1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* checksum.S: Sparc optimized checksum code.
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
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
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; \
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; \
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:
83 lduh [%o0 + 0x00], %g2
96 andcc %o1, 0xffffff80, %o3
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.
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
124 add %o0, 128, %o0 ! advance buf ptr
125 andcc %o1, 0x70, %g1 ! clears carry flag too
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 .globl __csum_partial_copy_start, __csum_partial_copy_end
148 __csum_partial_copy_start:
150 /* Work around cpp -rob */
152 #define EXECINSTR #execinstr
153 #define EX(x,y,a,b) \
155 .section .fixup,ALLOC,EXECINSTR; \
159 .section __ex_table,ALLOC; \
167 .section __ex_table,ALLOC; \
175 .section __ex_table,ALLOC; \
181 #define EXT(start,end,handler) \
182 .section __ex_table,ALLOC; \
184 .word start, 0, end, handler; \
188 /* This aligned version executes typically in 8.5 superscalar cycles, this
189 * is the best I can do. I say 8.5 because the final add will pair with
190 * the next ldd in the main unrolled loop. Thus the pipe is always full.
191 * If you change these macros (including order of instructions),
192 * please check the fixup code below as well.
194 #define CSUMCOPY_BIGCHUNK_ALIGNED(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \
195 ldd [src + off + 0x00], t0; \
196 ldd [src + off + 0x08], t2; \
197 addxcc t0, sum, sum; \
198 ldd [src + off + 0x10], t4; \
199 addxcc t1, sum, sum; \
200 ldd [src + off + 0x18], t6; \
201 addxcc t2, sum, sum; \
202 std t0, [dst + off + 0x00]; \
203 addxcc t3, sum, sum; \
204 std t2, [dst + off + 0x08]; \
205 addxcc t4, sum, sum; \
206 std t4, [dst + off + 0x10]; \
207 addxcc t5, sum, sum; \
208 std t6, [dst + off + 0x18]; \
209 addxcc t6, sum, sum; \
212 /* 12 superscalar cycles seems to be the limit for this case,
213 * because of this we thus do all the ldd's together to get
214 * Viking MXCC into streaming mode. Ho hum...
216 #define CSUMCOPY_BIGCHUNK(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \
217 ldd [src + off + 0x00], t0; \
218 ldd [src + off + 0x08], t2; \
219 ldd [src + off + 0x10], t4; \
220 ldd [src + off + 0x18], t6; \
221 st t0, [dst + off + 0x00]; \
222 addxcc t0, sum, sum; \
223 st t1, [dst + off + 0x04]; \
224 addxcc t1, sum, sum; \
225 st t2, [dst + off + 0x08]; \
226 addxcc t2, sum, sum; \
227 st t3, [dst + off + 0x0c]; \
228 addxcc t3, sum, sum; \
229 st t4, [dst + off + 0x10]; \
230 addxcc t4, sum, sum; \
231 st t5, [dst + off + 0x14]; \
232 addxcc t5, sum, sum; \
233 st t6, [dst + off + 0x18]; \
234 addxcc t6, sum, sum; \
235 st t7, [dst + off + 0x1c]; \
238 /* Yuck, 6 superscalar cycles... */
239 #define CSUMCOPY_LASTCHUNK(src, dst, sum, off, t0, t1, t2, t3) \
240 ldd [src - off - 0x08], t0; \
241 ldd [src - off - 0x00], t2; \
242 addxcc t0, sum, sum; \
243 st t0, [dst - off - 0x08]; \
244 addxcc t1, sum, sum; \
245 st t1, [dst - off - 0x04]; \
246 addxcc t2, sum, sum; \
247 st t2, [dst - off - 0x00]; \
248 addxcc t3, sum, sum; \
249 st t3, [dst - off + 0x04];
251 /* Handle the end cruft code out of band for better cache patterns. */
255 EX(ldd [%o0 + 0x00], %g2, and %o3, 0xf)
260 EX2(st %g2, [%o1 - 0x08])
263 EX2(st %g3, [%o1 - 0x04])
266 EX(ld [%o0 + 0x00], %g2, add %o3, 4)
269 EX2(st %g2, [%o1 - 0x04])
279 2: EX(lduh [%o0 + 0x00], %o4, add %o3, 2)
281 EX2(sth %o4, [%o1 + 0x00])
285 4: EX(ldub [%o0 + 0x00], %o5, add %g0, 1)
286 EX2(stb %o5, [%o1 + 0x00])
289 6: addcc %o4, %g7, %g7
293 /* Also, handle the alignment code out of band. */
301 andcc %o3, %o0, %g0 ! Check %o0 only (%o1 has the same last 2 bits)
304 1: andcc %o0, 0x1, %g0
309 EX(lduh [%o0 + 0x00], %g4, add %g1, 0)
311 EX2(sth %g4, [%o1 + 0x00])
324 andcc %g1, 0xffffff80, %g0
325 EX(ld [%o0 + 0x00], %g4, add %g1, 0)
327 EX2(st %g4, [%o1 + 0x00])
333 andcc %g1, 0xffffff80, %g0
335 /* Sun, you just can't beat me, you just can't. Stop trying,
336 * give up. I'm serious, I am going to kick the living shit
337 * out of you, game over, lights out.
340 .globl __csum_partial_copy_sparc_generic
341 EXPORT_SYMBOL(__csum_partial_copy_sparc_generic)
342 __csum_partial_copy_sparc_generic:
343 /* %o0=src, %o1=dest, %g1=len, %g7=sum */
344 xor %o0, %o1, %o4 ! get changing bits
345 andcc %o4, 3, %g0 ! check for mismatched alignment
346 bne ccslow ! better this than unaligned/fixups
347 andcc %o0, 7, %g0 ! need to align things?
348 bne cc_dword_align ! yes, we check for short lengths there
349 andcc %g1, 0xffffff80, %g0 ! can we use unrolled loop?
350 3: be 3f ! nope, less than one loop remains
351 andcc %o1, 4, %g0 ! dest aligned on 4 or 8 byte boundary?
352 be ccdbl + 4 ! 8 byte aligned, kick ass
353 5: CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
354 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
355 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
356 CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
357 10: EXT(5b, 10b, 20f) ! note for exception handling
358 sub %g1, 128, %g1 ! detract from length
359 addx %g0, %g7, %g7 ! add in last carry bit
360 andcc %g1, 0xffffff80, %g0 ! more to csum?
361 add %o0, 128, %o0 ! advance src ptr
362 bne 5b ! we did not go negative, continue looping
363 add %o1, 128, %o1 ! advance dest ptr
364 3: andcc %g1, 0x70, %o2 ! can use table?
365 ccmerge:be ccte ! nope, go and check for end cruft
366 andcc %g1, 0xf, %o3 ! get low bits of length (clears carry btw)
367 srl %o2, 1, %o4 ! begin negative offset computation
368 sethi %hi(12f), %o5 ! set up table ptr end
369 add %o0, %o2, %o0 ! advance src ptr
370 sub %o5, %o4, %o5 ! continue table calculation
371 sll %o2, 1, %g2 ! constant multiplies are fun...
372 sub %o5, %g2, %o5 ! some more adjustments
373 jmp %o5 + %lo(12f) ! jump into it, duff style, wheee...
374 add %o1, %o2, %o1 ! advance dest ptr (carry is clear btw)
375 cctbl: CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x68,%g2,%g3,%g4,%g5)
376 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x58,%g2,%g3,%g4,%g5)
377 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x48,%g2,%g3,%g4,%g5)
378 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x38,%g2,%g3,%g4,%g5)
379 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x28,%g2,%g3,%g4,%g5)
380 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x18,%g2,%g3,%g4,%g5)
381 CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x08,%g2,%g3,%g4,%g5)
382 12: EXT(cctbl, 12b, 22f) ! note for exception table handling
384 andcc %o3, 0xf, %g0 ! check for low bits set
385 ccte: bne cc_end_cruft ! something left, handle it out of band
386 andcc %o3, 8, %g0 ! begin checks for that code
388 mov %g7, %o0 ! give em the computed checksum
389 ccdbl: CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
390 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
391 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
392 CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
393 11: EXT(ccdbl, 11b, 21f) ! note for exception table handling
394 sub %g1, 128, %g1 ! detract from length
395 addx %g0, %g7, %g7 ! add in last carry bit
396 andcc %g1, 0xffffff80, %g0 ! more to csum?
397 add %o0, 128, %o0 ! advance src ptr
398 bne ccdbl ! we did not go negative, continue looping
399 add %o1, 128, %o1 ! advance dest ptr
400 b ccmerge ! finish it off, above
401 andcc %g1, 0x70, %o2 ! can use table? (clears carry btw)
410 EX(ldub [%o0], %g5, add %g1, 1)
421 EX(lduh [%o0], %o4, add %g1, 0)
427 EX2(stb %o4, [%o1 + 1])
439 EX2(stb %g3, [%o1 + 1])
441 EX2(stb %g2, [%o1 + 2])
443 EX2(stb %o4, [%o1 + 3])
444 addx %g5, %g0, %g5 ! I am now to lazy to optimize this (question it
445 add %o1, 4, %o1 ! is worthy). Maybe some day - with the sll/srl
446 subcc %g4, 1, %g4 ! tricks
456 EX(lduh [%o0], %o4, and %g1, 3)
462 EX2(stb %o4, [%o1 + 1])
466 EX(ldub [%o0], %g2, add %g0, 1)
471 1: addcc %o4, %g5, %g5
481 4: addcc %g7, %g5, %g7
484 __csum_partial_copy_end:
486 /* We do these strange calculations for the csum_*_from_user case only, ie.
487 * we only bother with faults on loads... */
489 /* o2 = ((g2%20)&3)*8
490 * o3 = g1 - (g2/20)*32 - o2 */
503 /* o2 = (!(g2 & 15) ? 0 : (((g2 & 15) + 1) & ~1)*8)
504 * o3 = g1 - (g2/16)*32 - o2 */
519 /* o0 += (g2/10)*16 - 0x70
520 * 01 += (g2/10)*16 - 0x70
521 * o2 = (g2 % 10) ? 8 : 0
522 * o3 += 0x70 - (g2/10)*16 - o2 */
548 * %o3 is # bytes to zero out
549 * %o4 is faulting address
550 * %o5 is %pc where fault occurred */
555 * %o2 is # of bytes to copy from src to dst
556 * %o3 is # bytes to zero out
557 * %o4 is faulting address
558 * %o5 is %pc where fault occurred */
567 add %g0, -EFAULT, %i5
585 ld [%sp + 168], %o2 ! struct_ptr of parent
590 .section __ex_table,#alloc