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blk: rq_data_dir() should not return a boolean
[cris-mirror.git] / arch / powerpc / kernel / align.c
blob86150fbb42c39111c7440523f482dbe55e0bd4d9
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/cache.h>
25 #include <asm/cputable.h>
26 #include <asm/emulated_ops.h>
27 #include <asm/switch_to.h>
28 #include <asm/disassemble.h>
29
30 struct aligninfo {
31 unsigned char len;
32 unsigned char flags;
33 };
34
35
36 #define INVALID { 0, 0 }
37
38 /* Bits in the flags field */
39 #define LD 0 /* load */
40 #define ST 1 /* store */
41 #define SE 2 /* sign-extend value, or FP ld/st as word */
42 #define F 4 /* to/from fp regs */
43 #define U 8 /* update index register */
44 #define M 0x10 /* multiple load/store */
45 #define SW 0x20 /* byte swap */
46 #define S 0x40 /* single-precision fp or... */
47 #define SX 0x40 /* ... byte count in XER */
48 #define HARD 0x80 /* string, stwcx. */
49 #define E4 0x40 /* SPE endianness is word */
50 #define E8 0x80 /* SPE endianness is double word */
51 #define SPLT 0x80 /* VSX SPLAT load */
52
53 /* DSISR bits reported for a DCBZ instruction: */
54 #define DCBZ 0x5f /* 8xx/82xx dcbz faults when cache not enabled */
55
56 /*
57 * The PowerPC stores certain bits of the instruction that caused the
58 * alignment exception in the DSISR register. This array maps those
59 * bits to information about the operand length and what the
60 * instruction would do.
61 */
62 static struct aligninfo aligninfo[128] = {
63 { 4, LD }, /* 00 0 0000: lwz / lwarx */
64 INVALID, /* 00 0 0001 */
65 { 4, ST }, /* 00 0 0010: stw */
66 INVALID, /* 00 0 0011 */
67 { 2, LD }, /* 00 0 0100: lhz */
68 { 2, LD+SE }, /* 00 0 0101: lha */
69 { 2, ST }, /* 00 0 0110: sth */
70 { 4, LD+M }, /* 00 0 0111: lmw */
71 { 4, LD+F+S }, /* 00 0 1000: lfs */
72 { 8, LD+F }, /* 00 0 1001: lfd */
73 { 4, ST+F+S }, /* 00 0 1010: stfs */
74 { 8, ST+F }, /* 00 0 1011: stfd */
75 { 16, LD }, /* 00 0 1100: lq */
76 { 8, LD }, /* 00 0 1101: ld/ldu/lwa */
77 INVALID, /* 00 0 1110 */
78 { 8, ST }, /* 00 0 1111: std/stdu */
79 { 4, LD+U }, /* 00 1 0000: lwzu */
80 INVALID, /* 00 1 0001 */
81 { 4, ST+U }, /* 00 1 0010: stwu */
82 INVALID, /* 00 1 0011 */
83 { 2, LD+U }, /* 00 1 0100: lhzu */
84 { 2, LD+SE+U }, /* 00 1 0101: lhau */
85 { 2, ST+U }, /* 00 1 0110: sthu */
86 { 4, ST+M }, /* 00 1 0111: stmw */
87 { 4, LD+F+S+U }, /* 00 1 1000: lfsu */
88 { 8, LD+F+U }, /* 00 1 1001: lfdu */
89 { 4, ST+F+S+U }, /* 00 1 1010: stfsu */
90 { 8, ST+F+U }, /* 00 1 1011: stfdu */
91 { 16, LD+F }, /* 00 1 1100: lfdp */
92 INVALID, /* 00 1 1101 */
93 { 16, ST+F }, /* 00 1 1110: stfdp */
94 INVALID, /* 00 1 1111 */
95 { 8, LD }, /* 01 0 0000: ldx */
96 INVALID, /* 01 0 0001 */
97 { 8, ST }, /* 01 0 0010: stdx */
98 INVALID, /* 01 0 0011 */
99 INVALID, /* 01 0 0100 */
100 { 4, LD+SE }, /* 01 0 0101: lwax */
101 INVALID, /* 01 0 0110 */
102 INVALID, /* 01 0 0111 */
103 { 4, LD+M+HARD+SX }, /* 01 0 1000: lswx */
104 { 4, LD+M+HARD }, /* 01 0 1001: lswi */
105 { 4, ST+M+HARD+SX }, /* 01 0 1010: stswx */
106 { 4, ST+M+HARD }, /* 01 0 1011: stswi */
107 INVALID, /* 01 0 1100 */
108 { 8, LD+U }, /* 01 0 1101: ldu */
109 INVALID, /* 01 0 1110 */
110 { 8, ST+U }, /* 01 0 1111: stdu */
111 { 8, LD+U }, /* 01 1 0000: ldux */
112 INVALID, /* 01 1 0001 */
113 { 8, ST+U }, /* 01 1 0010: stdux */
114 INVALID, /* 01 1 0011 */
115 INVALID, /* 01 1 0100 */
116 { 4, LD+SE+U }, /* 01 1 0101: lwaux */
117 INVALID, /* 01 1 0110 */
118 INVALID, /* 01 1 0111 */
119 INVALID, /* 01 1 1000 */
120 INVALID, /* 01 1 1001 */
121 INVALID, /* 01 1 1010 */
122 INVALID, /* 01 1 1011 */
123 INVALID, /* 01 1 1100 */
124 INVALID, /* 01 1 1101 */
125 INVALID, /* 01 1 1110 */
126 INVALID, /* 01 1 1111 */
127 INVALID, /* 10 0 0000 */
128 INVALID, /* 10 0 0001 */
129 INVALID, /* 10 0 0010: stwcx. */
130 INVALID, /* 10 0 0011 */
131 INVALID, /* 10 0 0100 */
132 INVALID, /* 10 0 0101 */
133 INVALID, /* 10 0 0110 */
134 INVALID, /* 10 0 0111 */
135 { 4, LD+SW }, /* 10 0 1000: lwbrx */
136 INVALID, /* 10 0 1001 */
137 { 4, ST+SW }, /* 10 0 1010: stwbrx */
138 INVALID, /* 10 0 1011 */
139 { 2, LD+SW }, /* 10 0 1100: lhbrx */
140 { 4, LD+SE }, /* 10 0 1101 lwa */
141 { 2, ST+SW }, /* 10 0 1110: sthbrx */
142 { 16, ST }, /* 10 0 1111: stq */
143 INVALID, /* 10 1 0000 */
144 INVALID, /* 10 1 0001 */
145 INVALID, /* 10 1 0010 */
146 INVALID, /* 10 1 0011 */
147 INVALID, /* 10 1 0100 */
148 INVALID, /* 10 1 0101 */
149 INVALID, /* 10 1 0110 */
150 INVALID, /* 10 1 0111 */
151 INVALID, /* 10 1 1000 */
152 INVALID, /* 10 1 1001 */
153 INVALID, /* 10 1 1010 */
154 INVALID, /* 10 1 1011 */
155 INVALID, /* 10 1 1100 */
156 INVALID, /* 10 1 1101 */
157 INVALID, /* 10 1 1110 */
158 { 0, ST+HARD }, /* 10 1 1111: dcbz */
159 { 4, LD }, /* 11 0 0000: lwzx */
160 INVALID, /* 11 0 0001 */
161 { 4, ST }, /* 11 0 0010: stwx */
162 INVALID, /* 11 0 0011 */
163 { 2, LD }, /* 11 0 0100: lhzx */
164 { 2, LD+SE }, /* 11 0 0101: lhax */
165 { 2, ST }, /* 11 0 0110: sthx */
166 INVALID, /* 11 0 0111 */
167 { 4, LD+F+S }, /* 11 0 1000: lfsx */
168 { 8, LD+F }, /* 11 0 1001: lfdx */
169 { 4, ST+F+S }, /* 11 0 1010: stfsx */
170 { 8, ST+F }, /* 11 0 1011: stfdx */
171 { 16, LD+F }, /* 11 0 1100: lfdpx */
172 { 4, LD+F+SE }, /* 11 0 1101: lfiwax */
173 { 16, ST+F }, /* 11 0 1110: stfdpx */
174 { 4, ST+F }, /* 11 0 1111: stfiwx */
175 { 4, LD+U }, /* 11 1 0000: lwzux */
176 INVALID, /* 11 1 0001 */
177 { 4, ST+U }, /* 11 1 0010: stwux */
178 INVALID, /* 11 1 0011 */
179 { 2, LD+U }, /* 11 1 0100: lhzux */
180 { 2, LD+SE+U }, /* 11 1 0101: lhaux */
181 { 2, ST+U }, /* 11 1 0110: sthux */
182 INVALID, /* 11 1 0111 */
183 { 4, LD+F+S+U }, /* 11 1 1000: lfsux */
184 { 8, LD+F+U }, /* 11 1 1001: lfdux */
185 { 4, ST+F+S+U }, /* 11 1 1010: stfsux */
186 { 8, ST+F+U }, /* 11 1 1011: stfdux */
187 INVALID, /* 11 1 1100 */
188 { 4, LD+F }, /* 11 1 1101: lfiwzx */
189 INVALID, /* 11 1 1110 */
190 INVALID, /* 11 1 1111 */
191 };
192
193 /*
194 * The dcbz (data cache block zero) instruction
195 * gives an alignment fault if used on non-cacheable
196 * memory. We handle the fault mainly for the
197 * case when we are running with the cache disabled
198 * for debugging.
199 */
200 static int emulate_dcbz(struct pt_regs *regs, unsigned char __user *addr)
201 {
202 long __user *p;
203 int i, size;
204
205 #ifdef __powerpc64__
206 size = ppc64_caches.dline_size;
207 #else
208 size = L1_CACHE_BYTES;
209 #endif
210 p = (long __user *) (regs->dar & -size);
211 if (user_mode(regs) && !access_ok(VERIFY_WRITE, p, size))
212 return -EFAULT;
213 for (i = 0; i < size / sizeof(long); ++i)
214 if (__put_user_inatomic(0, p+i))
215 return -EFAULT;
216 return 1;
217 }
218
219 /*
220 * Emulate load & store multiple instructions
221 * On 64-bit machines, these instructions only affect/use the
222 * bottom 4 bytes of each register, and the loads clear the
223 * top 4 bytes of the affected register.
224 */
225 #ifdef __BIG_ENDIAN__
226 #ifdef CONFIG_PPC64
227 #define REG_BYTE(rp, i) *((u8 *)((rp) + ((i) >> 2)) + ((i) & 3) + 4)
228 #else
229 #define REG_BYTE(rp, i) *((u8 *)(rp) + (i))
230 #endif
231 #endif
232
233 #ifdef __LITTLE_ENDIAN__
234 #define REG_BYTE(rp, i) (*(((u8 *)((rp) + ((i)>>2)) + ((i)&3))))
235 #endif
236
237 #define SWIZ_PTR(p) ((unsigned char __user *)((p) ^ swiz))
238
239 static int emulate_multiple(struct pt_regs *regs, unsigned char __user *addr,
240 unsigned int reg, unsigned int nb,
241 unsigned int flags, unsigned int instr,
242 unsigned long swiz)
243 {
244 unsigned long *rptr;
245 unsigned int nb0, i, bswiz;
246 unsigned long p;
247
248 /*
249 * We do not try to emulate 8 bytes multiple as they aren't really
250 * available in our operating environments and we don't try to
251 * emulate multiples operations in kernel land as they should never
252 * be used/generated there at least not on unaligned boundaries
253 */
254 if (unlikely((nb > 4) || !user_mode(regs)))
255 return 0;
256
257 /* lmw, stmw, lswi/x, stswi/x */
258 nb0 = 0;
259 if (flags & HARD) {
260 if (flags & SX) {
261 nb = regs->xer & 127;
262 if (nb == 0)
263 return 1;
264 } else {
265 unsigned long pc = regs->nip ^ (swiz & 4);
266
267 if (__get_user_inatomic(instr,
268 (unsigned int __user *)pc))
269 return -EFAULT;
270 if (swiz == 0 && (flags & SW))
271 instr = cpu_to_le32(instr);
272 nb = (instr >> 11) & 0x1f;
273 if (nb == 0)
274 nb = 32;
275 }
276 if (nb + reg * 4 > 128) {
277 nb0 = nb + reg * 4 - 128;
278 nb = 128 - reg * 4;
279 }
280 #ifdef __LITTLE_ENDIAN__
281 /*
282 * String instructions are endian neutral but the code
283 * below is not. Force byte swapping on so that the
284 * effects of swizzling are undone in the load/store
285 * loops below.
286 */
287 flags ^= SW;
288 #endif
289 } else {
290 /* lwm, stmw */
291 nb = (32 - reg) * 4;
292 }
293
294 if (!access_ok((flags & ST ? VERIFY_WRITE: VERIFY_READ), addr, nb+nb0))
295 return -EFAULT; /* bad address */
296
297 rptr = &regs->gpr[reg];
298 p = (unsigned long) addr;
299 bswiz = (flags & SW)? 3: 0;
300
301 if (!(flags & ST)) {
302 /*
303 * This zeroes the top 4 bytes of the affected registers
304 * in 64-bit mode, and also zeroes out any remaining
305 * bytes of the last register for lsw*.
306 */
307 memset(rptr, 0, ((nb + 3) / 4) * sizeof(unsigned long));
308 if (nb0 > 0)
309 memset(&regs->gpr[0], 0,
310 ((nb0 + 3) / 4) * sizeof(unsigned long));
311
312 for (i = 0; i < nb; ++i, ++p)
313 if (__get_user_inatomic(REG_BYTE(rptr, i ^ bswiz),
314 SWIZ_PTR(p)))
315 return -EFAULT;
316 if (nb0 > 0) {
317 rptr = &regs->gpr[0];
318 addr += nb;
319 for (i = 0; i < nb0; ++i, ++p)
320 if (__get_user_inatomic(REG_BYTE(rptr,
321 i ^ bswiz),
322 SWIZ_PTR(p)))
323 return -EFAULT;
324 }
325
326 } else {
327 for (i = 0; i < nb; ++i, ++p)
328 if (__put_user_inatomic(REG_BYTE(rptr, i ^ bswiz),
329 SWIZ_PTR(p)))
330 return -EFAULT;
331 if (nb0 > 0) {
332 rptr = &regs->gpr[0];
333 addr += nb;
334 for (i = 0; i < nb0; ++i, ++p)
335 if (__put_user_inatomic(REG_BYTE(rptr,
336 i ^ bswiz),
337 SWIZ_PTR(p)))
338 return -EFAULT;
339 }
340 }
341 return 1;
342 }
343
344 /*
345 * Emulate floating-point pair loads and stores.
346 * Only POWER6 has these instructions, and it does true little-endian,
347 * so we don't need the address swizzling.
348 */
349 static int emulate_fp_pair(unsigned char __user *addr, unsigned int reg,
350 unsigned int flags)
351 {
352 char *ptr0 = (char *) &current->thread.TS_FPR(reg);
353 char *ptr1 = (char *) &current->thread.TS_FPR(reg+1);
354 int i, ret, sw = 0;
355
356 if (reg & 1)
357 return 0; /* invalid form: FRS/FRT must be even */
358 if (flags & SW)
359 sw = 7;
360 ret = 0;
361 for (i = 0; i < 8; ++i) {
362 if (!(flags & ST)) {
363 ret |= __get_user(ptr0[i^sw], addr + i);
364 ret |= __get_user(ptr1[i^sw], addr + i + 8);
365 } else {
366 ret |= __put_user(ptr0[i^sw], addr + i);
367 ret |= __put_user(ptr1[i^sw], addr + i + 8);
368 }
369 }
370 if (ret)
371 return -EFAULT;
372 return 1; /* exception handled and fixed up */
373 }
374
375 #ifdef CONFIG_PPC64
376 static int emulate_lq_stq(struct pt_regs *regs, unsigned char __user *addr,
377 unsigned int reg, unsigned int flags)
378 {
379 char *ptr0 = (char *)&regs->gpr[reg];
380 char *ptr1 = (char *)&regs->gpr[reg+1];
381 int i, ret, sw = 0;
382
383 if (reg & 1)
384 return 0; /* invalid form: GPR must be even */
385 if (flags & SW)
386 sw = 7;
387 ret = 0;
388 for (i = 0; i < 8; ++i) {
389 if (!(flags & ST)) {
390 ret |= __get_user(ptr0[i^sw], addr + i);
391 ret |= __get_user(ptr1[i^sw], addr + i + 8);
392 } else {
393 ret |= __put_user(ptr0[i^sw], addr + i);
394 ret |= __put_user(ptr1[i^sw], addr + i + 8);
395 }
396 }
397 if (ret)
398 return -EFAULT;
399 return 1; /* exception handled and fixed up */
400 }
401 #endif /* CONFIG_PPC64 */
402
403 #ifdef CONFIG_SPE
404
405 static struct aligninfo spe_aligninfo[32] = {
406 { 8, LD+E8 }, /* 0 00 00: evldd[x] */
407 { 8, LD+E4 }, /* 0 00 01: evldw[x] */
408 { 8, LD }, /* 0 00 10: evldh[x] */
409 INVALID, /* 0 00 11 */
410 { 2, LD }, /* 0 01 00: evlhhesplat[x] */
411 INVALID, /* 0 01 01 */
412 { 2, LD }, /* 0 01 10: evlhhousplat[x] */
413 { 2, LD+SE }, /* 0 01 11: evlhhossplat[x] */
414 { 4, LD }, /* 0 10 00: evlwhe[x] */
415 INVALID, /* 0 10 01 */
416 { 4, LD }, /* 0 10 10: evlwhou[x] */
417 { 4, LD+SE }, /* 0 10 11: evlwhos[x] */
418 { 4, LD+E4 }, /* 0 11 00: evlwwsplat[x] */
419 INVALID, /* 0 11 01 */
420 { 4, LD }, /* 0 11 10: evlwhsplat[x] */
421 INVALID, /* 0 11 11 */
422
423 { 8, ST+E8 }, /* 1 00 00: evstdd[x] */
424 { 8, ST+E4 }, /* 1 00 01: evstdw[x] */
425 { 8, ST }, /* 1 00 10: evstdh[x] */
426 INVALID, /* 1 00 11 */
427 INVALID, /* 1 01 00 */
428 INVALID, /* 1 01 01 */
429 INVALID, /* 1 01 10 */
430 INVALID, /* 1 01 11 */
431 { 4, ST }, /* 1 10 00: evstwhe[x] */
432 INVALID, /* 1 10 01 */
433 { 4, ST }, /* 1 10 10: evstwho[x] */
434 INVALID, /* 1 10 11 */
435 { 4, ST+E4 }, /* 1 11 00: evstwwe[x] */
436 INVALID, /* 1 11 01 */
437 { 4, ST+E4 }, /* 1 11 10: evstwwo[x] */
438 INVALID, /* 1 11 11 */
439 };
440
441 #define EVLDD 0x00
442 #define EVLDW 0x01
443 #define EVLDH 0x02
444 #define EVLHHESPLAT 0x04
445 #define EVLHHOUSPLAT 0x06
446 #define EVLHHOSSPLAT 0x07
447 #define EVLWHE 0x08
448 #define EVLWHOU 0x0A
449 #define EVLWHOS 0x0B
450 #define EVLWWSPLAT 0x0C
451 #define EVLWHSPLAT 0x0E
452 #define EVSTDD 0x10
453 #define EVSTDW 0x11
454 #define EVSTDH 0x12
455 #define EVSTWHE 0x18
456 #define EVSTWHO 0x1A
457 #define EVSTWWE 0x1C
458 #define EVSTWWO 0x1E
459
460 /*
461 * Emulate SPE loads and stores.
462 * Only Book-E has these instructions, and it does true little-endian,
463 * so we don't need the address swizzling.
464 */
465 static int emulate_spe(struct pt_regs *regs, unsigned int reg,
466 unsigned int instr)
467 {
468 int ret;
469 union {
470 u64 ll;
471 u32 w[2];
472 u16 h[4];
473 u8 v[8];
474 } data, temp;
475 unsigned char __user *p, *addr;
476 unsigned long *evr = &current->thread.evr[reg];
477 unsigned int nb, flags;
478
479 instr = (instr >> 1) & 0x1f;
480
481 /* DAR has the operand effective address */
482 addr = (unsigned char __user *)regs->dar;
483
484 nb = spe_aligninfo[instr].len;
485 flags = spe_aligninfo[instr].flags;
486
487 /* Verify the address of the operand */
488 if (unlikely(user_mode(regs) &&
489 !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ),
490 addr, nb)))
491 return -EFAULT;
492
493 /* userland only */
494 if (unlikely(!user_mode(regs)))
495 return 0;
496
497 flush_spe_to_thread(current);
498
499 /* If we are loading, get the data from user space, else
500 * get it from register values
501 */
502 if (flags & ST) {
503 data.ll = 0;
504 switch (instr) {
505 case EVSTDD:
506 case EVSTDW:
507 case EVSTDH:
508 data.w[0] = *evr;
509 data.w[1] = regs->gpr[reg];
510 break;
511 case EVSTWHE:
512 data.h[2] = *evr >> 16;
513 data.h[3] = regs->gpr[reg] >> 16;
514 break;
515 case EVSTWHO:
516 data.h[2] = *evr & 0xffff;
517 data.h[3] = regs->gpr[reg] & 0xffff;
518 break;
519 case EVSTWWE:
520 data.w[1] = *evr;
521 break;
522 case EVSTWWO:
523 data.w[1] = regs->gpr[reg];
524 break;
525 default:
526 return -EINVAL;
527 }
528 } else {
529 temp.ll = data.ll = 0;
530 ret = 0;
531 p = addr;
532
533 switch (nb) {
534 case 8:
535 ret |= __get_user_inatomic(temp.v[0], p++);
536 ret |= __get_user_inatomic(temp.v[1], p++);
537 ret |= __get_user_inatomic(temp.v[2], p++);
538 ret |= __get_user_inatomic(temp.v[3], p++);
539 case 4:
540 ret |= __get_user_inatomic(temp.v[4], p++);
541 ret |= __get_user_inatomic(temp.v[5], p++);
542 case 2:
543 ret |= __get_user_inatomic(temp.v[6], p++);
544 ret |= __get_user_inatomic(temp.v[7], p++);
545 if (unlikely(ret))
546 return -EFAULT;
547 }
548
549 switch (instr) {
550 case EVLDD:
551 case EVLDW:
552 case EVLDH:
553 data.ll = temp.ll;
554 break;
555 case EVLHHESPLAT:
556 data.h[0] = temp.h[3];
557 data.h[2] = temp.h[3];
558 break;
559 case EVLHHOUSPLAT:
560 case EVLHHOSSPLAT:
561 data.h[1] = temp.h[3];
562 data.h[3] = temp.h[3];
563 break;
564 case EVLWHE:
565 data.h[0] = temp.h[2];
566 data.h[2] = temp.h[3];
567 break;
568 case EVLWHOU:
569 case EVLWHOS:
570 data.h[1] = temp.h[2];
571 data.h[3] = temp.h[3];
572 break;
573 case EVLWWSPLAT:
574 data.w[0] = temp.w[1];
575 data.w[1] = temp.w[1];
576 break;
577 case EVLWHSPLAT:
578 data.h[0] = temp.h[2];
579 data.h[1] = temp.h[2];
580 data.h[2] = temp.h[3];
581 data.h[3] = temp.h[3];
582 break;
583 default:
584 return -EINVAL;
585 }
586 }
587
588 if (flags & SW) {
589 switch (flags & 0xf0) {
590 case E8:
591 data.ll = swab64(data.ll);
592 break;
593 case E4:
594 data.w[0] = swab32(data.w[0]);
595 data.w[1] = swab32(data.w[1]);
596 break;
597 /* Its half word endian */
598 default:
599 data.h[0] = swab16(data.h[0]);
600 data.h[1] = swab16(data.h[1]);
601 data.h[2] = swab16(data.h[2]);
602 data.h[3] = swab16(data.h[3]);
603 break;
604 }
605 }
606
607 if (flags & SE) {
608 data.w[0] = (s16)data.h[1];
609 data.w[1] = (s16)data.h[3];
610 }
611
612 /* Store result to memory or update registers */
613 if (flags & ST) {
614 ret = 0;
615 p = addr;
616 switch (nb) {
617 case 8:
618 ret |= __put_user_inatomic(data.v[0], p++);
619 ret |= __put_user_inatomic(data.v[1], p++);
620 ret |= __put_user_inatomic(data.v[2], p++);
621 ret |= __put_user_inatomic(data.v[3], p++);
622 case 4:
623 ret |= __put_user_inatomic(data.v[4], p++);
624 ret |= __put_user_inatomic(data.v[5], p++);
625 case 2:
626 ret |= __put_user_inatomic(data.v[6], p++);
627 ret |= __put_user_inatomic(data.v[7], p++);
628 }
629 if (unlikely(ret))
630 return -EFAULT;
631 } else {
632 *evr = data.w[0];
633 regs->gpr[reg] = data.w[1];
634 }
635
636 return 1;
637 }
638 #endif /* CONFIG_SPE */
639
640 #ifdef CONFIG_VSX
641 /*
642 * Emulate VSX instructions...
643 */
644 static int emulate_vsx(unsigned char __user *addr, unsigned int reg,
645 unsigned int areg, struct pt_regs *regs,
646 unsigned int flags, unsigned int length,
647 unsigned int elsize)
648 {
649 char *ptr;
650 unsigned long *lptr;
651 int ret = 0;
652 int sw = 0;
653 int i, j;
654
655 /* userland only */
656 if (unlikely(!user_mode(regs)))
657 return 0;
658
659 flush_vsx_to_thread(current);
660
661 if (reg < 32)
662 ptr = (char *) &current->thread.fp_state.fpr[reg][0];
663 else
664 ptr = (char *) &current->thread.vr_state.vr[reg - 32];
665
666 lptr = (unsigned long *) ptr;
667
668 #ifdef __LITTLE_ENDIAN__
669 if (flags & SW) {
670 elsize = length;
671 sw = length-1;
672 } else {
673 /*
674 * The elements are BE ordered, even in LE mode, so process
675 * them in reverse order.
676 */
677 addr += length - elsize;
678
679 /* 8 byte memory accesses go in the top 8 bytes of the VR */
680 if (length == 8)
681 ptr += 8;
682 }
683 #else
684 if (flags & SW)
685 sw = elsize-1;
686 #endif
687
688 for (j = 0; j < length; j += elsize) {
689 for (i = 0; i < elsize; ++i) {
690 if (flags & ST)
691 ret |= __put_user(ptr[i^sw], addr + i);
692 else
693 ret |= __get_user(ptr[i^sw], addr + i);
694 }
695 ptr += elsize;
696 #ifdef __LITTLE_ENDIAN__
697 addr -= elsize;
698 #else
699 addr += elsize;
700 #endif
701 }
702
703 #ifdef __BIG_ENDIAN__
704 #define VSX_HI 0
705 #define VSX_LO 1
706 #else
707 #define VSX_HI 1
708 #define VSX_LO 0
709 #endif
710
711 if (!ret) {
712 if (flags & U)
713 regs->gpr[areg] = regs->dar;
714
715 /* Splat load copies the same data to top and bottom 8 bytes */
716 if (flags & SPLT)
717 lptr[VSX_LO] = lptr[VSX_HI];
718 /* For 8 byte loads, zero the low 8 bytes */
719 else if (!(flags & ST) && (8 == length))
720 lptr[VSX_LO] = 0;
721 } else
722 return -EFAULT;
723
724 return 1;
725 }
726 #endif
727
728 /*
729 * Called on alignment exception. Attempts to fixup
730 *
731 * Return 1 on success
732 * Return 0 if unable to handle the interrupt
733 * Return -EFAULT if data address is bad
734 */
735
736 int fix_alignment(struct pt_regs *regs)
737 {
738 unsigned int instr, nb, flags, instruction = 0;
739 unsigned int reg, areg;
740 unsigned int dsisr;
741 unsigned char __user *addr;
742 unsigned long p, swiz;
743 int ret, i;
744 union data {
745 u64 ll;
746 double dd;
747 unsigned char v[8];
748 struct {
749 #ifdef __LITTLE_ENDIAN__
750 int low32;
751 unsigned hi32;
752 #else
753 unsigned hi32;
754 int low32;
755 #endif
756 } x32;
757 struct {
758 #ifdef __LITTLE_ENDIAN__
759 short low16;
760 unsigned char hi48[6];
761 #else
762 unsigned char hi48[6];
763 short low16;
764 #endif
765 } x16;
766 } data;
767
768 /*
769 * We require a complete register set, if not, then our assembly
770 * is broken
771 */
772 CHECK_FULL_REGS(regs);
773
774 dsisr = regs->dsisr;
775
776 /* Some processors don't provide us with a DSISR we can use here,
777 * let's make one up from the instruction
778 */
779 if (cpu_has_feature(CPU_FTR_NODSISRALIGN)) {
780 unsigned long pc = regs->nip;
781
782 if (cpu_has_feature(CPU_FTR_PPC_LE) && (regs->msr & MSR_LE))
783 pc ^= 4;
784 if (unlikely(__get_user_inatomic(instr,
785 (unsigned int __user *)pc)))
786 return -EFAULT;
787 if (cpu_has_feature(CPU_FTR_REAL_LE) && (regs->msr & MSR_LE))
788 instr = cpu_to_le32(instr);
789 dsisr = make_dsisr(instr);
790 instruction = instr;
791 }
792
793 /* extract the operation and registers from the dsisr */
794 reg = (dsisr >> 5) & 0x1f; /* source/dest register */
795 areg = dsisr & 0x1f; /* register to update */
796
797 #ifdef CONFIG_SPE
798 if ((instr >> 26) == 0x4) {
799 PPC_WARN_ALIGNMENT(spe, regs);
800 return emulate_spe(regs, reg, instr);
801 }
802 #endif
803
804 instr = (dsisr >> 10) & 0x7f;
805 instr |= (dsisr >> 13) & 0x60;
806
807 /* Lookup the operation in our table */
808 nb = aligninfo[instr].len;
809 flags = aligninfo[instr].flags;
810
811 /* ldbrx/stdbrx overlap lfs/stfs in the DSISR unfortunately */
812 if (IS_XFORM(instruction) && ((instruction >> 1) & 0x3ff) == 532) {
813 nb = 8;
814 flags = LD+SW;
815 } else if (IS_XFORM(instruction) &&
816 ((instruction >> 1) & 0x3ff) == 660) {
817 nb = 8;
818 flags = ST+SW;
819 }
820
821 /* Byteswap little endian loads and stores */
822 swiz = 0;
823 if ((regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE)) {
824 flags ^= SW;
825 #ifdef __BIG_ENDIAN__
826 /*
827 * So-called "PowerPC little endian" mode works by
828 * swizzling addresses rather than by actually doing
829 * any byte-swapping. To emulate this, we XOR each
830 * byte address with 7. We also byte-swap, because
831 * the processor's address swizzling depends on the
832 * operand size (it xors the address with 7 for bytes,
833 * 6 for halfwords, 4 for words, 0 for doublewords) but
834 * we will xor with 7 and load/store each byte separately.
835 */
836 if (cpu_has_feature(CPU_FTR_PPC_LE))
837 swiz = 7;
838 #endif
839 }
840
841 /* DAR has the operand effective address */
842 addr = (unsigned char __user *)regs->dar;
843
844 #ifdef CONFIG_VSX
845 if ((instruction & 0xfc00003e) == 0x7c000018) {
846 unsigned int elsize;
847
848 /* Additional register addressing bit (64 VSX vs 32 FPR/GPR) */
849 reg |= (instruction & 0x1) << 5;
850 /* Simple inline decoder instead of a table */
851 /* VSX has only 8 and 16 byte memory accesses */
852 nb = 8;
853 if (instruction & 0x200)
854 nb = 16;
855
856 /* Vector stores in little-endian mode swap individual
857 elements, so process them separately */
858 elsize = 4;
859 if (instruction & 0x80)
860 elsize = 8;
861
862 flags = 0;
863 if ((regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE))
864 flags |= SW;
865 if (instruction & 0x100)
866 flags |= ST;
867 if (instruction & 0x040)
868 flags |= U;
869 /* splat load needs a special decoder */
870 if ((instruction & 0x400) == 0){
871 flags |= SPLT;
872 nb = 8;
873 }
874 PPC_WARN_ALIGNMENT(vsx, regs);
875 return emulate_vsx(addr, reg, areg, regs, flags, nb, elsize);
876 }
877 #endif
878 /* A size of 0 indicates an instruction we don't support, with
879 * the exception of DCBZ which is handled as a special case here
880 */
881 if (instr == DCBZ) {
882 PPC_WARN_ALIGNMENT(dcbz, regs);
883 return emulate_dcbz(regs, addr);
884 }
885 if (unlikely(nb == 0))
886 return 0;
887
888 /* Load/Store Multiple instructions are handled in their own
889 * function
890 */
891 if (flags & M) {
892 PPC_WARN_ALIGNMENT(multiple, regs);
893 return emulate_multiple(regs, addr, reg, nb,
894 flags, instr, swiz);
895 }
896
897 /* Verify the address of the operand */
898 if (unlikely(user_mode(regs) &&
899 !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ),
900 addr, nb)))
901 return -EFAULT;
902
903 /* Force the fprs into the save area so we can reference them */
904 if (flags & F) {
905 /* userland only */
906 if (unlikely(!user_mode(regs)))
907 return 0;
908 flush_fp_to_thread(current);
909 }
910
911 if (nb == 16) {
912 if (flags & F) {
913 /* Special case for 16-byte FP loads and stores */
914 PPC_WARN_ALIGNMENT(fp_pair, regs);
915 return emulate_fp_pair(addr, reg, flags);
916 } else {
917 #ifdef CONFIG_PPC64
918 /* Special case for 16-byte loads and stores */
919 PPC_WARN_ALIGNMENT(lq_stq, regs);
920 return emulate_lq_stq(regs, addr, reg, flags);
921 #else
922 return 0;
923 #endif
924 }
925 }
926
927 PPC_WARN_ALIGNMENT(unaligned, regs);
928
929 /* If we are loading, get the data from user space, else
930 * get it from register values
931 */
932 if (!(flags & ST)) {
933 unsigned int start = 0;
934
935 switch (nb) {
936 case 4:
937 start = offsetof(union data, x32.low32);
938 break;
939 case 2:
940 start = offsetof(union data, x16.low16);
941 break;
942 }
943
944 data.ll = 0;
945 ret = 0;
946 p = (unsigned long)addr;
947
948 for (i = 0; i < nb; i++)
949 ret |= __get_user_inatomic(data.v[start + i],
950 SWIZ_PTR(p++));
951
952 if (unlikely(ret))
953 return -EFAULT;
954
955 } else if (flags & F) {
956 data.ll = current->thread.TS_FPR(reg);
957 if (flags & S) {
958 /* Single-precision FP store requires conversion... */
959 #ifdef CONFIG_PPC_FPU
960 preempt_disable();
961 enable_kernel_fp();
962 cvt_df(&data.dd, (float *)&data.x32.low32);
963 preempt_enable();
964 #else
965 return 0;
966 #endif
967 }
968 } else
969 data.ll = regs->gpr[reg];
970
971 if (flags & SW) {
972 switch (nb) {
973 case 8:
974 data.ll = swab64(data.ll);
975 break;
976 case 4:
977 data.x32.low32 = swab32(data.x32.low32);
978 break;
979 case 2:
980 data.x16.low16 = swab16(data.x16.low16);
981 break;
982 }
983 }
984
985 /* Perform other misc operations like sign extension
986 * or floating point single precision conversion
987 */
988 switch (flags & ~(U|SW)) {
989 case LD+SE: /* sign extending integer loads */
990 case LD+F+SE: /* sign extend for lfiwax */
991 if ( nb == 2 )
992 data.ll = data.x16.low16;
993 else /* nb must be 4 */
994 data.ll = data.x32.low32;
995 break;
996
997 /* Single-precision FP load requires conversion... */
998 case LD+F+S:
999 #ifdef CONFIG_PPC_FPU
1000 preempt_disable();
1001 enable_kernel_fp();
1002 cvt_fd((float *)&data.x32.low32, &data.dd);
1003 preempt_enable();
1004 #else
1005 return 0;
1006 #endif
1007 break;
1008 }
1009
1010 /* Store result to memory or update registers */
1011 if (flags & ST) {
1012 unsigned int start = 0;
1013
1014 switch (nb) {
1015 case 4:
1016 start = offsetof(union data, x32.low32);
1017 break;
1018 case 2:
1019 start = offsetof(union data, x16.low16);
1020 break;
1021 }
1022
1023 ret = 0;
1024 p = (unsigned long)addr;
1025
1026 for (i = 0; i < nb; i++)
1027 ret |= __put_user_inatomic(data.v[start + i],
1028 SWIZ_PTR(p++));
1029
1030 if (unlikely(ret))
1031 return -EFAULT;
1032 } else if (flags & F)
1033 current->thread.TS_FPR(reg) = data.ll;
1034 else
1035 regs->gpr[reg] = data.ll;
1036
1037 /* Update RA as needed */
1038 if (flags & U)
1039 regs->gpr[areg] = regs->dar;
1040
1041 return 1;
1042 }
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