| blob | 7488d130faf730d6e96414ce987ff4a5e8b37ca6 |
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 <asm/errno.h>
18 #include <asm/export.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 #define EXT(start,end) \
159 .section __ex_table,ALLOC; \
160 .align 4; \
161 .word start, 0, end, cc_fault; \
162 .text; \
163 .align 4
165 /* This aligned version executes typically in 8.5 superscalar cycles, this
166 * is the best I can do. I say 8.5 because the final add will pair with
167 * the next ldd in the main unrolled loop. Thus the pipe is always full.
168 * If you change these macros (including order of instructions),
169 * please check the fixup code below as well.
170 */
171 #define CSUMCOPY_BIGCHUNK_ALIGNED(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \
172 ldd [src + off + 0x00], t0; \
173 ldd [src + off + 0x08], t2; \
174 addxcc t0, sum, sum; \
175 ldd [src + off + 0x10], t4; \
176 addxcc t1, sum, sum; \
177 ldd [src + off + 0x18], t6; \
178 addxcc t2, sum, sum; \
179 std t0, [dst + off + 0x00]; \
180 addxcc t3, sum, sum; \
181 std t2, [dst + off + 0x08]; \
182 addxcc t4, sum, sum; \
183 std t4, [dst + off + 0x10]; \
184 addxcc t5, sum, sum; \
185 std t6, [dst + off + 0x18]; \
186 addxcc t6, sum, sum; \
187 addxcc t7, sum, sum;
189 /* 12 superscalar cycles seems to be the limit for this case,
190 * because of this we thus do all the ldd's together to get
191 * Viking MXCC into streaming mode. Ho hum...
192 */
193 #define CSUMCOPY_BIGCHUNK(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \
194 ldd [src + off + 0x00], t0; \
195 ldd [src + off + 0x08], t2; \
196 ldd [src + off + 0x10], t4; \
197 ldd [src + off + 0x18], t6; \
198 st t0, [dst + off + 0x00]; \
199 addxcc t0, sum, sum; \
200 st t1, [dst + off + 0x04]; \
201 addxcc t1, sum, sum; \
202 st t2, [dst + off + 0x08]; \
203 addxcc t2, sum, sum; \
204 st t3, [dst + off + 0x0c]; \
205 addxcc t3, sum, sum; \
206 st t4, [dst + off + 0x10]; \
207 addxcc t4, sum, sum; \
208 st t5, [dst + off + 0x14]; \
209 addxcc t5, sum, sum; \
210 st t6, [dst + off + 0x18]; \
211 addxcc t6, sum, sum; \
212 st t7, [dst + off + 0x1c]; \
213 addxcc t7, sum, sum;
215 /* Yuck, 6 superscalar cycles... */
216 #define CSUMCOPY_LASTCHUNK(src, dst, sum, off, t0, t1, t2, t3) \
217 ldd [src - off - 0x08], t0; \
218 ldd [src - off - 0x00], t2; \
219 addxcc t0, sum, sum; \
220 st t0, [dst - off - 0x08]; \
221 addxcc t1, sum, sum; \
222 st t1, [dst - off - 0x04]; \
223 addxcc t2, sum, sum; \
224 st t2, [dst - off - 0x00]; \
225 addxcc t3, sum, sum; \
226 st t3, [dst - off + 0x04];
228 /* Handle the end cruft code out of band for better cache patterns. */
229 cc_end_cruft:
230 be 1f
231 andcc %o3, 4, %g0
232 EX(ldd [%o0 + 0x00], %g2)
233 add %o1, 8, %o1
234 addcc %g2, %g7, %g7
235 add %o0, 8, %o0
236 addxcc %g3, %g7, %g7
237 EX(st %g2, [%o1 - 0x08])
238 addx %g0, %g7, %g7
239 andcc %o3, 4, %g0
240 EX(st %g3, [%o1 - 0x04])
241 1: be 1f
242 andcc %o3, 3, %o3
243 EX(ld [%o0 + 0x00], %g2)
244 add %o1, 4, %o1
245 addcc %g2, %g7, %g7
246 EX(st %g2, [%o1 - 0x04])
247 addx %g0, %g7, %g7
248 andcc %o3, 3, %g0
249 add %o0, 4, %o0
250 1: be 1f
251 addcc %o3, -1, %g0
252 bne 2f
253 subcc %o3, 2, %o3
254 b 4f
255 or %g0, %g0, %o4
256 2: EX(lduh [%o0 + 0x00], %o4)
257 add %o0, 2, %o0
258 EX(sth %o4, [%o1 + 0x00])
259 be 6f
260 add %o1, 2, %o1
261 sll %o4, 16, %o4
262 4: EX(ldub [%o0 + 0x00], %o5)
263 EX(stb %o5, [%o1 + 0x00])
264 sll %o5, 8, %o5
265 or %o5, %o4, %o4
266 6: addcc %o4, %g7, %g7
267 1: retl
268 addx %g0, %g7, %o0
270 /* Also, handle the alignment code out of band. */
271 cc_dword_align:
272 cmp %g1, 16
273 bge 1f
274 srl %g1, 1, %o3
275 2: cmp %o3, 0
276 be,a ccte
277 andcc %g1, 0xf, %o3
278 andcc %o3, %o0, %g0 ! Check %o0 only (%o1 has the same last 2 bits)
279 be,a 2b
280 srl %o3, 1, %o3
281 1: andcc %o0, 0x1, %g0
282 bne ccslow
283 andcc %o0, 0x2, %g0
284 be 1f
285 andcc %o0, 0x4, %g0
286 EX(lduh [%o0 + 0x00], %g4)
287 sub %g1, 2, %g1
288 EX(sth %g4, [%o1 + 0x00])
289 add %o0, 2, %o0
290 sll %g4, 16, %g4
291 addcc %g4, %g7, %g7
292 add %o1, 2, %o1
293 srl %g7, 16, %g3
294 addx %g0, %g3, %g4
295 sll %g7, 16, %g7
296 sll %g4, 16, %g3
297 srl %g7, 16, %g7
298 andcc %o0, 0x4, %g0
299 or %g3, %g7, %g7
300 1: be 3f
301 andcc %g1, 0xffffff80, %g0
302 EX(ld [%o0 + 0x00], %g4)
303 sub %g1, 4, %g1
304 EX(st %g4, [%o1 + 0x00])
305 add %o0, 4, %o0
306 addcc %g4, %g7, %g7
307 add %o1, 4, %o1
308 addx %g0, %g7, %g7
309 b 3f
310 andcc %g1, 0xffffff80, %g0
312 /* Sun, you just can't beat me, you just can't. Stop trying,
313 * give up. I'm serious, I am going to kick the living shit
314 * out of you, game over, lights out.
315 */
316 .align 8
317 .globl __csum_partial_copy_sparc_generic
318 EXPORT_SYMBOL(__csum_partial_copy_sparc_generic)
319 __csum_partial_copy_sparc_generic:
320 /* %o0=src, %o1=dest, %g1=len, %g7=sum */
321 xor %o0, %o1, %o4 ! get changing bits
322 andcc %o4, 3, %g0 ! check for mismatched alignment
323 bne ccslow ! better this than unaligned/fixups
324 andcc %o0, 7, %g0 ! need to align things?
325 bne cc_dword_align ! yes, we check for short lengths there
326 andcc %g1, 0xffffff80, %g0 ! can we use unrolled loop?
327 3: be 3f ! nope, less than one loop remains
328 andcc %o1, 4, %g0 ! dest aligned on 4 or 8 byte boundary?
329 be ccdbl + 4 ! 8 byte aligned, kick ass
330 5: CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
331 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
332 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
333 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
334 10: EXT(5b, 10b) ! note for exception handling
335 sub %g1, 128, %g1 ! detract from length
336 addx %g0, %g7, %g7 ! add in last carry bit
337 andcc %g1, 0xffffff80, %g0 ! more to csum?
338 add %o0, 128, %o0 ! advance src ptr
339 bne 5b ! we did not go negative, continue looping
340 add %o1, 128, %o1 ! advance dest ptr
341 3: andcc %g1, 0x70, %o2 ! can use table?
342 ccmerge:be ccte ! nope, go and check for end cruft
343 andcc %g1, 0xf, %o3 ! get low bits of length (clears carry btw)
344 srl %o2, 1, %o4 ! begin negative offset computation
345 sethi %hi(12f), %o5 ! set up table ptr end
346 add %o0, %o2, %o0 ! advance src ptr
347 sub %o5, %o4, %o5 ! continue table calculation
348 sll %o2, 1, %g2 ! constant multiplies are fun...
349 sub %o5, %g2, %o5 ! some more adjustments
350 jmp %o5 + %lo(12f) ! jump into it, duff style, wheee...
351 add %o1, %o2, %o1 ! advance dest ptr (carry is clear btw)
352 cctbl: CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x68,%g2,%g3,%g4,%g5)
353 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x58,%g2,%g3,%g4,%g5)
354 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x48,%g2,%g3,%g4,%g5)
355 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x38,%g2,%g3,%g4,%g5)
356 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x28,%g2,%g3,%g4,%g5)
357 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x18,%g2,%g3,%g4,%g5)
358 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x08,%g2,%g3,%g4,%g5)
359 12: EXT(cctbl, 12b) ! note for exception table handling
360 addx %g0, %g7, %g7
361 andcc %o3, 0xf, %g0 ! check for low bits set
362 ccte: bne cc_end_cruft ! something left, handle it out of band
363 andcc %o3, 8, %g0 ! begin checks for that code
364 retl ! return
365 mov %g7, %o0 ! give em the computed checksum
366 ccdbl: CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
367 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
368 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
369 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
370 11: EXT(ccdbl, 11b) ! note for exception table handling
371 sub %g1, 128, %g1 ! detract from length
372 addx %g0, %g7, %g7 ! add in last carry bit
373 andcc %g1, 0xffffff80, %g0 ! more to csum?
374 add %o0, 128, %o0 ! advance src ptr
375 bne ccdbl ! we did not go negative, continue looping
376 add %o1, 128, %o1 ! advance dest ptr
377 b ccmerge ! finish it off, above
378 andcc %g1, 0x70, %o2 ! can use table? (clears carry btw)
380 ccslow: cmp %g1, 0
381 mov 0, %g5
382 bleu 4f
383 andcc %o0, 1, %o5
384 be,a 1f
385 srl %g1, 1, %g4
386 sub %g1, 1, %g1
387 EX(ldub [%o0], %g5)
388 add %o0, 1, %o0
389 EX(stb %g5, [%o1])
390 srl %g1, 1, %g4
391 add %o1, 1, %o1
392 1: cmp %g4, 0
393 be,a 3f
394 andcc %g1, 1, %g0
395 andcc %o0, 2, %g0
396 be,a 1f
397 srl %g4, 1, %g4
398 EX(lduh [%o0], %o4)
399 sub %g1, 2, %g1
400 srl %o4, 8, %g2
401 sub %g4, 1, %g4
402 EX(stb %g2, [%o1])
403 add %o4, %g5, %g5
404 EX(stb %o4, [%o1 + 1])
405 add %o0, 2, %o0
406 srl %g4, 1, %g4
407 add %o1, 2, %o1
408 1: cmp %g4, 0
409 be,a 2f
410 andcc %g1, 2, %g0
411 EX(ld [%o0], %o4)
412 5: srl %o4, 24, %g2
413 srl %o4, 16, %g3
414 EX(stb %g2, [%o1])
415 srl %o4, 8, %g2
416 EX(stb %g3, [%o1 + 1])
417 add %o0, 4, %o0
418 EX(stb %g2, [%o1 + 2])
419 addcc %o4, %g5, %g5
420 EX(stb %o4, [%o1 + 3])
421 addx %g5, %g0, %g5 ! I am now to lazy to optimize this (question it
422 add %o1, 4, %o1 ! is worthy). Maybe some day - with the sll/srl
423 subcc %g4, 1, %g4 ! tricks
424 bne,a 5b
425 EX(ld [%o0], %o4)
426 sll %g5, 16, %g2
427 srl %g5, 16, %g5
428 srl %g2, 16, %g2
429 andcc %g1, 2, %g0
430 add %g2, %g5, %g5
431 2: be,a 3f
432 andcc %g1, 1, %g0
433 EX(lduh [%o0], %o4)
434 andcc %g1, 1, %g0
435 srl %o4, 8, %g2
436 add %o0, 2, %o0
437 EX(stb %g2, [%o1])
438 add %g5, %o4, %g5
439 EX(stb %o4, [%o1 + 1])
440 add %o1, 2, %o1
441 3: be,a 1f
442 sll %g5, 16, %o4
443 EX(ldub [%o0], %g2)
444 sll %g2, 8, %o4
445 EX(stb %g2, [%o1])
446 add %g5, %o4, %g5
447 sll %g5, 16, %o4
448 1: addcc %o4, %g5, %g5
449 srl %g5, 16, %o4
450 addx %g0, %o4, %g5
451 orcc %o5, %g0, %g0
452 be 4f
453 srl %g5, 8, %o4
454 and %g5, 0xff, %g2
455 and %o4, 0xff, %o4
456 sll %g2, 8, %g2
457 or %g2, %o4, %g5
458 4: addcc %g7, %g5, %g7
459 retl
460 addx %g0, %g7, %o0
462 /* We do these strange calculations for the csum_*_from_user case only, ie.
463 * we only bother with faults on loads... */
465 cc_fault:
466 ret
467 clr %o0