aboutsummaryrefslogtreecommitdiff
path: root/arch/parisc/kernel/unaligned.c
blob: 92328fbddb3e8becf3ffa346a02d7d9988624e38 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
/*
 *    Unaligned memory access handler
 *
 *    Copyright (C) 2001 Randolph Chung <tausq@debian.org>
 *    Significantly tweaked by LaMont Jones <lamont@debian.org>
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/uaccess.h>

/* #define DEBUG_UNALIGNED 1 */

#ifdef DEBUG_UNALIGNED
#define DPRINTF(fmt, args...) do { printk(KERN_DEBUG "%s:%d:%s ", __FILE__, __LINE__, __FUNCTION__ ); printk(KERN_DEBUG fmt, ##args ); } while (0)
#else
#define DPRINTF(fmt, args...)
#endif

#ifdef __LP64__
#define RFMT "%016lx"
#else
#define RFMT "%08lx"
#endif

#define FIXUP_BRANCH(lbl) \
	"\tldil L%%" #lbl ", %%r1\n"			\
	"\tldo R%%" #lbl "(%%r1), %%r1\n"		\
	"\tbv,n %%r0(%%r1)\n"
/* If you use FIXUP_BRANCH, then you must list this clobber */
#define FIXUP_BRANCH_CLOBBER "r1"

/* 1111 1100 0000 0000 0001 0011 1100 0000 */
#define OPCODE1(a,b,c)	((a)<<26|(b)<<12|(c)<<6) 
#define OPCODE2(a,b)	((a)<<26|(b)<<1)
#define OPCODE3(a,b)	((a)<<26|(b)<<2)
#define OPCODE4(a)	((a)<<26)
#define OPCODE1_MASK	OPCODE1(0x3f,1,0xf)
#define OPCODE2_MASK 	OPCODE2(0x3f,1)
#define OPCODE3_MASK	OPCODE3(0x3f,1)
#define OPCODE4_MASK    OPCODE4(0x3f)

/* skip LDB - never unaligned (index) */
#define OPCODE_LDH_I	OPCODE1(0x03,0,0x1)
#define OPCODE_LDW_I	OPCODE1(0x03,0,0x2)
#define OPCODE_LDD_I	OPCODE1(0x03,0,0x3)
#define OPCODE_LDDA_I	OPCODE1(0x03,0,0x4)
#define OPCODE_LDCD_I	OPCODE1(0x03,0,0x5)
#define OPCODE_LDWA_I	OPCODE1(0x03,0,0x6)
#define OPCODE_LDCW_I	OPCODE1(0x03,0,0x7)
/* skip LDB - never unaligned (short) */
#define OPCODE_LDH_S	OPCODE1(0x03,1,0x1)
#define OPCODE_LDW_S	OPCODE1(0x03,1,0x2)
#define OPCODE_LDD_S	OPCODE1(0x03,1,0x3)
#define OPCODE_LDDA_S	OPCODE1(0x03,1,0x4)
#define OPCODE_LDCD_S	OPCODE1(0x03,1,0x5)
#define OPCODE_LDWA_S	OPCODE1(0x03,1,0x6)
#define OPCODE_LDCW_S	OPCODE1(0x03,1,0x7)
/* skip STB - never unaligned */
#define OPCODE_STH	OPCODE1(0x03,1,0x9)
#define OPCODE_STW	OPCODE1(0x03,1,0xa)
#define OPCODE_STD	OPCODE1(0x03,1,0xb)
/* skip STBY - never unaligned */
/* skip STDBY - never unaligned */
#define OPCODE_STWA	OPCODE1(0x03,1,0xe)
#define OPCODE_STDA	OPCODE1(0x03,1,0xf)

#define OPCODE_FLDWX	OPCODE1(0x09,0,0x0)
#define OPCODE_FLDWXR	OPCODE1(0x09,0,0x1)
#define OPCODE_FSTWX	OPCODE1(0x09,0,0x8)
#define OPCODE_FSTWXR	OPCODE1(0x09,0,0x9)
#define OPCODE_FLDWS	OPCODE1(0x09,1,0x0)
#define OPCODE_FLDWSR	OPCODE1(0x09,1,0x1)
#define OPCODE_FSTWS	OPCODE1(0x09,1,0x8)
#define OPCODE_FSTWSR	OPCODE1(0x09,1,0x9)
#define OPCODE_FLDDX	OPCODE1(0x0b,0,0x0)
#define OPCODE_FSTDX	OPCODE1(0x0b,0,0x8)
#define OPCODE_FLDDS	OPCODE1(0x0b,1,0x0)
#define OPCODE_FSTDS	OPCODE1(0x0b,1,0x8)

#define OPCODE_LDD_L	OPCODE2(0x14,0)
#define OPCODE_FLDD_L	OPCODE2(0x14,1)
#define OPCODE_STD_L	OPCODE2(0x1c,0)
#define OPCODE_FSTD_L	OPCODE2(0x1c,1)

#define OPCODE_LDW_M	OPCODE3(0x17,1)
#define OPCODE_FLDW_L	OPCODE3(0x17,0)
#define OPCODE_FSTW_L	OPCODE3(0x1f,0)
#define OPCODE_STW_M	OPCODE3(0x1f,1)

#define OPCODE_LDH_L    OPCODE4(0x11)
#define OPCODE_LDW_L    OPCODE4(0x12)
#define OPCODE_LDWM     OPCODE4(0x13)
#define OPCODE_STH_L    OPCODE4(0x19)
#define OPCODE_STW_L    OPCODE4(0x1A)
#define OPCODE_STWM     OPCODE4(0x1B)

#define MAJOR_OP(i) (((i)>>26)&0x3f)
#define R1(i) (((i)>>21)&0x1f)
#define R2(i) (((i)>>16)&0x1f)
#define R3(i) ((i)&0x1f)
#define FR3(i) ((((i)<<1)&0x1f)|(((i)>>6)&1))
#define IM(i,n) (((i)>>1&((1<<(n-1))-1))|((i)&1?((0-1L)<<(n-1)):0))
#define IM5_2(i) IM((i)>>16,5)
#define IM5_3(i) IM((i),5)
#define IM14(i) IM((i),14)

#define ERR_NOTHANDLED	-1
#define ERR_PAGEFAULT	-2

int unaligned_enabled __read_mostly = 1;

void die_if_kernel (char *str, struct pt_regs *regs, long err);

static int emulate_ldh(struct pt_regs *regs, int toreg)
{
	unsigned long saddr = regs->ior;
	unsigned long val = 0;
	int ret;

	DPRINTF("load " RFMT ":" RFMT " to r%d for 2 bytes\n", 
		regs->isr, regs->ior, toreg);

	__asm__ __volatile__  (
"	mtsp	%4, %%sr1\n"
"1:	ldbs	0(%%sr1,%3), %%r20\n"
"2:	ldbs	1(%%sr1,%3), %0\n"
"	depw	%%r20, 23, 24, %0\n"
"	copy	%%r0, %1\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %1\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (val), "=r" (ret)
	: "0" (val), "r" (saddr), "r" (regs->isr)
	: "r20", FIXUP_BRANCH_CLOBBER );

	DPRINTF("val = 0x" RFMT "\n", val);

	if (toreg)
		regs->gr[toreg] = val;

	return ret;
}

static int emulate_ldw(struct pt_regs *regs, int toreg, int flop)
{
	unsigned long saddr = regs->ior;
	unsigned long val = 0;
	int ret;

	DPRINTF("load " RFMT ":" RFMT " to r%d for 4 bytes\n", 
		regs->isr, regs->ior, toreg);

	__asm__ __volatile__  (
"	zdep	%3,28,2,%%r19\n"		/* r19=(ofs&3)*8 */
"	mtsp	%4, %%sr1\n"
"	depw	%%r0,31,2,%3\n"
"1:	ldw	0(%%sr1,%3),%0\n"
"2:	ldw	4(%%sr1,%3),%%r20\n"
"	subi	32,%%r19,%%r19\n"
"	mtctl	%%r19,11\n"
"	vshd	%0,%%r20,%0\n"
"	copy	%%r0, %1\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %1\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (val), "=r" (ret)
	: "0" (val), "r" (saddr), "r" (regs->isr)
	: "r19", "r20", FIXUP_BRANCH_CLOBBER );

	DPRINTF("val = 0x" RFMT "\n", val);

	if (flop)
		((__u32*)(regs->fr))[toreg] = val;
	else if (toreg)
		regs->gr[toreg] = val;

	return ret;
}
static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
{
	unsigned long saddr = regs->ior;
	__u64 val = 0;
	int ret;

	DPRINTF("load " RFMT ":" RFMT " to r%d for 8 bytes\n", 
		regs->isr, regs->ior, toreg);
#ifdef CONFIG_PA20

#ifndef __LP64__
	if (!flop)
		return -1;
#endif
	__asm__ __volatile__  (
"	depd,z	%3,60,3,%%r19\n"		/* r19=(ofs&7)*8 */
"	mtsp	%4, %%sr1\n"
"	depd	%%r0,63,3,%3\n"
"1:	ldd	0(%%sr1,%3),%0\n"
"2:	ldd	8(%%sr1,%3),%%r20\n"
"	subi	64,%%r19,%%r19\n"
"	mtsar	%%r19\n"
"	shrpd	%0,%%r20,%%sar,%0\n"
"	copy	%%r0, %1\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %1\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (val), "=r" (ret)
	: "0" (val), "r" (saddr), "r" (regs->isr)
	: "r19", "r20", FIXUP_BRANCH_CLOBBER );
#else
    {
	unsigned long valh=0,vall=0;
	__asm__ __volatile__  (
"	zdep	%5,29,2,%%r19\n"		/* r19=(ofs&3)*8 */
"	mtsp	%6, %%sr1\n"
"	dep	%%r0,31,2,%5\n"
"1:	ldw	0(%%sr1,%5),%0\n"
"2:	ldw	4(%%sr1,%5),%1\n"
"3:	ldw	8(%%sr1,%5),%%r20\n"
"	subi	32,%%r19,%%r19\n"
"	mtsar	%%r19\n"
"	vshd	%0,%1,%0\n"
"	vshd	%1,%%r20,%1\n"
"	copy	%%r0, %2\n"
"4:	\n"
"	.section .fixup,\"ax\"\n"
"5:	ldi	-2, %2\n"
	FIXUP_BRANCH(4b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,5b\n"
"	.dword  2b,5b\n"
"	.dword	3b,5b\n"
#else
"	.word	1b,5b\n"
"	.word	2b,5b\n"
"	.word	3b,5b\n"
#endif
"	.previous\n"
	: "=r" (valh), "=r" (vall), "=r" (ret)
	: "0" (valh), "1" (vall), "r" (saddr), "r" (regs->isr)
	: "r19", "r20", FIXUP_BRANCH_CLOBBER );
	val=((__u64)valh<<32)|(__u64)vall;
    }
#endif

	DPRINTF("val = 0x%llx\n", val);

	if (flop)
		regs->fr[toreg] = val;
	else if (toreg)
		regs->gr[toreg] = val;

	return ret;
}

static int emulate_sth(struct pt_regs *regs, int frreg)
{
	unsigned long val = regs->gr[frreg];
	int ret;

	if (!frreg)
		val = 0;

	DPRINTF("store r%d (0x" RFMT ") to " RFMT ":" RFMT " for 2 bytes\n", frreg, 
		val, regs->isr, regs->ior);

	__asm__ __volatile__ (
"	mtsp %3, %%sr1\n"
"	extrw,u %1, 23, 8, %%r19\n"
"1:	stb %1, 1(%%sr1, %2)\n"
"2:	stb %%r19, 0(%%sr1, %2)\n"
"	copy	%%r0, %0\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %0\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (ret)
	: "r" (val), "r" (regs->ior), "r" (regs->isr)
	: "r19", FIXUP_BRANCH_CLOBBER );

	return ret;
}

static int emulate_stw(struct pt_regs *regs, int frreg, int flop)
{
	unsigned long val;
	int ret;

	if (flop)
		val = ((__u32*)(regs->fr))[frreg];
	else if (frreg)
		val = regs->gr[frreg];
	else
		val = 0;

	DPRINTF("store r%d (0x" RFMT ") to " RFMT ":" RFMT " for 4 bytes\n", frreg, 
		val, regs->isr, regs->ior);


	__asm__ __volatile__ (
"	mtsp %3, %%sr1\n"
"	zdep	%2, 28, 2, %%r19\n"
"	dep	%%r0, 31, 2, %2\n"
"	mtsar	%%r19\n"
"	depwi,z	-2, %%sar, 32, %%r19\n"
"1:	ldw	0(%%sr1,%2),%%r20\n"
"2:	ldw	4(%%sr1,%2),%%r21\n"
"	vshd	%%r0, %1, %%r22\n"
"	vshd	%1, %%r0, %%r1\n"
"	and	%%r20, %%r19, %%r20\n"
"	andcm	%%r21, %%r19, %%r21\n"
"	or	%%r22, %%r20, %%r20\n"
"	or	%%r1, %%r21, %%r21\n"
"	stw	%%r20,0(%%sr1,%2)\n"
"	stw	%%r21,4(%%sr1,%2)\n"
"	copy	%%r0, %0\n"
"3:	\n"
"	.section .fixup,\"ax\"\n"
"4:	ldi	-2, %0\n"
	FIXUP_BRANCH(3b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,4b\n"
"	.dword  2b,4b\n"
#else
"	.word	1b,4b\n"
"	.word	2b,4b\n"
#endif
"	.previous\n"
	: "=r" (ret)
	: "r" (val), "r" (regs->ior), "r" (regs->isr)
	: "r19", "r20", "r21", "r22", "r1", FIXUP_BRANCH_CLOBBER );

	return 0;
}
static int emulate_std(struct pt_regs *regs, int frreg, int flop)
{
	__u64 val;
	int ret;

	if (flop)
		val = regs->fr[frreg];
	else if (frreg)
		val = regs->gr[frreg];
	else
		val = 0;

	DPRINTF("store r%d (0x%016llx) to " RFMT ":" RFMT " for 8 bytes\n", frreg, 
		val,  regs->isr, regs->ior);

#ifdef CONFIG_PA20
#ifndef __LP64__
	if (!flop)
		return -1;
#endif
	__asm__ __volatile__ (
"	mtsp %3, %%sr1\n"
"	depd,z	%2, 60, 3, %%r19\n"
"	depd	%%r0, 63, 3, %2\n"
"	mtsar	%%r19\n"
"	depdi,z	-2, %%sar, 64, %%r19\n"
"1:	ldd	0(%%sr1,%2),%%r20\n"
"2:	ldd	8(%%sr1,%2),%%r21\n"
"	shrpd	%%r0, %1, %%sar, %%r22\n"
"	shrpd	%1, %%r0, %%sar, %%r1\n"
"	and	%%r20, %%r19, %%r20\n"
"	andcm	%%r21, %%r19, %%r21\n"
"	or	%%r22, %%r20, %%r20\n"
"	or	%%r1, %%r21, %%r21\n"
"3:	std	%%r20,0(%%sr1,%2)\n"
"4:	std	%%r21,8(%%sr1,%2)\n"
"	copy	%%r0, %0\n"
"5:	\n"
"	.section .fixup,\"ax\"\n"
"6:	ldi	-2, %0\n"
	FIXUP_BRANCH(5b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,6b\n"
"	.dword  2b,6b\n"
"	.dword	3b,6b\n"
"	.dword  4b,6b\n"
#else
"	.word	1b,6b\n"
"	.word	2b,6b\n"
"	.word	3b,6b\n"
"	.word	4b,6b\n"
#endif
"	.previous\n"
	: "=r" (ret)
	: "r" (val), "r" (regs->ior), "r" (regs->isr)
	: "r19", "r20", "r21", "r22", "r1", FIXUP_BRANCH_CLOBBER );
#else
    {
	unsigned long valh=(val>>32),vall=(val&0xffffffffl);
	__asm__ __volatile__ (
"	mtsp	%4, %%sr1\n"
"	zdep	%2, 29, 2, %%r19\n"
"	dep	%%r0, 31, 2, %2\n"
"	mtsar	%%r19\n"
"	zvdepi	-2, 32, %%r19\n"
"1:	ldw	0(%%sr1,%3),%%r20\n"
"2:	ldw	8(%%sr1,%3),%%r21\n"
"	vshd	%1, %2, %%r1\n"
"	vshd	%%r0, %1, %1\n"
"	vshd	%2, %%r0, %2\n"
"	and	%%r20, %%r19, %%r20\n"
"	andcm	%%r21, %%r19, %%r21\n"
"	or	%1, %%r20, %1\n"
"	or	%2, %%r21, %2\n"
"3:	stw	%1,0(%%sr1,%1)\n"
"4:	stw	%%r1,4(%%sr1,%3)\n"
"5:	stw	%2,8(%%sr1,%3)\n"
"	copy	%%r0, %0\n"
"6:	\n"
"	.section .fixup,\"ax\"\n"
"7:	ldi	-2, %0\n"
	FIXUP_BRANCH(6b)
"	.previous\n"
"	.section __ex_table,\"aw\"\n"
#ifdef __LP64__
"	.dword	1b,7b\n"
"	.dword  2b,7b\n"
"	.dword	3b,7b\n"
"	.dword  4b,7b\n"
"	.dword  5b,7b\n"
#else
"	.word	1b,7b\n"
"	.word	2b,7b\n"
"	.word	3b,7b\n"
"	.word	4b,7b\n"
"	.word  	5b,7b\n"
#endif
"	.previous\n"
	: "=r" (ret)
	: "r" (valh), "r" (vall), "r" (regs->ior), "r" (regs->isr)
	: "r19", "r20", "r21", "r1", FIXUP_BRANCH_CLOBBER );
    }
#endif

	return ret;
}

void handle_unaligned(struct pt_regs *regs)
{
	static unsigned long unaligned_count = 0;
	static unsigned long last_time = 0;
	unsigned long newbase = R1(regs->iir)?regs->gr[R1(regs->iir)]:0;
	int modify = 0;
	int ret = ERR_NOTHANDLED;
	struct siginfo si;
	register int flop=0;	/* true if this is a flop */

	/* log a message with pacing */
	if (user_mode(regs)) {
		if (current->thread.flags & PARISC_UAC_SIGBUS) {
			goto force_sigbus;
		}

		if (unaligned_count > 5 && jiffies - last_time > 5*HZ) {
			unaligned_count = 0;
			last_time = jiffies;
		}

		if (!(current->thread.flags & PARISC_UAC_NOPRINT) 
		    && ++unaligned_count < 5) {
			char buf[256];
			sprintf(buf, "%s(%d): unaligned access to 0x" RFMT " at ip=0x" RFMT "\n",
				current->comm, current->pid, regs->ior, regs->iaoq[0]);
			printk(KERN_WARNING "%s", buf);
#ifdef DEBUG_UNALIGNED
			show_regs(regs);
#endif		
		}

		if (!unaligned_enabled)
			goto force_sigbus;
	}

	/* handle modification - OK, it's ugly, see the instruction manual */
	switch (MAJOR_OP(regs->iir))
	{
	case 0x03:
	case 0x09:
	case 0x0b:
		if (regs->iir&0x20)
		{
			modify = 1;
			if (regs->iir&0x1000)		/* short loads */
				if (regs->iir&0x200)
					newbase += IM5_3(regs->iir);
				else
					newbase += IM5_2(regs->iir);
			else if (regs->iir&0x2000)	/* scaled indexed */
			{
				int shift=0;
				switch (regs->iir & OPCODE1_MASK)
				{
				case OPCODE_LDH_I:
					shift= 1; break;
				case OPCODE_LDW_I:
					shift= 2; break;
				case OPCODE_LDD_I:
				case OPCODE_LDDA_I:
					shift= 3; break;
				}
				newbase += (R2(regs->iir)?regs->gr[R2(regs->iir)]:0)<<shift;
			} else				/* simple indexed */
				newbase += (R2(regs->iir)?regs->gr[R2(regs->iir)]:0);
		}
		break;
	case 0x13:
	case 0x1b:
		modify = 1;
		newbase += IM14(regs->iir);
		break;
	case 0x14:
	case 0x1c:
		if (regs->iir&8)
		{
			modify = 1;
			newbase += IM14(regs->iir&~0xe);
		}
		break;
	case 0x16:
	case 0x1e:
		modify = 1;
		newbase += IM14(regs->iir&6);
		break;
	case 0x17:
	case 0x1f:
		if (regs->iir&4)
		{
			modify = 1;
			newbase += IM14(regs->iir&~4);
		}
		break;
	}

	/* TODO: make this cleaner... */
	switch (regs->iir & OPCODE1_MASK)
	{
	case OPCODE_LDH_I:
	case OPCODE_LDH_S:
		ret = emulate_ldh(regs, R3(regs->iir));
		break;

	case OPCODE_LDW_I:
	case OPCODE_LDWA_I:
	case OPCODE_LDW_S:
	case OPCODE_LDWA_S:
		ret = emulate_ldw(regs, R3(regs->iir),0);
		break;

	case OPCODE_STH:
		ret = emulate_sth(regs, R2(regs->iir));
		break;

	case OPCODE_STW:
	case OPCODE_STWA:
		ret = emulate_stw(regs, R2(regs->iir),0);
		break;

#ifdef CONFIG_PA20
	case OPCODE_LDD_I:
	case OPCODE_LDDA_I:
	case OPCODE_LDD_S:
	case OPCODE_LDDA_S:
		ret = emulate_ldd(regs, R3(regs->iir),0);
		break;

	case OPCODE_STD:
	case OPCODE_STDA:
		ret = emulate_std(regs, R2(regs->iir),0);
		break;
#endif

	case OPCODE_FLDWX:
	case OPCODE_FLDWS:
	case OPCODE_FLDWXR:
	case OPCODE_FLDWSR:
		flop=1;
		ret = emulate_ldw(regs,FR3(regs->iir),1);
		break;

	case OPCODE_FLDDX:
	case OPCODE_FLDDS:
		flop=1;
		ret = emulate_ldd(regs,R3(regs->iir),1);
		break;

	case OPCODE_FSTWX:
	case OPCODE_FSTWS:
	case OPCODE_FSTWXR:
	case OPCODE_FSTWSR:
		flop=1;
		ret = emulate_stw(regs,FR3(regs->iir),1);
		break;

	case OPCODE_FSTDX:
	case OPCODE_FSTDS:
		flop=1;
		ret = emulate_std(regs,R3(regs->iir),1);
		break;

	case OPCODE_LDCD_I:
	case OPCODE_LDCW_I:
	case OPCODE_LDCD_S:
	case OPCODE_LDCW_S:
		ret = ERR_NOTHANDLED;	/* "undefined", but lets kill them. */
		break;
	}
#ifdef CONFIG_PA20
	switch (regs->iir & OPCODE2_MASK)
	{
	case OPCODE_FLDD_L:
		flop=1;
		ret = emulate_ldd(regs,R2(regs->iir),1);
		break;
	case OPCODE_FSTD_L:
		flop=1;
		ret = emulate_std(regs, R2(regs->iir),1);
		break;

#ifdef CONFIG_PA20
	case OPCODE_LDD_L:
		ret = emulate_ldd(regs, R2(regs->iir),0);
		break;
	case OPCODE_STD_L:
		ret = emulate_std(regs, R2(regs->iir),0);
		break;
#endif
	}
#endif
	switch (regs->iir & OPCODE3_MASK)
	{
	case OPCODE_FLDW_L:
		flop=1;
		ret = emulate_ldw(regs, R2(regs->iir),0);
		break;
	case OPCODE_LDW_M:
		ret = emulate_ldw(regs, R2(regs->iir),1);
		break;

	case OPCODE_FSTW_L:
		flop=1;
		ret = emulate_stw(regs, R2(regs->iir),1);
		break;
	case OPCODE_STW_M:
		ret = emulate_stw(regs, R2(regs->iir),0);
		break;
	}
	switch (regs->iir & OPCODE4_MASK)
	{
	case OPCODE_LDH_L:
		ret = emulate_ldh(regs, R2(regs->iir));
		break;
	case OPCODE_LDW_L:
	case OPCODE_LDWM:
		ret = emulate_ldw(regs, R2(regs->iir),0);
		break;
	case OPCODE_STH_L:
		ret = emulate_sth(regs, R2(regs->iir));
		break;
	case OPCODE_STW_L:
	case OPCODE_STWM:
		ret = emulate_stw(regs, R2(regs->iir),0);
		break;
	}

	if (modify && R1(regs->iir))
		regs->gr[R1(regs->iir)] = newbase;


	if (ret == ERR_NOTHANDLED)
		printk(KERN_CRIT "Not-handled unaligned insn 0x%08lx\n", regs->iir);

	DPRINTF("ret = %d\n", ret);

	if (ret)
	{
		printk(KERN_CRIT "Unaligned handler failed, ret = %d\n", ret);
		die_if_kernel("Unaligned data reference", regs, 28);

		if (ret == ERR_PAGEFAULT)
		{
			si.si_signo = SIGSEGV;
			si.si_errno = 0;
			si.si_code = SEGV_MAPERR;
			si.si_addr = (void __user *)regs->ior;
			force_sig_info(SIGSEGV, &si, current);
		}
		else
		{
force_sigbus:
			/* couldn't handle it ... */
			si.si_signo = SIGBUS;
			si.si_errno = 0;
			si.si_code = BUS_ADRALN;
			si.si_addr = (void __user *)regs->ior;
			force_sig_info(SIGBUS, &si, current);
		}
		
		return;
	}

	/* else we handled it, let life go on. */
	regs->gr[0]|=PSW_N;
}

/*
 * NB: check_unaligned() is only used for PCXS processors right
 * now, so we only check for PA1.1 encodings at this point.
 */

int
check_unaligned(struct pt_regs *regs)
{
	unsigned long align_mask;

	/* Get alignment mask */

	align_mask = 0UL;
	switch (regs->iir & OPCODE1_MASK) {

	case OPCODE_LDH_I:
	case OPCODE_LDH_S:
	case OPCODE_STH:
		align_mask = 1UL;
		break;

	case OPCODE_LDW_I:
	case OPCODE_LDWA_I:
	case OPCODE_LDW_S:
	case OPCODE_LDWA_S:
	case OPCODE_STW:
	case OPCODE_STWA:
		align_mask = 3UL;
		break;

	default:
		switch (regs->iir & OPCODE4_MASK) {
		case OPCODE_LDH_L:
		case OPCODE_STH_L:
			align_mask = 1UL;
			break;
		case OPCODE_LDW_L:
		case OPCODE_LDWM:
		case OPCODE_STW_L:
		case OPCODE_STWM:
			align_mask = 3UL;
			break;
		}
		break;
	}

	return (int)(regs->ior & align_mask);
}