Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Itanium 2-optimized version of memcpy and copy_user function | |
3 | * | |
4 | * Inputs: | |
5 | * in0: destination address | |
6 | * in1: source address | |
7 | * in2: number of bytes to copy | |
8 | * Output: | |
3e6e1556 CK |
9 | * for memcpy: return dest |
10 | * for copy_user: return 0 if success, | |
11 | * or number of byte NOT copied if error occurred. | |
1da177e4 LT |
12 | * |
13 | * Copyright (C) 2002 Intel Corp. | |
14 | * Copyright (C) 2002 Ken Chen <kenneth.w.chen@intel.com> | |
15 | */ | |
1da177e4 LT |
16 | #include <asm/asmmacro.h> |
17 | #include <asm/page.h> | |
e007c533 | 18 | #include <asm/export.h> |
1da177e4 LT |
19 | |
20 | #define EK(y...) EX(y) | |
21 | ||
22 | /* McKinley specific optimization */ | |
23 | ||
24 | #define retval r8 | |
25 | #define saved_pfs r31 | |
26 | #define saved_lc r10 | |
27 | #define saved_pr r11 | |
28 | #define saved_in0 r14 | |
29 | #define saved_in1 r15 | |
30 | #define saved_in2 r16 | |
31 | ||
32 | #define src0 r2 | |
33 | #define src1 r3 | |
34 | #define dst0 r17 | |
35 | #define dst1 r18 | |
36 | #define cnt r9 | |
37 | ||
38 | /* r19-r30 are temp for each code section */ | |
39 | #define PREFETCH_DIST 8 | |
40 | #define src_pre_mem r19 | |
41 | #define dst_pre_mem r20 | |
42 | #define src_pre_l2 r21 | |
43 | #define dst_pre_l2 r22 | |
44 | #define t1 r23 | |
45 | #define t2 r24 | |
46 | #define t3 r25 | |
47 | #define t4 r26 | |
48 | #define t5 t1 // alias! | |
49 | #define t6 t2 // alias! | |
50 | #define t7 t3 // alias! | |
51 | #define n8 r27 | |
52 | #define t9 t5 // alias! | |
53 | #define t10 t4 // alias! | |
54 | #define t11 t7 // alias! | |
55 | #define t12 t6 // alias! | |
56 | #define t14 t10 // alias! | |
57 | #define t13 r28 | |
58 | #define t15 r29 | |
59 | #define tmp r30 | |
60 | ||
61 | /* defines for long_copy block */ | |
62 | #define A 0 | |
63 | #define B (PREFETCH_DIST) | |
64 | #define C (B + PREFETCH_DIST) | |
65 | #define D (C + 1) | |
66 | #define N (D + 1) | |
67 | #define Nrot ((N + 7) & ~7) | |
68 | ||
69 | /* alias */ | |
70 | #define in0 r32 | |
71 | #define in1 r33 | |
72 | #define in2 r34 | |
73 | ||
74 | GLOBAL_ENTRY(memcpy) | |
75 | and r28=0x7,in0 | |
76 | and r29=0x7,in1 | |
77 | mov f6=f0 | |
3e6e1556 | 78 | mov retval=in0 |
1da177e4 LT |
79 | br.cond.sptk .common_code |
80 | ;; | |
512f6429 | 81 | END(memcpy) |
e007c533 | 82 | EXPORT_SYMBOL(memcpy) |
1da177e4 LT |
83 | GLOBAL_ENTRY(__copy_user) |
84 | .prologue | |
85 | // check dest alignment | |
86 | and r28=0x7,in0 | |
87 | and r29=0x7,in1 | |
88 | mov f6=f1 | |
89 | mov saved_in0=in0 // save dest pointer | |
90 | mov saved_in1=in1 // save src pointer | |
3e6e1556 | 91 | mov retval=r0 // initialize return value |
1da177e4 LT |
92 | ;; |
93 | .common_code: | |
94 | cmp.gt p15,p0=8,in2 // check for small size | |
95 | cmp.ne p13,p0=0,r28 // check dest alignment | |
96 | cmp.ne p14,p0=0,r29 // check src alignment | |
97 | add src0=0,in1 | |
98 | sub r30=8,r28 // for .align_dest | |
3e6e1556 | 99 | mov saved_in2=in2 // save len |
1da177e4 LT |
100 | ;; |
101 | add dst0=0,in0 | |
102 | add dst1=1,in0 // dest odd index | |
103 | cmp.le p6,p0 = 1,r30 // for .align_dest | |
104 | (p15) br.cond.dpnt .memcpy_short | |
105 | (p13) br.cond.dpnt .align_dest | |
106 | (p14) br.cond.dpnt .unaligned_src | |
107 | ;; | |
108 | ||
109 | // both dest and src are aligned on 8-byte boundary | |
110 | .aligned_src: | |
111 | .save ar.pfs, saved_pfs | |
112 | alloc saved_pfs=ar.pfs,3,Nrot-3,0,Nrot | |
113 | .save pr, saved_pr | |
114 | mov saved_pr=pr | |
115 | ||
116 | shr.u cnt=in2,7 // this much cache line | |
117 | ;; | |
118 | cmp.lt p6,p0=2*PREFETCH_DIST,cnt | |
119 | cmp.lt p7,p8=1,cnt | |
120 | .save ar.lc, saved_lc | |
121 | mov saved_lc=ar.lc | |
122 | .body | |
123 | add cnt=-1,cnt | |
124 | add src_pre_mem=0,in1 // prefetch src pointer | |
125 | add dst_pre_mem=0,in0 // prefetch dest pointer | |
126 | ;; | |
127 | (p7) mov ar.lc=cnt // prefetch count | |
128 | (p8) mov ar.lc=r0 | |
129 | (p6) br.cond.dpnt .long_copy | |
130 | ;; | |
131 | ||
132 | .prefetch: | |
133 | lfetch.fault [src_pre_mem], 128 | |
134 | lfetch.fault.excl [dst_pre_mem], 128 | |
135 | br.cloop.dptk.few .prefetch | |
136 | ;; | |
137 | ||
138 | .medium_copy: | |
139 | and tmp=31,in2 // copy length after iteration | |
140 | shr.u r29=in2,5 // number of 32-byte iteration | |
141 | add dst1=8,dst0 // 2nd dest pointer | |
142 | ;; | |
143 | add cnt=-1,r29 // ctop iteration adjustment | |
144 | cmp.eq p10,p0=r29,r0 // do we really need to loop? | |
145 | add src1=8,src0 // 2nd src pointer | |
146 | cmp.le p6,p0=8,tmp | |
147 | ;; | |
148 | cmp.le p7,p0=16,tmp | |
149 | mov ar.lc=cnt // loop setup | |
150 | cmp.eq p16,p17 = r0,r0 | |
151 | mov ar.ec=2 | |
152 | (p10) br.dpnt.few .aligned_src_tail | |
153 | ;; | |
154 | TEXT_ALIGN(32) | |
155 | 1: | |
156 | EX(.ex_handler, (p16) ld8 r34=[src0],16) | |
157 | EK(.ex_handler, (p16) ld8 r38=[src1],16) | |
158 | EX(.ex_handler, (p17) st8 [dst0]=r33,16) | |
159 | EK(.ex_handler, (p17) st8 [dst1]=r37,16) | |
160 | ;; | |
161 | EX(.ex_handler, (p16) ld8 r32=[src0],16) | |
162 | EK(.ex_handler, (p16) ld8 r36=[src1],16) | |
163 | EX(.ex_handler, (p16) st8 [dst0]=r34,16) | |
164 | EK(.ex_handler, (p16) st8 [dst1]=r38,16) | |
165 | br.ctop.dptk.few 1b | |
166 | ;; | |
167 | ||
168 | .aligned_src_tail: | |
169 | EX(.ex_handler, (p6) ld8 t1=[src0]) | |
170 | mov ar.lc=saved_lc | |
171 | mov ar.pfs=saved_pfs | |
172 | EX(.ex_hndlr_s, (p7) ld8 t2=[src1],8) | |
173 | cmp.le p8,p0=24,tmp | |
174 | and r21=-8,tmp | |
175 | ;; | |
176 | EX(.ex_hndlr_s, (p8) ld8 t3=[src1]) | |
177 | EX(.ex_handler, (p6) st8 [dst0]=t1) // store byte 1 | |
178 | and in2=7,tmp // remaining length | |
179 | EX(.ex_hndlr_d, (p7) st8 [dst1]=t2,8) // store byte 2 | |
180 | add src0=src0,r21 // setting up src pointer | |
181 | add dst0=dst0,r21 // setting up dest pointer | |
182 | ;; | |
183 | EX(.ex_handler, (p8) st8 [dst1]=t3) // store byte 3 | |
184 | mov pr=saved_pr,-1 | |
185 | br.dptk.many .memcpy_short | |
186 | ;; | |
187 | ||
188 | /* code taken from copy_page_mck */ | |
189 | .long_copy: | |
190 | .rotr v[2*PREFETCH_DIST] | |
191 | .rotp p[N] | |
192 | ||
193 | mov src_pre_mem = src0 | |
194 | mov pr.rot = 0x10000 | |
195 | mov ar.ec = 1 // special unrolled loop | |
196 | ||
197 | mov dst_pre_mem = dst0 | |
198 | ||
199 | add src_pre_l2 = 8*8, src0 | |
200 | add dst_pre_l2 = 8*8, dst0 | |
201 | ;; | |
202 | add src0 = 8, src_pre_mem // first t1 src | |
203 | mov ar.lc = 2*PREFETCH_DIST - 1 | |
204 | shr.u cnt=in2,7 // number of lines | |
205 | add src1 = 3*8, src_pre_mem // first t3 src | |
206 | add dst0 = 8, dst_pre_mem // first t1 dst | |
207 | add dst1 = 3*8, dst_pre_mem // first t3 dst | |
208 | ;; | |
209 | and tmp=127,in2 // remaining bytes after this block | |
210 | add cnt = -(2*PREFETCH_DIST) - 1, cnt | |
211 | // same as .line_copy loop, but with all predicated-off instructions removed: | |
212 | .prefetch_loop: | |
213 | EX(.ex_hndlr_lcpy_1, (p[A]) ld8 v[A] = [src_pre_mem], 128) // M0 | |
214 | EK(.ex_hndlr_lcpy_1, (p[B]) st8 [dst_pre_mem] = v[B], 128) // M2 | |
215 | br.ctop.sptk .prefetch_loop | |
216 | ;; | |
217 | cmp.eq p16, p0 = r0, r0 // reset p16 to 1 | |
218 | mov ar.lc = cnt | |
219 | mov ar.ec = N // # of stages in pipeline | |
220 | ;; | |
221 | .line_copy: | |
222 | EX(.ex_handler, (p[D]) ld8 t2 = [src0], 3*8) // M0 | |
223 | EK(.ex_handler, (p[D]) ld8 t4 = [src1], 3*8) // M1 | |
224 | EX(.ex_handler_lcpy, (p[B]) st8 [dst_pre_mem] = v[B], 128) // M2 prefetch dst from memory | |
225 | EK(.ex_handler_lcpy, (p[D]) st8 [dst_pre_l2] = n8, 128) // M3 prefetch dst from L2 | |
226 | ;; | |
227 | EX(.ex_handler_lcpy, (p[A]) ld8 v[A] = [src_pre_mem], 128) // M0 prefetch src from memory | |
228 | EK(.ex_handler_lcpy, (p[C]) ld8 n8 = [src_pre_l2], 128) // M1 prefetch src from L2 | |
229 | EX(.ex_handler, (p[D]) st8 [dst0] = t1, 8) // M2 | |
230 | EK(.ex_handler, (p[D]) st8 [dst1] = t3, 8) // M3 | |
231 | ;; | |
232 | EX(.ex_handler, (p[D]) ld8 t5 = [src0], 8) | |
233 | EK(.ex_handler, (p[D]) ld8 t7 = [src1], 3*8) | |
234 | EX(.ex_handler, (p[D]) st8 [dst0] = t2, 3*8) | |
235 | EK(.ex_handler, (p[D]) st8 [dst1] = t4, 3*8) | |
236 | ;; | |
237 | EX(.ex_handler, (p[D]) ld8 t6 = [src0], 3*8) | |
238 | EK(.ex_handler, (p[D]) ld8 t10 = [src1], 8) | |
239 | EX(.ex_handler, (p[D]) st8 [dst0] = t5, 8) | |
240 | EK(.ex_handler, (p[D]) st8 [dst1] = t7, 3*8) | |
241 | ;; | |
242 | EX(.ex_handler, (p[D]) ld8 t9 = [src0], 3*8) | |
243 | EK(.ex_handler, (p[D]) ld8 t11 = [src1], 3*8) | |
244 | EX(.ex_handler, (p[D]) st8 [dst0] = t6, 3*8) | |
245 | EK(.ex_handler, (p[D]) st8 [dst1] = t10, 8) | |
246 | ;; | |
247 | EX(.ex_handler, (p[D]) ld8 t12 = [src0], 8) | |
248 | EK(.ex_handler, (p[D]) ld8 t14 = [src1], 8) | |
249 | EX(.ex_handler, (p[D]) st8 [dst0] = t9, 3*8) | |
250 | EK(.ex_handler, (p[D]) st8 [dst1] = t11, 3*8) | |
251 | ;; | |
252 | EX(.ex_handler, (p[D]) ld8 t13 = [src0], 4*8) | |
253 | EK(.ex_handler, (p[D]) ld8 t15 = [src1], 4*8) | |
254 | EX(.ex_handler, (p[D]) st8 [dst0] = t12, 8) | |
255 | EK(.ex_handler, (p[D]) st8 [dst1] = t14, 8) | |
256 | ;; | |
257 | EX(.ex_handler, (p[C]) ld8 t1 = [src0], 8) | |
258 | EK(.ex_handler, (p[C]) ld8 t3 = [src1], 8) | |
259 | EX(.ex_handler, (p[D]) st8 [dst0] = t13, 4*8) | |
260 | EK(.ex_handler, (p[D]) st8 [dst1] = t15, 4*8) | |
261 | br.ctop.sptk .line_copy | |
262 | ;; | |
263 | ||
264 | add dst0=-8,dst0 | |
265 | add src0=-8,src0 | |
266 | mov in2=tmp | |
267 | .restore sp | |
268 | br.sptk.many .medium_copy | |
269 | ;; | |
270 | ||
271 | #define BLOCK_SIZE 128*32 | |
272 | #define blocksize r23 | |
273 | #define curlen r24 | |
274 | ||
275 | // dest is on 8-byte boundary, src is not. We need to do | |
276 | // ld8-ld8, shrp, then st8. Max 8 byte copy per cycle. | |
277 | .unaligned_src: | |
278 | .prologue | |
279 | .save ar.pfs, saved_pfs | |
280 | alloc saved_pfs=ar.pfs,3,5,0,8 | |
281 | .save ar.lc, saved_lc | |
282 | mov saved_lc=ar.lc | |
283 | .save pr, saved_pr | |
284 | mov saved_pr=pr | |
285 | .body | |
286 | .4k_block: | |
287 | mov saved_in0=dst0 // need to save all input arguments | |
288 | mov saved_in2=in2 | |
289 | mov blocksize=BLOCK_SIZE | |
290 | ;; | |
291 | cmp.lt p6,p7=blocksize,in2 | |
292 | mov saved_in1=src0 | |
293 | ;; | |
294 | (p6) mov in2=blocksize | |
295 | ;; | |
296 | shr.u r21=in2,7 // this much cache line | |
297 | shr.u r22=in2,4 // number of 16-byte iteration | |
298 | and curlen=15,in2 // copy length after iteration | |
299 | and r30=7,src0 // source alignment | |
300 | ;; | |
301 | cmp.lt p7,p8=1,r21 | |
302 | add cnt=-1,r21 | |
303 | ;; | |
304 | ||
305 | add src_pre_mem=0,src0 // prefetch src pointer | |
306 | add dst_pre_mem=0,dst0 // prefetch dest pointer | |
307 | and src0=-8,src0 // 1st src pointer | |
6118ec84 | 308 | (p7) mov ar.lc = cnt |
1da177e4 LT |
309 | (p8) mov ar.lc = r0 |
310 | ;; | |
311 | TEXT_ALIGN(32) | |
312 | 1: lfetch.fault [src_pre_mem], 128 | |
313 | lfetch.fault.excl [dst_pre_mem], 128 | |
314 | br.cloop.dptk.few 1b | |
315 | ;; | |
316 | ||
317 | shladd dst1=r22,3,dst0 // 2nd dest pointer | |
318 | shladd src1=r22,3,src0 // 2nd src pointer | |
319 | cmp.eq p8,p9=r22,r0 // do we really need to loop? | |
320 | cmp.le p6,p7=8,curlen; // have at least 8 byte remaining? | |
321 | add cnt=-1,r22 // ctop iteration adjustment | |
322 | ;; | |
323 | EX(.ex_handler, (p9) ld8 r33=[src0],8) // loop primer | |
324 | EK(.ex_handler, (p9) ld8 r37=[src1],8) | |
325 | (p8) br.dpnt.few .noloop | |
326 | ;; | |
327 | ||
328 | // The jump address is calculated based on src alignment. The COPYU | |
329 | // macro below need to confine its size to power of two, so an entry | |
330 | // can be caulated using shl instead of an expensive multiply. The | |
331 | // size is then hard coded by the following #define to match the | |
332 | // actual size. This make it somewhat tedious when COPYU macro gets | |
333 | // changed and this need to be adjusted to match. | |
334 | #define LOOP_SIZE 6 | |
335 | 1: | |
336 | mov r29=ip // jmp_table thread | |
337 | mov ar.lc=cnt | |
338 | ;; | |
339 | add r29=.jump_table - 1b - (.jmp1-.jump_table), r29 | |
340 | shl r28=r30, LOOP_SIZE // jmp_table thread | |
341 | mov ar.ec=2 // loop setup | |
342 | ;; | |
343 | add r29=r29,r28 // jmp_table thread | |
344 | cmp.eq p16,p17=r0,r0 | |
345 | ;; | |
346 | mov b6=r29 // jmp_table thread | |
347 | ;; | |
348 | br.cond.sptk.few b6 | |
349 | ||
350 | // for 8-15 byte case | |
351 | // We will skip the loop, but need to replicate the side effect | |
352 | // that the loop produces. | |
353 | .noloop: | |
354 | EX(.ex_handler, (p6) ld8 r37=[src1],8) | |
355 | add src0=8,src0 | |
356 | (p6) shl r25=r30,3 | |
357 | ;; | |
358 | EX(.ex_handler, (p6) ld8 r27=[src1]) | |
359 | (p6) shr.u r28=r37,r25 | |
360 | (p6) sub r26=64,r25 | |
361 | ;; | |
362 | (p6) shl r27=r27,r26 | |
363 | ;; | |
364 | (p6) or r21=r28,r27 | |
365 | ||
366 | .unaligned_src_tail: | |
367 | /* check if we have more than blocksize to copy, if so go back */ | |
368 | cmp.gt p8,p0=saved_in2,blocksize | |
369 | ;; | |
370 | (p8) add dst0=saved_in0,blocksize | |
371 | (p8) add src0=saved_in1,blocksize | |
372 | (p8) sub in2=saved_in2,blocksize | |
373 | (p8) br.dpnt .4k_block | |
374 | ;; | |
375 | ||
376 | /* we have up to 15 byte to copy in the tail. | |
377 | * part of work is already done in the jump table code | |
378 | * we are at the following state. | |
379 | * src side: | |
380 | * | |
381 | * xxxxxx xx <----- r21 has xxxxxxxx already | |
382 | * -------- -------- -------- | |
383 | * 0 8 16 | |
384 | * ^ | |
385 | * | | |
386 | * src1 | |
387 | * | |
388 | * dst | |
389 | * -------- -------- -------- | |
390 | * ^ | |
391 | * | | |
392 | * dst1 | |
393 | */ | |
394 | EX(.ex_handler, (p6) st8 [dst1]=r21,8) // more than 8 byte to copy | |
395 | (p6) add curlen=-8,curlen // update length | |
396 | mov ar.pfs=saved_pfs | |
397 | ;; | |
398 | mov ar.lc=saved_lc | |
399 | mov pr=saved_pr,-1 | |
400 | mov in2=curlen // remaining length | |
401 | mov dst0=dst1 // dest pointer | |
402 | add src0=src1,r30 // forward by src alignment | |
403 | ;; | |
404 | ||
405 | // 7 byte or smaller. | |
406 | .memcpy_short: | |
407 | cmp.le p8,p9 = 1,in2 | |
408 | cmp.le p10,p11 = 2,in2 | |
409 | cmp.le p12,p13 = 3,in2 | |
410 | cmp.le p14,p15 = 4,in2 | |
411 | add src1=1,src0 // second src pointer | |
412 | add dst1=1,dst0 // second dest pointer | |
413 | ;; | |
414 | ||
415 | EX(.ex_handler_short, (p8) ld1 t1=[src0],2) | |
416 | EK(.ex_handler_short, (p10) ld1 t2=[src1],2) | |
417 | (p9) br.ret.dpnt rp // 0 byte copy | |
418 | ;; | |
419 | ||
420 | EX(.ex_handler_short, (p8) st1 [dst0]=t1,2) | |
421 | EK(.ex_handler_short, (p10) st1 [dst1]=t2,2) | |
422 | (p11) br.ret.dpnt rp // 1 byte copy | |
423 | ||
424 | EX(.ex_handler_short, (p12) ld1 t3=[src0],2) | |
425 | EK(.ex_handler_short, (p14) ld1 t4=[src1],2) | |
426 | (p13) br.ret.dpnt rp // 2 byte copy | |
427 | ;; | |
428 | ||
429 | cmp.le p6,p7 = 5,in2 | |
430 | cmp.le p8,p9 = 6,in2 | |
431 | cmp.le p10,p11 = 7,in2 | |
432 | ||
433 | EX(.ex_handler_short, (p12) st1 [dst0]=t3,2) | |
434 | EK(.ex_handler_short, (p14) st1 [dst1]=t4,2) | |
435 | (p15) br.ret.dpnt rp // 3 byte copy | |
436 | ;; | |
437 | ||
438 | EX(.ex_handler_short, (p6) ld1 t5=[src0],2) | |
439 | EK(.ex_handler_short, (p8) ld1 t6=[src1],2) | |
440 | (p7) br.ret.dpnt rp // 4 byte copy | |
441 | ;; | |
442 | ||
443 | EX(.ex_handler_short, (p6) st1 [dst0]=t5,2) | |
444 | EK(.ex_handler_short, (p8) st1 [dst1]=t6,2) | |
445 | (p9) br.ret.dptk rp // 5 byte copy | |
446 | ||
447 | EX(.ex_handler_short, (p10) ld1 t7=[src0],2) | |
448 | (p11) br.ret.dptk rp // 6 byte copy | |
449 | ;; | |
450 | ||
451 | EX(.ex_handler_short, (p10) st1 [dst0]=t7,2) | |
452 | br.ret.dptk rp // done all cases | |
453 | ||
454 | ||
455 | /* Align dest to nearest 8-byte boundary. We know we have at | |
456 | * least 7 bytes to copy, enough to crawl to 8-byte boundary. | |
457 | * Actual number of byte to crawl depend on the dest alignment. | |
458 | * 7 byte or less is taken care at .memcpy_short | |
459 | ||
460 | * src0 - source even index | |
461 | * src1 - source odd index | |
462 | * dst0 - dest even index | |
463 | * dst1 - dest odd index | |
464 | * r30 - distance to 8-byte boundary | |
465 | */ | |
466 | ||
467 | .align_dest: | |
468 | add src1=1,in1 // source odd index | |
469 | cmp.le p7,p0 = 2,r30 // for .align_dest | |
470 | cmp.le p8,p0 = 3,r30 // for .align_dest | |
471 | EX(.ex_handler_short, (p6) ld1 t1=[src0],2) | |
472 | cmp.le p9,p0 = 4,r30 // for .align_dest | |
473 | cmp.le p10,p0 = 5,r30 | |
474 | ;; | |
475 | EX(.ex_handler_short, (p7) ld1 t2=[src1],2) | |
476 | EK(.ex_handler_short, (p8) ld1 t3=[src0],2) | |
477 | cmp.le p11,p0 = 6,r30 | |
478 | EX(.ex_handler_short, (p6) st1 [dst0] = t1,2) | |
479 | cmp.le p12,p0 = 7,r30 | |
480 | ;; | |
481 | EX(.ex_handler_short, (p9) ld1 t4=[src1],2) | |
482 | EK(.ex_handler_short, (p10) ld1 t5=[src0],2) | |
483 | EX(.ex_handler_short, (p7) st1 [dst1] = t2,2) | |
484 | EK(.ex_handler_short, (p8) st1 [dst0] = t3,2) | |
485 | ;; | |
486 | EX(.ex_handler_short, (p11) ld1 t6=[src1],2) | |
487 | EK(.ex_handler_short, (p12) ld1 t7=[src0],2) | |
488 | cmp.eq p6,p7=r28,r29 | |
489 | EX(.ex_handler_short, (p9) st1 [dst1] = t4,2) | |
490 | EK(.ex_handler_short, (p10) st1 [dst0] = t5,2) | |
491 | sub in2=in2,r30 | |
492 | ;; | |
493 | EX(.ex_handler_short, (p11) st1 [dst1] = t6,2) | |
494 | EK(.ex_handler_short, (p12) st1 [dst0] = t7) | |
495 | add dst0=in0,r30 // setup arguments | |
496 | add src0=in1,r30 | |
497 | (p6) br.cond.dptk .aligned_src | |
498 | (p7) br.cond.dpnt .unaligned_src | |
499 | ;; | |
500 | ||
501 | /* main loop body in jump table format */ | |
502 | #define COPYU(shift) \ | |
503 | 1: \ | |
504 | EX(.ex_handler, (p16) ld8 r32=[src0],8); /* 1 */ \ | |
505 | EK(.ex_handler, (p16) ld8 r36=[src1],8); \ | |
506 | (p17) shrp r35=r33,r34,shift;; /* 1 */ \ | |
507 | EX(.ex_handler, (p6) ld8 r22=[src1]); /* common, prime for tail section */ \ | |
508 | nop.m 0; \ | |
509 | (p16) shrp r38=r36,r37,shift; \ | |
510 | EX(.ex_handler, (p17) st8 [dst0]=r35,8); /* 1 */ \ | |
511 | EK(.ex_handler, (p17) st8 [dst1]=r39,8); \ | |
512 | br.ctop.dptk.few 1b;; \ | |
513 | (p7) add src1=-8,src1; /* back out for <8 byte case */ \ | |
514 | shrp r21=r22,r38,shift; /* speculative work */ \ | |
515 | br.sptk.few .unaligned_src_tail /* branch out of jump table */ \ | |
516 | ;; | |
517 | TEXT_ALIGN(32) | |
518 | .jump_table: | |
519 | COPYU(8) // unaligned cases | |
520 | .jmp1: | |
521 | COPYU(16) | |
522 | COPYU(24) | |
523 | COPYU(32) | |
524 | COPYU(40) | |
525 | COPYU(48) | |
526 | COPYU(56) | |
527 | ||
528 | #undef A | |
529 | #undef B | |
530 | #undef C | |
531 | #undef D | |
1da177e4 LT |
532 | |
533 | /* | |
534 | * Due to lack of local tag support in gcc 2.x assembler, it is not clear which | |
535 | * instruction failed in the bundle. The exception algorithm is that we | |
536 | * first figure out the faulting address, then detect if there is any | |
537 | * progress made on the copy, if so, redo the copy from last known copied | |
538 | * location up to the faulting address (exclusive). In the copy_from_user | |
539 | * case, remaining byte in kernel buffer will be zeroed. | |
540 | * | |
541 | * Take copy_from_user as an example, in the code there are multiple loads | |
542 | * in a bundle and those multiple loads could span over two pages, the | |
543 | * faulting address is calculated as page_round_down(max(src0, src1)). | |
544 | * This is based on knowledge that if we can access one byte in a page, we | |
545 | * can access any byte in that page. | |
546 | * | |
547 | * predicate used in the exception handler: | |
548 | * p6-p7: direction | |
549 | * p10-p11: src faulting addr calculation | |
550 | * p12-p13: dst faulting addr calculation | |
551 | */ | |
552 | ||
553 | #define A r19 | |
554 | #define B r20 | |
555 | #define C r21 | |
556 | #define D r22 | |
557 | #define F r28 | |
558 | ||
559 | #define memset_arg0 r32 | |
560 | #define memset_arg2 r33 | |
561 | ||
562 | #define saved_retval loc0 | |
563 | #define saved_rtlink loc1 | |
564 | #define saved_pfs_stack loc2 | |
565 | ||
566 | .ex_hndlr_s: | |
567 | add src0=8,src0 | |
568 | br.sptk .ex_handler | |
569 | ;; | |
570 | .ex_hndlr_d: | |
571 | add dst0=8,dst0 | |
572 | br.sptk .ex_handler | |
573 | ;; | |
574 | .ex_hndlr_lcpy_1: | |
575 | mov src1=src_pre_mem | |
576 | mov dst1=dst_pre_mem | |
577 | cmp.gtu p10,p11=src_pre_mem,saved_in1 | |
578 | cmp.gtu p12,p13=dst_pre_mem,saved_in0 | |
579 | ;; | |
580 | (p10) add src0=8,saved_in1 | |
581 | (p11) mov src0=saved_in1 | |
582 | (p12) add dst0=8,saved_in0 | |
583 | (p13) mov dst0=saved_in0 | |
584 | br.sptk .ex_handler | |
585 | .ex_handler_lcpy: | |
586 | // in line_copy block, the preload addresses should always ahead | |
587 | // of the other two src/dst pointers. Furthermore, src1/dst1 should | |
588 | // always ahead of src0/dst0. | |
589 | mov src1=src_pre_mem | |
590 | mov dst1=dst_pre_mem | |
591 | .ex_handler: | |
592 | mov pr=saved_pr,-1 // first restore pr, lc, and pfs | |
593 | mov ar.lc=saved_lc | |
594 | mov ar.pfs=saved_pfs | |
595 | ;; | |
596 | .ex_handler_short: // fault occurred in these sections didn't change pr, lc, pfs | |
597 | cmp.ltu p6,p7=saved_in0, saved_in1 // get the copy direction | |
598 | cmp.ltu p10,p11=src0,src1 | |
599 | cmp.ltu p12,p13=dst0,dst1 | |
600 | fcmp.eq p8,p0=f6,f0 // is it memcpy? | |
601 | mov tmp = dst0 | |
602 | ;; | |
603 | (p11) mov src1 = src0 // pick the larger of the two | |
604 | (p13) mov dst0 = dst1 // make dst0 the smaller one | |
605 | (p13) mov dst1 = tmp // and dst1 the larger one | |
606 | ;; | |
607 | (p6) dep F = r0,dst1,0,PAGE_SHIFT // usr dst round down to page boundary | |
608 | (p7) dep F = r0,src1,0,PAGE_SHIFT // usr src round down to page boundary | |
609 | ;; | |
610 | (p6) cmp.le p14,p0=dst0,saved_in0 // no progress has been made on store | |
611 | (p7) cmp.le p14,p0=src0,saved_in1 // no progress has been made on load | |
612 | mov retval=saved_in2 | |
613 | (p8) ld1 tmp=[src1] // force an oops for memcpy call | |
614 | (p8) st1 [dst1]=r0 // force an oops for memcpy call | |
615 | (p14) br.ret.sptk.many rp | |
616 | ||
617 | /* | |
618 | * The remaining byte to copy is calculated as: | |
619 | * | |
620 | * A = (faulting_addr - orig_src) -> len to faulting ld address | |
621 | * or | |
622 | * (faulting_addr - orig_dst) -> len to faulting st address | |
623 | * B = (cur_dst - orig_dst) -> len copied so far | |
624 | * C = A - B -> len need to be copied | |
625 | * D = orig_len - A -> len need to be zeroed | |
626 | */ | |
627 | (p6) sub A = F, saved_in0 | |
628 | (p7) sub A = F, saved_in1 | |
629 | clrrrb | |
630 | ;; | |
631 | alloc saved_pfs_stack=ar.pfs,3,3,3,0 | |
295bd892 | 632 | cmp.lt p8,p0=A,r0 |
1da177e4 LT |
633 | sub B = dst0, saved_in0 // how many byte copied so far |
634 | ;; | |
295bd892 CK |
635 | (p8) mov A = 0; // A shouldn't be negative, cap it |
636 | ;; | |
1da177e4 LT |
637 | sub C = A, B |
638 | sub D = saved_in2, A | |
639 | ;; | |
640 | cmp.gt p8,p0=C,r0 // more than 1 byte? | |
641 | add memset_arg0=saved_in0, A | |
642 | (p6) mov memset_arg2=0 // copy_to_user should not call memset | |
643 | (p7) mov memset_arg2=D // copy_from_user need to have kbuf zeroed | |
644 | mov r8=0 | |
645 | mov saved_retval = D | |
646 | mov saved_rtlink = b0 | |
647 | ||
648 | add out0=saved_in0, B | |
649 | add out1=saved_in1, B | |
650 | mov out2=C | |
651 | (p8) br.call.sptk.few b0=__copy_user // recursive call | |
652 | ;; | |
653 | ||
654 | add saved_retval=saved_retval,r8 // above might return non-zero value | |
655 | cmp.gt p8,p0=memset_arg2,r0 // more than 1 byte? | |
656 | mov out0=memset_arg0 // *s | |
657 | mov out1=r0 // c | |
658 | mov out2=memset_arg2 // n | |
659 | (p8) br.call.sptk.few b0=memset | |
660 | ;; | |
661 | ||
662 | mov retval=saved_retval | |
663 | mov ar.pfs=saved_pfs_stack | |
664 | mov b0=saved_rtlink | |
665 | br.ret.sptk.many rp | |
666 | ||
667 | /* end of McKinley specific optimization */ | |
668 | END(__copy_user) | |
e007c533 | 669 | EXPORT_SYMBOL(__copy_user) |