .section __ex_table,ALLOC; \
153 .align 4; \
154 .word 98b, cc_fault; \
155 .text; \
156 .align 4
158 /* This aligned version executes typically in 8.5 superscalar cycles, this
159 * is the best I can do. I say 8.5 because the final add will pair with
160 * the next ldd in the main unrolled loop. Thus the pipe is always full.
161 * If you change these macros (including order of instructions),
162 * please check the fixup code below as well.
163 */
164 #define CSUMCOPY_BIGCHUNK_ALIGNED(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \
165 EX(ldd [src + off + 0x00], t0); \
166 EX(ldd [src + off + 0x08], t2); \
167 addxcc t0, sum, sum; \
168 EX(ldd [src + off + 0x10], t4); \
169 addxcc t1, sum, sum; \
170 EX(ldd [src + off + 0x18], t6); \
171 addxcc t2, sum, sum; \
172 EX(std t0, [dst + off + 0x00]); \
173 addxcc t3, sum, sum; \
174 EX(std t2, [dst + off + 0x08]); \
175 addxcc t4, sum, sum; \
176 EX(std t4, [dst + off + 0x10]); \
177 addxcc t5, sum, sum; \
178 EX(std t6, [dst + off + 0x18]); \
179 addxcc t6, sum, sum; \
180 addxcc t7, sum, sum;
182 /* 12 superscalar cycles seems to be the limit for this case,
183 * because of this we thus do all the ldd's together to get
184 * Viking MXCC into streaming mode. Ho hum...
185 */
186 #define CSUMCOPY_BIGCHUNK(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \
187 EX(ldd [src + off + 0x00], t0); \
188 EX(ldd [src + off + 0x08], t2); \
189 EX(ldd [src + off + 0x10], t4); \
190 EX(ldd [src + off + 0x18], t6); \
191 EX(st t0, [dst + off + 0x00]); \
192 addxcc t0, sum, sum; \
193 EX(st t1, [dst + off + 0x04]); \
194 addxcc t1, sum, sum; \
195 EX(st t2, [dst + off + 0x08]); \
196 addxcc t2, sum, sum; \
197 EX(st t3, [dst + off + 0x0c]); \
198 addxcc t3, sum, sum; \
199 EX(st t4, [dst + off + 0x10]); \
200 addxcc t4, sum, sum; \
201 EX(st t5, [dst + off + 0x14]); \
202 addxcc t5, sum, sum; \
203 EX(st t6, [dst + off + 0x18]); \
204 addxcc t6, sum, sum; \
205 EX(st t7, [dst + off + 0x1c]); \
206 addxcc t7, sum, sum;
208 /* Yuck, 6 superscalar cycles... */
209 #define CSUMCOPY_LASTCHUNK(src, dst, sum, off, t0, t1, t2, t3) \
210 EX(ldd [src - off - 0x08], t0); \
211 EX(ldd [src - off - 0x00], t2); \
212 addxcc t0, sum, sum; \
213 EX(st t0, [dst - off - 0x08]); \
214 addxcc t1, sum, sum; \
215 EX(st t1, [dst - off - 0x04]); \
216 addxcc t2, sum, sum; \
217 EX(st t2, [dst - off - 0x00]); \
218 addxcc t3, sum, sum; \
219 EX(st t3, [dst - off + 0x04]);
221 /* Handle the end cruft code out of band for better cache patterns. */
222 cc_end_cruft:
223 be 1f
224 andcc %o3, 4, %g0
225 EX(ldd [%o0 + 0x00], %g2)
226 add %o1, 8, %o1
227 addcc %g2, %g7, %g7
228 add %o0, 8, %o0
229 addxcc %g3, %g7, %g7
230 EX(st %g2, [%o1 - 0x08])
231 addx %g0, %g7, %g7
232 andcc %o3, 4, %g0
233 EX(st %g3, [%o1 - 0x04])
234 1: be 1f
235 andcc %o3, 3, %o3
236 EX(ld [%o0 + 0x00], %g2)
237 add %o1, 4, %o1
238 addcc %g2, %g7, %g7
239 EX(st %g2, [%o1 - 0x04])
240 addx %g0, %g7, %g7
241 andcc %o3, 3, %g0
242 add %o0, 4, %o0
243 1: be 1f
244 addcc %o3, -1, %g0
245 bne 2f
246 subcc %o3, 2, %o3
247 b 4f
248 or %g0, %g0, %o4
249 2: EX(lduh [%o0 + 0x00], %o4)
250 add %o0, 2, %o0
251 EX(sth %o4, [%o1 + 0x00])
252 be 6f
253 add %o1, 2, %o1
254 sll %o4, 16, %o4
255 4: EX(ldub [%o0 + 0x00], %o5)
256 EX(stb %o5, [%o1 + 0x00])
257 sll %o5, 8, %o5
258 or %o5, %o4, %o4
259 6: addcc %o4, %g7, %g7
260 1: retl
261 addx %g0, %g7, %o0
263 /* Also, handle the alignment code out of band. */
264 cc_dword_align:
265 cmp %g1, 16
266 bge 1f
267 srl %g1, 1, %o3
268 2: cmp %o3, 0
269 be,a ccte
270 andcc %g1, 0xf, %o3
271 andcc %o3, %o0, %g0 ! Check %o0 only (%o1 has the same last 2 bits)
272 be,a 2b
273 srl %o3, 1, %o3
274 1: andcc %o0, 0x1, %g0
275 bne ccslow
276 andcc %o0, 0x2, %g0
277 be 1f
278 andcc %o0, 0x4, %g0
279 EX(lduh [%o0 + 0x00], %g4)
280 sub %g1, 2, %g1
281 EX(sth %g4, [%o1 + 0x00])
282 add %o0, 2, %o0
283 sll %g4, 16, %g4
284 addcc %g4, %g7, %g7
285 add %o1, 2, %o1
286 srl %g7, 16, %g3
287 addx %g0, %g3, %g4
288 sll %g7, 16, %g7
289 sll %g4, 16, %g3
290 srl %g7, 16, %g7
291 andcc %o0, 0x4, %g0
292 or %g3, %g7, %g7
293 1: be 3f
294 andcc %g1, 0xffffff80, %g0
295 EX(ld [%o0 + 0x00], %g4)
296 sub %g1, 4, %g1
297 EX(st %g4, [%o1 + 0x00])
298 add %o0, 4, %o0
299 addcc %g4, %g7, %g7
300 add %o1, 4, %o1
301 addx %g0, %g7, %g7
302 b 3f
303 andcc %g1, 0xffffff80, %g0
305 /* Sun, you just can't beat me, you just can't. Stop trying,
306 * give up. I'm serious, I am going to kick the living shit
307 * out of you, game over, lights out.
308 */
309 .align 8
310 .globl __csum_partial_copy_sparc_generic
311 EXPORT_SYMBOL(__csum_partial_copy_sparc_generic)
312 __csum_partial_copy_sparc_generic:
313 /* %o0=src, %o1=dest, %g1=len, %g7=sum */
314 xor %o0, %o1, %o4 ! get changing bits
315 andcc %o4, 3, %g0 ! check for mismatched alignment
316 bne ccslow ! better this than unaligned/fixups
317 andcc %o0, 7, %g0 ! need to align things?
318 bne cc_dword_align ! yes, we check for short lengths there
319 andcc %g1, 0xffffff80, %g0 ! can we use unrolled loop?
320 3: be 3f ! nope, less than one loop remains
321 andcc %o1, 4, %g0 ! dest aligned on 4 or 8 byte boundary?
322 be ccdbl + 4 ! 8 byte aligned, kick ass
323 5: CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
324 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
325 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
326 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
327 sub %g1, 128, %g1 ! detract from length
328 addx %g0, %g7, %g7 ! add in last carry bit
329 andcc %g1, 0xffffff80, %g0 ! more to csum?
330 add %o0, 128, %o0 ! advance src ptr
331 bne 5b ! we did not go negative, continue looping
332 add %o1, 128, %o1 ! advance dest ptr
333 3: andcc %g1, 0x70, %o2 ! can use table?
334 ccmerge:be ccte ! nope, go and check for end cruft
335 andcc %g1, 0xf, %o3 ! get low bits of length (clears carry btw)
336 srl %o2, 1, %o4 ! begin negative offset computation
337 sethi %hi(12f), %o5 ! set up table ptr end
338 add %o0, %o2, %o0 ! advance src ptr
339 sub %o5, %o4, %o5 ! continue table calculation
340 sll %o2, 1, %g2 ! constant multiplies are fun...
341 sub %o5, %g2, %o5 ! some more adjustments
342 jmp %o5 + %lo(12f) ! jump into it, duff style, wheee...
343 add %o1, %o2, %o1 ! advance dest ptr (carry is clear btw)
344 cctbl: CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x68,%g2,%g3,%g4,%g5)
345 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x58,%g2,%g3,%g4,%g5)
346 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x48,%g2,%g3,%g4,%g5)
347 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x38,%g2,%g3,%g4,%g5)
348 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x28,%g2,%g3,%g4,%g5)
349 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x18,%g2,%g3,%g4,%g5)
350 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x08,%g2,%g3,%g4,%g5)
351 12: addx %g0, %g7, %g7
352 andcc %o3, 0xf, %g0 ! check for low bits set
353 ccte: bne cc_end_cruft ! something left, handle it out of band
354 andcc %o3, 8, %g0 ! begin checks for that code
355 retl ! return
356 mov %g7, %o0 ! give em the computed checksum
357 ccdbl: CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
358 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
359 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
360 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
361 sub %g1, 128, %g1 ! detract from length
362 addx %g0, %g7, %g7 ! add in last carry bit
363 andcc %g1, 0xffffff80, %g0 ! more to csum?
364 add %o0, 128, %o0 ! advance src ptr
365 bne ccdbl ! we did not go negative, continue looping
366 add %o1, 128, %o1 ! advance dest ptr
367 b ccmerge ! finish it off, above
368 andcc %g1, 0x70, %o2 ! can use table? (clears carry btw)
370 ccslow: cmp %g1, 0
371 mov 0, %g5
372 bleu 4f
373 andcc %o0, 1, %o5
374 be,a 1f
375 srl %g1, 1, %g4
376 sub %g1, 1, %g1
377 EX(ldub [%o0], %g5)
378 add %o0, 1, %o0
379 EX(stb %g5, [%o1])
380 srl %g1, 1, %g4
381 add %o1, 1, %o1
382 1: cmp %g4, 0
383 be,a 3f
384 andcc %g1, 1, %g0
385 andcc %o0, 2, %g0
386 be,a 1f
387 srl %g4, 1, %g4
388 EX(lduh [%o0], %o4)
389 sub %g1, 2, %g1
390 srl %o4, 8, %g2
391 sub %g4, 1, %g4
392 EX(stb %g2, [%o1])
393 add %o4, %g5, %g5
394 EX(stb %o4, [%o1 + 1])
395 add %o0, 2, %o0
396 srl %g4, 1, %g4
397 add %o1, 2, %o1
398 1: cmp %g4, 0
399 be,a 2f
400 andcc %g1, 2, %g0
401 EX(ld [%o0], %o4)
402 5: srl %o4, 24, %g2
403 srl %o4, 16, %g3
404 EX(stb %g2, [%o1])
405 srl %o4, 8, %g2
406 EX(stb %g3, [%o1 + 1])
407 add %o0, 4, %o0
408 EX(stb %g2, [%o1 + 2])
409 addcc %o4, %g5, %g5
410 EX(stb %o4, [%o1 + 3])
411 addx %g5, %g0, %g5 ! I am now to lazy to optimize this (question it
412 add %o1, 4, %o1 ! is worthy). Maybe some day - with the sll/srl
413 subcc %g4, 1, %g4 ! tricks
414 bne,a 5b
415 EX(ld [%o0], %o4)
416 sll %g5, 16, %g2
417 srl %g5, 16, %g5
418 srl %g2, 16, %g2
419 andcc %g1, 2, %g0
420 add %g2, %g5, %g5
421 2: be,a 3f
422 andcc %g1, 1, %g0
423 EX(lduh [%o0], %o4)
424 andcc %g1, 1, %g0
425 srl %o4, 8, %g2
426 add %o0, 2, %o0
427 EX(stb %g2, [%o1])
428 add %g5, %o4, %g5
429 EX(stb %o4, [%o1 + 1])
430 add %o1, 2, %o1
431 3: be,a 1f
432 sll %g5, 16, %o4
433 EX(ldub [%o0], %g2)
434 sll %g2, 8, %o4
435 EX(stb %g2, [%o1])
436 add %g5, %o4, %g5
437 sll %g5, 16, %o4
438 1: addcc %o4, %g5, %g5
439 srl %g5, 16, %o4
440 addx %g0, %o4, %g5
441 orcc %o5, %g0, %g0
442 be 4f
443 srl %g5, 8, %o4
444 and %g5, 0xff, %g2
445 and %o4, 0xff, %o4
446 sll %g2, 8, %g2
447 or %g2, %o4, %g5
448 4: addcc %g7, %g5, %g7
449 retl
450 addx %g0, %g7, %o0
452 /* We do these strange calculations for the csum_*_from_user case only, ie.
453 * we only bother with faults on loads... */
455 cc_fault:
456 retl
457 clr %o0