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[pohmelfs.git] / arch / powerpc / kernel / align.c
blob8184ee97e484e9b86dcb8c0d0f226e88066796d4
1 /* align.c - handle alignment exceptions for the Power PC.
2 *
3 * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
4 * Copyright (c) 1998-1999 TiVo, Inc.
5 * PowerPC 403GCX modifications.
6 * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
7 * PowerPC 403GCX/405GP modifications.
8 * Copyright (c) 2001-2002 PPC64 team, IBM Corp
9 * 64-bit and Power4 support
10 * Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp
11 * <benh@kernel.crashing.org>
12 * Merge ppc32 and ppc64 implementations
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 */
19
20 #include <linux/kernel.h>
21 #include <linux/mm.h>
22 #include <asm/processor.h>
23 #include <asm/uaccess.h>
24 #include <asm/system.h>
25 #include <asm/cache.h>
26 #include <asm/cputable.h>
27 #include <asm/emulated_ops.h>
28
29 struct aligninfo {
30 unsigned char len;
31 unsigned char flags;
32 };
33
34 #define IS_XFORM(inst) (((inst) >> 26) == 31)
35 #define IS_DSFORM(inst) (((inst) >> 26) >= 56)
36
37 #define INVALID { 0, 0 }
38
39 /* Bits in the flags field */
40 #define LD 0 /* load */
41 #define ST 1 /* store */
42 #define SE 2 /* sign-extend value, or FP ld/st as word */
43 #define F 4 /* to/from fp regs */
44 #define U 8 /* update index register */
45 #define M 0x10 /* multiple load/store */
46 #define SW 0x20 /* byte swap */
47 #define S 0x40 /* single-precision fp or... */
48 #define SX 0x40 /* ... byte count in XER */
49 #define HARD 0x80 /* string, stwcx. */
50 #define E4 0x40 /* SPE endianness is word */
51 #define E8 0x80 /* SPE endianness is double word */
52 #define SPLT 0x80 /* VSX SPLAT load */
53
54 /* DSISR bits reported for a DCBZ instruction: */
55 #define DCBZ 0x5f /* 8xx/82xx dcbz faults when cache not enabled */
56
57 #define SWAP(a, b) (t = (a), (a) = (b), (b) = t)
58
59 /*
60 * The PowerPC stores certain bits of the instruction that caused the
61 * alignment exception in the DSISR register. This array maps those
62 * bits to information about the operand length and what the
63 * instruction would do.
64 */
65 static struct aligninfo aligninfo[128] = {
66 { 4, LD }, /* 00 0 0000: lwz / lwarx */
67 INVALID, /* 00 0 0001 */
68 { 4, ST }, /* 00 0 0010: stw */
69 INVALID, /* 00 0 0011 */
70 { 2, LD }, /* 00 0 0100: lhz */
71 { 2, LD+SE }, /* 00 0 0101: lha */
72 { 2, ST }, /* 00 0 0110: sth */
73 { 4, LD+M }, /* 00 0 0111: lmw */
74 { 4, LD+F+S }, /* 00 0 1000: lfs */
75 { 8, LD+F }, /* 00 0 1001: lfd */
76 { 4, ST+F+S }, /* 00 0 1010: stfs */
77 { 8, ST+F }, /* 00 0 1011: stfd */
78 INVALID, /* 00 0 1100 */
79 { 8, LD }, /* 00 0 1101: ld/ldu/lwa */
80 INVALID, /* 00 0 1110 */
81 { 8, ST }, /* 00 0 1111: std/stdu */
82 { 4, LD+U }, /* 00 1 0000: lwzu */
83 INVALID, /* 00 1 0001 */
84 { 4, ST+U }, /* 00 1 0010: stwu */
85 INVALID, /* 00 1 0011 */
86 { 2, LD+U }, /* 00 1 0100: lhzu */
87 { 2, LD+SE+U }, /* 00 1 0101: lhau */
88 { 2, ST+U }, /* 00 1 0110: sthu */
89 { 4, ST+M }, /* 00 1 0111: stmw */
90 { 4, LD+F+S+U }, /* 00 1 1000: lfsu */
91 { 8, LD+F+U }, /* 00 1 1001: lfdu */
92 { 4, ST+F+S+U }, /* 00 1 1010: stfsu */
93 { 8, ST+F+U }, /* 00 1 1011: stfdu */
94 { 16, LD+F }, /* 00 1 1100: lfdp */
95 INVALID, /* 00 1 1101 */
96 { 16, ST+F }, /* 00 1 1110: stfdp */
97 INVALID, /* 00 1 1111 */
98 { 8, LD }, /* 01 0 0000: ldx */
99 INVALID, /* 01 0 0001 */
100 { 8, ST }, /* 01 0 0010: stdx */
101 INVALID, /* 01 0 0011 */
102 INVALID, /* 01 0 0100 */
103 { 4, LD+SE }, /* 01 0 0101: lwax */
104 INVALID, /* 01 0 0110 */
105 INVALID, /* 01 0 0111 */
106 { 4, LD+M+HARD+SX }, /* 01 0 1000: lswx */
107 { 4, LD+M+HARD }, /* 01 0 1001: lswi */
108 { 4, ST+M+HARD+SX }, /* 01 0 1010: stswx */
109 { 4, ST+M+HARD }, /* 01 0 1011: stswi */
110 INVALID, /* 01 0 1100 */
111 { 8, LD+U }, /* 01 0 1101: ldu */
112 INVALID, /* 01 0 1110 */
113 { 8, ST+U }, /* 01 0 1111: stdu */
114 { 8, LD+U }, /* 01 1 0000: ldux */
115 INVALID, /* 01 1 0001 */
116 { 8, ST+U }, /* 01 1 0010: stdux */
117 INVALID, /* 01 1 0011 */
118 INVALID, /* 01 1 0100 */
119 { 4, LD+SE+U }, /* 01 1 0101: lwaux */
120 INVALID, /* 01 1 0110 */
121 INVALID, /* 01 1 0111 */
122 INVALID, /* 01 1 1000 */
123 INVALID, /* 01 1 1001 */
124 INVALID, /* 01 1 1010 */
125 INVALID, /* 01 1 1011 */
126 INVALID, /* 01 1 1100 */
127 INVALID, /* 01 1 1101 */
128 INVALID, /* 01 1 1110 */
129 INVALID, /* 01 1 1111 */
130 INVALID, /* 10 0 0000 */
131 INVALID, /* 10 0 0001 */
132 INVALID, /* 10 0 0010: stwcx. */
133 INVALID, /* 10 0 0011 */
134 INVALID, /* 10 0 0100 */
135 INVALID, /* 10 0 0101 */
136 INVALID, /* 10 0 0110 */
137 INVALID, /* 10 0 0111 */
138 { 4, LD+SW }, /* 10 0 1000: lwbrx */
139 INVALID, /* 10 0 1001 */
140 { 4, ST+SW }, /* 10 0 1010: stwbrx */
141 INVALID, /* 10 0 1011 */
142 { 2, LD+SW }, /* 10 0 1100: lhbrx */
143 { 4, LD+SE }, /* 10 0 1101 lwa */
144 { 2, ST+SW }, /* 10 0 1110: sthbrx */
145 INVALID, /* 10 0 1111 */
146 INVALID, /* 10 1 0000 */
147 INVALID, /* 10 1 0001 */
148 INVALID, /* 10 1 0010 */
149 INVALID, /* 10 1 0011 */
150 INVALID, /* 10 1 0100 */
151 INVALID, /* 10 1 0101 */
152 INVALID, /* 10 1 0110 */
153 INVALID, /* 10 1 0111 */
154 INVALID, /* 10 1 1000 */
155 INVALID, /* 10 1 1001 */
156 INVALID, /* 10 1 1010 */
157 INVALID, /* 10 1 1011 */
158 INVALID, /* 10 1 1100 */
159 INVALID, /* 10 1 1101 */
160 INVALID, /* 10 1 1110 */
161 { 0, ST+HARD }, /* 10 1 1111: dcbz */
162 { 4, LD }, /* 11 0 0000: lwzx */
163 INVALID, /* 11 0 0001 */
164 { 4, ST }, /* 11 0 0010: stwx */
165 INVALID, /* 11 0 0011 */
166 { 2, LD }, /* 11 0 0100: lhzx */
167 { 2, LD+SE }, /* 11 0 0101: lhax */
168 { 2, ST }, /* 11 0 0110: sthx */
169 INVALID, /* 11 0 0111 */
170 { 4, LD+F+S }, /* 11 0 1000: lfsx */
171 { 8, LD+F }, /* 11 0 1001: lfdx */
172 { 4, ST+F+S }, /* 11 0 1010: stfsx */
173 { 8, ST+F }, /* 11 0 1011: stfdx */
174 { 16, LD+F }, /* 11 0 1100: lfdpx */
175 { 4, LD+F+SE }, /* 11 0 1101: lfiwax */
176 { 16, ST+F }, /* 11 0 1110: stfdpx */
177 { 4, ST+F }, /* 11 0 1111: stfiwx */
178 { 4, LD+U }, /* 11 1 0000: lwzux */
179 INVALID, /* 11 1 0001 */
180 { 4, ST+U }, /* 11 1 0010: stwux */
181 INVALID, /* 11 1 0011 */
182 { 2, LD+U }, /* 11 1 0100: lhzux */
183 { 2, LD+SE+U }, /* 11 1 0101: lhaux */
184 { 2, ST+U }, /* 11 1 0110: sthux */
185 INVALID, /* 11 1 0111 */
186 { 4, LD+F+S+U }, /* 11 1 1000: lfsux */
187 { 8, LD+F+U }, /* 11 1 1001: lfdux */
188 { 4, ST+F+S+U }, /* 11 1 1010: stfsux */
189 { 8, ST+F+U }, /* 11 1 1011: stfdux */
190 INVALID, /* 11 1 1100 */
191 { 4, LD+F }, /* 11 1 1101: lfiwzx */
192 INVALID, /* 11 1 1110 */
193 INVALID, /* 11 1 1111 */
194 };
195
196 /*
197 * Create a DSISR value from the instruction
198 */
199 static inline unsigned make_dsisr(unsigned instr)
200 {
201 unsigned dsisr;
202
203
204 /* bits 6:15 --> 22:31 */
205 dsisr = (instr & 0x03ff0000) >> 16;
206
207 if (IS_XFORM(instr)) {
208 /* bits 29:30 --> 15:16 */
209 dsisr |= (instr & 0x00000006) << 14;
210 /* bit 25 --> 17 */
211 dsisr |= (instr & 0x00000040) << 8;
212 /* bits 21:24 --> 18:21 */
213 dsisr |= (instr & 0x00000780) << 3;
214 } else {
215 /* bit 5 --> 17 */
216 dsisr |= (instr & 0x04000000) >> 12;
217 /* bits 1: 4 --> 18:21 */
218 dsisr |= (instr & 0x78000000) >> 17;
219 /* bits 30:31 --> 12:13 */
220 if (IS_DSFORM(instr))
221 dsisr |= (instr & 0x00000003) << 18;
222 }
223
224 return dsisr;
225 }
226
227 /*
228 * The dcbz (data cache block zero) instruction
229 * gives an alignment fault if used on non-cacheable
230 * memory. We handle the fault mainly for the
231 * case when we are running with the cache disabled
232 * for debugging.
233 */
234 static int emulate_dcbz(struct pt_regs *regs, unsigned char __user *addr)
235 {
236 long __user *p;
237 int i, size;
238
239 #ifdef __powerpc64__
240 size = ppc64_caches.dline_size;
241 #else
242 size = L1_CACHE_BYTES;
243 #endif
244 p = (long __user *) (regs->dar & -size);
245 if (user_mode(regs) && !access_ok(VERIFY_WRITE, p, size))
246 return -EFAULT;
247 for (i = 0; i < size / sizeof(long); ++i)
248 if (__put_user_inatomic(0, p+i))
249 return -EFAULT;
250 return 1;
251 }
252
253 /*
254 * Emulate load & store multiple instructions
255 * On 64-bit machines, these instructions only affect/use the
256 * bottom 4 bytes of each register, and the loads clear the
257 * top 4 bytes of the affected register.
258 */
259 #ifdef CONFIG_PPC64
260 #define REG_BYTE(rp, i) *((u8 *)((rp) + ((i) >> 2)) + ((i) & 3) + 4)
261 #else
262 #define REG_BYTE(rp, i) *((u8 *)(rp) + (i))
263 #endif
264
265 #define SWIZ_PTR(p) ((unsigned char __user *)((p) ^ swiz))
266
267 static int emulate_multiple(struct pt_regs *regs, unsigned char __user *addr,
268 unsigned int reg, unsigned int nb,
269 unsigned int flags, unsigned int instr,
270 unsigned long swiz)
271 {
272 unsigned long *rptr;
273 unsigned int nb0, i, bswiz;
274 unsigned long p;
275
276 /*
277 * We do not try to emulate 8 bytes multiple as they aren't really
278 * available in our operating environments and we don't try to
279 * emulate multiples operations in kernel land as they should never
280 * be used/generated there at least not on unaligned boundaries
281 */
282 if (unlikely((nb > 4) || !user_mode(regs)))
283 return 0;
284
285 /* lmw, stmw, lswi/x, stswi/x */
286 nb0 = 0;
287 if (flags & HARD) {
288 if (flags & SX) {
289 nb = regs->xer & 127;
290 if (nb == 0)
291 return 1;
292 } else {
293 unsigned long pc = regs->nip ^ (swiz & 4);
294
295 if (__get_user_inatomic(instr,
296 (unsigned int __user *)pc))
297 return -EFAULT;
298 if (swiz == 0 && (flags & SW))
299 instr = cpu_to_le32(instr);
300 nb = (instr >> 11) & 0x1f;
301 if (nb == 0)
302 nb = 32;
303 }
304 if (nb + reg * 4 > 128) {
305 nb0 = nb + reg * 4 - 128;
306 nb = 128 - reg * 4;
307 }
308 } else {
309 /* lwm, stmw */
310 nb = (32 - reg) * 4;
311 }
312
313 if (!access_ok((flags & ST ? VERIFY_WRITE: VERIFY_READ), addr, nb+nb0))
314 return -EFAULT; /* bad address */
315
316 rptr = &regs->gpr[reg];
317 p = (unsigned long) addr;
318 bswiz = (flags & SW)? 3: 0;
319
320 if (!(flags & ST)) {
321 /*
322 * This zeroes the top 4 bytes of the affected registers
323 * in 64-bit mode, and also zeroes out any remaining
324 * bytes of the last register for lsw*.
325 */
326 memset(rptr, 0, ((nb + 3) / 4) * sizeof(unsigned long));
327 if (nb0 > 0)
328 memset(&regs->gpr[0], 0,
329 ((nb0 + 3) / 4) * sizeof(unsigned long));
330
331 for (i = 0; i < nb; ++i, ++p)
332 if (__get_user_inatomic(REG_BYTE(rptr, i ^ bswiz),
333 SWIZ_PTR(p)))
334 return -EFAULT;
335 if (nb0 > 0) {
336 rptr = &regs->gpr[0];
337 addr += nb;
338 for (i = 0; i < nb0; ++i, ++p)
339 if (__get_user_inatomic(REG_BYTE(rptr,
340 i ^ bswiz),
341 SWIZ_PTR(p)))
342 return -EFAULT;
343 }
344
345 } else {
346 for (i = 0; i < nb; ++i, ++p)
347 if (__put_user_inatomic(REG_BYTE(rptr, i ^ bswiz),
348 SWIZ_PTR(p)))
349 return -EFAULT;
350 if (nb0 > 0) {
351 rptr = &regs->gpr[0];
352 addr += nb;
353 for (i = 0; i < nb0; ++i, ++p)
354 if (__put_user_inatomic(REG_BYTE(rptr,
355 i ^ bswiz),
356 SWIZ_PTR(p)))
357 return -EFAULT;
358 }
359 }
360 return 1;
361 }
362
363 /*
364 * Emulate floating-point pair loads and stores.
365 * Only POWER6 has these instructions, and it does true little-endian,
366 * so we don't need the address swizzling.
367 */
368 static int emulate_fp_pair(unsigned char __user *addr, unsigned int reg,
369 unsigned int flags)
370 {
371 char *ptr0 = (char *) &current->thread.TS_FPR(reg);
372 char *ptr1 = (char *) &current->thread.TS_FPR(reg+1);
373 int i, ret, sw = 0;
374
375 if (!(flags & F))
376 return 0;
377 if (reg & 1)
378 return 0; /* invalid form: FRS/FRT must be even */
379 if (flags & SW)
380 sw = 7;
381 ret = 0;
382 for (i = 0; i < 8; ++i) {
383 if (!(flags & ST)) {
384 ret |= __get_user(ptr0[i^sw], addr + i);
385 ret |= __get_user(ptr1[i^sw], addr + i + 8);
386 } else {
387 ret |= __put_user(ptr0[i^sw], addr + i);
388 ret |= __put_user(ptr1[i^sw], addr + i + 8);
389 }
390 }
391 if (ret)
392 return -EFAULT;
393 return 1; /* exception handled and fixed up */
394 }
395
396 #ifdef CONFIG_SPE
397
398 static struct aligninfo spe_aligninfo[32] = {
399 { 8, LD+E8 }, /* 0 00 00: evldd[x] */
400 { 8, LD+E4 }, /* 0 00 01: evldw[x] */
401 { 8, LD }, /* 0 00 10: evldh[x] */
402 INVALID, /* 0 00 11 */
403 { 2, LD }, /* 0 01 00: evlhhesplat[x] */
404 INVALID, /* 0 01 01 */
405 { 2, LD }, /* 0 01 10: evlhhousplat[x] */
406 { 2, LD+SE }, /* 0 01 11: evlhhossplat[x] */
407 { 4, LD }, /* 0 10 00: evlwhe[x] */
408 INVALID, /* 0 10 01 */
409 { 4, LD }, /* 0 10 10: evlwhou[x] */
410 { 4, LD+SE }, /* 0 10 11: evlwhos[x] */
411 { 4, LD+E4 }, /* 0 11 00: evlwwsplat[x] */
412 INVALID, /* 0 11 01 */
413 { 4, LD }, /* 0 11 10: evlwhsplat[x] */
414 INVALID, /* 0 11 11 */
415
416 { 8, ST+E8 }, /* 1 00 00: evstdd[x] */
417 { 8, ST+E4 }, /* 1 00 01: evstdw[x] */
418 { 8, ST }, /* 1 00 10: evstdh[x] */
419 INVALID, /* 1 00 11 */
420 INVALID, /* 1 01 00 */
421 INVALID, /* 1 01 01 */
422 INVALID, /* 1 01 10 */
423 INVALID, /* 1 01 11 */
424 { 4, ST }, /* 1 10 00: evstwhe[x] */
425 INVALID, /* 1 10 01 */
426 { 4, ST }, /* 1 10 10: evstwho[x] */
427 INVALID, /* 1 10 11 */
428 { 4, ST+E4 }, /* 1 11 00: evstwwe[x] */
429 INVALID, /* 1 11 01 */
430 { 4, ST+E4 }, /* 1 11 10: evstwwo[x] */
431 INVALID, /* 1 11 11 */
432 };
433
434 #define EVLDD 0x00
435 #define EVLDW 0x01
436 #define EVLDH 0x02
437 #define EVLHHESPLAT 0x04
438 #define EVLHHOUSPLAT 0x06
439 #define EVLHHOSSPLAT 0x07
440 #define EVLWHE 0x08
441 #define EVLWHOU 0x0A
442 #define EVLWHOS 0x0B
443 #define EVLWWSPLAT 0x0C
444 #define EVLWHSPLAT 0x0E
445 #define EVSTDD 0x10
446 #define EVSTDW 0x11
447 #define EVSTDH 0x12
448 #define EVSTWHE 0x18
449 #define EVSTWHO 0x1A
450 #define EVSTWWE 0x1C
451 #define EVSTWWO 0x1E
452
453 /*
454 * Emulate SPE loads and stores.
455 * Only Book-E has these instructions, and it does true little-endian,
456 * so we don't need the address swizzling.
457 */
458 static int emulate_spe(struct pt_regs *regs, unsigned int reg,
459 unsigned int instr)
460 {
461 int t, ret;
462 union {
463 u64 ll;
464 u32 w[2];
465 u16 h[4];
466 u8 v[8];
467 } data, temp;
468 unsigned char __user *p, *addr;
469 unsigned long *evr = &current->thread.evr[reg];
470 unsigned int nb, flags;
471
472 instr = (instr >> 1) & 0x1f;
473
474 /* DAR has the operand effective address */
475 addr = (unsigned char __user *)regs->dar;
476
477 nb = spe_aligninfo[instr].len;
478 flags = spe_aligninfo[instr].flags;
479
480 /* Verify the address of the operand */
481 if (unlikely(user_mode(regs) &&
482 !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ),
483 addr, nb)))
484 return -EFAULT;
485
486 /* userland only */
487 if (unlikely(!user_mode(regs)))
488 return 0;
489
490 flush_spe_to_thread(current);
491
492 /* If we are loading, get the data from user space, else
493 * get it from register values
494 */
495 if (flags & ST) {
496 data.ll = 0;
497 switch (instr) {
498 case EVSTDD:
499 case EVSTDW:
500 case EVSTDH:
501 data.w[0] = *evr;
502 data.w[1] = regs->gpr[reg];
503 break;
504 case EVSTWHE:
505 data.h[2] = *evr >> 16;
506 data.h[3] = regs->gpr[reg] >> 16;
507 break;
508 case EVSTWHO:
509 data.h[2] = *evr & 0xffff;
510 data.h[3] = regs->gpr[reg] & 0xffff;
511 break;
512 case EVSTWWE:
513 data.w[1] = *evr;
514 break;
515 case EVSTWWO:
516 data.w[1] = regs->gpr[reg];
517 break;
518 default:
519 return -EINVAL;
520 }
521 } else {
522 temp.ll = data.ll = 0;
523 ret = 0;
524 p = addr;
525
526 switch (nb) {
527 case 8:
528 ret |= __get_user_inatomic(temp.v[0], p++);
529 ret |= __get_user_inatomic(temp.v[1], p++);
530 ret |= __get_user_inatomic(temp.v[2], p++);
531 ret |= __get_user_inatomic(temp.v[3], p++);
532 case 4:
533 ret |= __get_user_inatomic(temp.v[4], p++);
534 ret |= __get_user_inatomic(temp.v[5], p++);
535 case 2:
536 ret |= __get_user_inatomic(temp.v[6], p++);
537 ret |= __get_user_inatomic(temp.v[7], p++);
538 if (unlikely(ret))
539 return -EFAULT;
540 }
541
542 switch (instr) {
543 case EVLDD:
544 case EVLDW:
545 case EVLDH:
546 data.ll = temp.ll;
547 break;
548 case EVLHHESPLAT:
549 data.h[0] = temp.h[3];
550 data.h[2] = temp.h[3];
551 break;
552 case EVLHHOUSPLAT:
553 case EVLHHOSSPLAT:
554 data.h[1] = temp.h[3];
555 data.h[3] = temp.h[3];
556 break;
557 case EVLWHE:
558 data.h[0] = temp.h[2];
559 data.h[2] = temp.h[3];
560 break;
561 case EVLWHOU:
562 case EVLWHOS:
563 data.h[1] = temp.h[2];
564 data.h[3] = temp.h[3];
565 break;
566 case EVLWWSPLAT:
567 data.w[0] = temp.w[1];
568 data.w[1] = temp.w[1];
569 break;
570 case EVLWHSPLAT:
571 data.h[0] = temp.h[2];
572 data.h[1] = temp.h[2];
573 data.h[2] = temp.h[3];
574 data.h[3] = temp.h[3];
575 break;
576 default:
577 return -EINVAL;
578 }
579 }
580
581 if (flags & SW) {
582 switch (flags & 0xf0) {
583 case E8:
584 SWAP(data.v[0], data.v[7]);
585 SWAP(data.v[1], data.v[6]);
586 SWAP(data.v[2], data.v[5]);
587 SWAP(data.v[3], data.v[4]);
588 break;
589 case E4:
590
591 SWAP(data.v[0], data.v[3]);
592 SWAP(data.v[1], data.v[2]);
593 SWAP(data.v[4], data.v[7]);
594 SWAP(data.v[5], data.v[6]);
595 break;
596 /* Its half word endian */
597 default:
598 SWAP(data.v[0], data.v[1]);
599 SWAP(data.v[2], data.v[3]);
600 SWAP(data.v[4], data.v[5]);
601 SWAP(data.v[6], data.v[7]);
602 break;
603 }
604 }
605
606 if (flags & SE) {
607 data.w[0] = (s16)data.h[1];
608 data.w[1] = (s16)data.h[3];
609 }
610
611 /* Store result to memory or update registers */
612 if (flags & ST) {
613 ret = 0;
614 p = addr;
615 switch (nb) {
616 case 8:
617 ret |= __put_user_inatomic(data.v[0], p++);
618 ret |= __put_user_inatomic(data.v[1], p++);
619 ret |= __put_user_inatomic(data.v[2], p++);
620 ret |= __put_user_inatomic(data.v[3], p++);
621 case 4:
622 ret |= __put_user_inatomic(data.v[4], p++);
623 ret |= __put_user_inatomic(data.v[5], p++);
624 case 2:
625 ret |= __put_user_inatomic(data.v[6], p++);
626 ret |= __put_user_inatomic(data.v[7], p++);
627 }
628 if (unlikely(ret))
629 return -EFAULT;
630 } else {
631 *evr = data.w[0];
632 regs->gpr[reg] = data.w[1];
633 }
634
635 return 1;
636 }
637 #endif /* CONFIG_SPE */
638
639 #ifdef CONFIG_VSX
640 /*
641 * Emulate VSX instructions...
642 */
643 static int emulate_vsx(unsigned char __user *addr, unsigned int reg,
644 unsigned int areg, struct pt_regs *regs,
645 unsigned int flags, unsigned int length,
646 unsigned int elsize)
647 {
648 char *ptr;
649 unsigned long *lptr;
650 int ret = 0;
651 int sw = 0;
652 int i, j;
653
654 flush_vsx_to_thread(current);
655
656 if (reg < 32)
657 ptr = (char *) &current->thread.TS_FPR(reg);
658 else
659 ptr = (char *) &current->thread.vr[reg - 32];
660
661 lptr = (unsigned long *) ptr;
662
663 if (flags & SW)
664 sw = elsize-1;
665
666 for (j = 0; j < length; j += elsize) {
667 for (i = 0; i < elsize; ++i) {
668 if (flags & ST)
669 ret |= __put_user(ptr[i^sw], addr + i);
670 else
671 ret |= __get_user(ptr[i^sw], addr + i);
672 }
673 ptr += elsize;
674 addr += elsize;
675 }
676
677 if (!ret) {
678 if (flags & U)
679 regs->gpr[areg] = regs->dar;
680
681 /* Splat load copies the same data to top and bottom 8 bytes */
682 if (flags & SPLT)
683 lptr[1] = lptr[0];
684 /* For 8 byte loads, zero the top 8 bytes */
685 else if (!(flags & ST) && (8 == length))
686 lptr[1] = 0;
687 } else
688 return -EFAULT;
689
690 return 1;
691 }
692 #endif
693
694 /*
695 * Called on alignment exception. Attempts to fixup
696 *
697 * Return 1 on success
698 * Return 0 if unable to handle the interrupt
699 * Return -EFAULT if data address is bad
700 */
701
702 int fix_alignment(struct pt_regs *regs)
703 {
704 unsigned int instr, nb, flags, instruction = 0;
705 unsigned int reg, areg;
706 unsigned int dsisr;
707 unsigned char __user *addr;
708 unsigned long p, swiz;
709 int ret, t;
710 union {
711 u64 ll;
712 double dd;
713 unsigned char v[8];
714 struct {
715 unsigned hi32;
716 int low32;
717 } x32;
718 struct {
719 unsigned char hi48[6];
720 short low16;
721 } x16;
722 } data;
723
724 /*
725 * We require a complete register set, if not, then our assembly
726 * is broken
727 */
728 CHECK_FULL_REGS(regs);
729
730 dsisr = regs->dsisr;
731
732 /* Some processors don't provide us with a DSISR we can use here,
733 * let's make one up from the instruction
734 */
735 if (cpu_has_feature(CPU_FTR_NODSISRALIGN)) {
736 unsigned long pc = regs->nip;
737
738 if (cpu_has_feature(CPU_FTR_PPC_LE) && (regs->msr & MSR_LE))
739 pc ^= 4;
740 if (unlikely(__get_user_inatomic(instr,
741 (unsigned int __user *)pc)))
742 return -EFAULT;
743 if (cpu_has_feature(CPU_FTR_REAL_LE) && (regs->msr & MSR_LE))
744 instr = cpu_to_le32(instr);
745 dsisr = make_dsisr(instr);
746 instruction = instr;
747 }
748
749 /* extract the operation and registers from the dsisr */
750 reg = (dsisr >> 5) & 0x1f; /* source/dest register */
751 areg = dsisr & 0x1f; /* register to update */
752
753 #ifdef CONFIG_SPE
754 if ((instr >> 26) == 0x4) {
755 PPC_WARN_ALIGNMENT(spe, regs);
756 return emulate_spe(regs, reg, instr);
757 }
758 #endif
759
760 instr = (dsisr >> 10) & 0x7f;
761 instr |= (dsisr >> 13) & 0x60;
762
763 /* Lookup the operation in our table */
764 nb = aligninfo[instr].len;
765 flags = aligninfo[instr].flags;
766
767 /* Byteswap little endian loads and stores */
768 swiz = 0;
769 if (regs->msr & MSR_LE) {
770 flags ^= SW;
771 /*
772 * So-called "PowerPC little endian" mode works by
773 * swizzling addresses rather than by actually doing
774 * any byte-swapping. To emulate this, we XOR each
775 * byte address with 7. We also byte-swap, because
776 * the processor's address swizzling depends on the
777 * operand size (it xors the address with 7 for bytes,
778 * 6 for halfwords, 4 for words, 0 for doublewords) but
779 * we will xor with 7 and load/store each byte separately.
780 */
781 if (cpu_has_feature(CPU_FTR_PPC_LE))
782 swiz = 7;
783 }
784
785 /* DAR has the operand effective address */
786 addr = (unsigned char __user *)regs->dar;
787
788 #ifdef CONFIG_VSX
789 if ((instruction & 0xfc00003e) == 0x7c000018) {
790 unsigned int elsize;
791
792 /* Additional register addressing bit (64 VSX vs 32 FPR/GPR) */
793 reg |= (instruction & 0x1) << 5;
794 /* Simple inline decoder instead of a table */
795 /* VSX has only 8 and 16 byte memory accesses */
796 nb = 8;
797 if (instruction & 0x200)
798 nb = 16;
799
800 /* Vector stores in little-endian mode swap individual
801 elements, so process them separately */
802 elsize = 4;
803 if (instruction & 0x80)
804 elsize = 8;
805
806 flags = 0;
807 if (regs->msr & MSR_LE)
808 flags |= SW;
809 if (instruction & 0x100)
810 flags |= ST;
811 if (instruction & 0x040)
812 flags |= U;
813 /* splat load needs a special decoder */
814 if ((instruction & 0x400) == 0){
815 flags |= SPLT;
816 nb = 8;
817 }
818 PPC_WARN_ALIGNMENT(vsx, regs);
819 return emulate_vsx(addr, reg, areg, regs, flags, nb, elsize);
820 }
821 #endif
822 /* A size of 0 indicates an instruction we don't support, with
823 * the exception of DCBZ which is handled as a special case here
824 */
825 if (instr == DCBZ) {
826 PPC_WARN_ALIGNMENT(dcbz, regs);
827 return emulate_dcbz(regs, addr);
828 }
829 if (unlikely(nb == 0))
830 return 0;
831
832 /* Load/Store Multiple instructions are handled in their own
833 * function
834 */
835 if (flags & M) {
836 PPC_WARN_ALIGNMENT(multiple, regs);
837 return emulate_multiple(regs, addr, reg, nb,
838 flags, instr, swiz);
839 }
840
841 /* Verify the address of the operand */
842 if (unlikely(user_mode(regs) &&
843 !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ),
844 addr, nb)))
845 return -EFAULT;
846
847 /* Force the fprs into the save area so we can reference them */
848 if (flags & F) {
849 /* userland only */
850 if (unlikely(!user_mode(regs)))
851 return 0;
852 flush_fp_to_thread(current);
853 }
854
855 /* Special case for 16-byte FP loads and stores */
856 if (nb == 16) {
857 PPC_WARN_ALIGNMENT(fp_pair, regs);
858 return emulate_fp_pair(addr, reg, flags);
859 }
860
861 PPC_WARN_ALIGNMENT(unaligned, regs);
862
863 /* If we are loading, get the data from user space, else
864 * get it from register values
865 */
866 if (!(flags & ST)) {
867 data.ll = 0;
868 ret = 0;
869 p = (unsigned long) addr;
870 switch (nb) {
871 case 8:
872 ret |= __get_user_inatomic(data.v[0], SWIZ_PTR(p++));
873 ret |= __get_user_inatomic(data.v[1], SWIZ_PTR(p++));
874 ret |= __get_user_inatomic(data.v[2], SWIZ_PTR(p++));
875 ret |= __get_user_inatomic(data.v[3], SWIZ_PTR(p++));
876 case 4:
877 ret |= __get_user_inatomic(data.v[4], SWIZ_PTR(p++));
878 ret |= __get_user_inatomic(data.v[5], SWIZ_PTR(p++));
879 case 2:
880 ret |= __get_user_inatomic(data.v[6], SWIZ_PTR(p++));
881 ret |= __get_user_inatomic(data.v[7], SWIZ_PTR(p++));
882 if (unlikely(ret))
883 return -EFAULT;
884 }
885 } else if (flags & F) {
886 data.dd = current->thread.TS_FPR(reg);
887 if (flags & S) {
888 /* Single-precision FP store requires conversion... */
889 #ifdef CONFIG_PPC_FPU
890 preempt_disable();
891 enable_kernel_fp();
892 cvt_df(&data.dd, (float *)&data.v[4]);
893 preempt_enable();
894 #else
895 return 0;
896 #endif
897 }
898 } else
899 data.ll = regs->gpr[reg];
900
901 if (flags & SW) {
902 switch (nb) {
903 case 8:
904 SWAP(data.v[0], data.v[7]);
905 SWAP(data.v[1], data.v[6]);
906 SWAP(data.v[2], data.v[5]);
907 SWAP(data.v[3], data.v[4]);
908 break;
909 case 4:
910 SWAP(data.v[4], data.v[7]);
911 SWAP(data.v[5], data.v[6]);
912 break;
913 case 2:
914 SWAP(data.v[6], data.v[7]);
915 break;
916 }
917 }
918
919 /* Perform other misc operations like sign extension
920 * or floating point single precision conversion
921 */
922 switch (flags & ~(U|SW)) {
923 case LD+SE: /* sign extending integer loads */
924 case LD+F+SE: /* sign extend for lfiwax */
925 if ( nb == 2 )
926 data.ll = data.x16.low16;
927 else /* nb must be 4 */
928 data.ll = data.x32.low32;
929 break;
930
931 /* Single-precision FP load requires conversion... */
932 case LD+F+S:
933 #ifdef CONFIG_PPC_FPU
934 preempt_disable();
935 enable_kernel_fp();
936 cvt_fd((float *)&data.v[4], &data.dd);
937 preempt_enable();
938 #else
939 return 0;
940 #endif
941 break;
942 }
943
944 /* Store result to memory or update registers */
945 if (flags & ST) {
946 ret = 0;
947 p = (unsigned long) addr;
948 switch (nb) {
949 case 8:
950 ret |= __put_user_inatomic(data.v[0], SWIZ_PTR(p++));
951 ret |= __put_user_inatomic(data.v[1], SWIZ_PTR(p++));
952 ret |= __put_user_inatomic(data.v[2], SWIZ_PTR(p++));
953 ret |= __put_user_inatomic(data.v[3], SWIZ_PTR(p++));
954 case 4:
955 ret |= __put_user_inatomic(data.v[4], SWIZ_PTR(p++));
956 ret |= __put_user_inatomic(data.v[5], SWIZ_PTR(p++));
957 case 2:
958 ret |= __put_user_inatomic(data.v[6], SWIZ_PTR(p++));
959 ret |= __put_user_inatomic(data.v[7], SWIZ_PTR(p++));
960 }
961 if (unlikely(ret))
962 return -EFAULT;
963 } else if (flags & F)
964 current->thread.TS_FPR(reg) = data.dd;
965 else
966 regs->gpr[reg] = data.ll;
967
968 /* Update RA as needed */
969 if (flags & U)
970 regs->gpr[areg] = regs->dar;
971
972 return 1;
973 }