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1 /* align.c - handle alignment exceptions for the Power PC.
2  *
3  * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
4  * Copyright (c) 1998-1999 TiVo, Inc.
5  *   PowerPC 403GCX modifications.
6  * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
7  *   PowerPC 403GCX/405GP modifications.
8  * Copyright (c) 2001-2002 PPC64 team, IBM Corp
9  *   64-bit and Power4 support
10  * Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp
11  *                    <benh@kernel.crashing.org>
12  *   Merge ppc32 and ppc64 implementations
13  *
14  * This program is free software; you can redistribute it and/or
15  * modify it under the terms of the GNU General Public License
16  * as published by the Free Software Foundation; either version
17  * 2 of the License, or (at your option) any later version.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/mm.h>
22 #include <asm/processor.h>
23 #include <asm/uaccess.h>
24 #include <asm/cache.h>
25 #include <asm/cputable.h>
26 #include <asm/emulated_ops.h>
27 #include <asm/switch_to.h>
28 #include <asm/disassemble.h>
29 
30 struct aligninfo {
31 	unsigned char len;
32 	unsigned char flags;
33 };
34 
35 
36 #define INVALID	{ 0, 0 }
37 
38 /* Bits in the flags field */
39 #define LD	0	/* load */
40 #define ST	1	/* store */
41 #define SE	2	/* sign-extend value, or FP ld/st as word */
42 #define F	4	/* to/from fp regs */
43 #define U	8	/* update index register */
44 #define M	0x10	/* multiple load/store */
45 #define SW	0x20	/* byte swap */
46 #define S	0x40	/* single-precision fp or... */
47 #define SX	0x40	/* ... byte count in XER */
48 #define HARD	0x80	/* string, stwcx. */
49 #define E4	0x40	/* SPE endianness is word */
50 #define E8	0x80	/* SPE endianness is double word */
51 #define SPLT	0x80	/* VSX SPLAT load */
52 
53 /* DSISR bits reported for a DCBZ instruction: */
54 #define DCBZ	0x5f	/* 8xx/82xx dcbz faults when cache not enabled */
55 
56 /*
57  * The PowerPC stores certain bits of the instruction that caused the
58  * alignment exception in the DSISR register.  This array maps those
59  * bits to information about the operand length and what the
60  * instruction would do.
61  */
62 static struct aligninfo aligninfo[128] = {
63 	{ 4, LD },		/* 00 0 0000: lwz / lwarx */
64 	INVALID,		/* 00 0 0001 */
65 	{ 4, ST },		/* 00 0 0010: stw */
66 	INVALID,		/* 00 0 0011 */
67 	{ 2, LD },		/* 00 0 0100: lhz */
68 	{ 2, LD+SE },		/* 00 0 0101: lha */
69 	{ 2, ST },		/* 00 0 0110: sth */
70 	{ 4, LD+M },		/* 00 0 0111: lmw */
71 	{ 4, LD+F+S },		/* 00 0 1000: lfs */
72 	{ 8, LD+F },		/* 00 0 1001: lfd */
73 	{ 4, ST+F+S },		/* 00 0 1010: stfs */
74 	{ 8, ST+F },		/* 00 0 1011: stfd */
75 	{ 16, LD },		/* 00 0 1100: lq */
76 	{ 8, LD },		/* 00 0 1101: ld/ldu/lwa */
77 	INVALID,		/* 00 0 1110 */
78 	{ 8, ST },		/* 00 0 1111: std/stdu */
79 	{ 4, LD+U },		/* 00 1 0000: lwzu */
80 	INVALID,		/* 00 1 0001 */
81 	{ 4, ST+U },		/* 00 1 0010: stwu */
82 	INVALID,		/* 00 1 0011 */
83 	{ 2, LD+U },		/* 00 1 0100: lhzu */
84 	{ 2, LD+SE+U },		/* 00 1 0101: lhau */
85 	{ 2, ST+U },		/* 00 1 0110: sthu */
86 	{ 4, ST+M },		/* 00 1 0111: stmw */
87 	{ 4, LD+F+S+U },	/* 00 1 1000: lfsu */
88 	{ 8, LD+F+U },		/* 00 1 1001: lfdu */
89 	{ 4, ST+F+S+U },	/* 00 1 1010: stfsu */
90 	{ 8, ST+F+U },		/* 00 1 1011: stfdu */
91 	{ 16, LD+F },		/* 00 1 1100: lfdp */
92 	INVALID,		/* 00 1 1101 */
93 	{ 16, ST+F },		/* 00 1 1110: stfdp */
94 	INVALID,		/* 00 1 1111 */
95 	{ 8, LD },		/* 01 0 0000: ldx */
96 	INVALID,		/* 01 0 0001 */
97 	{ 8, ST },		/* 01 0 0010: stdx */
98 	INVALID,		/* 01 0 0011 */
99 	INVALID,		/* 01 0 0100 */
100 	{ 4, LD+SE },		/* 01 0 0101: lwax */
101 	INVALID,		/* 01 0 0110 */
102 	INVALID,		/* 01 0 0111 */
103 	{ 4, LD+M+HARD+SX },	/* 01 0 1000: lswx */
104 	{ 4, LD+M+HARD },	/* 01 0 1001: lswi */
105 	{ 4, ST+M+HARD+SX },	/* 01 0 1010: stswx */
106 	{ 4, ST+M+HARD },	/* 01 0 1011: stswi */
107 	INVALID,		/* 01 0 1100 */
108 	{ 8, LD+U },		/* 01 0 1101: ldu */
109 	INVALID,		/* 01 0 1110 */
110 	{ 8, ST+U },		/* 01 0 1111: stdu */
111 	{ 8, LD+U },		/* 01 1 0000: ldux */
112 	INVALID,		/* 01 1 0001 */
113 	{ 8, ST+U },		/* 01 1 0010: stdux */
114 	INVALID,		/* 01 1 0011 */
115 	INVALID,		/* 01 1 0100 */
116 	{ 4, LD+SE+U },		/* 01 1 0101: lwaux */
117 	INVALID,		/* 01 1 0110 */
118 	INVALID,		/* 01 1 0111 */
119 	INVALID,		/* 01 1 1000 */
120 	INVALID,		/* 01 1 1001 */
121 	INVALID,		/* 01 1 1010 */
122 	INVALID,		/* 01 1 1011 */
123 	INVALID,		/* 01 1 1100 */
124 	INVALID,		/* 01 1 1101 */
125 	INVALID,		/* 01 1 1110 */
126 	INVALID,		/* 01 1 1111 */
127 	INVALID,		/* 10 0 0000 */
128 	INVALID,		/* 10 0 0001 */
129 	INVALID,		/* 10 0 0010: stwcx. */
130 	INVALID,		/* 10 0 0011 */
131 	INVALID,		/* 10 0 0100 */
132 	INVALID,		/* 10 0 0101 */
133 	INVALID,		/* 10 0 0110 */
134 	INVALID,		/* 10 0 0111 */
135 	{ 4, LD+SW },		/* 10 0 1000: lwbrx */
136 	INVALID,		/* 10 0 1001 */
137 	{ 4, ST+SW },		/* 10 0 1010: stwbrx */
138 	INVALID,		/* 10 0 1011 */
139 	{ 2, LD+SW },		/* 10 0 1100: lhbrx */
140 	{ 4, LD+SE },		/* 10 0 1101  lwa */
141 	{ 2, ST+SW },		/* 10 0 1110: sthbrx */
142 	{ 16, ST },		/* 10 0 1111: stq */
143 	INVALID,		/* 10 1 0000 */
144 	INVALID,		/* 10 1 0001 */
145 	INVALID,		/* 10 1 0010 */
146 	INVALID,		/* 10 1 0011 */
147 	INVALID,		/* 10 1 0100 */
148 	INVALID,		/* 10 1 0101 */
149 	INVALID,		/* 10 1 0110 */
150 	INVALID,		/* 10 1 0111 */
151 	INVALID,		/* 10 1 1000 */
152 	INVALID,		/* 10 1 1001 */
153 	INVALID,		/* 10 1 1010 */
154 	INVALID,		/* 10 1 1011 */
155 	INVALID,		/* 10 1 1100 */
156 	INVALID,		/* 10 1 1101 */
157 	INVALID,		/* 10 1 1110 */
158 	{ 0, ST+HARD },		/* 10 1 1111: dcbz */
159 	{ 4, LD },		/* 11 0 0000: lwzx */
160 	INVALID,		/* 11 0 0001 */
161 	{ 4, ST },		/* 11 0 0010: stwx */
162 	INVALID,		/* 11 0 0011 */
163 	{ 2, LD },		/* 11 0 0100: lhzx */
164 	{ 2, LD+SE },		/* 11 0 0101: lhax */
165 	{ 2, ST },		/* 11 0 0110: sthx */
166 	INVALID,		/* 11 0 0111 */
167 	{ 4, LD+F+S },		/* 11 0 1000: lfsx */
168 	{ 8, LD+F },		/* 11 0 1001: lfdx */
169 	{ 4, ST+F+S },		/* 11 0 1010: stfsx */
170 	{ 8, ST+F },		/* 11 0 1011: stfdx */
171 	{ 16, LD+F },		/* 11 0 1100: lfdpx */
172 	{ 4, LD+F+SE },		/* 11 0 1101: lfiwax */
173 	{ 16, ST+F },		/* 11 0 1110: stfdpx */
174 	{ 4, ST+F },		/* 11 0 1111: stfiwx */
175 	{ 4, LD+U },		/* 11 1 0000: lwzux */
176 	INVALID,		/* 11 1 0001 */
177 	{ 4, ST+U },		/* 11 1 0010: stwux */
178 	INVALID,		/* 11 1 0011 */
179 	{ 2, LD+U },		/* 11 1 0100: lhzux */
180 	{ 2, LD+SE+U },		/* 11 1 0101: lhaux */
181 	{ 2, ST+U },		/* 11 1 0110: sthux */
182 	INVALID,		/* 11 1 0111 */
183 	{ 4, LD+F+S+U },	/* 11 1 1000: lfsux */
184 	{ 8, LD+F+U },		/* 11 1 1001: lfdux */
185 	{ 4, ST+F+S+U },	/* 11 1 1010: stfsux */
186 	{ 8, ST+F+U },		/* 11 1 1011: stfdux */
187 	INVALID,		/* 11 1 1100 */
188 	{ 4, LD+F },		/* 11 1 1101: lfiwzx */
189 	INVALID,		/* 11 1 1110 */
190 	INVALID,		/* 11 1 1111 */
191 };
192 
193 /*
194  * The dcbz (data cache block zero) instruction
195  * gives an alignment fault if used on non-cacheable
196  * memory.  We handle the fault mainly for the
197  * case when we are running with the cache disabled
198  * for debugging.
199  */
emulate_dcbz(struct pt_regs * regs,unsigned char __user * addr)200 static int emulate_dcbz(struct pt_regs *regs, unsigned char __user *addr)
201 {
202 	long __user *p;
203 	int i, size;
204 
205 #ifdef __powerpc64__
206 	size = ppc64_caches.dline_size;
207 #else
208 	size = L1_CACHE_BYTES;
209 #endif
210 	p = (long __user *) (regs->dar & -size);
211 	if (user_mode(regs) && !access_ok(VERIFY_WRITE, p, size))
212 		return -EFAULT;
213 	for (i = 0; i < size / sizeof(long); ++i)
214 		if (__put_user_inatomic(0, p+i))
215 			return -EFAULT;
216 	return 1;
217 }
218 
219 /*
220  * Emulate load & store multiple instructions
221  * On 64-bit machines, these instructions only affect/use the
222  * bottom 4 bytes of each register, and the loads clear the
223  * top 4 bytes of the affected register.
224  */
225 #ifdef __BIG_ENDIAN__
226 #ifdef CONFIG_PPC64
227 #define REG_BYTE(rp, i)		*((u8 *)((rp) + ((i) >> 2)) + ((i) & 3) + 4)
228 #else
229 #define REG_BYTE(rp, i)		*((u8 *)(rp) + (i))
230 #endif
231 #endif
232 
233 #ifdef __LITTLE_ENDIAN__
234 #define REG_BYTE(rp, i)		(*(((u8 *)((rp) + ((i)>>2)) + ((i)&3))))
235 #endif
236 
237 #define SWIZ_PTR(p)		((unsigned char __user *)((p) ^ swiz))
238 
239 #define __get_user_or_set_dar(_regs, _dest, _addr)		\
240 	({							\
241 		int rc = 0;					\
242 		typeof(_addr) __addr = (_addr);			\
243 		if (__get_user_inatomic(_dest, __addr)) {	\
244 			_regs->dar = (unsigned long)__addr;	\
245 			rc = -EFAULT;				\
246 		}						\
247 		rc;						\
248 	})
249 
250 #define __put_user_or_set_dar(_regs, _src, _addr)		\
251 	({							\
252 		int rc = 0;					\
253 		typeof(_addr) __addr = (_addr);			\
254 		if (__put_user_inatomic(_src, __addr)) {	\
255 			_regs->dar = (unsigned long)__addr;	\
256 			rc = -EFAULT;				\
257 		}						\
258 		rc;						\
259 	})
260 
emulate_multiple(struct pt_regs * regs,unsigned char __user * addr,unsigned int reg,unsigned int nb,unsigned int flags,unsigned int instr,unsigned long swiz)261 static int emulate_multiple(struct pt_regs *regs, unsigned char __user *addr,
262 			    unsigned int reg, unsigned int nb,
263 			    unsigned int flags, unsigned int instr,
264 			    unsigned long swiz)
265 {
266 	unsigned long *rptr;
267 	unsigned int nb0, i, bswiz;
268 	unsigned long p;
269 
270 	/*
271 	 * We do not try to emulate 8 bytes multiple as they aren't really
272 	 * available in our operating environments and we don't try to
273 	 * emulate multiples operations in kernel land as they should never
274 	 * be used/generated there at least not on unaligned boundaries
275 	 */
276 	if (unlikely((nb > 4) || !user_mode(regs)))
277 		return 0;
278 
279 	/* lmw, stmw, lswi/x, stswi/x */
280 	nb0 = 0;
281 	if (flags & HARD) {
282 		if (flags & SX) {
283 			nb = regs->xer & 127;
284 			if (nb == 0)
285 				return 1;
286 		} else {
287 			unsigned long pc = regs->nip ^ (swiz & 4);
288 
289 			if (__get_user_or_set_dar(regs, instr,
290 						  (unsigned int __user *)pc))
291 				return -EFAULT;
292 
293 			if (swiz == 0 && (flags & SW))
294 				instr = cpu_to_le32(instr);
295 			nb = (instr >> 11) & 0x1f;
296 			if (nb == 0)
297 				nb = 32;
298 		}
299 		if (nb + reg * 4 > 128) {
300 			nb0 = nb + reg * 4 - 128;
301 			nb = 128 - reg * 4;
302 		}
303 #ifdef __LITTLE_ENDIAN__
304 		/*
305 		 *  String instructions are endian neutral but the code
306 		 *  below is not.  Force byte swapping on so that the
307 		 *  effects of swizzling are undone in the load/store
308 		 *  loops below.
309 		 */
310 		flags ^= SW;
311 #endif
312 	} else {
313 		/* lwm, stmw */
314 		nb = (32 - reg) * 4;
315 	}
316 
317 	if (!access_ok((flags & ST ? VERIFY_WRITE: VERIFY_READ), addr, nb+nb0))
318 		return -EFAULT;	/* bad address */
319 
320 	rptr = &regs->gpr[reg];
321 	p = (unsigned long) addr;
322 	bswiz = (flags & SW)? 3: 0;
323 
324 	if (!(flags & ST)) {
325 		/*
326 		 * This zeroes the top 4 bytes of the affected registers
327 		 * in 64-bit mode, and also zeroes out any remaining
328 		 * bytes of the last register for lsw*.
329 		 */
330 		memset(rptr, 0, ((nb + 3) / 4) * sizeof(unsigned long));
331 		if (nb0 > 0)
332 			memset(&regs->gpr[0], 0,
333 			       ((nb0 + 3) / 4) * sizeof(unsigned long));
334 
335 		for (i = 0; i < nb; ++i, ++p)
336 			if (__get_user_or_set_dar(regs, REG_BYTE(rptr, i ^ bswiz),
337 						  SWIZ_PTR(p)))
338 				return -EFAULT;
339 		if (nb0 > 0) {
340 			rptr = &regs->gpr[0];
341 			addr += nb;
342 			for (i = 0; i < nb0; ++i, ++p)
343 				if (__get_user_or_set_dar(regs,
344 							  REG_BYTE(rptr, i ^ bswiz),
345 							  SWIZ_PTR(p)))
346 					return -EFAULT;
347 		}
348 
349 	} else {
350 		for (i = 0; i < nb; ++i, ++p)
351 			if (__put_user_or_set_dar(regs, REG_BYTE(rptr, i ^ bswiz),
352 						  SWIZ_PTR(p)))
353 				return -EFAULT;
354 		if (nb0 > 0) {
355 			rptr = &regs->gpr[0];
356 			addr += nb;
357 			for (i = 0; i < nb0; ++i, ++p)
358 				if (__put_user_or_set_dar(regs,
359 							  REG_BYTE(rptr, i ^ bswiz),
360 							  SWIZ_PTR(p)))
361 					return -EFAULT;
362 		}
363 	}
364 	return 1;
365 }
366 
367 /*
368  * Emulate floating-point pair loads and stores.
369  * Only POWER6 has these instructions, and it does true little-endian,
370  * so we don't need the address swizzling.
371  */
emulate_fp_pair(struct pt_regs * regs,unsigned char __user * addr,unsigned int reg,unsigned int flags)372 static int emulate_fp_pair(struct pt_regs *regs, unsigned char __user *addr,
373 			   unsigned int reg, unsigned int flags)
374 {
375 	char *ptr0 = (char *) &current->thread.TS_FPR(reg);
376 	char *ptr1 = (char *) &current->thread.TS_FPR(reg+1);
377 	int i, sw = 0;
378 
379 	if (reg & 1)
380 		return 0;	/* invalid form: FRS/FRT must be even */
381 	if (flags & SW)
382 		sw = 7;
383 
384 	for (i = 0; i < 8; ++i) {
385 		if (!(flags & ST)) {
386 			if (__get_user_or_set_dar(regs, ptr0[i^sw], addr + i))
387 				return -EFAULT;
388 			if (__get_user_or_set_dar(regs, ptr1[i^sw], addr + i + 8))
389 				return -EFAULT;
390 		} else {
391 			if (__put_user_or_set_dar(regs, ptr0[i^sw], addr + i))
392 				return -EFAULT;
393 			if (__put_user_or_set_dar(regs, ptr1[i^sw], addr + i + 8))
394 				return -EFAULT;
395 		}
396 	}
397 
398 	return 1;	/* exception handled and fixed up */
399 }
400 
401 #ifdef CONFIG_PPC64
emulate_lq_stq(struct pt_regs * regs,unsigned char __user * addr,unsigned int reg,unsigned int flags)402 static int emulate_lq_stq(struct pt_regs *regs, unsigned char __user *addr,
403 			  unsigned int reg, unsigned int flags)
404 {
405 	char *ptr0 = (char *)&regs->gpr[reg];
406 	char *ptr1 = (char *)&regs->gpr[reg+1];
407 	int i, sw = 0;
408 
409 	if (reg & 1)
410 		return 0;	/* invalid form: GPR must be even */
411 	if (flags & SW)
412 		sw = 7;
413 
414 	for (i = 0; i < 8; ++i) {
415 		if (!(flags & ST)) {
416 			if (__get_user_or_set_dar(regs, ptr0[i^sw], addr + i))
417 				return -EFAULT;
418 			if (__get_user_or_set_dar(regs, ptr1[i^sw], addr + i + 8))
419 				return -EFAULT;
420 		} else {
421 			if (__put_user_or_set_dar(regs, ptr0[i^sw], addr + i))
422 				return -EFAULT;
423 			if (__put_user_or_set_dar(regs, ptr1[i^sw], addr + i + 8))
424 				return -EFAULT;
425 		}
426 	}
427 
428 	return 1;	/* exception handled and fixed up */
429 }
430 #endif /* CONFIG_PPC64 */
431 
432 #ifdef CONFIG_SPE
433 
434 static struct aligninfo spe_aligninfo[32] = {
435 	{ 8, LD+E8 },		/* 0 00 00: evldd[x] */
436 	{ 8, LD+E4 },		/* 0 00 01: evldw[x] */
437 	{ 8, LD },		/* 0 00 10: evldh[x] */
438 	INVALID,		/* 0 00 11 */
439 	{ 2, LD },		/* 0 01 00: evlhhesplat[x] */
440 	INVALID,		/* 0 01 01 */
441 	{ 2, LD },		/* 0 01 10: evlhhousplat[x] */
442 	{ 2, LD+SE },		/* 0 01 11: evlhhossplat[x] */
443 	{ 4, LD },		/* 0 10 00: evlwhe[x] */
444 	INVALID,		/* 0 10 01 */
445 	{ 4, LD },		/* 0 10 10: evlwhou[x] */
446 	{ 4, LD+SE },		/* 0 10 11: evlwhos[x] */
447 	{ 4, LD+E4 },		/* 0 11 00: evlwwsplat[x] */
448 	INVALID,		/* 0 11 01 */
449 	{ 4, LD },		/* 0 11 10: evlwhsplat[x] */
450 	INVALID,		/* 0 11 11 */
451 
452 	{ 8, ST+E8 },		/* 1 00 00: evstdd[x] */
453 	{ 8, ST+E4 },		/* 1 00 01: evstdw[x] */
454 	{ 8, ST },		/* 1 00 10: evstdh[x] */
455 	INVALID,		/* 1 00 11 */
456 	INVALID,		/* 1 01 00 */
457 	INVALID,		/* 1 01 01 */
458 	INVALID,		/* 1 01 10 */
459 	INVALID,		/* 1 01 11 */
460 	{ 4, ST },		/* 1 10 00: evstwhe[x] */
461 	INVALID,		/* 1 10 01 */
462 	{ 4, ST },		/* 1 10 10: evstwho[x] */
463 	INVALID,		/* 1 10 11 */
464 	{ 4, ST+E4 },		/* 1 11 00: evstwwe[x] */
465 	INVALID,		/* 1 11 01 */
466 	{ 4, ST+E4 },		/* 1 11 10: evstwwo[x] */
467 	INVALID,		/* 1 11 11 */
468 };
469 
470 #define	EVLDD		0x00
471 #define	EVLDW		0x01
472 #define	EVLDH		0x02
473 #define	EVLHHESPLAT	0x04
474 #define	EVLHHOUSPLAT	0x06
475 #define	EVLHHOSSPLAT	0x07
476 #define	EVLWHE		0x08
477 #define	EVLWHOU		0x0A
478 #define	EVLWHOS		0x0B
479 #define	EVLWWSPLAT	0x0C
480 #define	EVLWHSPLAT	0x0E
481 #define	EVSTDD		0x10
482 #define	EVSTDW		0x11
483 #define	EVSTDH		0x12
484 #define	EVSTWHE		0x18
485 #define	EVSTWHO		0x1A
486 #define	EVSTWWE		0x1C
487 #define	EVSTWWO		0x1E
488 
489 /*
490  * Emulate SPE loads and stores.
491  * Only Book-E has these instructions, and it does true little-endian,
492  * so we don't need the address swizzling.
493  */
emulate_spe(struct pt_regs * regs,unsigned int reg,unsigned int instr)494 static int emulate_spe(struct pt_regs *regs, unsigned int reg,
495 		       unsigned int instr)
496 {
497 	int ret;
498 	union {
499 		u64 ll;
500 		u32 w[2];
501 		u16 h[4];
502 		u8 v[8];
503 	} data, temp;
504 	unsigned char __user *p, *addr;
505 	unsigned long *evr = &current->thread.evr[reg];
506 	unsigned int nb, flags;
507 
508 	instr = (instr >> 1) & 0x1f;
509 
510 	/* DAR has the operand effective address */
511 	addr = (unsigned char __user *)regs->dar;
512 
513 	nb = spe_aligninfo[instr].len;
514 	flags = spe_aligninfo[instr].flags;
515 
516 	/* Verify the address of the operand */
517 	if (unlikely(user_mode(regs) &&
518 		     !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ),
519 				addr, nb)))
520 		return -EFAULT;
521 
522 	/* userland only */
523 	if (unlikely(!user_mode(regs)))
524 		return 0;
525 
526 	flush_spe_to_thread(current);
527 
528 	/* If we are loading, get the data from user space, else
529 	 * get it from register values
530 	 */
531 	if (flags & ST) {
532 		data.ll = 0;
533 		switch (instr) {
534 		case EVSTDD:
535 		case EVSTDW:
536 		case EVSTDH:
537 			data.w[0] = *evr;
538 			data.w[1] = regs->gpr[reg];
539 			break;
540 		case EVSTWHE:
541 			data.h[2] = *evr >> 16;
542 			data.h[3] = regs->gpr[reg] >> 16;
543 			break;
544 		case EVSTWHO:
545 			data.h[2] = *evr & 0xffff;
546 			data.h[3] = regs->gpr[reg] & 0xffff;
547 			break;
548 		case EVSTWWE:
549 			data.w[1] = *evr;
550 			break;
551 		case EVSTWWO:
552 			data.w[1] = regs->gpr[reg];
553 			break;
554 		default:
555 			return -EINVAL;
556 		}
557 	} else {
558 		temp.ll = data.ll = 0;
559 		ret = 0;
560 		p = addr;
561 
562 		switch (nb) {
563 		case 8:
564 			ret |= __get_user_inatomic(temp.v[0], p++);
565 			ret |= __get_user_inatomic(temp.v[1], p++);
566 			ret |= __get_user_inatomic(temp.v[2], p++);
567 			ret |= __get_user_inatomic(temp.v[3], p++);
568 		case 4:
569 			ret |= __get_user_inatomic(temp.v[4], p++);
570 			ret |= __get_user_inatomic(temp.v[5], p++);
571 		case 2:
572 			ret |= __get_user_inatomic(temp.v[6], p++);
573 			ret |= __get_user_inatomic(temp.v[7], p++);
574 			if (unlikely(ret))
575 				return -EFAULT;
576 		}
577 
578 		switch (instr) {
579 		case EVLDD:
580 		case EVLDW:
581 		case EVLDH:
582 			data.ll = temp.ll;
583 			break;
584 		case EVLHHESPLAT:
585 			data.h[0] = temp.h[3];
586 			data.h[2] = temp.h[3];
587 			break;
588 		case EVLHHOUSPLAT:
589 		case EVLHHOSSPLAT:
590 			data.h[1] = temp.h[3];
591 			data.h[3] = temp.h[3];
592 			break;
593 		case EVLWHE:
594 			data.h[0] = temp.h[2];
595 			data.h[2] = temp.h[3];
596 			break;
597 		case EVLWHOU:
598 		case EVLWHOS:
599 			data.h[1] = temp.h[2];
600 			data.h[3] = temp.h[3];
601 			break;
602 		case EVLWWSPLAT:
603 			data.w[0] = temp.w[1];
604 			data.w[1] = temp.w[1];
605 			break;
606 		case EVLWHSPLAT:
607 			data.h[0] = temp.h[2];
608 			data.h[1] = temp.h[2];
609 			data.h[2] = temp.h[3];
610 			data.h[3] = temp.h[3];
611 			break;
612 		default:
613 			return -EINVAL;
614 		}
615 	}
616 
617 	if (flags & SW) {
618 		switch (flags & 0xf0) {
619 		case E8:
620 			data.ll = swab64(data.ll);
621 			break;
622 		case E4:
623 			data.w[0] = swab32(data.w[0]);
624 			data.w[1] = swab32(data.w[1]);
625 			break;
626 		/* Its half word endian */
627 		default:
628 			data.h[0] = swab16(data.h[0]);
629 			data.h[1] = swab16(data.h[1]);
630 			data.h[2] = swab16(data.h[2]);
631 			data.h[3] = swab16(data.h[3]);
632 			break;
633 		}
634 	}
635 
636 	if (flags & SE) {
637 		data.w[0] = (s16)data.h[1];
638 		data.w[1] = (s16)data.h[3];
639 	}
640 
641 	/* Store result to memory or update registers */
642 	if (flags & ST) {
643 		ret = 0;
644 		p = addr;
645 		switch (nb) {
646 		case 8:
647 			ret |= __put_user_inatomic(data.v[0], p++);
648 			ret |= __put_user_inatomic(data.v[1], p++);
649 			ret |= __put_user_inatomic(data.v[2], p++);
650 			ret |= __put_user_inatomic(data.v[3], p++);
651 		case 4:
652 			ret |= __put_user_inatomic(data.v[4], p++);
653 			ret |= __put_user_inatomic(data.v[5], p++);
654 		case 2:
655 			ret |= __put_user_inatomic(data.v[6], p++);
656 			ret |= __put_user_inatomic(data.v[7], p++);
657 		}
658 		if (unlikely(ret))
659 			return -EFAULT;
660 	} else {
661 		*evr = data.w[0];
662 		regs->gpr[reg] = data.w[1];
663 	}
664 
665 	return 1;
666 }
667 #endif /* CONFIG_SPE */
668 
669 #ifdef CONFIG_VSX
670 /*
671  * Emulate VSX instructions...
672  */
emulate_vsx(unsigned char __user * addr,unsigned int reg,unsigned int areg,struct pt_regs * regs,unsigned int flags,unsigned int length,unsigned int elsize)673 static int emulate_vsx(unsigned char __user *addr, unsigned int reg,
674 		       unsigned int areg, struct pt_regs *regs,
675 		       unsigned int flags, unsigned int length,
676 		       unsigned int elsize)
677 {
678 	char *ptr;
679 	unsigned long *lptr;
680 	int ret = 0;
681 	int sw = 0;
682 	int i, j;
683 
684 	/* userland only */
685 	if (unlikely(!user_mode(regs)))
686 		return 0;
687 
688 	flush_vsx_to_thread(current);
689 
690 	if (reg < 32)
691 		ptr = (char *) &current->thread.fp_state.fpr[reg][0];
692 	else
693 		ptr = (char *) &current->thread.vr_state.vr[reg - 32];
694 
695 	lptr = (unsigned long *) ptr;
696 
697 #ifdef __LITTLE_ENDIAN__
698 	if (flags & SW) {
699 		elsize = length;
700 		sw = length-1;
701 	} else {
702 		/*
703 		 * The elements are BE ordered, even in LE mode, so process
704 		 * them in reverse order.
705 		 */
706 		addr += length - elsize;
707 
708 		/* 8 byte memory accesses go in the top 8 bytes of the VR */
709 		if (length == 8)
710 			ptr += 8;
711 	}
712 #else
713 	if (flags & SW)
714 		sw = elsize-1;
715 #endif
716 
717 	for (j = 0; j < length; j += elsize) {
718 		for (i = 0; i < elsize; ++i) {
719 			if (flags & ST)
720 				ret = __put_user_or_set_dar(regs, ptr[i^sw],
721 							    addr + i);
722 			else
723 				ret = __get_user_or_set_dar(regs, ptr[i^sw],
724 							    addr + i);
725 
726 			if (ret)
727 				return ret;
728 		}
729 		ptr  += elsize;
730 #ifdef __LITTLE_ENDIAN__
731 		addr -= elsize;
732 #else
733 		addr += elsize;
734 #endif
735 	}
736 
737 #ifdef __BIG_ENDIAN__
738 #define VSX_HI 0
739 #define VSX_LO 1
740 #else
741 #define VSX_HI 1
742 #define VSX_LO 0
743 #endif
744 
745 	if (!ret) {
746 		if (flags & U)
747 			regs->gpr[areg] = regs->dar;
748 
749 		/* Splat load copies the same data to top and bottom 8 bytes */
750 		if (flags & SPLT)
751 			lptr[VSX_LO] = lptr[VSX_HI];
752 		/* For 8 byte loads, zero the low 8 bytes */
753 		else if (!(flags & ST) && (8 == length))
754 			lptr[VSX_LO] = 0;
755 	} else
756 		return -EFAULT;
757 
758 	return 1;
759 }
760 #endif
761 
762 /*
763  * Called on alignment exception. Attempts to fixup
764  *
765  * Return 1 on success
766  * Return 0 if unable to handle the interrupt
767  * Return -EFAULT if data address is bad
768  */
769 
fix_alignment(struct pt_regs * regs)770 int fix_alignment(struct pt_regs *regs)
771 {
772 	unsigned int instr, nb, flags, instruction = 0;
773 	unsigned int reg, areg;
774 	unsigned int dsisr;
775 	unsigned char __user *addr;
776 	unsigned long p, swiz;
777 	int i;
778 	union data {
779 		u64 ll;
780 		double dd;
781 		unsigned char v[8];
782 		struct {
783 #ifdef __LITTLE_ENDIAN__
784 			int	 low32;
785 			unsigned hi32;
786 #else
787 			unsigned hi32;
788 			int	 low32;
789 #endif
790 		} x32;
791 		struct {
792 #ifdef __LITTLE_ENDIAN__
793 			short	      low16;
794 			unsigned char hi48[6];
795 #else
796 			unsigned char hi48[6];
797 			short	      low16;
798 #endif
799 		} x16;
800 	} data;
801 
802 	/*
803 	 * We require a complete register set, if not, then our assembly
804 	 * is broken
805 	 */
806 	CHECK_FULL_REGS(regs);
807 
808 	dsisr = regs->dsisr;
809 
810 	/* Some processors don't provide us with a DSISR we can use here,
811 	 * let's make one up from the instruction
812 	 */
813 	if (cpu_has_feature(CPU_FTR_NODSISRALIGN)) {
814 		unsigned long pc = regs->nip;
815 
816 		if (cpu_has_feature(CPU_FTR_PPC_LE) && (regs->msr & MSR_LE))
817 			pc ^= 4;
818 		if (unlikely(__get_user_inatomic(instr,
819 						 (unsigned int __user *)pc)))
820 			return -EFAULT;
821 		if (cpu_has_feature(CPU_FTR_REAL_LE) && (regs->msr & MSR_LE))
822 			instr = cpu_to_le32(instr);
823 		dsisr = make_dsisr(instr);
824 		instruction = instr;
825 	}
826 
827 	/* extract the operation and registers from the dsisr */
828 	reg = (dsisr >> 5) & 0x1f;	/* source/dest register */
829 	areg = dsisr & 0x1f;		/* register to update */
830 
831 #ifdef CONFIG_SPE
832 	if ((instr >> 26) == 0x4) {
833 		PPC_WARN_ALIGNMENT(spe, regs);
834 		return emulate_spe(regs, reg, instr);
835 	}
836 #endif
837 
838 	instr = (dsisr >> 10) & 0x7f;
839 	instr |= (dsisr >> 13) & 0x60;
840 
841 	/* Lookup the operation in our table */
842 	nb = aligninfo[instr].len;
843 	flags = aligninfo[instr].flags;
844 
845 	/*
846 	 * Handle some cases which give overlaps in the DSISR values.
847 	 */
848 	if (IS_XFORM(instruction)) {
849 		switch (get_xop(instruction)) {
850 		case 532:	/* ldbrx */
851 			nb = 8;
852 			flags = LD+SW;
853 			break;
854 		case 660:	/* stdbrx */
855 			nb = 8;
856 			flags = ST+SW;
857 			break;
858 		case 20:	/* lwarx */
859 		case 84:	/* ldarx */
860 		case 116:	/* lharx */
861 		case 276:	/* lqarx */
862 			return 0;	/* not emulated ever */
863 		}
864 	}
865 
866 	/* Byteswap little endian loads and stores */
867 	swiz = 0;
868 	if ((regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE)) {
869 		flags ^= SW;
870 #ifdef __BIG_ENDIAN__
871 		/*
872 		 * So-called "PowerPC little endian" mode works by
873 		 * swizzling addresses rather than by actually doing
874 		 * any byte-swapping.  To emulate this, we XOR each
875 		 * byte address with 7.  We also byte-swap, because
876 		 * the processor's address swizzling depends on the
877 		 * operand size (it xors the address with 7 for bytes,
878 		 * 6 for halfwords, 4 for words, 0 for doublewords) but
879 		 * we will xor with 7 and load/store each byte separately.
880 		 */
881 		if (cpu_has_feature(CPU_FTR_PPC_LE))
882 			swiz = 7;
883 #endif
884 	}
885 
886 	/* DAR has the operand effective address */
887 	addr = (unsigned char __user *)regs->dar;
888 
889 #ifdef CONFIG_VSX
890 	if ((instruction & 0xfc00003e) == 0x7c000018) {
891 		unsigned int elsize;
892 
893 		/* Additional register addressing bit (64 VSX vs 32 FPR/GPR) */
894 		reg |= (instruction & 0x1) << 5;
895 		/* Simple inline decoder instead of a table */
896 		/* VSX has only 8 and 16 byte memory accesses */
897 		nb = 8;
898 		if (instruction & 0x200)
899 			nb = 16;
900 
901 		/* Vector stores in little-endian mode swap individual
902 		   elements, so process them separately */
903 		elsize = 4;
904 		if (instruction & 0x80)
905 			elsize = 8;
906 
907 		flags = 0;
908 		if ((regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE))
909 			flags |= SW;
910 		if (instruction & 0x100)
911 			flags |= ST;
912 		if (instruction & 0x040)
913 			flags |= U;
914 		/* splat load needs a special decoder */
915 		if ((instruction & 0x400) == 0){
916 			flags |= SPLT;
917 			nb = 8;
918 		}
919 		PPC_WARN_ALIGNMENT(vsx, regs);
920 		return emulate_vsx(addr, reg, areg, regs, flags, nb, elsize);
921 	}
922 #endif
923 	/* A size of 0 indicates an instruction we don't support, with
924 	 * the exception of DCBZ which is handled as a special case here
925 	 */
926 	if (instr == DCBZ) {
927 		PPC_WARN_ALIGNMENT(dcbz, regs);
928 		return emulate_dcbz(regs, addr);
929 	}
930 	if (unlikely(nb == 0))
931 		return 0;
932 
933 	/* Load/Store Multiple instructions are handled in their own
934 	 * function
935 	 */
936 	if (flags & M) {
937 		PPC_WARN_ALIGNMENT(multiple, regs);
938 		return emulate_multiple(regs, addr, reg, nb,
939 					flags, instr, swiz);
940 	}
941 
942 	/* Verify the address of the operand */
943 	if (unlikely(user_mode(regs) &&
944 		     !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ),
945 				addr, nb)))
946 		return -EFAULT;
947 
948 	/* Force the fprs into the save area so we can reference them */
949 	if (flags & F) {
950 		/* userland only */
951 		if (unlikely(!user_mode(regs)))
952 			return 0;
953 		flush_fp_to_thread(current);
954 	}
955 
956 	if (nb == 16) {
957 		if (flags & F) {
958 			/* Special case for 16-byte FP loads and stores */
959 			PPC_WARN_ALIGNMENT(fp_pair, regs);
960 			return emulate_fp_pair(regs, addr, reg, flags);
961 		} else {
962 #ifdef CONFIG_PPC64
963 			/* Special case for 16-byte loads and stores */
964 			PPC_WARN_ALIGNMENT(lq_stq, regs);
965 			return emulate_lq_stq(regs, addr, reg, flags);
966 #else
967 			return 0;
968 #endif
969 		}
970 	}
971 
972 	PPC_WARN_ALIGNMENT(unaligned, regs);
973 
974 	/* If we are loading, get the data from user space, else
975 	 * get it from register values
976 	 */
977 	if (!(flags & ST)) {
978 		unsigned int start = 0;
979 
980 		switch (nb) {
981 		case 4:
982 			start = offsetof(union data, x32.low32);
983 			break;
984 		case 2:
985 			start = offsetof(union data, x16.low16);
986 			break;
987 		}
988 
989 		data.ll = 0;
990 		p = (unsigned long)addr;
991 
992 		for (i = 0; i < nb; i++)
993 			if (__get_user_or_set_dar(regs, data.v[start + i],
994 						  SWIZ_PTR(p++)))
995 				return -EFAULT;
996 
997 	} else if (flags & F) {
998 		data.ll = current->thread.TS_FPR(reg);
999 		if (flags & S) {
1000 			/* Single-precision FP store requires conversion... */
1001 #ifdef CONFIG_PPC_FPU
1002 			preempt_disable();
1003 			enable_kernel_fp();
1004 			cvt_df(&data.dd, (float *)&data.x32.low32);
1005 			preempt_enable();
1006 #else
1007 			return 0;
1008 #endif
1009 		}
1010 	} else
1011 		data.ll = regs->gpr[reg];
1012 
1013 	if (flags & SW) {
1014 		switch (nb) {
1015 		case 8:
1016 			data.ll = swab64(data.ll);
1017 			break;
1018 		case 4:
1019 			data.x32.low32 = swab32(data.x32.low32);
1020 			break;
1021 		case 2:
1022 			data.x16.low16 = swab16(data.x16.low16);
1023 			break;
1024 		}
1025 	}
1026 
1027 	/* Perform other misc operations like sign extension
1028 	 * or floating point single precision conversion
1029 	 */
1030 	switch (flags & ~(U|SW)) {
1031 	case LD+SE:	/* sign extending integer loads */
1032 	case LD+F+SE:	/* sign extend for lfiwax */
1033 		if ( nb == 2 )
1034 			data.ll = data.x16.low16;
1035 		else	/* nb must be 4 */
1036 			data.ll = data.x32.low32;
1037 		break;
1038 
1039 	/* Single-precision FP load requires conversion... */
1040 	case LD+F+S:
1041 #ifdef CONFIG_PPC_FPU
1042 		preempt_disable();
1043 		enable_kernel_fp();
1044 		cvt_fd((float *)&data.x32.low32, &data.dd);
1045 		preempt_enable();
1046 #else
1047 		return 0;
1048 #endif
1049 		break;
1050 	}
1051 
1052 	/* Store result to memory or update registers */
1053 	if (flags & ST) {
1054 		unsigned int start = 0;
1055 
1056 		switch (nb) {
1057 		case 4:
1058 			start = offsetof(union data, x32.low32);
1059 			break;
1060 		case 2:
1061 			start = offsetof(union data, x16.low16);
1062 			break;
1063 		}
1064 
1065 		p = (unsigned long)addr;
1066 
1067 		for (i = 0; i < nb; i++)
1068 			if (__put_user_or_set_dar(regs, data.v[start + i],
1069 						  SWIZ_PTR(p++)))
1070 				return -EFAULT;
1071 
1072 	} else if (flags & F)
1073 		current->thread.TS_FPR(reg) = data.ll;
1074 	else
1075 		regs->gpr[reg] = data.ll;
1076 
1077 	/* Update RA as needed */
1078 	if (flags & U)
1079 		regs->gpr[areg] = regs->dar;
1080 
1081 	return 1;
1082 }
1083