xref: /openbmc/linux/arch/powerpc/lib/sstep.c (revision 5bd8e16d)
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 		if (instr & 0x04000000) {		/* update forms */
104 			if ((instr>>26) != 47) 		/* stmw is not an update form */
105 				regs->gpr[ra] = ea;
106 		}
107 	}
108 
109 	return truncate_if_32bit(regs->msr, ea);
110 }
111 
112 #ifdef __powerpc64__
113 /*
114  * Calculate effective address for a DS-form instruction
115  */
116 static unsigned long __kprobes dsform_ea(unsigned int instr, struct pt_regs *regs)
117 {
118 	int ra;
119 	unsigned long ea;
120 
121 	ra = (instr >> 16) & 0x1f;
122 	ea = (signed short) (instr & ~3);	/* sign-extend */
123 	if (ra) {
124 		ea += regs->gpr[ra];
125 		if ((instr & 3) == 1)		/* update forms */
126 			regs->gpr[ra] = ea;
127 	}
128 
129 	return truncate_if_32bit(regs->msr, ea);
130 }
131 #endif /* __powerpc64 */
132 
133 /*
134  * Calculate effective address for an X-form instruction
135  */
136 static unsigned long __kprobes xform_ea(unsigned int instr, struct pt_regs *regs,
137 				     int do_update)
138 {
139 	int ra, rb;
140 	unsigned long ea;
141 
142 	ra = (instr >> 16) & 0x1f;
143 	rb = (instr >> 11) & 0x1f;
144 	ea = regs->gpr[rb];
145 	if (ra) {
146 		ea += regs->gpr[ra];
147 		if (do_update)		/* update forms */
148 			regs->gpr[ra] = ea;
149 	}
150 
151 	return truncate_if_32bit(regs->msr, ea);
152 }
153 
154 /*
155  * Return the largest power of 2, not greater than sizeof(unsigned long),
156  * such that x is a multiple of it.
157  */
158 static inline unsigned long max_align(unsigned long x)
159 {
160 	x |= sizeof(unsigned long);
161 	return x & -x;		/* isolates rightmost bit */
162 }
163 
164 
165 static inline unsigned long byterev_2(unsigned long x)
166 {
167 	return ((x >> 8) & 0xff) | ((x & 0xff) << 8);
168 }
169 
170 static inline unsigned long byterev_4(unsigned long x)
171 {
172 	return ((x >> 24) & 0xff) | ((x >> 8) & 0xff00) |
173 		((x & 0xff00) << 8) | ((x & 0xff) << 24);
174 }
175 
176 #ifdef __powerpc64__
177 static inline unsigned long byterev_8(unsigned long x)
178 {
179 	return (byterev_4(x) << 32) | byterev_4(x >> 32);
180 }
181 #endif
182 
183 static int __kprobes read_mem_aligned(unsigned long *dest, unsigned long ea,
184 				      int nb)
185 {
186 	int err = 0;
187 	unsigned long x = 0;
188 
189 	switch (nb) {
190 	case 1:
191 		err = __get_user(x, (unsigned char __user *) ea);
192 		break;
193 	case 2:
194 		err = __get_user(x, (unsigned short __user *) ea);
195 		break;
196 	case 4:
197 		err = __get_user(x, (unsigned int __user *) ea);
198 		break;
199 #ifdef __powerpc64__
200 	case 8:
201 		err = __get_user(x, (unsigned long __user *) ea);
202 		break;
203 #endif
204 	}
205 	if (!err)
206 		*dest = x;
207 	return err;
208 }
209 
210 static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
211 					int nb, struct pt_regs *regs)
212 {
213 	int err;
214 	unsigned long x, b, c;
215 
216 	/* unaligned, do this in pieces */
217 	x = 0;
218 	for (; nb > 0; nb -= c) {
219 		c = max_align(ea);
220 		if (c > nb)
221 			c = max_align(nb);
222 		err = read_mem_aligned(&b, ea, c);
223 		if (err)
224 			return err;
225 		x = (x << (8 * c)) + b;
226 		ea += c;
227 	}
228 	*dest = x;
229 	return 0;
230 }
231 
232 /*
233  * Read memory at address ea for nb bytes, return 0 for success
234  * or -EFAULT if an error occurred.
235  */
236 static int __kprobes read_mem(unsigned long *dest, unsigned long ea, int nb,
237 			      struct pt_regs *regs)
238 {
239 	if (!address_ok(regs, ea, nb))
240 		return -EFAULT;
241 	if ((ea & (nb - 1)) == 0)
242 		return read_mem_aligned(dest, ea, nb);
243 	return read_mem_unaligned(dest, ea, nb, regs);
244 }
245 
246 static int __kprobes write_mem_aligned(unsigned long val, unsigned long ea,
247 				       int nb)
248 {
249 	int err = 0;
250 
251 	switch (nb) {
252 	case 1:
253 		err = __put_user(val, (unsigned char __user *) ea);
254 		break;
255 	case 2:
256 		err = __put_user(val, (unsigned short __user *) ea);
257 		break;
258 	case 4:
259 		err = __put_user(val, (unsigned int __user *) ea);
260 		break;
261 #ifdef __powerpc64__
262 	case 8:
263 		err = __put_user(val, (unsigned long __user *) ea);
264 		break;
265 #endif
266 	}
267 	return err;
268 }
269 
270 static int __kprobes write_mem_unaligned(unsigned long val, unsigned long ea,
271 					 int nb, struct pt_regs *regs)
272 {
273 	int err;
274 	unsigned long c;
275 
276 	/* unaligned or little-endian, do this in pieces */
277 	for (; nb > 0; nb -= c) {
278 		c = max_align(ea);
279 		if (c > nb)
280 			c = max_align(nb);
281 		err = write_mem_aligned(val >> (nb - c) * 8, ea, c);
282 		if (err)
283 			return err;
284 		ea += c;
285 	}
286 	return 0;
287 }
288 
289 /*
290  * Write memory at address ea for nb bytes, return 0 for success
291  * or -EFAULT if an error occurred.
292  */
293 static int __kprobes write_mem(unsigned long val, unsigned long ea, int nb,
294 			       struct pt_regs *regs)
295 {
296 	if (!address_ok(regs, ea, nb))
297 		return -EFAULT;
298 	if ((ea & (nb - 1)) == 0)
299 		return write_mem_aligned(val, ea, nb);
300 	return write_mem_unaligned(val, ea, nb, regs);
301 }
302 
303 #ifdef CONFIG_PPC_FPU
304 /*
305  * Check the address and alignment, and call func to do the actual
306  * load or store.
307  */
308 static int __kprobes do_fp_load(int rn, int (*func)(int, unsigned long),
309 				unsigned long ea, int nb,
310 				struct pt_regs *regs)
311 {
312 	int err;
313 	unsigned long val[sizeof(double) / sizeof(long)];
314 	unsigned long ptr;
315 
316 	if (!address_ok(regs, ea, nb))
317 		return -EFAULT;
318 	if ((ea & 3) == 0)
319 		return (*func)(rn, ea);
320 	ptr = (unsigned long) &val[0];
321 	if (sizeof(unsigned long) == 8 || nb == 4) {
322 		err = read_mem_unaligned(&val[0], ea, nb, regs);
323 		ptr += sizeof(unsigned long) - nb;
324 	} else {
325 		/* reading a double on 32-bit */
326 		err = read_mem_unaligned(&val[0], ea, 4, regs);
327 		if (!err)
328 			err = read_mem_unaligned(&val[1], ea + 4, 4, regs);
329 	}
330 	if (err)
331 		return err;
332 	return (*func)(rn, ptr);
333 }
334 
335 static int __kprobes do_fp_store(int rn, int (*func)(int, unsigned long),
336 				 unsigned long ea, int nb,
337 				 struct pt_regs *regs)
338 {
339 	int err;
340 	unsigned long val[sizeof(double) / sizeof(long)];
341 	unsigned long ptr;
342 
343 	if (!address_ok(regs, ea, nb))
344 		return -EFAULT;
345 	if ((ea & 3) == 0)
346 		return (*func)(rn, ea);
347 	ptr = (unsigned long) &val[0];
348 	if (sizeof(unsigned long) == 8 || nb == 4) {
349 		ptr += sizeof(unsigned long) - nb;
350 		err = (*func)(rn, ptr);
351 		if (err)
352 			return err;
353 		err = write_mem_unaligned(val[0], ea, nb, regs);
354 	} else {
355 		/* writing a double on 32-bit */
356 		err = (*func)(rn, ptr);
357 		if (err)
358 			return err;
359 		err = write_mem_unaligned(val[0], ea, 4, regs);
360 		if (!err)
361 			err = write_mem_unaligned(val[1], ea + 4, 4, regs);
362 	}
363 	return err;
364 }
365 #endif
366 
367 #ifdef CONFIG_ALTIVEC
368 /* For Altivec/VMX, no need to worry about alignment */
369 static int __kprobes do_vec_load(int rn, int (*func)(int, unsigned long),
370 				 unsigned long ea, struct pt_regs *regs)
371 {
372 	if (!address_ok(regs, ea & ~0xfUL, 16))
373 		return -EFAULT;
374 	return (*func)(rn, ea);
375 }
376 
377 static int __kprobes do_vec_store(int rn, int (*func)(int, unsigned long),
378 				  unsigned long ea, struct pt_regs *regs)
379 {
380 	if (!address_ok(regs, ea & ~0xfUL, 16))
381 		return -EFAULT;
382 	return (*func)(rn, ea);
383 }
384 #endif /* CONFIG_ALTIVEC */
385 
386 #ifdef CONFIG_VSX
387 static int __kprobes do_vsx_load(int rn, int (*func)(int, unsigned long),
388 				 unsigned long ea, struct pt_regs *regs)
389 {
390 	int err;
391 	unsigned long val[2];
392 
393 	if (!address_ok(regs, ea, 16))
394 		return -EFAULT;
395 	if ((ea & 3) == 0)
396 		return (*func)(rn, ea);
397 	err = read_mem_unaligned(&val[0], ea, 8, regs);
398 	if (!err)
399 		err = read_mem_unaligned(&val[1], ea + 8, 8, regs);
400 	if (!err)
401 		err = (*func)(rn, (unsigned long) &val[0]);
402 	return err;
403 }
404 
405 static int __kprobes do_vsx_store(int rn, int (*func)(int, unsigned long),
406 				 unsigned long ea, struct pt_regs *regs)
407 {
408 	int err;
409 	unsigned long val[2];
410 
411 	if (!address_ok(regs, ea, 16))
412 		return -EFAULT;
413 	if ((ea & 3) == 0)
414 		return (*func)(rn, ea);
415 	err = (*func)(rn, (unsigned long) &val[0]);
416 	if (err)
417 		return err;
418 	err = write_mem_unaligned(val[0], ea, 8, regs);
419 	if (!err)
420 		err = write_mem_unaligned(val[1], ea + 8, 8, regs);
421 	return err;
422 }
423 #endif /* CONFIG_VSX */
424 
425 #define __put_user_asmx(x, addr, err, op, cr)		\
426 	__asm__ __volatile__(				\
427 		"1:	" op " %2,0,%3\n"		\
428 		"	mfcr	%1\n"			\
429 		"2:\n"					\
430 		".section .fixup,\"ax\"\n"		\
431 		"3:	li	%0,%4\n"		\
432 		"	b	2b\n"			\
433 		".previous\n"				\
434 		".section __ex_table,\"a\"\n"		\
435 			PPC_LONG_ALIGN "\n"		\
436 			PPC_LONG "1b,3b\n"		\
437 		".previous"				\
438 		: "=r" (err), "=r" (cr)			\
439 		: "r" (x), "r" (addr), "i" (-EFAULT), "0" (err))
440 
441 #define __get_user_asmx(x, addr, err, op)		\
442 	__asm__ __volatile__(				\
443 		"1:	"op" %1,0,%2\n"			\
444 		"2:\n"					\
445 		".section .fixup,\"ax\"\n"		\
446 		"3:	li	%0,%3\n"		\
447 		"	b	2b\n"			\
448 		".previous\n"				\
449 		".section __ex_table,\"a\"\n"		\
450 			PPC_LONG_ALIGN "\n"		\
451 			PPC_LONG "1b,3b\n"		\
452 		".previous"				\
453 		: "=r" (err), "=r" (x)			\
454 		: "r" (addr), "i" (-EFAULT), "0" (err))
455 
456 #define __cacheop_user_asmx(addr, err, op)		\
457 	__asm__ __volatile__(				\
458 		"1:	"op" 0,%1\n"			\
459 		"2:\n"					\
460 		".section .fixup,\"ax\"\n"		\
461 		"3:	li	%0,%3\n"		\
462 		"	b	2b\n"			\
463 		".previous\n"				\
464 		".section __ex_table,\"a\"\n"		\
465 			PPC_LONG_ALIGN "\n"		\
466 			PPC_LONG "1b,3b\n"		\
467 		".previous"				\
468 		: "=r" (err)				\
469 		: "r" (addr), "i" (-EFAULT), "0" (err))
470 
471 static void __kprobes set_cr0(struct pt_regs *regs, int rd)
472 {
473 	long val = regs->gpr[rd];
474 
475 	regs->ccr = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000);
476 #ifdef __powerpc64__
477 	if (!(regs->msr & MSR_64BIT))
478 		val = (int) val;
479 #endif
480 	if (val < 0)
481 		regs->ccr |= 0x80000000;
482 	else if (val > 0)
483 		regs->ccr |= 0x40000000;
484 	else
485 		regs->ccr |= 0x20000000;
486 }
487 
488 static void __kprobes add_with_carry(struct pt_regs *regs, int rd,
489 				     unsigned long val1, unsigned long val2,
490 				     unsigned long carry_in)
491 {
492 	unsigned long val = val1 + val2;
493 
494 	if (carry_in)
495 		++val;
496 	regs->gpr[rd] = val;
497 #ifdef __powerpc64__
498 	if (!(regs->msr & MSR_64BIT)) {
499 		val = (unsigned int) val;
500 		val1 = (unsigned int) val1;
501 	}
502 #endif
503 	if (val < val1 || (carry_in && val == val1))
504 		regs->xer |= XER_CA;
505 	else
506 		regs->xer &= ~XER_CA;
507 }
508 
509 static void __kprobes do_cmp_signed(struct pt_regs *regs, long v1, long v2,
510 				    int crfld)
511 {
512 	unsigned int crval, shift;
513 
514 	crval = (regs->xer >> 31) & 1;		/* get SO bit */
515 	if (v1 < v2)
516 		crval |= 8;
517 	else if (v1 > v2)
518 		crval |= 4;
519 	else
520 		crval |= 2;
521 	shift = (7 - crfld) * 4;
522 	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
523 }
524 
525 static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
526 				      unsigned long v2, int crfld)
527 {
528 	unsigned int crval, shift;
529 
530 	crval = (regs->xer >> 31) & 1;		/* get SO bit */
531 	if (v1 < v2)
532 		crval |= 8;
533 	else if (v1 > v2)
534 		crval |= 4;
535 	else
536 		crval |= 2;
537 	shift = (7 - crfld) * 4;
538 	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
539 }
540 
541 /*
542  * Elements of 32-bit rotate and mask instructions.
543  */
544 #define MASK32(mb, me)	((0xffffffffUL >> (mb)) + \
545 			 ((signed long)-0x80000000L >> (me)) + ((me) >= (mb)))
546 #ifdef __powerpc64__
547 #define MASK64_L(mb)	(~0UL >> (mb))
548 #define MASK64_R(me)	((signed long)-0x8000000000000000L >> (me))
549 #define MASK64(mb, me)	(MASK64_L(mb) + MASK64_R(me) + ((me) >= (mb)))
550 #define DATA32(x)	(((x) & 0xffffffffUL) | (((x) & 0xffffffffUL) << 32))
551 #else
552 #define DATA32(x)	(x)
553 #endif
554 #define ROTATE(x, n)	((n) ? (((x) << (n)) | ((x) >> (8 * sizeof(long) - (n)))) : (x))
555 
556 /*
557  * Emulate instructions that cause a transfer of control,
558  * loads and stores, and a few other instructions.
559  * Returns 1 if the step was emulated, 0 if not,
560  * or -1 if the instruction is one that should not be stepped,
561  * such as an rfid, or a mtmsrd that would clear MSR_RI.
562  */
563 int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
564 {
565 	unsigned int opcode, ra, rb, rd, spr, u;
566 	unsigned long int imm;
567 	unsigned long int val, val2;
568 	unsigned long int ea;
569 	unsigned int cr, mb, me, sh;
570 	int err;
571 	unsigned long old_ra, val3;
572 	long ival;
573 
574 	opcode = instr >> 26;
575 	switch (opcode) {
576 	case 16:	/* bc */
577 		imm = (signed short)(instr & 0xfffc);
578 		if ((instr & 2) == 0)
579 			imm += regs->nip;
580 		regs->nip += 4;
581 		regs->nip = truncate_if_32bit(regs->msr, regs->nip);
582 		if (instr & 1)
583 			regs->link = regs->nip;
584 		if (branch_taken(instr, regs))
585 			regs->nip = truncate_if_32bit(regs->msr, imm);
586 		return 1;
587 #ifdef CONFIG_PPC64
588 	case 17:	/* sc */
589 		/*
590 		 * N.B. this uses knowledge about how the syscall
591 		 * entry code works.  If that is changed, this will
592 		 * need to be changed also.
593 		 */
594 		if (regs->gpr[0] == 0x1ebe &&
595 		    cpu_has_feature(CPU_FTR_REAL_LE)) {
596 			regs->msr ^= MSR_LE;
597 			goto instr_done;
598 		}
599 		regs->gpr[9] = regs->gpr[13];
600 		regs->gpr[10] = MSR_KERNEL;
601 		regs->gpr[11] = regs->nip + 4;
602 		regs->gpr[12] = regs->msr & MSR_MASK;
603 		regs->gpr[13] = (unsigned long) get_paca();
604 		regs->nip = (unsigned long) &system_call_common;
605 		regs->msr = MSR_KERNEL;
606 		return 1;
607 #endif
608 	case 18:	/* b */
609 		imm = instr & 0x03fffffc;
610 		if (imm & 0x02000000)
611 			imm -= 0x04000000;
612 		if ((instr & 2) == 0)
613 			imm += regs->nip;
614 		if (instr & 1)
615 			regs->link = truncate_if_32bit(regs->msr, regs->nip + 4);
616 		imm = truncate_if_32bit(regs->msr, imm);
617 		regs->nip = imm;
618 		return 1;
619 	case 19:
620 		switch ((instr >> 1) & 0x3ff) {
621 		case 16:	/* bclr */
622 		case 528:	/* bcctr */
623 			imm = (instr & 0x400)? regs->ctr: regs->link;
624 			regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
625 			imm = truncate_if_32bit(regs->msr, imm);
626 			if (instr & 1)
627 				regs->link = regs->nip;
628 			if (branch_taken(instr, regs))
629 				regs->nip = imm;
630 			return 1;
631 
632 		case 18:	/* rfid, scary */
633 			return -1;
634 
635 		case 150:	/* isync */
636 			isync();
637 			goto instr_done;
638 
639 		case 33:	/* crnor */
640 		case 129:	/* crandc */
641 		case 193:	/* crxor */
642 		case 225:	/* crnand */
643 		case 257:	/* crand */
644 		case 289:	/* creqv */
645 		case 417:	/* crorc */
646 		case 449:	/* cror */
647 			ra = (instr >> 16) & 0x1f;
648 			rb = (instr >> 11) & 0x1f;
649 			rd = (instr >> 21) & 0x1f;
650 			ra = (regs->ccr >> (31 - ra)) & 1;
651 			rb = (regs->ccr >> (31 - rb)) & 1;
652 			val = (instr >> (6 + ra * 2 + rb)) & 1;
653 			regs->ccr = (regs->ccr & ~(1UL << (31 - rd))) |
654 				(val << (31 - rd));
655 			goto instr_done;
656 		}
657 		break;
658 	case 31:
659 		switch ((instr >> 1) & 0x3ff) {
660 		case 598:	/* sync */
661 #ifdef __powerpc64__
662 			switch ((instr >> 21) & 3) {
663 			case 1:		/* lwsync */
664 				asm volatile("lwsync" : : : "memory");
665 				goto instr_done;
666 			case 2:		/* ptesync */
667 				asm volatile("ptesync" : : : "memory");
668 				goto instr_done;
669 			}
670 #endif
671 			mb();
672 			goto instr_done;
673 
674 		case 854:	/* eieio */
675 			eieio();
676 			goto instr_done;
677 		}
678 		break;
679 	}
680 
681 	/* Following cases refer to regs->gpr[], so we need all regs */
682 	if (!FULL_REGS(regs))
683 		return 0;
684 
685 	rd = (instr >> 21) & 0x1f;
686 	ra = (instr >> 16) & 0x1f;
687 	rb = (instr >> 11) & 0x1f;
688 
689 	switch (opcode) {
690 	case 7:		/* mulli */
691 		regs->gpr[rd] = regs->gpr[ra] * (short) instr;
692 		goto instr_done;
693 
694 	case 8:		/* subfic */
695 		imm = (short) instr;
696 		add_with_carry(regs, rd, ~regs->gpr[ra], imm, 1);
697 		goto instr_done;
698 
699 	case 10:	/* cmpli */
700 		imm = (unsigned short) instr;
701 		val = regs->gpr[ra];
702 #ifdef __powerpc64__
703 		if ((rd & 1) == 0)
704 			val = (unsigned int) val;
705 #endif
706 		do_cmp_unsigned(regs, val, imm, rd >> 2);
707 		goto instr_done;
708 
709 	case 11:	/* cmpi */
710 		imm = (short) instr;
711 		val = regs->gpr[ra];
712 #ifdef __powerpc64__
713 		if ((rd & 1) == 0)
714 			val = (int) val;
715 #endif
716 		do_cmp_signed(regs, val, imm, rd >> 2);
717 		goto instr_done;
718 
719 	case 12:	/* addic */
720 		imm = (short) instr;
721 		add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
722 		goto instr_done;
723 
724 	case 13:	/* addic. */
725 		imm = (short) instr;
726 		add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
727 		set_cr0(regs, rd);
728 		goto instr_done;
729 
730 	case 14:	/* addi */
731 		imm = (short) instr;
732 		if (ra)
733 			imm += regs->gpr[ra];
734 		regs->gpr[rd] = imm;
735 		goto instr_done;
736 
737 	case 15:	/* addis */
738 		imm = ((short) instr) << 16;
739 		if (ra)
740 			imm += regs->gpr[ra];
741 		regs->gpr[rd] = imm;
742 		goto instr_done;
743 
744 	case 20:	/* rlwimi */
745 		mb = (instr >> 6) & 0x1f;
746 		me = (instr >> 1) & 0x1f;
747 		val = DATA32(regs->gpr[rd]);
748 		imm = MASK32(mb, me);
749 		regs->gpr[ra] = (regs->gpr[ra] & ~imm) | (ROTATE(val, rb) & imm);
750 		goto logical_done;
751 
752 	case 21:	/* rlwinm */
753 		mb = (instr >> 6) & 0x1f;
754 		me = (instr >> 1) & 0x1f;
755 		val = DATA32(regs->gpr[rd]);
756 		regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
757 		goto logical_done;
758 
759 	case 23:	/* rlwnm */
760 		mb = (instr >> 6) & 0x1f;
761 		me = (instr >> 1) & 0x1f;
762 		rb = regs->gpr[rb] & 0x1f;
763 		val = DATA32(regs->gpr[rd]);
764 		regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
765 		goto logical_done;
766 
767 	case 24:	/* ori */
768 		imm = (unsigned short) instr;
769 		regs->gpr[ra] = regs->gpr[rd] | imm;
770 		goto instr_done;
771 
772 	case 25:	/* oris */
773 		imm = (unsigned short) instr;
774 		regs->gpr[ra] = regs->gpr[rd] | (imm << 16);
775 		goto instr_done;
776 
777 	case 26:	/* xori */
778 		imm = (unsigned short) instr;
779 		regs->gpr[ra] = regs->gpr[rd] ^ imm;
780 		goto instr_done;
781 
782 	case 27:	/* xoris */
783 		imm = (unsigned short) instr;
784 		regs->gpr[ra] = regs->gpr[rd] ^ (imm << 16);
785 		goto instr_done;
786 
787 	case 28:	/* andi. */
788 		imm = (unsigned short) instr;
789 		regs->gpr[ra] = regs->gpr[rd] & imm;
790 		set_cr0(regs, ra);
791 		goto instr_done;
792 
793 	case 29:	/* andis. */
794 		imm = (unsigned short) instr;
795 		regs->gpr[ra] = regs->gpr[rd] & (imm << 16);
796 		set_cr0(regs, ra);
797 		goto instr_done;
798 
799 #ifdef __powerpc64__
800 	case 30:	/* rld* */
801 		mb = ((instr >> 6) & 0x1f) | (instr & 0x20);
802 		val = regs->gpr[rd];
803 		if ((instr & 0x10) == 0) {
804 			sh = rb | ((instr & 2) << 4);
805 			val = ROTATE(val, sh);
806 			switch ((instr >> 2) & 3) {
807 			case 0:		/* rldicl */
808 				regs->gpr[ra] = val & MASK64_L(mb);
809 				goto logical_done;
810 			case 1:		/* rldicr */
811 				regs->gpr[ra] = val & MASK64_R(mb);
812 				goto logical_done;
813 			case 2:		/* rldic */
814 				regs->gpr[ra] = val & MASK64(mb, 63 - sh);
815 				goto logical_done;
816 			case 3:		/* rldimi */
817 				imm = MASK64(mb, 63 - sh);
818 				regs->gpr[ra] = (regs->gpr[ra] & ~imm) |
819 					(val & imm);
820 				goto logical_done;
821 			}
822 		} else {
823 			sh = regs->gpr[rb] & 0x3f;
824 			val = ROTATE(val, sh);
825 			switch ((instr >> 1) & 7) {
826 			case 0:		/* rldcl */
827 				regs->gpr[ra] = val & MASK64_L(mb);
828 				goto logical_done;
829 			case 1:		/* rldcr */
830 				regs->gpr[ra] = val & MASK64_R(mb);
831 				goto logical_done;
832 			}
833 		}
834 #endif
835 
836 	case 31:
837 		switch ((instr >> 1) & 0x3ff) {
838 		case 83:	/* mfmsr */
839 			if (regs->msr & MSR_PR)
840 				break;
841 			regs->gpr[rd] = regs->msr & MSR_MASK;
842 			goto instr_done;
843 		case 146:	/* mtmsr */
844 			if (regs->msr & MSR_PR)
845 				break;
846 			imm = regs->gpr[rd];
847 			if ((imm & MSR_RI) == 0)
848 				/* can't step mtmsr that would clear MSR_RI */
849 				return -1;
850 			regs->msr = imm;
851 			goto instr_done;
852 #ifdef CONFIG_PPC64
853 		case 178:	/* mtmsrd */
854 			/* only MSR_EE and MSR_RI get changed if bit 15 set */
855 			/* mtmsrd doesn't change MSR_HV and MSR_ME */
856 			if (regs->msr & MSR_PR)
857 				break;
858 			imm = (instr & 0x10000)? 0x8002: 0xefffffffffffefffUL;
859 			imm = (regs->msr & MSR_MASK & ~imm)
860 				| (regs->gpr[rd] & imm);
861 			if ((imm & MSR_RI) == 0)
862 				/* can't step mtmsrd that would clear MSR_RI */
863 				return -1;
864 			regs->msr = imm;
865 			goto instr_done;
866 #endif
867 		case 19:	/* mfcr */
868 			regs->gpr[rd] = regs->ccr;
869 			regs->gpr[rd] &= 0xffffffffUL;
870 			goto instr_done;
871 
872 		case 144:	/* mtcrf */
873 			imm = 0xf0000000UL;
874 			val = regs->gpr[rd];
875 			for (sh = 0; sh < 8; ++sh) {
876 				if (instr & (0x80000 >> sh))
877 					regs->ccr = (regs->ccr & ~imm) |
878 						(val & imm);
879 				imm >>= 4;
880 			}
881 			goto instr_done;
882 
883 		case 339:	/* mfspr */
884 			spr = (instr >> 11) & 0x3ff;
885 			switch (spr) {
886 			case 0x20:	/* mfxer */
887 				regs->gpr[rd] = regs->xer;
888 				regs->gpr[rd] &= 0xffffffffUL;
889 				goto instr_done;
890 			case 0x100:	/* mflr */
891 				regs->gpr[rd] = regs->link;
892 				goto instr_done;
893 			case 0x120:	/* mfctr */
894 				regs->gpr[rd] = regs->ctr;
895 				goto instr_done;
896 			}
897 			break;
898 
899 		case 467:	/* mtspr */
900 			spr = (instr >> 11) & 0x3ff;
901 			switch (spr) {
902 			case 0x20:	/* mtxer */
903 				regs->xer = (regs->gpr[rd] & 0xffffffffUL);
904 				goto instr_done;
905 			case 0x100:	/* mtlr */
906 				regs->link = regs->gpr[rd];
907 				goto instr_done;
908 			case 0x120:	/* mtctr */
909 				regs->ctr = regs->gpr[rd];
910 				goto instr_done;
911 			}
912 			break;
913 
914 /*
915  * Compare instructions
916  */
917 		case 0:	/* cmp */
918 			val = regs->gpr[ra];
919 			val2 = regs->gpr[rb];
920 #ifdef __powerpc64__
921 			if ((rd & 1) == 0) {
922 				/* word (32-bit) compare */
923 				val = (int) val;
924 				val2 = (int) val2;
925 			}
926 #endif
927 			do_cmp_signed(regs, val, val2, rd >> 2);
928 			goto instr_done;
929 
930 		case 32:	/* cmpl */
931 			val = regs->gpr[ra];
932 			val2 = regs->gpr[rb];
933 #ifdef __powerpc64__
934 			if ((rd & 1) == 0) {
935 				/* word (32-bit) compare */
936 				val = (unsigned int) val;
937 				val2 = (unsigned int) val2;
938 			}
939 #endif
940 			do_cmp_unsigned(regs, val, val2, rd >> 2);
941 			goto instr_done;
942 
943 /*
944  * Arithmetic instructions
945  */
946 		case 8:	/* subfc */
947 			add_with_carry(regs, rd, ~regs->gpr[ra],
948 				       regs->gpr[rb], 1);
949 			goto arith_done;
950 #ifdef __powerpc64__
951 		case 9:	/* mulhdu */
952 			asm("mulhdu %0,%1,%2" : "=r" (regs->gpr[rd]) :
953 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
954 			goto arith_done;
955 #endif
956 		case 10:	/* addc */
957 			add_with_carry(regs, rd, regs->gpr[ra],
958 				       regs->gpr[rb], 0);
959 			goto arith_done;
960 
961 		case 11:	/* mulhwu */
962 			asm("mulhwu %0,%1,%2" : "=r" (regs->gpr[rd]) :
963 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
964 			goto arith_done;
965 
966 		case 40:	/* subf */
967 			regs->gpr[rd] = regs->gpr[rb] - regs->gpr[ra];
968 			goto arith_done;
969 #ifdef __powerpc64__
970 		case 73:	/* mulhd */
971 			asm("mulhd %0,%1,%2" : "=r" (regs->gpr[rd]) :
972 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
973 			goto arith_done;
974 #endif
975 		case 75:	/* mulhw */
976 			asm("mulhw %0,%1,%2" : "=r" (regs->gpr[rd]) :
977 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
978 			goto arith_done;
979 
980 		case 104:	/* neg */
981 			regs->gpr[rd] = -regs->gpr[ra];
982 			goto arith_done;
983 
984 		case 136:	/* subfe */
985 			add_with_carry(regs, rd, ~regs->gpr[ra], regs->gpr[rb],
986 				       regs->xer & XER_CA);
987 			goto arith_done;
988 
989 		case 138:	/* adde */
990 			add_with_carry(regs, rd, regs->gpr[ra], regs->gpr[rb],
991 				       regs->xer & XER_CA);
992 			goto arith_done;
993 
994 		case 200:	/* subfze */
995 			add_with_carry(regs, rd, ~regs->gpr[ra], 0L,
996 				       regs->xer & XER_CA);
997 			goto arith_done;
998 
999 		case 202:	/* addze */
1000 			add_with_carry(regs, rd, regs->gpr[ra], 0L,
1001 				       regs->xer & XER_CA);
1002 			goto arith_done;
1003 
1004 		case 232:	/* subfme */
1005 			add_with_carry(regs, rd, ~regs->gpr[ra], -1L,
1006 				       regs->xer & XER_CA);
1007 			goto arith_done;
1008 #ifdef __powerpc64__
1009 		case 233:	/* mulld */
1010 			regs->gpr[rd] = regs->gpr[ra] * regs->gpr[rb];
1011 			goto arith_done;
1012 #endif
1013 		case 234:	/* addme */
1014 			add_with_carry(regs, rd, regs->gpr[ra], -1L,
1015 				       regs->xer & XER_CA);
1016 			goto arith_done;
1017 
1018 		case 235:	/* mullw */
1019 			regs->gpr[rd] = (unsigned int) regs->gpr[ra] *
1020 				(unsigned int) regs->gpr[rb];
1021 			goto arith_done;
1022 
1023 		case 266:	/* add */
1024 			regs->gpr[rd] = regs->gpr[ra] + regs->gpr[rb];
1025 			goto arith_done;
1026 #ifdef __powerpc64__
1027 		case 457:	/* divdu */
1028 			regs->gpr[rd] = regs->gpr[ra] / regs->gpr[rb];
1029 			goto arith_done;
1030 #endif
1031 		case 459:	/* divwu */
1032 			regs->gpr[rd] = (unsigned int) regs->gpr[ra] /
1033 				(unsigned int) regs->gpr[rb];
1034 			goto arith_done;
1035 #ifdef __powerpc64__
1036 		case 489:	/* divd */
1037 			regs->gpr[rd] = (long int) regs->gpr[ra] /
1038 				(long int) regs->gpr[rb];
1039 			goto arith_done;
1040 #endif
1041 		case 491:	/* divw */
1042 			regs->gpr[rd] = (int) regs->gpr[ra] /
1043 				(int) regs->gpr[rb];
1044 			goto arith_done;
1045 
1046 
1047 /*
1048  * Logical instructions
1049  */
1050 		case 26:	/* cntlzw */
1051 			asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) :
1052 			    "r" (regs->gpr[rd]));
1053 			goto logical_done;
1054 #ifdef __powerpc64__
1055 		case 58:	/* cntlzd */
1056 			asm("cntlzd %0,%1" : "=r" (regs->gpr[ra]) :
1057 			    "r" (regs->gpr[rd]));
1058 			goto logical_done;
1059 #endif
1060 		case 28:	/* and */
1061 			regs->gpr[ra] = regs->gpr[rd] & regs->gpr[rb];
1062 			goto logical_done;
1063 
1064 		case 60:	/* andc */
1065 			regs->gpr[ra] = regs->gpr[rd] & ~regs->gpr[rb];
1066 			goto logical_done;
1067 
1068 		case 124:	/* nor */
1069 			regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]);
1070 			goto logical_done;
1071 
1072 		case 284:	/* xor */
1073 			regs->gpr[ra] = ~(regs->gpr[rd] ^ regs->gpr[rb]);
1074 			goto logical_done;
1075 
1076 		case 316:	/* xor */
1077 			regs->gpr[ra] = regs->gpr[rd] ^ regs->gpr[rb];
1078 			goto logical_done;
1079 
1080 		case 412:	/* orc */
1081 			regs->gpr[ra] = regs->gpr[rd] | ~regs->gpr[rb];
1082 			goto logical_done;
1083 
1084 		case 444:	/* or */
1085 			regs->gpr[ra] = regs->gpr[rd] | regs->gpr[rb];
1086 			goto logical_done;
1087 
1088 		case 476:	/* nand */
1089 			regs->gpr[ra] = ~(regs->gpr[rd] & regs->gpr[rb]);
1090 			goto logical_done;
1091 
1092 		case 922:	/* extsh */
1093 			regs->gpr[ra] = (signed short) regs->gpr[rd];
1094 			goto logical_done;
1095 
1096 		case 954:	/* extsb */
1097 			regs->gpr[ra] = (signed char) regs->gpr[rd];
1098 			goto logical_done;
1099 #ifdef __powerpc64__
1100 		case 986:	/* extsw */
1101 			regs->gpr[ra] = (signed int) regs->gpr[rd];
1102 			goto logical_done;
1103 #endif
1104 
1105 /*
1106  * Shift instructions
1107  */
1108 		case 24:	/* slw */
1109 			sh = regs->gpr[rb] & 0x3f;
1110 			if (sh < 32)
1111 				regs->gpr[ra] = (regs->gpr[rd] << sh) & 0xffffffffUL;
1112 			else
1113 				regs->gpr[ra] = 0;
1114 			goto logical_done;
1115 
1116 		case 536:	/* srw */
1117 			sh = regs->gpr[rb] & 0x3f;
1118 			if (sh < 32)
1119 				regs->gpr[ra] = (regs->gpr[rd] & 0xffffffffUL) >> sh;
1120 			else
1121 				regs->gpr[ra] = 0;
1122 			goto logical_done;
1123 
1124 		case 792:	/* sraw */
1125 			sh = regs->gpr[rb] & 0x3f;
1126 			ival = (signed int) regs->gpr[rd];
1127 			regs->gpr[ra] = ival >> (sh < 32 ? sh : 31);
1128 			if (ival < 0 && (sh >= 32 || (ival & ((1 << sh) - 1)) != 0))
1129 				regs->xer |= XER_CA;
1130 			else
1131 				regs->xer &= ~XER_CA;
1132 			goto logical_done;
1133 
1134 		case 824:	/* srawi */
1135 			sh = rb;
1136 			ival = (signed int) regs->gpr[rd];
1137 			regs->gpr[ra] = ival >> sh;
1138 			if (ival < 0 && (ival & ((1 << sh) - 1)) != 0)
1139 				regs->xer |= XER_CA;
1140 			else
1141 				regs->xer &= ~XER_CA;
1142 			goto logical_done;
1143 
1144 #ifdef __powerpc64__
1145 		case 27:	/* sld */
1146 			sh = regs->gpr[rd] & 0x7f;
1147 			if (sh < 64)
1148 				regs->gpr[ra] = regs->gpr[rd] << sh;
1149 			else
1150 				regs->gpr[ra] = 0;
1151 			goto logical_done;
1152 
1153 		case 539:	/* srd */
1154 			sh = regs->gpr[rb] & 0x7f;
1155 			if (sh < 64)
1156 				regs->gpr[ra] = regs->gpr[rd] >> sh;
1157 			else
1158 				regs->gpr[ra] = 0;
1159 			goto logical_done;
1160 
1161 		case 794:	/* srad */
1162 			sh = regs->gpr[rb] & 0x7f;
1163 			ival = (signed long int) regs->gpr[rd];
1164 			regs->gpr[ra] = ival >> (sh < 64 ? sh : 63);
1165 			if (ival < 0 && (sh >= 64 || (ival & ((1 << sh) - 1)) != 0))
1166 				regs->xer |= XER_CA;
1167 			else
1168 				regs->xer &= ~XER_CA;
1169 			goto logical_done;
1170 
1171 		case 826:	/* sradi with sh_5 = 0 */
1172 		case 827:	/* sradi with sh_5 = 1 */
1173 			sh = rb | ((instr & 2) << 4);
1174 			ival = (signed long int) regs->gpr[rd];
1175 			regs->gpr[ra] = ival >> sh;
1176 			if (ival < 0 && (ival & ((1 << sh) - 1)) != 0)
1177 				regs->xer |= XER_CA;
1178 			else
1179 				regs->xer &= ~XER_CA;
1180 			goto logical_done;
1181 #endif /* __powerpc64__ */
1182 
1183 /*
1184  * Cache instructions
1185  */
1186 		case 54:	/* dcbst */
1187 			ea = xform_ea(instr, regs, 0);
1188 			if (!address_ok(regs, ea, 8))
1189 				return 0;
1190 			err = 0;
1191 			__cacheop_user_asmx(ea, err, "dcbst");
1192 			if (err)
1193 				return 0;
1194 			goto instr_done;
1195 
1196 		case 86:	/* dcbf */
1197 			ea = xform_ea(instr, regs, 0);
1198 			if (!address_ok(regs, ea, 8))
1199 				return 0;
1200 			err = 0;
1201 			__cacheop_user_asmx(ea, err, "dcbf");
1202 			if (err)
1203 				return 0;
1204 			goto instr_done;
1205 
1206 		case 246:	/* dcbtst */
1207 			if (rd == 0) {
1208 				ea = xform_ea(instr, regs, 0);
1209 				prefetchw((void *) ea);
1210 			}
1211 			goto instr_done;
1212 
1213 		case 278:	/* dcbt */
1214 			if (rd == 0) {
1215 				ea = xform_ea(instr, regs, 0);
1216 				prefetch((void *) ea);
1217 			}
1218 			goto instr_done;
1219 
1220 		}
1221 		break;
1222 	}
1223 
1224 	/*
1225 	 * Following cases are for loads and stores, so bail out
1226 	 * if we're in little-endian mode.
1227 	 */
1228 	if (regs->msr & MSR_LE)
1229 		return 0;
1230 
1231 	/*
1232 	 * Save register RA in case it's an update form load or store
1233 	 * and the access faults.
1234 	 */
1235 	old_ra = regs->gpr[ra];
1236 
1237 	switch (opcode) {
1238 	case 31:
1239 		u = instr & 0x40;
1240 		switch ((instr >> 1) & 0x3ff) {
1241 		case 20:	/* lwarx */
1242 			ea = xform_ea(instr, regs, 0);
1243 			if (ea & 3)
1244 				break;		/* can't handle misaligned */
1245 			err = -EFAULT;
1246 			if (!address_ok(regs, ea, 4))
1247 				goto ldst_done;
1248 			err = 0;
1249 			__get_user_asmx(val, ea, err, "lwarx");
1250 			if (!err)
1251 				regs->gpr[rd] = val;
1252 			goto ldst_done;
1253 
1254 		case 150:	/* stwcx. */
1255 			ea = xform_ea(instr, regs, 0);
1256 			if (ea & 3)
1257 				break;		/* can't handle misaligned */
1258 			err = -EFAULT;
1259 			if (!address_ok(regs, ea, 4))
1260 				goto ldst_done;
1261 			err = 0;
1262 			__put_user_asmx(regs->gpr[rd], ea, err, "stwcx.", cr);
1263 			if (!err)
1264 				regs->ccr = (regs->ccr & 0x0fffffff) |
1265 					(cr & 0xe0000000) |
1266 					((regs->xer >> 3) & 0x10000000);
1267 			goto ldst_done;
1268 
1269 #ifdef __powerpc64__
1270 		case 84:	/* ldarx */
1271 			ea = xform_ea(instr, regs, 0);
1272 			if (ea & 7)
1273 				break;		/* can't handle misaligned */
1274 			err = -EFAULT;
1275 			if (!address_ok(regs, ea, 8))
1276 				goto ldst_done;
1277 			err = 0;
1278 			__get_user_asmx(val, ea, err, "ldarx");
1279 			if (!err)
1280 				regs->gpr[rd] = val;
1281 			goto ldst_done;
1282 
1283 		case 214:	/* stdcx. */
1284 			ea = xform_ea(instr, regs, 0);
1285 			if (ea & 7)
1286 				break;		/* can't handle misaligned */
1287 			err = -EFAULT;
1288 			if (!address_ok(regs, ea, 8))
1289 				goto ldst_done;
1290 			err = 0;
1291 			__put_user_asmx(regs->gpr[rd], ea, err, "stdcx.", cr);
1292 			if (!err)
1293 				regs->ccr = (regs->ccr & 0x0fffffff) |
1294 					(cr & 0xe0000000) |
1295 					((regs->xer >> 3) & 0x10000000);
1296 			goto ldst_done;
1297 
1298 		case 21:	/* ldx */
1299 		case 53:	/* ldux */
1300 			err = read_mem(&regs->gpr[rd], xform_ea(instr, regs, u),
1301 				       8, regs);
1302 			goto ldst_done;
1303 #endif
1304 
1305 		case 23:	/* lwzx */
1306 		case 55:	/* lwzux */
1307 			err = read_mem(&regs->gpr[rd], xform_ea(instr, regs, u),
1308 				       4, regs);
1309 			goto ldst_done;
1310 
1311 		case 87:	/* lbzx */
1312 		case 119:	/* lbzux */
1313 			err = read_mem(&regs->gpr[rd], xform_ea(instr, regs, u),
1314 				       1, regs);
1315 			goto ldst_done;
1316 
1317 #ifdef CONFIG_ALTIVEC
1318 		case 103:	/* lvx */
1319 		case 359:	/* lvxl */
1320 			if (!(regs->msr & MSR_VEC))
1321 				break;
1322 			ea = xform_ea(instr, regs, 0);
1323 			err = do_vec_load(rd, do_lvx, ea, regs);
1324 			goto ldst_done;
1325 
1326 		case 231:	/* stvx */
1327 		case 487:	/* stvxl */
1328 			if (!(regs->msr & MSR_VEC))
1329 				break;
1330 			ea = xform_ea(instr, regs, 0);
1331 			err = do_vec_store(rd, do_stvx, ea, regs);
1332 			goto ldst_done;
1333 #endif /* CONFIG_ALTIVEC */
1334 
1335 #ifdef __powerpc64__
1336 		case 149:	/* stdx */
1337 		case 181:	/* stdux */
1338 			val = regs->gpr[rd];
1339 			err = write_mem(val, xform_ea(instr, regs, u), 8, regs);
1340 			goto ldst_done;
1341 #endif
1342 
1343 		case 151:	/* stwx */
1344 		case 183:	/* stwux */
1345 			val = regs->gpr[rd];
1346 			err = write_mem(val, xform_ea(instr, regs, u), 4, regs);
1347 			goto ldst_done;
1348 
1349 		case 215:	/* stbx */
1350 		case 247:	/* stbux */
1351 			val = regs->gpr[rd];
1352 			err = write_mem(val, xform_ea(instr, regs, u), 1, regs);
1353 			goto ldst_done;
1354 
1355 		case 279:	/* lhzx */
1356 		case 311:	/* lhzux */
1357 			err = read_mem(&regs->gpr[rd], xform_ea(instr, regs, u),
1358 				       2, regs);
1359 			goto ldst_done;
1360 
1361 #ifdef __powerpc64__
1362 		case 341:	/* lwax */
1363 		case 373:	/* lwaux */
1364 			err = read_mem(&regs->gpr[rd], xform_ea(instr, regs, u),
1365 				       4, regs);
1366 			if (!err)
1367 				regs->gpr[rd] = (signed int) regs->gpr[rd];
1368 			goto ldst_done;
1369 #endif
1370 
1371 		case 343:	/* lhax */
1372 		case 375:	/* lhaux */
1373 			err = read_mem(&regs->gpr[rd], xform_ea(instr, regs, u),
1374 				       2, regs);
1375 			if (!err)
1376 				regs->gpr[rd] = (signed short) regs->gpr[rd];
1377 			goto ldst_done;
1378 
1379 		case 407:	/* sthx */
1380 		case 439:	/* sthux */
1381 			val = regs->gpr[rd];
1382 			err = write_mem(val, xform_ea(instr, regs, u), 2, regs);
1383 			goto ldst_done;
1384 
1385 #ifdef __powerpc64__
1386 		case 532:	/* ldbrx */
1387 			err = read_mem(&val, xform_ea(instr, regs, 0), 8, regs);
1388 			if (!err)
1389 				regs->gpr[rd] = byterev_8(val);
1390 			goto ldst_done;
1391 
1392 #endif
1393 
1394 		case 534:	/* lwbrx */
1395 			err = read_mem(&val, xform_ea(instr, regs, 0), 4, regs);
1396 			if (!err)
1397 				regs->gpr[rd] = byterev_4(val);
1398 			goto ldst_done;
1399 
1400 #ifdef CONFIG_PPC_CPU
1401 		case 535:	/* lfsx */
1402 		case 567:	/* lfsux */
1403 			if (!(regs->msr & MSR_FP))
1404 				break;
1405 			ea = xform_ea(instr, regs, u);
1406 			err = do_fp_load(rd, do_lfs, ea, 4, regs);
1407 			goto ldst_done;
1408 
1409 		case 599:	/* lfdx */
1410 		case 631:	/* lfdux */
1411 			if (!(regs->msr & MSR_FP))
1412 				break;
1413 			ea = xform_ea(instr, regs, u);
1414 			err = do_fp_load(rd, do_lfd, ea, 8, regs);
1415 			goto ldst_done;
1416 
1417 		case 663:	/* stfsx */
1418 		case 695:	/* stfsux */
1419 			if (!(regs->msr & MSR_FP))
1420 				break;
1421 			ea = xform_ea(instr, regs, u);
1422 			err = do_fp_store(rd, do_stfs, ea, 4, regs);
1423 			goto ldst_done;
1424 
1425 		case 727:	/* stfdx */
1426 		case 759:	/* stfdux */
1427 			if (!(regs->msr & MSR_FP))
1428 				break;
1429 			ea = xform_ea(instr, regs, u);
1430 			err = do_fp_store(rd, do_stfd, ea, 8, regs);
1431 			goto ldst_done;
1432 #endif
1433 
1434 #ifdef __powerpc64__
1435 		case 660:	/* stdbrx */
1436 			val = byterev_8(regs->gpr[rd]);
1437 			err = write_mem(val, xform_ea(instr, regs, 0), 8, regs);
1438 			goto ldst_done;
1439 
1440 #endif
1441 		case 662:	/* stwbrx */
1442 			val = byterev_4(regs->gpr[rd]);
1443 			err = write_mem(val, xform_ea(instr, regs, 0), 4, regs);
1444 			goto ldst_done;
1445 
1446 		case 790:	/* lhbrx */
1447 			err = read_mem(&val, xform_ea(instr, regs, 0), 2, regs);
1448 			if (!err)
1449 				regs->gpr[rd] = byterev_2(val);
1450 			goto ldst_done;
1451 
1452 		case 918:	/* sthbrx */
1453 			val = byterev_2(regs->gpr[rd]);
1454 			err = write_mem(val, xform_ea(instr, regs, 0), 2, regs);
1455 			goto ldst_done;
1456 
1457 #ifdef CONFIG_VSX
1458 		case 844:	/* lxvd2x */
1459 		case 876:	/* lxvd2ux */
1460 			if (!(regs->msr & MSR_VSX))
1461 				break;
1462 			rd |= (instr & 1) << 5;
1463 			ea = xform_ea(instr, regs, u);
1464 			err = do_vsx_load(rd, do_lxvd2x, ea, regs);
1465 			goto ldst_done;
1466 
1467 		case 972:	/* stxvd2x */
1468 		case 1004:	/* stxvd2ux */
1469 			if (!(regs->msr & MSR_VSX))
1470 				break;
1471 			rd |= (instr & 1) << 5;
1472 			ea = xform_ea(instr, regs, u);
1473 			err = do_vsx_store(rd, do_stxvd2x, ea, regs);
1474 			goto ldst_done;
1475 
1476 #endif /* CONFIG_VSX */
1477 		}
1478 		break;
1479 
1480 	case 32:	/* lwz */
1481 	case 33:	/* lwzu */
1482 		err = read_mem(&regs->gpr[rd], dform_ea(instr, regs), 4, regs);
1483 		goto ldst_done;
1484 
1485 	case 34:	/* lbz */
1486 	case 35:	/* lbzu */
1487 		err = read_mem(&regs->gpr[rd], dform_ea(instr, regs), 1, regs);
1488 		goto ldst_done;
1489 
1490 	case 36:	/* stw */
1491 		val = regs->gpr[rd];
1492 		err = write_mem(val, dform_ea(instr, regs), 4, regs);
1493 		goto ldst_done;
1494 
1495 	case 37:	/* stwu */
1496 		val = regs->gpr[rd];
1497 		val3 = dform_ea(instr, regs);
1498 		/*
1499 		 * For PPC32 we always use stwu to change stack point with r1. So
1500 		 * this emulated store may corrupt the exception frame, now we
1501 		 * have to provide the exception frame trampoline, which is pushed
1502 		 * below the kprobed function stack. So we only update gpr[1] but
1503 		 * don't emulate the real store operation. We will do real store
1504 		 * operation safely in exception return code by checking this flag.
1505 		 */
1506 		if ((ra == 1) && !(regs->msr & MSR_PR) \
1507 			&& (val3 >= (regs->gpr[1] - STACK_INT_FRAME_SIZE))) {
1508 			/*
1509 			 * Check if we will touch kernel sack overflow
1510 			 */
1511 			if (val3 - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) {
1512 				printk(KERN_CRIT "Can't kprobe this since Kernel stack overflow.\n");
1513 				err = -EINVAL;
1514 				break;
1515 			}
1516 
1517 			/*
1518 			 * Check if we already set since that means we'll
1519 			 * lose the previous value.
1520 			 */
1521 			WARN_ON(test_thread_flag(TIF_EMULATE_STACK_STORE));
1522 			set_thread_flag(TIF_EMULATE_STACK_STORE);
1523 			err = 0;
1524 		} else
1525 			err = write_mem(val, val3, 4, regs);
1526 		goto ldst_done;
1527 
1528 	case 38:	/* stb */
1529 	case 39:	/* stbu */
1530 		val = regs->gpr[rd];
1531 		err = write_mem(val, dform_ea(instr, regs), 1, regs);
1532 		goto ldst_done;
1533 
1534 	case 40:	/* lhz */
1535 	case 41:	/* lhzu */
1536 		err = read_mem(&regs->gpr[rd], dform_ea(instr, regs), 2, regs);
1537 		goto ldst_done;
1538 
1539 	case 42:	/* lha */
1540 	case 43:	/* lhau */
1541 		err = read_mem(&regs->gpr[rd], dform_ea(instr, regs), 2, regs);
1542 		if (!err)
1543 			regs->gpr[rd] = (signed short) regs->gpr[rd];
1544 		goto ldst_done;
1545 
1546 	case 44:	/* sth */
1547 	case 45:	/* sthu */
1548 		val = regs->gpr[rd];
1549 		err = write_mem(val, dform_ea(instr, regs), 2, regs);
1550 		goto ldst_done;
1551 
1552 	case 46:	/* lmw */
1553 		ra = (instr >> 16) & 0x1f;
1554 		if (ra >= rd)
1555 			break;		/* invalid form, ra in range to load */
1556 		ea = dform_ea(instr, regs);
1557 		do {
1558 			err = read_mem(&regs->gpr[rd], ea, 4, regs);
1559 			if (err)
1560 				return 0;
1561 			ea += 4;
1562 		} while (++rd < 32);
1563 		goto instr_done;
1564 
1565 	case 47:	/* stmw */
1566 		ea = dform_ea(instr, regs);
1567 		do {
1568 			err = write_mem(regs->gpr[rd], ea, 4, regs);
1569 			if (err)
1570 				return 0;
1571 			ea += 4;
1572 		} while (++rd < 32);
1573 		goto instr_done;
1574 
1575 #ifdef CONFIG_PPC_FPU
1576 	case 48:	/* lfs */
1577 	case 49:	/* lfsu */
1578 		if (!(regs->msr & MSR_FP))
1579 			break;
1580 		ea = dform_ea(instr, regs);
1581 		err = do_fp_load(rd, do_lfs, ea, 4, regs);
1582 		goto ldst_done;
1583 
1584 	case 50:	/* lfd */
1585 	case 51:	/* lfdu */
1586 		if (!(regs->msr & MSR_FP))
1587 			break;
1588 		ea = dform_ea(instr, regs);
1589 		err = do_fp_load(rd, do_lfd, ea, 8, regs);
1590 		goto ldst_done;
1591 
1592 	case 52:	/* stfs */
1593 	case 53:	/* stfsu */
1594 		if (!(regs->msr & MSR_FP))
1595 			break;
1596 		ea = dform_ea(instr, regs);
1597 		err = do_fp_store(rd, do_stfs, ea, 4, regs);
1598 		goto ldst_done;
1599 
1600 	case 54:	/* stfd */
1601 	case 55:	/* stfdu */
1602 		if (!(regs->msr & MSR_FP))
1603 			break;
1604 		ea = dform_ea(instr, regs);
1605 		err = do_fp_store(rd, do_stfd, ea, 8, regs);
1606 		goto ldst_done;
1607 #endif
1608 
1609 #ifdef __powerpc64__
1610 	case 58:	/* ld[u], lwa */
1611 		switch (instr & 3) {
1612 		case 0:		/* ld */
1613 			err = read_mem(&regs->gpr[rd], dsform_ea(instr, regs),
1614 				       8, regs);
1615 			goto ldst_done;
1616 		case 1:		/* ldu */
1617 			err = read_mem(&regs->gpr[rd], dsform_ea(instr, regs),
1618 				       8, regs);
1619 			goto ldst_done;
1620 		case 2:		/* lwa */
1621 			err = read_mem(&regs->gpr[rd], dsform_ea(instr, regs),
1622 				       4, regs);
1623 			if (!err)
1624 				regs->gpr[rd] = (signed int) regs->gpr[rd];
1625 			goto ldst_done;
1626 		}
1627 		break;
1628 
1629 	case 62:	/* std[u] */
1630 		val = regs->gpr[rd];
1631 		switch (instr & 3) {
1632 		case 0:		/* std */
1633 			err = write_mem(val, dsform_ea(instr, regs), 8, regs);
1634 			goto ldst_done;
1635 		case 1:		/* stdu */
1636 			err = write_mem(val, dsform_ea(instr, regs), 8, regs);
1637 			goto ldst_done;
1638 		}
1639 		break;
1640 #endif /* __powerpc64__ */
1641 
1642 	}
1643 	err = -EINVAL;
1644 
1645  ldst_done:
1646 	if (err) {
1647 		regs->gpr[ra] = old_ra;
1648 		return 0;	/* invoke DSI if -EFAULT? */
1649 	}
1650  instr_done:
1651 	regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
1652 	return 1;
1653 
1654  logical_done:
1655 	if (instr & 1)
1656 		set_cr0(regs, ra);
1657 	goto instr_done;
1658 
1659  arith_done:
1660 	if (instr & 1)
1661 		set_cr0(regs, rd);
1662 	goto instr_done;
1663 }
1664