xref: /linux/arch/powerpc/lib/sstep.c (revision 24bfa6a9e0d4fe414dfc4ad06c93e10c4c37194e)
1 /*
2  * Single-step support.
3  *
4  * Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 #include <linux/kernel.h>
12 #include <linux/kprobes.h>
13 #include <linux/ptrace.h>
14 #include <linux/prefetch.h>
15 #include <asm/sstep.h>
16 #include <asm/processor.h>
17 #include <asm/uaccess.h>
18 #include <asm/cputable.h>
19 
20 extern char system_call_common[];
21 
22 #ifdef CONFIG_PPC64
23 /* Bits in SRR1 that are copied from MSR */
24 #define MSR_MASK	0xffffffff87c0ffffUL
25 #else
26 #define MSR_MASK	0x87c0ffff
27 #endif
28 
29 /* Bits in XER */
30 #define XER_SO		0x80000000U
31 #define XER_OV		0x40000000U
32 #define XER_CA		0x20000000U
33 
34 #ifdef CONFIG_PPC_FPU
35 /*
36  * Functions in ldstfp.S
37  */
38 extern int do_lfs(int rn, unsigned long ea);
39 extern int do_lfd(int rn, unsigned long ea);
40 extern int do_stfs(int rn, unsigned long ea);
41 extern int do_stfd(int rn, unsigned long ea);
42 extern int do_lvx(int rn, unsigned long ea);
43 extern int do_stvx(int rn, unsigned long ea);
44 extern int do_lxvd2x(int rn, unsigned long ea);
45 extern int do_stxvd2x(int rn, unsigned long ea);
46 #endif
47 
48 /*
49  * Emulate the truncation of 64 bit values in 32-bit mode.
50  */
51 static unsigned long truncate_if_32bit(unsigned long msr, unsigned long val)
52 {
53 #ifdef __powerpc64__
54 	if ((msr & MSR_64BIT) == 0)
55 		val &= 0xffffffffUL;
56 #endif
57 	return val;
58 }
59 
60 /*
61  * Determine whether a conditional branch instruction would branch.
62  */
63 static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs)
64 {
65 	unsigned int bo = (instr >> 21) & 0x1f;
66 	unsigned int bi;
67 
68 	if ((bo & 4) == 0) {
69 		/* decrement counter */
70 		--regs->ctr;
71 		if (((bo >> 1) & 1) ^ (regs->ctr == 0))
72 			return 0;
73 	}
74 	if ((bo & 0x10) == 0) {
75 		/* check bit from CR */
76 		bi = (instr >> 16) & 0x1f;
77 		if (((regs->ccr >> (31 - bi)) & 1) != ((bo >> 3) & 1))
78 			return 0;
79 	}
80 	return 1;
81 }
82 
83 
84 static long __kprobes address_ok(struct pt_regs *regs, unsigned long ea, int nb)
85 {
86 	if (!user_mode(regs))
87 		return 1;
88 	return __access_ok(ea, nb, USER_DS);
89 }
90 
91 /*
92  * Calculate effective address for a D-form instruction
93  */
94 static unsigned long __kprobes dform_ea(unsigned int instr, struct pt_regs *regs)
95 {
96 	int ra;
97 	unsigned long ea;
98 
99 	ra = (instr >> 16) & 0x1f;
100 	ea = (signed short) instr;		/* sign-extend */
101 	if (ra)
102 		ea += regs->gpr[ra];
103 
104 	return truncate_if_32bit(regs->msr, ea);
105 }
106 
107 #ifdef __powerpc64__
108 /*
109  * Calculate effective address for a DS-form instruction
110  */
111 static unsigned long __kprobes dsform_ea(unsigned int instr, struct pt_regs *regs)
112 {
113 	int ra;
114 	unsigned long ea;
115 
116 	ra = (instr >> 16) & 0x1f;
117 	ea = (signed short) (instr & ~3);	/* sign-extend */
118 	if (ra)
119 		ea += regs->gpr[ra];
120 
121 	return truncate_if_32bit(regs->msr, ea);
122 }
123 #endif /* __powerpc64 */
124 
125 /*
126  * Calculate effective address for an X-form instruction
127  */
128 static unsigned long __kprobes xform_ea(unsigned int instr,
129 					struct pt_regs *regs)
130 {
131 	int ra, rb;
132 	unsigned long ea;
133 
134 	ra = (instr >> 16) & 0x1f;
135 	rb = (instr >> 11) & 0x1f;
136 	ea = regs->gpr[rb];
137 	if (ra)
138 		ea += regs->gpr[ra];
139 
140 	return truncate_if_32bit(regs->msr, ea);
141 }
142 
143 /*
144  * Return the largest power of 2, not greater than sizeof(unsigned long),
145  * such that x is a multiple of it.
146  */
147 static inline unsigned long max_align(unsigned long x)
148 {
149 	x |= sizeof(unsigned long);
150 	return x & -x;		/* isolates rightmost bit */
151 }
152 
153 
154 static inline unsigned long byterev_2(unsigned long x)
155 {
156 	return ((x >> 8) & 0xff) | ((x & 0xff) << 8);
157 }
158 
159 static inline unsigned long byterev_4(unsigned long x)
160 {
161 	return ((x >> 24) & 0xff) | ((x >> 8) & 0xff00) |
162 		((x & 0xff00) << 8) | ((x & 0xff) << 24);
163 }
164 
165 #ifdef __powerpc64__
166 static inline unsigned long byterev_8(unsigned long x)
167 {
168 	return (byterev_4(x) << 32) | byterev_4(x >> 32);
169 }
170 #endif
171 
172 static int __kprobes read_mem_aligned(unsigned long *dest, unsigned long ea,
173 				      int nb)
174 {
175 	int err = 0;
176 	unsigned long x = 0;
177 
178 	switch (nb) {
179 	case 1:
180 		err = __get_user(x, (unsigned char __user *) ea);
181 		break;
182 	case 2:
183 		err = __get_user(x, (unsigned short __user *) ea);
184 		break;
185 	case 4:
186 		err = __get_user(x, (unsigned int __user *) ea);
187 		break;
188 #ifdef __powerpc64__
189 	case 8:
190 		err = __get_user(x, (unsigned long __user *) ea);
191 		break;
192 #endif
193 	}
194 	if (!err)
195 		*dest = x;
196 	return err;
197 }
198 
199 static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
200 					int nb, struct pt_regs *regs)
201 {
202 	int err;
203 	unsigned long x, b, c;
204 #ifdef __LITTLE_ENDIAN__
205 	int len = nb; /* save a copy of the length for byte reversal */
206 #endif
207 
208 	/* unaligned, do this in pieces */
209 	x = 0;
210 	for (; nb > 0; nb -= c) {
211 #ifdef __LITTLE_ENDIAN__
212 		c = 1;
213 #endif
214 #ifdef __BIG_ENDIAN__
215 		c = max_align(ea);
216 #endif
217 		if (c > nb)
218 			c = max_align(nb);
219 		err = read_mem_aligned(&b, ea, c);
220 		if (err)
221 			return err;
222 		x = (x << (8 * c)) + b;
223 		ea += c;
224 	}
225 #ifdef __LITTLE_ENDIAN__
226 	switch (len) {
227 	case 2:
228 		*dest = byterev_2(x);
229 		break;
230 	case 4:
231 		*dest = byterev_4(x);
232 		break;
233 #ifdef __powerpc64__
234 	case 8:
235 		*dest = byterev_8(x);
236 		break;
237 #endif
238 	}
239 #endif
240 #ifdef __BIG_ENDIAN__
241 	*dest = x;
242 #endif
243 	return 0;
244 }
245 
246 /*
247  * Read memory at address ea for nb bytes, return 0 for success
248  * or -EFAULT if an error occurred.
249  */
250 static int __kprobes read_mem(unsigned long *dest, unsigned long ea, int nb,
251 			      struct pt_regs *regs)
252 {
253 	if (!address_ok(regs, ea, nb))
254 		return -EFAULT;
255 	if ((ea & (nb - 1)) == 0)
256 		return read_mem_aligned(dest, ea, nb);
257 	return read_mem_unaligned(dest, ea, nb, regs);
258 }
259 
260 static int __kprobes write_mem_aligned(unsigned long val, unsigned long ea,
261 				       int nb)
262 {
263 	int err = 0;
264 
265 	switch (nb) {
266 	case 1:
267 		err = __put_user(val, (unsigned char __user *) ea);
268 		break;
269 	case 2:
270 		err = __put_user(val, (unsigned short __user *) ea);
271 		break;
272 	case 4:
273 		err = __put_user(val, (unsigned int __user *) ea);
274 		break;
275 #ifdef __powerpc64__
276 	case 8:
277 		err = __put_user(val, (unsigned long __user *) ea);
278 		break;
279 #endif
280 	}
281 	return err;
282 }
283 
284 static int __kprobes write_mem_unaligned(unsigned long val, unsigned long ea,
285 					 int nb, struct pt_regs *regs)
286 {
287 	int err;
288 	unsigned long c;
289 
290 #ifdef __LITTLE_ENDIAN__
291 	switch (nb) {
292 	case 2:
293 		val = byterev_2(val);
294 		break;
295 	case 4:
296 		val = byterev_4(val);
297 		break;
298 #ifdef __powerpc64__
299 	case 8:
300 		val = byterev_8(val);
301 		break;
302 #endif
303 	}
304 #endif
305 	/* unaligned or little-endian, do this in pieces */
306 	for (; nb > 0; nb -= c) {
307 #ifdef __LITTLE_ENDIAN__
308 		c = 1;
309 #endif
310 #ifdef __BIG_ENDIAN__
311 		c = max_align(ea);
312 #endif
313 		if (c > nb)
314 			c = max_align(nb);
315 		err = write_mem_aligned(val >> (nb - c) * 8, ea, c);
316 		if (err)
317 			return err;
318 		ea += c;
319 	}
320 	return 0;
321 }
322 
323 /*
324  * Write memory at address ea for nb bytes, return 0 for success
325  * or -EFAULT if an error occurred.
326  */
327 static int __kprobes write_mem(unsigned long val, unsigned long ea, int nb,
328 			       struct pt_regs *regs)
329 {
330 	if (!address_ok(regs, ea, nb))
331 		return -EFAULT;
332 	if ((ea & (nb - 1)) == 0)
333 		return write_mem_aligned(val, ea, nb);
334 	return write_mem_unaligned(val, ea, nb, regs);
335 }
336 
337 #ifdef CONFIG_PPC_FPU
338 /*
339  * Check the address and alignment, and call func to do the actual
340  * load or store.
341  */
342 static int __kprobes do_fp_load(int rn, int (*func)(int, unsigned long),
343 				unsigned long ea, int nb,
344 				struct pt_regs *regs)
345 {
346 	int err;
347 	union {
348 		double dbl;
349 		unsigned long ul[2];
350 		struct {
351 #ifdef __BIG_ENDIAN__
352 			unsigned _pad_;
353 			unsigned word;
354 #endif
355 #ifdef __LITTLE_ENDIAN__
356 			unsigned word;
357 			unsigned _pad_;
358 #endif
359 		} single;
360 	} data;
361 	unsigned long ptr;
362 
363 	if (!address_ok(regs, ea, nb))
364 		return -EFAULT;
365 	if ((ea & 3) == 0)
366 		return (*func)(rn, ea);
367 	ptr = (unsigned long) &data.ul;
368 	if (sizeof(unsigned long) == 8 || nb == 4) {
369 		err = read_mem_unaligned(&data.ul[0], ea, nb, regs);
370 		if (nb == 4)
371 			ptr = (unsigned long)&(data.single.word);
372 	} else {
373 		/* reading a double on 32-bit */
374 		err = read_mem_unaligned(&data.ul[0], ea, 4, regs);
375 		if (!err)
376 			err = read_mem_unaligned(&data.ul[1], ea + 4, 4, regs);
377 	}
378 	if (err)
379 		return err;
380 	return (*func)(rn, ptr);
381 }
382 
383 static int __kprobes do_fp_store(int rn, int (*func)(int, unsigned long),
384 				 unsigned long ea, int nb,
385 				 struct pt_regs *regs)
386 {
387 	int err;
388 	union {
389 		double dbl;
390 		unsigned long ul[2];
391 		struct {
392 #ifdef __BIG_ENDIAN__
393 			unsigned _pad_;
394 			unsigned word;
395 #endif
396 #ifdef __LITTLE_ENDIAN__
397 			unsigned word;
398 			unsigned _pad_;
399 #endif
400 		} single;
401 	} data;
402 	unsigned long ptr;
403 
404 	if (!address_ok(regs, ea, nb))
405 		return -EFAULT;
406 	if ((ea & 3) == 0)
407 		return (*func)(rn, ea);
408 	ptr = (unsigned long) &data.ul[0];
409 	if (sizeof(unsigned long) == 8 || nb == 4) {
410 		if (nb == 4)
411 			ptr = (unsigned long)&(data.single.word);
412 		err = (*func)(rn, ptr);
413 		if (err)
414 			return err;
415 		err = write_mem_unaligned(data.ul[0], ea, nb, regs);
416 	} else {
417 		/* writing a double on 32-bit */
418 		err = (*func)(rn, ptr);
419 		if (err)
420 			return err;
421 		err = write_mem_unaligned(data.ul[0], ea, 4, regs);
422 		if (!err)
423 			err = write_mem_unaligned(data.ul[1], ea + 4, 4, regs);
424 	}
425 	return err;
426 }
427 #endif
428 
429 #ifdef CONFIG_ALTIVEC
430 /* For Altivec/VMX, no need to worry about alignment */
431 static int __kprobes do_vec_load(int rn, int (*func)(int, unsigned long),
432 				 unsigned long ea, struct pt_regs *regs)
433 {
434 	if (!address_ok(regs, ea & ~0xfUL, 16))
435 		return -EFAULT;
436 	return (*func)(rn, ea);
437 }
438 
439 static int __kprobes do_vec_store(int rn, int (*func)(int, unsigned long),
440 				  unsigned long ea, struct pt_regs *regs)
441 {
442 	if (!address_ok(regs, ea & ~0xfUL, 16))
443 		return -EFAULT;
444 	return (*func)(rn, ea);
445 }
446 #endif /* CONFIG_ALTIVEC */
447 
448 #ifdef CONFIG_VSX
449 static int __kprobes do_vsx_load(int rn, int (*func)(int, unsigned long),
450 				 unsigned long ea, struct pt_regs *regs)
451 {
452 	int err;
453 	unsigned long val[2];
454 
455 	if (!address_ok(regs, ea, 16))
456 		return -EFAULT;
457 	if ((ea & 3) == 0)
458 		return (*func)(rn, ea);
459 	err = read_mem_unaligned(&val[0], ea, 8, regs);
460 	if (!err)
461 		err = read_mem_unaligned(&val[1], ea + 8, 8, regs);
462 	if (!err)
463 		err = (*func)(rn, (unsigned long) &val[0]);
464 	return err;
465 }
466 
467 static int __kprobes do_vsx_store(int rn, int (*func)(int, unsigned long),
468 				 unsigned long ea, struct pt_regs *regs)
469 {
470 	int err;
471 	unsigned long val[2];
472 
473 	if (!address_ok(regs, ea, 16))
474 		return -EFAULT;
475 	if ((ea & 3) == 0)
476 		return (*func)(rn, ea);
477 	err = (*func)(rn, (unsigned long) &val[0]);
478 	if (err)
479 		return err;
480 	err = write_mem_unaligned(val[0], ea, 8, regs);
481 	if (!err)
482 		err = write_mem_unaligned(val[1], ea + 8, 8, regs);
483 	return err;
484 }
485 #endif /* CONFIG_VSX */
486 
487 #define __put_user_asmx(x, addr, err, op, cr)		\
488 	__asm__ __volatile__(				\
489 		"1:	" op " %2,0,%3\n"		\
490 		"	mfcr	%1\n"			\
491 		"2:\n"					\
492 		".section .fixup,\"ax\"\n"		\
493 		"3:	li	%0,%4\n"		\
494 		"	b	2b\n"			\
495 		".previous\n"				\
496 		EX_TABLE(1b, 3b)			\
497 		: "=r" (err), "=r" (cr)			\
498 		: "r" (x), "r" (addr), "i" (-EFAULT), "0" (err))
499 
500 #define __get_user_asmx(x, addr, err, op)		\
501 	__asm__ __volatile__(				\
502 		"1:	"op" %1,0,%2\n"			\
503 		"2:\n"					\
504 		".section .fixup,\"ax\"\n"		\
505 		"3:	li	%0,%3\n"		\
506 		"	b	2b\n"			\
507 		".previous\n"				\
508 		EX_TABLE(1b, 3b)			\
509 		: "=r" (err), "=r" (x)			\
510 		: "r" (addr), "i" (-EFAULT), "0" (err))
511 
512 #define __cacheop_user_asmx(addr, err, op)		\
513 	__asm__ __volatile__(				\
514 		"1:	"op" 0,%1\n"			\
515 		"2:\n"					\
516 		".section .fixup,\"ax\"\n"		\
517 		"3:	li	%0,%3\n"		\
518 		"	b	2b\n"			\
519 		".previous\n"				\
520 		EX_TABLE(1b, 3b)			\
521 		: "=r" (err)				\
522 		: "r" (addr), "i" (-EFAULT), "0" (err))
523 
524 static void __kprobes set_cr0(struct pt_regs *regs, int rd)
525 {
526 	long val = regs->gpr[rd];
527 
528 	regs->ccr = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000);
529 #ifdef __powerpc64__
530 	if (!(regs->msr & MSR_64BIT))
531 		val = (int) val;
532 #endif
533 	if (val < 0)
534 		regs->ccr |= 0x80000000;
535 	else if (val > 0)
536 		regs->ccr |= 0x40000000;
537 	else
538 		regs->ccr |= 0x20000000;
539 }
540 
541 static void __kprobes add_with_carry(struct pt_regs *regs, int rd,
542 				     unsigned long val1, unsigned long val2,
543 				     unsigned long carry_in)
544 {
545 	unsigned long val = val1 + val2;
546 
547 	if (carry_in)
548 		++val;
549 	regs->gpr[rd] = val;
550 #ifdef __powerpc64__
551 	if (!(regs->msr & MSR_64BIT)) {
552 		val = (unsigned int) val;
553 		val1 = (unsigned int) val1;
554 	}
555 #endif
556 	if (val < val1 || (carry_in && val == val1))
557 		regs->xer |= XER_CA;
558 	else
559 		regs->xer &= ~XER_CA;
560 }
561 
562 static void __kprobes do_cmp_signed(struct pt_regs *regs, long v1, long v2,
563 				    int crfld)
564 {
565 	unsigned int crval, shift;
566 
567 	crval = (regs->xer >> 31) & 1;		/* get SO bit */
568 	if (v1 < v2)
569 		crval |= 8;
570 	else if (v1 > v2)
571 		crval |= 4;
572 	else
573 		crval |= 2;
574 	shift = (7 - crfld) * 4;
575 	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
576 }
577 
578 static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
579 				      unsigned long v2, int crfld)
580 {
581 	unsigned int crval, shift;
582 
583 	crval = (regs->xer >> 31) & 1;		/* get SO bit */
584 	if (v1 < v2)
585 		crval |= 8;
586 	else if (v1 > v2)
587 		crval |= 4;
588 	else
589 		crval |= 2;
590 	shift = (7 - crfld) * 4;
591 	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
592 }
593 
594 static int __kprobes trap_compare(long v1, long v2)
595 {
596 	int ret = 0;
597 
598 	if (v1 < v2)
599 		ret |= 0x10;
600 	else if (v1 > v2)
601 		ret |= 0x08;
602 	else
603 		ret |= 0x04;
604 	if ((unsigned long)v1 < (unsigned long)v2)
605 		ret |= 0x02;
606 	else if ((unsigned long)v1 > (unsigned long)v2)
607 		ret |= 0x01;
608 	return ret;
609 }
610 
611 /*
612  * Elements of 32-bit rotate and mask instructions.
613  */
614 #define MASK32(mb, me)	((0xffffffffUL >> (mb)) + \
615 			 ((signed long)-0x80000000L >> (me)) + ((me) >= (mb)))
616 #ifdef __powerpc64__
617 #define MASK64_L(mb)	(~0UL >> (mb))
618 #define MASK64_R(me)	((signed long)-0x8000000000000000L >> (me))
619 #define MASK64(mb, me)	(MASK64_L(mb) + MASK64_R(me) + ((me) >= (mb)))
620 #define DATA32(x)	(((x) & 0xffffffffUL) | (((x) & 0xffffffffUL) << 32))
621 #else
622 #define DATA32(x)	(x)
623 #endif
624 #define ROTATE(x, n)	((n) ? (((x) << (n)) | ((x) >> (8 * sizeof(long) - (n)))) : (x))
625 
626 /*
627  * Decode an instruction, and execute it if that can be done just by
628  * modifying *regs (i.e. integer arithmetic and logical instructions,
629  * branches, and barrier instructions).
630  * Returns 1 if the instruction has been executed, or 0 if not.
631  * Sets *op to indicate what the instruction does.
632  */
633 int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
634 			    unsigned int instr)
635 {
636 	unsigned int opcode, ra, rb, rd, spr, u;
637 	unsigned long int imm;
638 	unsigned long int val, val2;
639 	unsigned int mb, me, sh;
640 	long ival;
641 
642 	op->type = COMPUTE;
643 
644 	opcode = instr >> 26;
645 	switch (opcode) {
646 	case 16:	/* bc */
647 		op->type = BRANCH;
648 		imm = (signed short)(instr & 0xfffc);
649 		if ((instr & 2) == 0)
650 			imm += regs->nip;
651 		regs->nip += 4;
652 		regs->nip = truncate_if_32bit(regs->msr, regs->nip);
653 		if (instr & 1)
654 			regs->link = regs->nip;
655 		if (branch_taken(instr, regs))
656 			regs->nip = truncate_if_32bit(regs->msr, imm);
657 		return 1;
658 #ifdef CONFIG_PPC64
659 	case 17:	/* sc */
660 		if ((instr & 0xfe2) == 2)
661 			op->type = SYSCALL;
662 		else
663 			op->type = UNKNOWN;
664 		return 0;
665 #endif
666 	case 18:	/* b */
667 		op->type = BRANCH;
668 		imm = instr & 0x03fffffc;
669 		if (imm & 0x02000000)
670 			imm -= 0x04000000;
671 		if ((instr & 2) == 0)
672 			imm += regs->nip;
673 		if (instr & 1)
674 			regs->link = truncate_if_32bit(regs->msr, regs->nip + 4);
675 		imm = truncate_if_32bit(regs->msr, imm);
676 		regs->nip = imm;
677 		return 1;
678 	case 19:
679 		switch ((instr >> 1) & 0x3ff) {
680 		case 0:		/* mcrf */
681 			rd = (instr >> 21) & 0x1c;
682 			ra = (instr >> 16) & 0x1c;
683 			val = (regs->ccr >> ra) & 0xf;
684 			regs->ccr = (regs->ccr & ~(0xfUL << rd)) | (val << rd);
685 			goto instr_done;
686 
687 		case 16:	/* bclr */
688 		case 528:	/* bcctr */
689 			op->type = BRANCH;
690 			imm = (instr & 0x400)? regs->ctr: regs->link;
691 			regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
692 			imm = truncate_if_32bit(regs->msr, imm);
693 			if (instr & 1)
694 				regs->link = regs->nip;
695 			if (branch_taken(instr, regs))
696 				regs->nip = imm;
697 			return 1;
698 
699 		case 18:	/* rfid, scary */
700 			if (regs->msr & MSR_PR)
701 				goto priv;
702 			op->type = RFI;
703 			return 0;
704 
705 		case 150:	/* isync */
706 			op->type = BARRIER;
707 			isync();
708 			goto instr_done;
709 
710 		case 33:	/* crnor */
711 		case 129:	/* crandc */
712 		case 193:	/* crxor */
713 		case 225:	/* crnand */
714 		case 257:	/* crand */
715 		case 289:	/* creqv */
716 		case 417:	/* crorc */
717 		case 449:	/* cror */
718 			ra = (instr >> 16) & 0x1f;
719 			rb = (instr >> 11) & 0x1f;
720 			rd = (instr >> 21) & 0x1f;
721 			ra = (regs->ccr >> (31 - ra)) & 1;
722 			rb = (regs->ccr >> (31 - rb)) & 1;
723 			val = (instr >> (6 + ra * 2 + rb)) & 1;
724 			regs->ccr = (regs->ccr & ~(1UL << (31 - rd))) |
725 				(val << (31 - rd));
726 			goto instr_done;
727 		}
728 		break;
729 	case 31:
730 		switch ((instr >> 1) & 0x3ff) {
731 		case 598:	/* sync */
732 			op->type = BARRIER;
733 #ifdef __powerpc64__
734 			switch ((instr >> 21) & 3) {
735 			case 1:		/* lwsync */
736 				asm volatile("lwsync" : : : "memory");
737 				goto instr_done;
738 			case 2:		/* ptesync */
739 				asm volatile("ptesync" : : : "memory");
740 				goto instr_done;
741 			}
742 #endif
743 			mb();
744 			goto instr_done;
745 
746 		case 854:	/* eieio */
747 			op->type = BARRIER;
748 			eieio();
749 			goto instr_done;
750 		}
751 		break;
752 	}
753 
754 	/* Following cases refer to regs->gpr[], so we need all regs */
755 	if (!FULL_REGS(regs))
756 		return 0;
757 
758 	rd = (instr >> 21) & 0x1f;
759 	ra = (instr >> 16) & 0x1f;
760 	rb = (instr >> 11) & 0x1f;
761 
762 	switch (opcode) {
763 #ifdef __powerpc64__
764 	case 2:		/* tdi */
765 		if (rd & trap_compare(regs->gpr[ra], (short) instr))
766 			goto trap;
767 		goto instr_done;
768 #endif
769 	case 3:		/* twi */
770 		if (rd & trap_compare((int)regs->gpr[ra], (short) instr))
771 			goto trap;
772 		goto instr_done;
773 
774 	case 7:		/* mulli */
775 		regs->gpr[rd] = regs->gpr[ra] * (short) instr;
776 		goto instr_done;
777 
778 	case 8:		/* subfic */
779 		imm = (short) instr;
780 		add_with_carry(regs, rd, ~regs->gpr[ra], imm, 1);
781 		goto instr_done;
782 
783 	case 10:	/* cmpli */
784 		imm = (unsigned short) instr;
785 		val = regs->gpr[ra];
786 #ifdef __powerpc64__
787 		if ((rd & 1) == 0)
788 			val = (unsigned int) val;
789 #endif
790 		do_cmp_unsigned(regs, val, imm, rd >> 2);
791 		goto instr_done;
792 
793 	case 11:	/* cmpi */
794 		imm = (short) instr;
795 		val = regs->gpr[ra];
796 #ifdef __powerpc64__
797 		if ((rd & 1) == 0)
798 			val = (int) val;
799 #endif
800 		do_cmp_signed(regs, val, imm, rd >> 2);
801 		goto instr_done;
802 
803 	case 12:	/* addic */
804 		imm = (short) instr;
805 		add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
806 		goto instr_done;
807 
808 	case 13:	/* addic. */
809 		imm = (short) instr;
810 		add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
811 		set_cr0(regs, rd);
812 		goto instr_done;
813 
814 	case 14:	/* addi */
815 		imm = (short) instr;
816 		if (ra)
817 			imm += regs->gpr[ra];
818 		regs->gpr[rd] = imm;
819 		goto instr_done;
820 
821 	case 15:	/* addis */
822 		imm = ((short) instr) << 16;
823 		if (ra)
824 			imm += regs->gpr[ra];
825 		regs->gpr[rd] = imm;
826 		goto instr_done;
827 
828 	case 20:	/* rlwimi */
829 		mb = (instr >> 6) & 0x1f;
830 		me = (instr >> 1) & 0x1f;
831 		val = DATA32(regs->gpr[rd]);
832 		imm = MASK32(mb, me);
833 		regs->gpr[ra] = (regs->gpr[ra] & ~imm) | (ROTATE(val, rb) & imm);
834 		goto logical_done;
835 
836 	case 21:	/* rlwinm */
837 		mb = (instr >> 6) & 0x1f;
838 		me = (instr >> 1) & 0x1f;
839 		val = DATA32(regs->gpr[rd]);
840 		regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
841 		goto logical_done;
842 
843 	case 23:	/* rlwnm */
844 		mb = (instr >> 6) & 0x1f;
845 		me = (instr >> 1) & 0x1f;
846 		rb = regs->gpr[rb] & 0x1f;
847 		val = DATA32(regs->gpr[rd]);
848 		regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
849 		goto logical_done;
850 
851 	case 24:	/* ori */
852 		imm = (unsigned short) instr;
853 		regs->gpr[ra] = regs->gpr[rd] | imm;
854 		goto instr_done;
855 
856 	case 25:	/* oris */
857 		imm = (unsigned short) instr;
858 		regs->gpr[ra] = regs->gpr[rd] | (imm << 16);
859 		goto instr_done;
860 
861 	case 26:	/* xori */
862 		imm = (unsigned short) instr;
863 		regs->gpr[ra] = regs->gpr[rd] ^ imm;
864 		goto instr_done;
865 
866 	case 27:	/* xoris */
867 		imm = (unsigned short) instr;
868 		regs->gpr[ra] = regs->gpr[rd] ^ (imm << 16);
869 		goto instr_done;
870 
871 	case 28:	/* andi. */
872 		imm = (unsigned short) instr;
873 		regs->gpr[ra] = regs->gpr[rd] & imm;
874 		set_cr0(regs, ra);
875 		goto instr_done;
876 
877 	case 29:	/* andis. */
878 		imm = (unsigned short) instr;
879 		regs->gpr[ra] = regs->gpr[rd] & (imm << 16);
880 		set_cr0(regs, ra);
881 		goto instr_done;
882 
883 #ifdef __powerpc64__
884 	case 30:	/* rld* */
885 		mb = ((instr >> 6) & 0x1f) | (instr & 0x20);
886 		val = regs->gpr[rd];
887 		if ((instr & 0x10) == 0) {
888 			sh = rb | ((instr & 2) << 4);
889 			val = ROTATE(val, sh);
890 			switch ((instr >> 2) & 3) {
891 			case 0:		/* rldicl */
892 				regs->gpr[ra] = val & MASK64_L(mb);
893 				goto logical_done;
894 			case 1:		/* rldicr */
895 				regs->gpr[ra] = val & MASK64_R(mb);
896 				goto logical_done;
897 			case 2:		/* rldic */
898 				regs->gpr[ra] = val & MASK64(mb, 63 - sh);
899 				goto logical_done;
900 			case 3:		/* rldimi */
901 				imm = MASK64(mb, 63 - sh);
902 				regs->gpr[ra] = (regs->gpr[ra] & ~imm) |
903 					(val & imm);
904 				goto logical_done;
905 			}
906 		} else {
907 			sh = regs->gpr[rb] & 0x3f;
908 			val = ROTATE(val, sh);
909 			switch ((instr >> 1) & 7) {
910 			case 0:		/* rldcl */
911 				regs->gpr[ra] = val & MASK64_L(mb);
912 				goto logical_done;
913 			case 1:		/* rldcr */
914 				regs->gpr[ra] = val & MASK64_R(mb);
915 				goto logical_done;
916 			}
917 		}
918 #endif
919 	break; /* illegal instruction */
920 
921 	case 31:
922 		switch ((instr >> 1) & 0x3ff) {
923 		case 4:		/* tw */
924 			if (rd == 0x1f ||
925 			    (rd & trap_compare((int)regs->gpr[ra],
926 					       (int)regs->gpr[rb])))
927 				goto trap;
928 			goto instr_done;
929 #ifdef __powerpc64__
930 		case 68:	/* td */
931 			if (rd & trap_compare(regs->gpr[ra], regs->gpr[rb]))
932 				goto trap;
933 			goto instr_done;
934 #endif
935 		case 83:	/* mfmsr */
936 			if (regs->msr & MSR_PR)
937 				goto priv;
938 			op->type = MFMSR;
939 			op->reg = rd;
940 			return 0;
941 		case 146:	/* mtmsr */
942 			if (regs->msr & MSR_PR)
943 				goto priv;
944 			op->type = MTMSR;
945 			op->reg = rd;
946 			op->val = 0xffffffff & ~(MSR_ME | MSR_LE);
947 			return 0;
948 #ifdef CONFIG_PPC64
949 		case 178:	/* mtmsrd */
950 			if (regs->msr & MSR_PR)
951 				goto priv;
952 			op->type = MTMSR;
953 			op->reg = rd;
954 			/* only MSR_EE and MSR_RI get changed if bit 15 set */
955 			/* mtmsrd doesn't change MSR_HV, MSR_ME or MSR_LE */
956 			imm = (instr & 0x10000)? 0x8002: 0xefffffffffffeffeUL;
957 			op->val = imm;
958 			return 0;
959 #endif
960 
961 		case 19:	/* mfcr */
962 			regs->gpr[rd] = regs->ccr;
963 			regs->gpr[rd] &= 0xffffffffUL;
964 			goto instr_done;
965 
966 		case 144:	/* mtcrf */
967 			imm = 0xf0000000UL;
968 			val = regs->gpr[rd];
969 			for (sh = 0; sh < 8; ++sh) {
970 				if (instr & (0x80000 >> sh))
971 					regs->ccr = (regs->ccr & ~imm) |
972 						(val & imm);
973 				imm >>= 4;
974 			}
975 			goto instr_done;
976 
977 		case 339:	/* mfspr */
978 			spr = ((instr >> 16) & 0x1f) | ((instr >> 6) & 0x3e0);
979 			switch (spr) {
980 			case SPRN_XER:	/* mfxer */
981 				regs->gpr[rd] = regs->xer;
982 				regs->gpr[rd] &= 0xffffffffUL;
983 				goto instr_done;
984 			case SPRN_LR:	/* mflr */
985 				regs->gpr[rd] = regs->link;
986 				goto instr_done;
987 			case SPRN_CTR:	/* mfctr */
988 				regs->gpr[rd] = regs->ctr;
989 				goto instr_done;
990 			default:
991 				op->type = MFSPR;
992 				op->reg = rd;
993 				op->spr = spr;
994 				return 0;
995 			}
996 			break;
997 
998 		case 467:	/* mtspr */
999 			spr = ((instr >> 16) & 0x1f) | ((instr >> 6) & 0x3e0);
1000 			switch (spr) {
1001 			case SPRN_XER:	/* mtxer */
1002 				regs->xer = (regs->gpr[rd] & 0xffffffffUL);
1003 				goto instr_done;
1004 			case SPRN_LR:	/* mtlr */
1005 				regs->link = regs->gpr[rd];
1006 				goto instr_done;
1007 			case SPRN_CTR:	/* mtctr */
1008 				regs->ctr = regs->gpr[rd];
1009 				goto instr_done;
1010 			default:
1011 				op->type = MTSPR;
1012 				op->val = regs->gpr[rd];
1013 				op->spr = spr;
1014 				return 0;
1015 			}
1016 			break;
1017 
1018 /*
1019  * Compare instructions
1020  */
1021 		case 0:	/* cmp */
1022 			val = regs->gpr[ra];
1023 			val2 = regs->gpr[rb];
1024 #ifdef __powerpc64__
1025 			if ((rd & 1) == 0) {
1026 				/* word (32-bit) compare */
1027 				val = (int) val;
1028 				val2 = (int) val2;
1029 			}
1030 #endif
1031 			do_cmp_signed(regs, val, val2, rd >> 2);
1032 			goto instr_done;
1033 
1034 		case 32:	/* cmpl */
1035 			val = regs->gpr[ra];
1036 			val2 = regs->gpr[rb];
1037 #ifdef __powerpc64__
1038 			if ((rd & 1) == 0) {
1039 				/* word (32-bit) compare */
1040 				val = (unsigned int) val;
1041 				val2 = (unsigned int) val2;
1042 			}
1043 #endif
1044 			do_cmp_unsigned(regs, val, val2, rd >> 2);
1045 			goto instr_done;
1046 
1047 /*
1048  * Arithmetic instructions
1049  */
1050 		case 8:	/* subfc */
1051 			add_with_carry(regs, rd, ~regs->gpr[ra],
1052 				       regs->gpr[rb], 1);
1053 			goto arith_done;
1054 #ifdef __powerpc64__
1055 		case 9:	/* mulhdu */
1056 			asm("mulhdu %0,%1,%2" : "=r" (regs->gpr[rd]) :
1057 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1058 			goto arith_done;
1059 #endif
1060 		case 10:	/* addc */
1061 			add_with_carry(regs, rd, regs->gpr[ra],
1062 				       regs->gpr[rb], 0);
1063 			goto arith_done;
1064 
1065 		case 11:	/* mulhwu */
1066 			asm("mulhwu %0,%1,%2" : "=r" (regs->gpr[rd]) :
1067 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1068 			goto arith_done;
1069 
1070 		case 40:	/* subf */
1071 			regs->gpr[rd] = regs->gpr[rb] - regs->gpr[ra];
1072 			goto arith_done;
1073 #ifdef __powerpc64__
1074 		case 73:	/* mulhd */
1075 			asm("mulhd %0,%1,%2" : "=r" (regs->gpr[rd]) :
1076 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1077 			goto arith_done;
1078 #endif
1079 		case 75:	/* mulhw */
1080 			asm("mulhw %0,%1,%2" : "=r" (regs->gpr[rd]) :
1081 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1082 			goto arith_done;
1083 
1084 		case 104:	/* neg */
1085 			regs->gpr[rd] = -regs->gpr[ra];
1086 			goto arith_done;
1087 
1088 		case 136:	/* subfe */
1089 			add_with_carry(regs, rd, ~regs->gpr[ra], regs->gpr[rb],
1090 				       regs->xer & XER_CA);
1091 			goto arith_done;
1092 
1093 		case 138:	/* adde */
1094 			add_with_carry(regs, rd, regs->gpr[ra], regs->gpr[rb],
1095 				       regs->xer & XER_CA);
1096 			goto arith_done;
1097 
1098 		case 200:	/* subfze */
1099 			add_with_carry(regs, rd, ~regs->gpr[ra], 0L,
1100 				       regs->xer & XER_CA);
1101 			goto arith_done;
1102 
1103 		case 202:	/* addze */
1104 			add_with_carry(regs, rd, regs->gpr[ra], 0L,
1105 				       regs->xer & XER_CA);
1106 			goto arith_done;
1107 
1108 		case 232:	/* subfme */
1109 			add_with_carry(regs, rd, ~regs->gpr[ra], -1L,
1110 				       regs->xer & XER_CA);
1111 			goto arith_done;
1112 #ifdef __powerpc64__
1113 		case 233:	/* mulld */
1114 			regs->gpr[rd] = regs->gpr[ra] * regs->gpr[rb];
1115 			goto arith_done;
1116 #endif
1117 		case 234:	/* addme */
1118 			add_with_carry(regs, rd, regs->gpr[ra], -1L,
1119 				       regs->xer & XER_CA);
1120 			goto arith_done;
1121 
1122 		case 235:	/* mullw */
1123 			regs->gpr[rd] = (unsigned int) regs->gpr[ra] *
1124 				(unsigned int) regs->gpr[rb];
1125 			goto arith_done;
1126 
1127 		case 266:	/* add */
1128 			regs->gpr[rd] = regs->gpr[ra] + regs->gpr[rb];
1129 			goto arith_done;
1130 #ifdef __powerpc64__
1131 		case 457:	/* divdu */
1132 			regs->gpr[rd] = regs->gpr[ra] / regs->gpr[rb];
1133 			goto arith_done;
1134 #endif
1135 		case 459:	/* divwu */
1136 			regs->gpr[rd] = (unsigned int) regs->gpr[ra] /
1137 				(unsigned int) regs->gpr[rb];
1138 			goto arith_done;
1139 #ifdef __powerpc64__
1140 		case 489:	/* divd */
1141 			regs->gpr[rd] = (long int) regs->gpr[ra] /
1142 				(long int) regs->gpr[rb];
1143 			goto arith_done;
1144 #endif
1145 		case 491:	/* divw */
1146 			regs->gpr[rd] = (int) regs->gpr[ra] /
1147 				(int) regs->gpr[rb];
1148 			goto arith_done;
1149 
1150 
1151 /*
1152  * Logical instructions
1153  */
1154 		case 26:	/* cntlzw */
1155 			asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) :
1156 			    "r" (regs->gpr[rd]));
1157 			goto logical_done;
1158 #ifdef __powerpc64__
1159 		case 58:	/* cntlzd */
1160 			asm("cntlzd %0,%1" : "=r" (regs->gpr[ra]) :
1161 			    "r" (regs->gpr[rd]));
1162 			goto logical_done;
1163 #endif
1164 		case 28:	/* and */
1165 			regs->gpr[ra] = regs->gpr[rd] & regs->gpr[rb];
1166 			goto logical_done;
1167 
1168 		case 60:	/* andc */
1169 			regs->gpr[ra] = regs->gpr[rd] & ~regs->gpr[rb];
1170 			goto logical_done;
1171 
1172 		case 124:	/* nor */
1173 			regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]);
1174 			goto logical_done;
1175 
1176 		case 284:	/* xor */
1177 			regs->gpr[ra] = ~(regs->gpr[rd] ^ regs->gpr[rb]);
1178 			goto logical_done;
1179 
1180 		case 316:	/* xor */
1181 			regs->gpr[ra] = regs->gpr[rd] ^ regs->gpr[rb];
1182 			goto logical_done;
1183 
1184 		case 412:	/* orc */
1185 			regs->gpr[ra] = regs->gpr[rd] | ~regs->gpr[rb];
1186 			goto logical_done;
1187 
1188 		case 444:	/* or */
1189 			regs->gpr[ra] = regs->gpr[rd] | regs->gpr[rb];
1190 			goto logical_done;
1191 
1192 		case 476:	/* nand */
1193 			regs->gpr[ra] = ~(regs->gpr[rd] & regs->gpr[rb]);
1194 			goto logical_done;
1195 
1196 		case 922:	/* extsh */
1197 			regs->gpr[ra] = (signed short) regs->gpr[rd];
1198 			goto logical_done;
1199 
1200 		case 954:	/* extsb */
1201 			regs->gpr[ra] = (signed char) regs->gpr[rd];
1202 			goto logical_done;
1203 #ifdef __powerpc64__
1204 		case 986:	/* extsw */
1205 			regs->gpr[ra] = (signed int) regs->gpr[rd];
1206 			goto logical_done;
1207 #endif
1208 
1209 /*
1210  * Shift instructions
1211  */
1212 		case 24:	/* slw */
1213 			sh = regs->gpr[rb] & 0x3f;
1214 			if (sh < 32)
1215 				regs->gpr[ra] = (regs->gpr[rd] << sh) & 0xffffffffUL;
1216 			else
1217 				regs->gpr[ra] = 0;
1218 			goto logical_done;
1219 
1220 		case 536:	/* srw */
1221 			sh = regs->gpr[rb] & 0x3f;
1222 			if (sh < 32)
1223 				regs->gpr[ra] = (regs->gpr[rd] & 0xffffffffUL) >> sh;
1224 			else
1225 				regs->gpr[ra] = 0;
1226 			goto logical_done;
1227 
1228 		case 792:	/* sraw */
1229 			sh = regs->gpr[rb] & 0x3f;
1230 			ival = (signed int) regs->gpr[rd];
1231 			regs->gpr[ra] = ival >> (sh < 32 ? sh : 31);
1232 			if (ival < 0 && (sh >= 32 || (ival & ((1ul << sh) - 1)) != 0))
1233 				regs->xer |= XER_CA;
1234 			else
1235 				regs->xer &= ~XER_CA;
1236 			goto logical_done;
1237 
1238 		case 824:	/* srawi */
1239 			sh = rb;
1240 			ival = (signed int) regs->gpr[rd];
1241 			regs->gpr[ra] = ival >> sh;
1242 			if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0)
1243 				regs->xer |= XER_CA;
1244 			else
1245 				regs->xer &= ~XER_CA;
1246 			goto logical_done;
1247 
1248 #ifdef __powerpc64__
1249 		case 27:	/* sld */
1250 			sh = regs->gpr[rb] & 0x7f;
1251 			if (sh < 64)
1252 				regs->gpr[ra] = regs->gpr[rd] << sh;
1253 			else
1254 				regs->gpr[ra] = 0;
1255 			goto logical_done;
1256 
1257 		case 539:	/* srd */
1258 			sh = regs->gpr[rb] & 0x7f;
1259 			if (sh < 64)
1260 				regs->gpr[ra] = regs->gpr[rd] >> sh;
1261 			else
1262 				regs->gpr[ra] = 0;
1263 			goto logical_done;
1264 
1265 		case 794:	/* srad */
1266 			sh = regs->gpr[rb] & 0x7f;
1267 			ival = (signed long int) regs->gpr[rd];
1268 			regs->gpr[ra] = ival >> (sh < 64 ? sh : 63);
1269 			if (ival < 0 && (sh >= 64 || (ival & ((1ul << sh) - 1)) != 0))
1270 				regs->xer |= XER_CA;
1271 			else
1272 				regs->xer &= ~XER_CA;
1273 			goto logical_done;
1274 
1275 		case 826:	/* sradi with sh_5 = 0 */
1276 		case 827:	/* sradi with sh_5 = 1 */
1277 			sh = rb | ((instr & 2) << 4);
1278 			ival = (signed long int) regs->gpr[rd];
1279 			regs->gpr[ra] = ival >> sh;
1280 			if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0)
1281 				regs->xer |= XER_CA;
1282 			else
1283 				regs->xer &= ~XER_CA;
1284 			goto logical_done;
1285 #endif /* __powerpc64__ */
1286 
1287 /*
1288  * Cache instructions
1289  */
1290 		case 54:	/* dcbst */
1291 			op->type = MKOP(CACHEOP, DCBST, 0);
1292 			op->ea = xform_ea(instr, regs);
1293 			return 0;
1294 
1295 		case 86:	/* dcbf */
1296 			op->type = MKOP(CACHEOP, DCBF, 0);
1297 			op->ea = xform_ea(instr, regs);
1298 			return 0;
1299 
1300 		case 246:	/* dcbtst */
1301 			op->type = MKOP(CACHEOP, DCBTST, 0);
1302 			op->ea = xform_ea(instr, regs);
1303 			op->reg = rd;
1304 			return 0;
1305 
1306 		case 278:	/* dcbt */
1307 			op->type = MKOP(CACHEOP, DCBTST, 0);
1308 			op->ea = xform_ea(instr, regs);
1309 			op->reg = rd;
1310 			return 0;
1311 
1312 		case 982:	/* icbi */
1313 			op->type = MKOP(CACHEOP, ICBI, 0);
1314 			op->ea = xform_ea(instr, regs);
1315 			return 0;
1316 		}
1317 		break;
1318 	}
1319 
1320 	/*
1321 	 * Loads and stores.
1322 	 */
1323 	op->type = UNKNOWN;
1324 	op->update_reg = ra;
1325 	op->reg = rd;
1326 	op->val = regs->gpr[rd];
1327 	u = (instr >> 20) & UPDATE;
1328 
1329 	switch (opcode) {
1330 	case 31:
1331 		u = instr & UPDATE;
1332 		op->ea = xform_ea(instr, regs);
1333 		switch ((instr >> 1) & 0x3ff) {
1334 		case 20:	/* lwarx */
1335 			op->type = MKOP(LARX, 0, 4);
1336 			break;
1337 
1338 		case 150:	/* stwcx. */
1339 			op->type = MKOP(STCX, 0, 4);
1340 			break;
1341 
1342 #ifdef __powerpc64__
1343 		case 84:	/* ldarx */
1344 			op->type = MKOP(LARX, 0, 8);
1345 			break;
1346 
1347 		case 214:	/* stdcx. */
1348 			op->type = MKOP(STCX, 0, 8);
1349 			break;
1350 
1351 		case 21:	/* ldx */
1352 		case 53:	/* ldux */
1353 			op->type = MKOP(LOAD, u, 8);
1354 			break;
1355 #endif
1356 
1357 		case 23:	/* lwzx */
1358 		case 55:	/* lwzux */
1359 			op->type = MKOP(LOAD, u, 4);
1360 			break;
1361 
1362 		case 87:	/* lbzx */
1363 		case 119:	/* lbzux */
1364 			op->type = MKOP(LOAD, u, 1);
1365 			break;
1366 
1367 #ifdef CONFIG_ALTIVEC
1368 		case 103:	/* lvx */
1369 		case 359:	/* lvxl */
1370 			if (!(regs->msr & MSR_VEC))
1371 				goto vecunavail;
1372 			op->type = MKOP(LOAD_VMX, 0, 16);
1373 			break;
1374 
1375 		case 231:	/* stvx */
1376 		case 487:	/* stvxl */
1377 			if (!(regs->msr & MSR_VEC))
1378 				goto vecunavail;
1379 			op->type = MKOP(STORE_VMX, 0, 16);
1380 			break;
1381 #endif /* CONFIG_ALTIVEC */
1382 
1383 #ifdef __powerpc64__
1384 		case 149:	/* stdx */
1385 		case 181:	/* stdux */
1386 			op->type = MKOP(STORE, u, 8);
1387 			break;
1388 #endif
1389 
1390 		case 151:	/* stwx */
1391 		case 183:	/* stwux */
1392 			op->type = MKOP(STORE, u, 4);
1393 			break;
1394 
1395 		case 215:	/* stbx */
1396 		case 247:	/* stbux */
1397 			op->type = MKOP(STORE, u, 1);
1398 			break;
1399 
1400 		case 279:	/* lhzx */
1401 		case 311:	/* lhzux */
1402 			op->type = MKOP(LOAD, u, 2);
1403 			break;
1404 
1405 #ifdef __powerpc64__
1406 		case 341:	/* lwax */
1407 		case 373:	/* lwaux */
1408 			op->type = MKOP(LOAD, SIGNEXT | u, 4);
1409 			break;
1410 #endif
1411 
1412 		case 343:	/* lhax */
1413 		case 375:	/* lhaux */
1414 			op->type = MKOP(LOAD, SIGNEXT | u, 2);
1415 			break;
1416 
1417 		case 407:	/* sthx */
1418 		case 439:	/* sthux */
1419 			op->type = MKOP(STORE, u, 2);
1420 			break;
1421 
1422 #ifdef __powerpc64__
1423 		case 532:	/* ldbrx */
1424 			op->type = MKOP(LOAD, BYTEREV, 8);
1425 			break;
1426 
1427 #endif
1428 		case 533:	/* lswx */
1429 			op->type = MKOP(LOAD_MULTI, 0, regs->xer & 0x7f);
1430 			break;
1431 
1432 		case 534:	/* lwbrx */
1433 			op->type = MKOP(LOAD, BYTEREV, 4);
1434 			break;
1435 
1436 		case 597:	/* lswi */
1437 			if (rb == 0)
1438 				rb = 32;	/* # bytes to load */
1439 			op->type = MKOP(LOAD_MULTI, 0, rb);
1440 			op->ea = 0;
1441 			if (ra)
1442 				op->ea = truncate_if_32bit(regs->msr,
1443 							   regs->gpr[ra]);
1444 			break;
1445 
1446 #ifdef CONFIG_PPC_FPU
1447 		case 535:	/* lfsx */
1448 		case 567:	/* lfsux */
1449 			if (!(regs->msr & MSR_FP))
1450 				goto fpunavail;
1451 			op->type = MKOP(LOAD_FP, u, 4);
1452 			break;
1453 
1454 		case 599:	/* lfdx */
1455 		case 631:	/* lfdux */
1456 			if (!(regs->msr & MSR_FP))
1457 				goto fpunavail;
1458 			op->type = MKOP(LOAD_FP, u, 8);
1459 			break;
1460 
1461 		case 663:	/* stfsx */
1462 		case 695:	/* stfsux */
1463 			if (!(regs->msr & MSR_FP))
1464 				goto fpunavail;
1465 			op->type = MKOP(STORE_FP, u, 4);
1466 			break;
1467 
1468 		case 727:	/* stfdx */
1469 		case 759:	/* stfdux */
1470 			if (!(regs->msr & MSR_FP))
1471 				goto fpunavail;
1472 			op->type = MKOP(STORE_FP, u, 8);
1473 			break;
1474 #endif
1475 
1476 #ifdef __powerpc64__
1477 		case 660:	/* stdbrx */
1478 			op->type = MKOP(STORE, BYTEREV, 8);
1479 			op->val = byterev_8(regs->gpr[rd]);
1480 			break;
1481 
1482 #endif
1483 		case 661:	/* stswx */
1484 			op->type = MKOP(STORE_MULTI, 0, regs->xer & 0x7f);
1485 			break;
1486 
1487 		case 662:	/* stwbrx */
1488 			op->type = MKOP(STORE, BYTEREV, 4);
1489 			op->val = byterev_4(regs->gpr[rd]);
1490 			break;
1491 
1492 		case 725:
1493 			if (rb == 0)
1494 				rb = 32;	/* # bytes to store */
1495 			op->type = MKOP(STORE_MULTI, 0, rb);
1496 			op->ea = 0;
1497 			if (ra)
1498 				op->ea = truncate_if_32bit(regs->msr,
1499 							   regs->gpr[ra]);
1500 			break;
1501 
1502 		case 790:	/* lhbrx */
1503 			op->type = MKOP(LOAD, BYTEREV, 2);
1504 			break;
1505 
1506 		case 918:	/* sthbrx */
1507 			op->type = MKOP(STORE, BYTEREV, 2);
1508 			op->val = byterev_2(regs->gpr[rd]);
1509 			break;
1510 
1511 #ifdef CONFIG_VSX
1512 		case 844:	/* lxvd2x */
1513 		case 876:	/* lxvd2ux */
1514 			if (!(regs->msr & MSR_VSX))
1515 				goto vsxunavail;
1516 			op->reg = rd | ((instr & 1) << 5);
1517 			op->type = MKOP(LOAD_VSX, u, 16);
1518 			break;
1519 
1520 		case 972:	/* stxvd2x */
1521 		case 1004:	/* stxvd2ux */
1522 			if (!(regs->msr & MSR_VSX))
1523 				goto vsxunavail;
1524 			op->reg = rd | ((instr & 1) << 5);
1525 			op->type = MKOP(STORE_VSX, u, 16);
1526 			break;
1527 
1528 #endif /* CONFIG_VSX */
1529 		}
1530 		break;
1531 
1532 	case 32:	/* lwz */
1533 	case 33:	/* lwzu */
1534 		op->type = MKOP(LOAD, u, 4);
1535 		op->ea = dform_ea(instr, regs);
1536 		break;
1537 
1538 	case 34:	/* lbz */
1539 	case 35:	/* lbzu */
1540 		op->type = MKOP(LOAD, u, 1);
1541 		op->ea = dform_ea(instr, regs);
1542 		break;
1543 
1544 	case 36:	/* stw */
1545 	case 37:	/* stwu */
1546 		op->type = MKOP(STORE, u, 4);
1547 		op->ea = dform_ea(instr, regs);
1548 		break;
1549 
1550 	case 38:	/* stb */
1551 	case 39:	/* stbu */
1552 		op->type = MKOP(STORE, u, 1);
1553 		op->ea = dform_ea(instr, regs);
1554 		break;
1555 
1556 	case 40:	/* lhz */
1557 	case 41:	/* lhzu */
1558 		op->type = MKOP(LOAD, u, 2);
1559 		op->ea = dform_ea(instr, regs);
1560 		break;
1561 
1562 	case 42:	/* lha */
1563 	case 43:	/* lhau */
1564 		op->type = MKOP(LOAD, SIGNEXT | u, 2);
1565 		op->ea = dform_ea(instr, regs);
1566 		break;
1567 
1568 	case 44:	/* sth */
1569 	case 45:	/* sthu */
1570 		op->type = MKOP(STORE, u, 2);
1571 		op->ea = dform_ea(instr, regs);
1572 		break;
1573 
1574 	case 46:	/* lmw */
1575 		if (ra >= rd)
1576 			break;		/* invalid form, ra in range to load */
1577 		op->type = MKOP(LOAD_MULTI, 0, 4 * (32 - rd));
1578 		op->ea = dform_ea(instr, regs);
1579 		break;
1580 
1581 	case 47:	/* stmw */
1582 		op->type = MKOP(STORE_MULTI, 0, 4 * (32 - rd));
1583 		op->ea = dform_ea(instr, regs);
1584 		break;
1585 
1586 #ifdef CONFIG_PPC_FPU
1587 	case 48:	/* lfs */
1588 	case 49:	/* lfsu */
1589 		if (!(regs->msr & MSR_FP))
1590 			goto fpunavail;
1591 		op->type = MKOP(LOAD_FP, u, 4);
1592 		op->ea = dform_ea(instr, regs);
1593 		break;
1594 
1595 	case 50:	/* lfd */
1596 	case 51:	/* lfdu */
1597 		if (!(regs->msr & MSR_FP))
1598 			goto fpunavail;
1599 		op->type = MKOP(LOAD_FP, u, 8);
1600 		op->ea = dform_ea(instr, regs);
1601 		break;
1602 
1603 	case 52:	/* stfs */
1604 	case 53:	/* stfsu */
1605 		if (!(regs->msr & MSR_FP))
1606 			goto fpunavail;
1607 		op->type = MKOP(STORE_FP, u, 4);
1608 		op->ea = dform_ea(instr, regs);
1609 		break;
1610 
1611 	case 54:	/* stfd */
1612 	case 55:	/* stfdu */
1613 		if (!(regs->msr & MSR_FP))
1614 			goto fpunavail;
1615 		op->type = MKOP(STORE_FP, u, 8);
1616 		op->ea = dform_ea(instr, regs);
1617 		break;
1618 #endif
1619 
1620 #ifdef __powerpc64__
1621 	case 58:	/* ld[u], lwa */
1622 		op->ea = dsform_ea(instr, regs);
1623 		switch (instr & 3) {
1624 		case 0:		/* ld */
1625 			op->type = MKOP(LOAD, 0, 8);
1626 			break;
1627 		case 1:		/* ldu */
1628 			op->type = MKOP(LOAD, UPDATE, 8);
1629 			break;
1630 		case 2:		/* lwa */
1631 			op->type = MKOP(LOAD, SIGNEXT, 4);
1632 			break;
1633 		}
1634 		break;
1635 
1636 	case 62:	/* std[u] */
1637 		op->ea = dsform_ea(instr, regs);
1638 		switch (instr & 3) {
1639 		case 0:		/* std */
1640 			op->type = MKOP(STORE, 0, 8);
1641 			break;
1642 		case 1:		/* stdu */
1643 			op->type = MKOP(STORE, UPDATE, 8);
1644 			break;
1645 		}
1646 		break;
1647 #endif /* __powerpc64__ */
1648 
1649 	}
1650 	return 0;
1651 
1652  logical_done:
1653 	if (instr & 1)
1654 		set_cr0(regs, ra);
1655 	goto instr_done;
1656 
1657  arith_done:
1658 	if (instr & 1)
1659 		set_cr0(regs, rd);
1660 
1661  instr_done:
1662 	regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
1663 	return 1;
1664 
1665  priv:
1666 	op->type = INTERRUPT | 0x700;
1667 	op->val = SRR1_PROGPRIV;
1668 	return 0;
1669 
1670  trap:
1671 	op->type = INTERRUPT | 0x700;
1672 	op->val = SRR1_PROGTRAP;
1673 	return 0;
1674 
1675 #ifdef CONFIG_PPC_FPU
1676  fpunavail:
1677 	op->type = INTERRUPT | 0x800;
1678 	return 0;
1679 #endif
1680 
1681 #ifdef CONFIG_ALTIVEC
1682  vecunavail:
1683 	op->type = INTERRUPT | 0xf20;
1684 	return 0;
1685 #endif
1686 
1687 #ifdef CONFIG_VSX
1688  vsxunavail:
1689 	op->type = INTERRUPT | 0xf40;
1690 	return 0;
1691 #endif
1692 }
1693 EXPORT_SYMBOL_GPL(analyse_instr);
1694 
1695 /*
1696  * For PPC32 we always use stwu with r1 to change the stack pointer.
1697  * So this emulated store may corrupt the exception frame, now we
1698  * have to provide the exception frame trampoline, which is pushed
1699  * below the kprobed function stack. So we only update gpr[1] but
1700  * don't emulate the real store operation. We will do real store
1701  * operation safely in exception return code by checking this flag.
1702  */
1703 static __kprobes int handle_stack_update(unsigned long ea, struct pt_regs *regs)
1704 {
1705 #ifdef CONFIG_PPC32
1706 	/*
1707 	 * Check if we will touch kernel stack overflow
1708 	 */
1709 	if (ea - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) {
1710 		printk(KERN_CRIT "Can't kprobe this since kernel stack would overflow.\n");
1711 		return -EINVAL;
1712 	}
1713 #endif /* CONFIG_PPC32 */
1714 	/*
1715 	 * Check if we already set since that means we'll
1716 	 * lose the previous value.
1717 	 */
1718 	WARN_ON(test_thread_flag(TIF_EMULATE_STACK_STORE));
1719 	set_thread_flag(TIF_EMULATE_STACK_STORE);
1720 	return 0;
1721 }
1722 
1723 static __kprobes void do_signext(unsigned long *valp, int size)
1724 {
1725 	switch (size) {
1726 	case 2:
1727 		*valp = (signed short) *valp;
1728 		break;
1729 	case 4:
1730 		*valp = (signed int) *valp;
1731 		break;
1732 	}
1733 }
1734 
1735 static __kprobes void do_byterev(unsigned long *valp, int size)
1736 {
1737 	switch (size) {
1738 	case 2:
1739 		*valp = byterev_2(*valp);
1740 		break;
1741 	case 4:
1742 		*valp = byterev_4(*valp);
1743 		break;
1744 #ifdef __powerpc64__
1745 	case 8:
1746 		*valp = byterev_8(*valp);
1747 		break;
1748 #endif
1749 	}
1750 }
1751 
1752 /*
1753  * Emulate instructions that cause a transfer of control,
1754  * loads and stores, and a few other instructions.
1755  * Returns 1 if the step was emulated, 0 if not,
1756  * or -1 if the instruction is one that should not be stepped,
1757  * such as an rfid, or a mtmsrd that would clear MSR_RI.
1758  */
1759 int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
1760 {
1761 	struct instruction_op op;
1762 	int r, err, size;
1763 	unsigned long val;
1764 	unsigned int cr;
1765 	int i, rd, nb;
1766 
1767 	r = analyse_instr(&op, regs, instr);
1768 	if (r != 0)
1769 		return r;
1770 
1771 	err = 0;
1772 	size = GETSIZE(op.type);
1773 	switch (op.type & INSTR_TYPE_MASK) {
1774 	case CACHEOP:
1775 		if (!address_ok(regs, op.ea, 8))
1776 			return 0;
1777 		switch (op.type & CACHEOP_MASK) {
1778 		case DCBST:
1779 			__cacheop_user_asmx(op.ea, err, "dcbst");
1780 			break;
1781 		case DCBF:
1782 			__cacheop_user_asmx(op.ea, err, "dcbf");
1783 			break;
1784 		case DCBTST:
1785 			if (op.reg == 0)
1786 				prefetchw((void *) op.ea);
1787 			break;
1788 		case DCBT:
1789 			if (op.reg == 0)
1790 				prefetch((void *) op.ea);
1791 			break;
1792 		case ICBI:
1793 			__cacheop_user_asmx(op.ea, err, "icbi");
1794 			break;
1795 		}
1796 		if (err)
1797 			return 0;
1798 		goto instr_done;
1799 
1800 	case LARX:
1801 		if (regs->msr & MSR_LE)
1802 			return 0;
1803 		if (op.ea & (size - 1))
1804 			break;		/* can't handle misaligned */
1805 		err = -EFAULT;
1806 		if (!address_ok(regs, op.ea, size))
1807 			goto ldst_done;
1808 		err = 0;
1809 		switch (size) {
1810 		case 4:
1811 			__get_user_asmx(val, op.ea, err, "lwarx");
1812 			break;
1813 #ifdef __powerpc64__
1814 		case 8:
1815 			__get_user_asmx(val, op.ea, err, "ldarx");
1816 			break;
1817 #endif
1818 		default:
1819 			return 0;
1820 		}
1821 		if (!err)
1822 			regs->gpr[op.reg] = val;
1823 		goto ldst_done;
1824 
1825 	case STCX:
1826 		if (regs->msr & MSR_LE)
1827 			return 0;
1828 		if (op.ea & (size - 1))
1829 			break;		/* can't handle misaligned */
1830 		err = -EFAULT;
1831 		if (!address_ok(regs, op.ea, size))
1832 			goto ldst_done;
1833 		err = 0;
1834 		switch (size) {
1835 		case 4:
1836 			__put_user_asmx(op.val, op.ea, err, "stwcx.", cr);
1837 			break;
1838 #ifdef __powerpc64__
1839 		case 8:
1840 			__put_user_asmx(op.val, op.ea, err, "stdcx.", cr);
1841 			break;
1842 #endif
1843 		default:
1844 			return 0;
1845 		}
1846 		if (!err)
1847 			regs->ccr = (regs->ccr & 0x0fffffff) |
1848 				(cr & 0xe0000000) |
1849 				((regs->xer >> 3) & 0x10000000);
1850 		goto ldst_done;
1851 
1852 	case LOAD:
1853 		if (regs->msr & MSR_LE)
1854 			return 0;
1855 		err = read_mem(&regs->gpr[op.reg], op.ea, size, regs);
1856 		if (!err) {
1857 			if (op.type & SIGNEXT)
1858 				do_signext(&regs->gpr[op.reg], size);
1859 			if (op.type & BYTEREV)
1860 				do_byterev(&regs->gpr[op.reg], size);
1861 		}
1862 		goto ldst_done;
1863 
1864 #ifdef CONFIG_PPC_FPU
1865 	case LOAD_FP:
1866 		if (regs->msr & MSR_LE)
1867 			return 0;
1868 		if (size == 4)
1869 			err = do_fp_load(op.reg, do_lfs, op.ea, size, regs);
1870 		else
1871 			err = do_fp_load(op.reg, do_lfd, op.ea, size, regs);
1872 		goto ldst_done;
1873 #endif
1874 #ifdef CONFIG_ALTIVEC
1875 	case LOAD_VMX:
1876 		if (regs->msr & MSR_LE)
1877 			return 0;
1878 		err = do_vec_load(op.reg, do_lvx, op.ea & ~0xfUL, regs);
1879 		goto ldst_done;
1880 #endif
1881 #ifdef CONFIG_VSX
1882 	case LOAD_VSX:
1883 		if (regs->msr & MSR_LE)
1884 			return 0;
1885 		err = do_vsx_load(op.reg, do_lxvd2x, op.ea, regs);
1886 		goto ldst_done;
1887 #endif
1888 	case LOAD_MULTI:
1889 		if (regs->msr & MSR_LE)
1890 			return 0;
1891 		rd = op.reg;
1892 		for (i = 0; i < size; i += 4) {
1893 			nb = size - i;
1894 			if (nb > 4)
1895 				nb = 4;
1896 			err = read_mem(&regs->gpr[rd], op.ea, nb, regs);
1897 			if (err)
1898 				return 0;
1899 			if (nb < 4)	/* left-justify last bytes */
1900 				regs->gpr[rd] <<= 32 - 8 * nb;
1901 			op.ea += 4;
1902 			++rd;
1903 		}
1904 		goto instr_done;
1905 
1906 	case STORE:
1907 		if (regs->msr & MSR_LE)
1908 			return 0;
1909 		if ((op.type & UPDATE) && size == sizeof(long) &&
1910 		    op.reg == 1 && op.update_reg == 1 &&
1911 		    !(regs->msr & MSR_PR) &&
1912 		    op.ea >= regs->gpr[1] - STACK_INT_FRAME_SIZE) {
1913 			err = handle_stack_update(op.ea, regs);
1914 			goto ldst_done;
1915 		}
1916 		err = write_mem(op.val, op.ea, size, regs);
1917 		goto ldst_done;
1918 
1919 #ifdef CONFIG_PPC_FPU
1920 	case STORE_FP:
1921 		if (regs->msr & MSR_LE)
1922 			return 0;
1923 		if (size == 4)
1924 			err = do_fp_store(op.reg, do_stfs, op.ea, size, regs);
1925 		else
1926 			err = do_fp_store(op.reg, do_stfd, op.ea, size, regs);
1927 		goto ldst_done;
1928 #endif
1929 #ifdef CONFIG_ALTIVEC
1930 	case STORE_VMX:
1931 		if (regs->msr & MSR_LE)
1932 			return 0;
1933 		err = do_vec_store(op.reg, do_stvx, op.ea & ~0xfUL, regs);
1934 		goto ldst_done;
1935 #endif
1936 #ifdef CONFIG_VSX
1937 	case STORE_VSX:
1938 		if (regs->msr & MSR_LE)
1939 			return 0;
1940 		err = do_vsx_store(op.reg, do_stxvd2x, op.ea, regs);
1941 		goto ldst_done;
1942 #endif
1943 	case STORE_MULTI:
1944 		if (regs->msr & MSR_LE)
1945 			return 0;
1946 		rd = op.reg;
1947 		for (i = 0; i < size; i += 4) {
1948 			val = regs->gpr[rd];
1949 			nb = size - i;
1950 			if (nb > 4)
1951 				nb = 4;
1952 			else
1953 				val >>= 32 - 8 * nb;
1954 			err = write_mem(val, op.ea, nb, regs);
1955 			if (err)
1956 				return 0;
1957 			op.ea += 4;
1958 			++rd;
1959 		}
1960 		goto instr_done;
1961 
1962 	case MFMSR:
1963 		regs->gpr[op.reg] = regs->msr & MSR_MASK;
1964 		goto instr_done;
1965 
1966 	case MTMSR:
1967 		val = regs->gpr[op.reg];
1968 		if ((val & MSR_RI) == 0)
1969 			/* can't step mtmsr[d] that would clear MSR_RI */
1970 			return -1;
1971 		/* here op.val is the mask of bits to change */
1972 		regs->msr = (regs->msr & ~op.val) | (val & op.val);
1973 		goto instr_done;
1974 
1975 #ifdef CONFIG_PPC64
1976 	case SYSCALL:	/* sc */
1977 		/*
1978 		 * N.B. this uses knowledge about how the syscall
1979 		 * entry code works.  If that is changed, this will
1980 		 * need to be changed also.
1981 		 */
1982 		if (regs->gpr[0] == 0x1ebe &&
1983 		    cpu_has_feature(CPU_FTR_REAL_LE)) {
1984 			regs->msr ^= MSR_LE;
1985 			goto instr_done;
1986 		}
1987 		regs->gpr[9] = regs->gpr[13];
1988 		regs->gpr[10] = MSR_KERNEL;
1989 		regs->gpr[11] = regs->nip + 4;
1990 		regs->gpr[12] = regs->msr & MSR_MASK;
1991 		regs->gpr[13] = (unsigned long) get_paca();
1992 		regs->nip = (unsigned long) &system_call_common;
1993 		regs->msr = MSR_KERNEL;
1994 		return 1;
1995 
1996 	case RFI:
1997 		return -1;
1998 #endif
1999 	}
2000 	return 0;
2001 
2002  ldst_done:
2003 	if (err)
2004 		return 0;
2005 	if (op.type & UPDATE)
2006 		regs->gpr[op.update_reg] = op.ea;
2007 
2008  instr_done:
2009 	regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
2010 	return 1;
2011 }
2012