Linux Audio

Check our new training course

Loading...
Note: File does not exist in v5.14.15.
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * arch/sh/kernel/traps_64.c
  4 *
  5 * Copyright (C) 2000, 2001  Paolo Alberelli
  6 * Copyright (C) 2003, 2004  Paul Mundt
  7 * Copyright (C) 2003, 2004  Richard Curnow
  8 */
  9#include <linux/sched.h>
 10#include <linux/sched/debug.h>
 11#include <linux/kernel.h>
 12#include <linux/string.h>
 13#include <linux/errno.h>
 14#include <linux/ptrace.h>
 15#include <linux/timer.h>
 16#include <linux/mm.h>
 17#include <linux/smp.h>
 18#include <linux/init.h>
 19#include <linux/delay.h>
 20#include <linux/spinlock.h>
 21#include <linux/kallsyms.h>
 22#include <linux/interrupt.h>
 23#include <linux/sysctl.h>
 24#include <linux/module.h>
 25#include <linux/perf_event.h>
 26#include <linux/uaccess.h>
 27#include <asm/io.h>
 28#include <asm/alignment.h>
 29#include <asm/processor.h>
 30#include <asm/pgtable.h>
 31#include <asm/fpu.h>
 32
 33static int read_opcode(reg_size_t pc, insn_size_t *result_opcode, int from_user_mode)
 34{
 35	int get_user_error;
 36	unsigned long aligned_pc;
 37	insn_size_t opcode;
 38
 39	if ((pc & 3) == 1) {
 40		/* SHmedia */
 41		aligned_pc = pc & ~3;
 42		if (from_user_mode) {
 43			if (!access_ok(aligned_pc, sizeof(insn_size_t))) {
 44				get_user_error = -EFAULT;
 45			} else {
 46				get_user_error = __get_user(opcode, (insn_size_t *)aligned_pc);
 47				*result_opcode = opcode;
 48			}
 49			return get_user_error;
 50		} else {
 51			/* If the fault was in the kernel, we can either read
 52			 * this directly, or if not, we fault.
 53			*/
 54			*result_opcode = *(insn_size_t *)aligned_pc;
 55			return 0;
 56		}
 57	} else if ((pc & 1) == 0) {
 58		/* SHcompact */
 59		/* TODO : provide handling for this.  We don't really support
 60		   user-mode SHcompact yet, and for a kernel fault, this would
 61		   have to come from a module built for SHcompact.  */
 62		return -EFAULT;
 63	} else {
 64		/* misaligned */
 65		return -EFAULT;
 66	}
 67}
 68
 69static int address_is_sign_extended(__u64 a)
 70{
 71	__u64 b;
 72#if (NEFF == 32)
 73	b = (__u64)(__s64)(__s32)(a & 0xffffffffUL);
 74	return (b == a) ? 1 : 0;
 75#else
 76#error "Sign extend check only works for NEFF==32"
 77#endif
 78}
 79
 80/* return -1 for fault, 0 for OK */
 81static int generate_and_check_address(struct pt_regs *regs,
 82				      insn_size_t opcode,
 83				      int displacement_not_indexed,
 84				      int width_shift,
 85				      __u64 *address)
 86{
 87	__u64 base_address, addr;
 88	int basereg;
 89
 90	switch (1 << width_shift) {
 91	case 1: inc_unaligned_byte_access(); break;
 92	case 2: inc_unaligned_word_access(); break;
 93	case 4: inc_unaligned_dword_access(); break;
 94	case 8: inc_unaligned_multi_access(); break;
 95	}
 96
 97	basereg = (opcode >> 20) & 0x3f;
 98	base_address = regs->regs[basereg];
 99	if (displacement_not_indexed) {
100		__s64 displacement;
101		displacement = (opcode >> 10) & 0x3ff;
102		displacement = sign_extend64(displacement, 9);
103		addr = (__u64)((__s64)base_address + (displacement << width_shift));
104	} else {
105		__u64 offset;
106		int offsetreg;
107		offsetreg = (opcode >> 10) & 0x3f;
108		offset = regs->regs[offsetreg];
109		addr = base_address + offset;
110	}
111
112	/* Check sign extended */
113	if (!address_is_sign_extended(addr))
114		return -1;
115
116	/* Check accessible.  For misaligned access in the kernel, assume the
117	   address is always accessible (and if not, just fault when the
118	   load/store gets done.) */
119	if (user_mode(regs)) {
120		inc_unaligned_user_access();
121
122		if (addr >= TASK_SIZE)
123			return -1;
124	} else
125		inc_unaligned_kernel_access();
126
127	*address = addr;
128
129	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, addr);
130	unaligned_fixups_notify(current, opcode, regs);
131
132	return 0;
133}
134
135static void misaligned_kernel_word_load(__u64 address, int do_sign_extend, __u64 *result)
136{
137	unsigned short x;
138	unsigned char *p, *q;
139	p = (unsigned char *) (int) address;
140	q = (unsigned char *) &x;
141	q[0] = p[0];
142	q[1] = p[1];
143
144	if (do_sign_extend) {
145		*result = (__u64)(__s64) *(short *) &x;
146	} else {
147		*result = (__u64) x;
148	}
149}
150
151static void misaligned_kernel_word_store(__u64 address, __u64 value)
152{
153	unsigned short x;
154	unsigned char *p, *q;
155	p = (unsigned char *) (int) address;
156	q = (unsigned char *) &x;
157
158	x = (__u16) value;
159	p[0] = q[0];
160	p[1] = q[1];
161}
162
163static int misaligned_load(struct pt_regs *regs,
164			   insn_size_t opcode,
165			   int displacement_not_indexed,
166			   int width_shift,
167			   int do_sign_extend)
168{
169	/* Return -1 for a fault, 0 for OK */
170	int error;
171	int destreg;
172	__u64 address;
173
174	error = generate_and_check_address(regs, opcode,
175			displacement_not_indexed, width_shift, &address);
176	if (error < 0)
177		return error;
178
179	destreg = (opcode >> 4) & 0x3f;
180	if (user_mode(regs)) {
181		__u64 buffer;
182
183		if (!access_ok((unsigned long) address, 1UL<<width_shift)) {
184			return -1;
185		}
186
187		if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
188			return -1; /* fault */
189		}
190		switch (width_shift) {
191		case 1:
192			if (do_sign_extend) {
193				regs->regs[destreg] = (__u64)(__s64) *(__s16 *) &buffer;
194			} else {
195				regs->regs[destreg] = (__u64) *(__u16 *) &buffer;
196			}
197			break;
198		case 2:
199			regs->regs[destreg] = (__u64)(__s64) *(__s32 *) &buffer;
200			break;
201		case 3:
202			regs->regs[destreg] = buffer;
203			break;
204		default:
205			printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
206				width_shift, (unsigned long) regs->pc);
207			break;
208		}
209	} else {
210		/* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
211		__u64 lo, hi;
212
213		switch (width_shift) {
214		case 1:
215			misaligned_kernel_word_load(address, do_sign_extend, &regs->regs[destreg]);
216			break;
217		case 2:
218			asm ("ldlo.l %1, 0, %0" : "=r" (lo) : "r" (address));
219			asm ("ldhi.l %1, 3, %0" : "=r" (hi) : "r" (address));
220			regs->regs[destreg] = lo | hi;
221			break;
222		case 3:
223			asm ("ldlo.q %1, 0, %0" : "=r" (lo) : "r" (address));
224			asm ("ldhi.q %1, 7, %0" : "=r" (hi) : "r" (address));
225			regs->regs[destreg] = lo | hi;
226			break;
227
228		default:
229			printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
230				width_shift, (unsigned long) regs->pc);
231			break;
232		}
233	}
234
235	return 0;
236}
237
238static int misaligned_store(struct pt_regs *regs,
239			    insn_size_t opcode,
240			    int displacement_not_indexed,
241			    int width_shift)
242{
243	/* Return -1 for a fault, 0 for OK */
244	int error;
245	int srcreg;
246	__u64 address;
247
248	error = generate_and_check_address(regs, opcode,
249			displacement_not_indexed, width_shift, &address);
250	if (error < 0)
251		return error;
252
253	srcreg = (opcode >> 4) & 0x3f;
254	if (user_mode(regs)) {
255		__u64 buffer;
256
257		if (!access_ok((unsigned long) address, 1UL<<width_shift)) {
258			return -1;
259		}
260
261		switch (width_shift) {
262		case 1:
263			*(__u16 *) &buffer = (__u16) regs->regs[srcreg];
264			break;
265		case 2:
266			*(__u32 *) &buffer = (__u32) regs->regs[srcreg];
267			break;
268		case 3:
269			buffer = regs->regs[srcreg];
270			break;
271		default:
272			printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
273				width_shift, (unsigned long) regs->pc);
274			break;
275		}
276
277		if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
278			return -1; /* fault */
279		}
280	} else {
281		/* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
282		__u64 val = regs->regs[srcreg];
283
284		switch (width_shift) {
285		case 1:
286			misaligned_kernel_word_store(address, val);
287			break;
288		case 2:
289			asm ("stlo.l %1, 0, %0" : : "r" (val), "r" (address));
290			asm ("sthi.l %1, 3, %0" : : "r" (val), "r" (address));
291			break;
292		case 3:
293			asm ("stlo.q %1, 0, %0" : : "r" (val), "r" (address));
294			asm ("sthi.q %1, 7, %0" : : "r" (val), "r" (address));
295			break;
296
297		default:
298			printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
299				width_shift, (unsigned long) regs->pc);
300			break;
301		}
302	}
303
304	return 0;
305}
306
307/* Never need to fix up misaligned FPU accesses within the kernel since that's a real
308   error. */
309static int misaligned_fpu_load(struct pt_regs *regs,
310			   insn_size_t opcode,
311			   int displacement_not_indexed,
312			   int width_shift,
313			   int do_paired_load)
314{
315	/* Return -1 for a fault, 0 for OK */
316	int error;
317	int destreg;
318	__u64 address;
319
320	error = generate_and_check_address(regs, opcode,
321			displacement_not_indexed, width_shift, &address);
322	if (error < 0)
323		return error;
324
325	destreg = (opcode >> 4) & 0x3f;
326	if (user_mode(regs)) {
327		__u64 buffer;
328		__u32 buflo, bufhi;
329
330		if (!access_ok((unsigned long) address, 1UL<<width_shift)) {
331			return -1;
332		}
333
334		if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
335			return -1; /* fault */
336		}
337		/* 'current' may be the current owner of the FPU state, so
338		   context switch the registers into memory so they can be
339		   indexed by register number. */
340		if (last_task_used_math == current) {
341			enable_fpu();
342			save_fpu(current);
343			disable_fpu();
344			last_task_used_math = NULL;
345			regs->sr |= SR_FD;
346		}
347
348		buflo = *(__u32*) &buffer;
349		bufhi = *(1 + (__u32*) &buffer);
350
351		switch (width_shift) {
352		case 2:
353			current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
354			break;
355		case 3:
356			if (do_paired_load) {
357				current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
358				current->thread.xstate->hardfpu.fp_regs[destreg+1] = bufhi;
359			} else {
360#if defined(CONFIG_CPU_LITTLE_ENDIAN)
361				current->thread.xstate->hardfpu.fp_regs[destreg] = bufhi;
362				current->thread.xstate->hardfpu.fp_regs[destreg+1] = buflo;
363#else
364				current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
365				current->thread.xstate->hardfpu.fp_regs[destreg+1] = bufhi;
366#endif
367			}
368			break;
369		default:
370			printk("Unexpected width_shift %d in misaligned_fpu_load, PC=%08lx\n",
371				width_shift, (unsigned long) regs->pc);
372			break;
373		}
374		return 0;
375	} else {
376		die ("Misaligned FPU load inside kernel", regs, 0);
377		return -1;
378	}
379}
380
381static int misaligned_fpu_store(struct pt_regs *regs,
382			   insn_size_t opcode,
383			   int displacement_not_indexed,
384			   int width_shift,
385			   int do_paired_load)
386{
387	/* Return -1 for a fault, 0 for OK */
388	int error;
389	int srcreg;
390	__u64 address;
391
392	error = generate_and_check_address(regs, opcode,
393			displacement_not_indexed, width_shift, &address);
394	if (error < 0)
395		return error;
396
397	srcreg = (opcode >> 4) & 0x3f;
398	if (user_mode(regs)) {
399		__u64 buffer;
400		/* Initialise these to NaNs. */
401		__u32 buflo=0xffffffffUL, bufhi=0xffffffffUL;
402
403		if (!access_ok((unsigned long) address, 1UL<<width_shift)) {
404			return -1;
405		}
406
407		/* 'current' may be the current owner of the FPU state, so
408		   context switch the registers into memory so they can be
409		   indexed by register number. */
410		if (last_task_used_math == current) {
411			enable_fpu();
412			save_fpu(current);
413			disable_fpu();
414			last_task_used_math = NULL;
415			regs->sr |= SR_FD;
416		}
417
418		switch (width_shift) {
419		case 2:
420			buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
421			break;
422		case 3:
423			if (do_paired_load) {
424				buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
425				bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
426			} else {
427#if defined(CONFIG_CPU_LITTLE_ENDIAN)
428				bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg];
429				buflo = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
430#else
431				buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
432				bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
433#endif
434			}
435			break;
436		default:
437			printk("Unexpected width_shift %d in misaligned_fpu_store, PC=%08lx\n",
438				width_shift, (unsigned long) regs->pc);
439			break;
440		}
441
442		*(__u32*) &buffer = buflo;
443		*(1 + (__u32*) &buffer) = bufhi;
444		if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
445			return -1; /* fault */
446		}
447		return 0;
448	} else {
449		die ("Misaligned FPU load inside kernel", regs, 0);
450		return -1;
451	}
452}
453
454static int misaligned_fixup(struct pt_regs *regs)
455{
456	insn_size_t opcode;
457	int error;
458	int major, minor;
459	unsigned int user_action;
460
461	user_action = unaligned_user_action();
462	if (!(user_action & UM_FIXUP))
463		return -1;
464
465	error = read_opcode(regs->pc, &opcode, user_mode(regs));
466	if (error < 0) {
467		return error;
468	}
469	major = (opcode >> 26) & 0x3f;
470	minor = (opcode >> 16) & 0xf;
471
472	switch (major) {
473		case (0x84>>2): /* LD.W */
474			error = misaligned_load(regs, opcode, 1, 1, 1);
475			break;
476		case (0xb0>>2): /* LD.UW */
477			error = misaligned_load(regs, opcode, 1, 1, 0);
478			break;
479		case (0x88>>2): /* LD.L */
480			error = misaligned_load(regs, opcode, 1, 2, 1);
481			break;
482		case (0x8c>>2): /* LD.Q */
483			error = misaligned_load(regs, opcode, 1, 3, 0);
484			break;
485
486		case (0xa4>>2): /* ST.W */
487			error = misaligned_store(regs, opcode, 1, 1);
488			break;
489		case (0xa8>>2): /* ST.L */
490			error = misaligned_store(regs, opcode, 1, 2);
491			break;
492		case (0xac>>2): /* ST.Q */
493			error = misaligned_store(regs, opcode, 1, 3);
494			break;
495
496		case (0x40>>2): /* indexed loads */
497			switch (minor) {
498				case 0x1: /* LDX.W */
499					error = misaligned_load(regs, opcode, 0, 1, 1);
500					break;
501				case 0x5: /* LDX.UW */
502					error = misaligned_load(regs, opcode, 0, 1, 0);
503					break;
504				case 0x2: /* LDX.L */
505					error = misaligned_load(regs, opcode, 0, 2, 1);
506					break;
507				case 0x3: /* LDX.Q */
508					error = misaligned_load(regs, opcode, 0, 3, 0);
509					break;
510				default:
511					error = -1;
512					break;
513			}
514			break;
515
516		case (0x60>>2): /* indexed stores */
517			switch (minor) {
518				case 0x1: /* STX.W */
519					error = misaligned_store(regs, opcode, 0, 1);
520					break;
521				case 0x2: /* STX.L */
522					error = misaligned_store(regs, opcode, 0, 2);
523					break;
524				case 0x3: /* STX.Q */
525					error = misaligned_store(regs, opcode, 0, 3);
526					break;
527				default:
528					error = -1;
529					break;
530			}
531			break;
532
533		case (0x94>>2): /* FLD.S */
534			error = misaligned_fpu_load(regs, opcode, 1, 2, 0);
535			break;
536		case (0x98>>2): /* FLD.P */
537			error = misaligned_fpu_load(regs, opcode, 1, 3, 1);
538			break;
539		case (0x9c>>2): /* FLD.D */
540			error = misaligned_fpu_load(regs, opcode, 1, 3, 0);
541			break;
542		case (0x1c>>2): /* floating indexed loads */
543			switch (minor) {
544			case 0x8: /* FLDX.S */
545				error = misaligned_fpu_load(regs, opcode, 0, 2, 0);
546				break;
547			case 0xd: /* FLDX.P */
548				error = misaligned_fpu_load(regs, opcode, 0, 3, 1);
549				break;
550			case 0x9: /* FLDX.D */
551				error = misaligned_fpu_load(regs, opcode, 0, 3, 0);
552				break;
553			default:
554				error = -1;
555				break;
556			}
557			break;
558		case (0xb4>>2): /* FLD.S */
559			error = misaligned_fpu_store(regs, opcode, 1, 2, 0);
560			break;
561		case (0xb8>>2): /* FLD.P */
562			error = misaligned_fpu_store(regs, opcode, 1, 3, 1);
563			break;
564		case (0xbc>>2): /* FLD.D */
565			error = misaligned_fpu_store(regs, opcode, 1, 3, 0);
566			break;
567		case (0x3c>>2): /* floating indexed stores */
568			switch (minor) {
569			case 0x8: /* FSTX.S */
570				error = misaligned_fpu_store(regs, opcode, 0, 2, 0);
571				break;
572			case 0xd: /* FSTX.P */
573				error = misaligned_fpu_store(regs, opcode, 0, 3, 1);
574				break;
575			case 0x9: /* FSTX.D */
576				error = misaligned_fpu_store(regs, opcode, 0, 3, 0);
577				break;
578			default:
579				error = -1;
580				break;
581			}
582			break;
583
584		default:
585			/* Fault */
586			error = -1;
587			break;
588	}
589
590	if (error < 0) {
591		return error;
592	} else {
593		regs->pc += 4; /* Skip the instruction that's just been emulated */
594		return 0;
595	}
596}
597
598static void do_unhandled_exception(int signr, char *str, unsigned long error,
599				   struct pt_regs *regs)
600{
601	if (user_mode(regs))
602		force_sig(signr);
603
604	die_if_no_fixup(str, regs, error);
605}
606
607#define DO_ERROR(signr, str, name) \
608asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \
609{ \
610	do_unhandled_exception(signr, str, error_code, regs); \
611}
612
613DO_ERROR(SIGILL,  "illegal slot instruction", illegal_slot_inst)
614DO_ERROR(SIGSEGV, "address error (exec)", address_error_exec)
615
616#if defined(CONFIG_SH64_ID2815_WORKAROUND)
617
618#define OPCODE_INVALID      0
619#define OPCODE_USER_VALID   1
620#define OPCODE_PRIV_VALID   2
621
622/* getcon/putcon - requires checking which control register is referenced. */
623#define OPCODE_CTRL_REG     3
624
625/* Table of valid opcodes for SHmedia mode.
626   Form a 10-bit value by concatenating the major/minor opcodes i.e.
627   opcode[31:26,20:16].  The 6 MSBs of this value index into the following
628   array.  The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to
629   LSBs==4'b0000 etc). */
630static unsigned long shmedia_opcode_table[64] = {
631	0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015,
632	0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000,
633	0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000,
634	0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000,
635	0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
636	0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
637	0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
638	0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000
639};
640
641/* Workaround SH5-101 cut2 silicon defect #2815 :
642   in some situations, inter-mode branches from SHcompact -> SHmedia
643   which should take ITLBMISS or EXECPROT exceptions at the target
644   falsely take RESINST at the target instead. */
645void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
646{
647	insn_size_t opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
648	unsigned long pc, aligned_pc;
649	unsigned long index, shift;
650	unsigned long major, minor, combined;
651	unsigned long reserved_field;
652	int opcode_state;
653	int get_user_error;
654	int signr = SIGILL;
655	char *exception_name = "reserved_instruction";
656
657	pc = regs->pc;
658
659	/* SHcompact is not handled */
660	if (unlikely((pc & 3) == 0))
661		goto out;
662
663	/* SHmedia : check for defect.  This requires executable vmas
664	   to be readable too. */
665	aligned_pc = pc & ~3;
666	if (!access_ok(aligned_pc, sizeof(insn_size_t)))
667		get_user_error = -EFAULT;
668	else
669		get_user_error = __get_user(opcode, (insn_size_t *)aligned_pc);
670
671	if (get_user_error < 0) {
672		/*
673		 * Error trying to read opcode.  This typically means a
674		 * real fault, not a RESINST any more.  So change the
675		 * codes.
676		 */
677		exception_name = "address error (exec)";
678		signr = SIGSEGV;
679		goto out;
680	}
681
682	/* These bits are currently reserved as zero in all valid opcodes */
683	reserved_field = opcode & 0xf;
684	if (unlikely(reserved_field))
685		goto out;	/* invalid opcode */
686
687	major = (opcode >> 26) & 0x3f;
688	minor = (opcode >> 16) & 0xf;
689	combined = (major << 4) | minor;
690	index = major;
691	shift = minor << 1;
692	opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3;
693	switch (opcode_state) {
694	case OPCODE_INVALID:
695		/* Trap. */
696		break;
697	case OPCODE_USER_VALID:
698		/*
699		 * Restart the instruction: the branch to the instruction
700		 * will now be from an RTE not from SHcompact so the
701		 * silicon defect won't be triggered.
702		 */
703		return;
704	case OPCODE_PRIV_VALID:
705		if (!user_mode(regs)) {
706			/*
707			 * Should only ever get here if a module has
708			 * SHcompact code inside it. If so, the same fix
709			 * up is needed.
710			 */
711			return; /* same reason */
712		}
713
714		/*
715		 * Otherwise, user mode trying to execute a privileged
716		 * instruction - fall through to trap.
717		 */
718		break;
719	case OPCODE_CTRL_REG:
720		/* If in privileged mode, return as above. */
721		if (!user_mode(regs))
722			return;
723
724		/* In user mode ... */
725		if (combined == 0x9f) { /* GETCON */
726			unsigned long regno = (opcode >> 20) & 0x3f;
727
728			if (regno >= 62)
729				return;
730
731			/* reserved/privileged control register => trap */
732		} else if (combined == 0x1bf) { /* PUTCON */
733			unsigned long regno = (opcode >> 4) & 0x3f;
734
735			if (regno >= 62)
736				return;
737
738			/* reserved/privileged control register => trap */
739		}
740
741		break;
742	default:
743		/* Fall through to trap. */
744		break;
745	}
746
747out:
748	do_unhandled_exception(signr, exception_name, error_code, regs);
749}
750
751#else /* CONFIG_SH64_ID2815_WORKAROUND */
752
753/* If the workaround isn't needed, this is just a straightforward reserved
754   instruction */
755DO_ERROR(SIGILL, "reserved instruction", reserved_inst)
756
757#endif /* CONFIG_SH64_ID2815_WORKAROUND */
758
759/* Called with interrupts disabled */
760asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs)
761{
762	die_if_kernel("exception", regs, ex);
763}
764
765asmlinkage int do_unknown_trapa(unsigned long scId, struct pt_regs *regs)
766{
767	/* Syscall debug */
768	printk("System call ID error: [0x1#args:8 #syscall:16  0x%lx]\n", scId);
769
770	die_if_kernel("unknown trapa", regs, scId);
771
772	return -ENOSYS;
773}
774
775/* Implement misaligned load/store handling for kernel (and optionally for user
776   mode too).  Limitation : only SHmedia mode code is handled - there is no
777   handling at all for misaligned accesses occurring in SHcompact code yet. */
778
779asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs)
780{
781	if (misaligned_fixup(regs) < 0)
782		do_unhandled_exception(SIGSEGV, "address error(load)",
783				       error_code, regs);
784}
785
786asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs)
787{
788	if (misaligned_fixup(regs) < 0)
789		do_unhandled_exception(SIGSEGV, "address error(store)",
790				error_code, regs);
791}
792
793asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs)
794{
795	u64 peek_real_address_q(u64 addr);
796	u64 poke_real_address_q(u64 addr, u64 val);
797	unsigned long long DM_EXP_CAUSE_PHY = 0x0c100010;
798	unsigned long long exp_cause;
799	/* It's not worth ioremapping the debug module registers for the amount
800	   of access we make to them - just go direct to their physical
801	   addresses. */
802	exp_cause = peek_real_address_q(DM_EXP_CAUSE_PHY);
803	if (exp_cause & ~4)
804		printk("DM.EXP_CAUSE had unexpected bits set (=%08lx)\n",
805			(unsigned long)(exp_cause & 0xffffffff));
806	show_state();
807	/* Clear all DEBUGINT causes */
808	poke_real_address_q(DM_EXP_CAUSE_PHY, 0x0);
809}
810
811void per_cpu_trap_init(void)
812{
813	/* Nothing to do for now, VBR initialization later. */
814}