summaryrefslogtreecommitdiff
path: root/arch/loongarch/kernel/traps.c
blob: de8ebe20b666cf5934751801e615f6f16ea21f4a (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Author: Huacai Chen <chenhuacai@loongson.cn>
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/compiler.h>
#include <linux/context_tracking.h>
#include <linux/entry-common.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/module.h>
#include <linux/extable.h>
#include <linux/mm.h>
#include <linux/sched/mm.h>
#include <linux/sched/debug.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/memblock.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/kprobes.h>
#include <linux/notifier.h>
#include <linux/irq.h>
#include <linux/perf_event.h>

#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/branch.h>
#include <asm/break.h>
#include <asm/cpu.h>
#include <asm/fpu.h>
#include <asm/loongarch.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/siginfo.h>
#include <asm/stacktrace.h>
#include <asm/tlb.h>
#include <asm/types.h>
#include <asm/unwind.h>

#include "access-helper.h"

extern asmlinkage void handle_ade(void);
extern asmlinkage void handle_ale(void);
extern asmlinkage void handle_sys(void);
extern asmlinkage void handle_bp(void);
extern asmlinkage void handle_ri(void);
extern asmlinkage void handle_fpu(void);
extern asmlinkage void handle_fpe(void);
extern asmlinkage void handle_lbt(void);
extern asmlinkage void handle_lsx(void);
extern asmlinkage void handle_lasx(void);
extern asmlinkage void handle_reserved(void);
extern asmlinkage void handle_watch(void);
extern asmlinkage void handle_vint(void);

static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
			   const char *loglvl, bool user)
{
	unsigned long addr;
	struct unwind_state state;
	struct pt_regs *pregs = (struct pt_regs *)regs;

	if (!task)
		task = current;

	printk("%sCall Trace:", loglvl);
	for (unwind_start(&state, task, pregs);
	      !unwind_done(&state); unwind_next_frame(&state)) {
		addr = unwind_get_return_address(&state);
		print_ip_sym(loglvl, addr);
	}
	printk("%s\n", loglvl);
}

static void show_stacktrace(struct task_struct *task,
	const struct pt_regs *regs, const char *loglvl, bool user)
{
	int i;
	const int field = 2 * sizeof(unsigned long);
	unsigned long stackdata;
	unsigned long *sp = (unsigned long *)regs->regs[3];

	printk("%sStack :", loglvl);
	i = 0;
	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
		if (i && ((i % (64 / field)) == 0)) {
			pr_cont("\n");
			printk("%s       ", loglvl);
		}
		if (i > 39) {
			pr_cont(" ...");
			break;
		}

		if (__get_addr(&stackdata, sp++, user)) {
			pr_cont(" (Bad stack address)");
			break;
		}

		pr_cont(" %0*lx", field, stackdata);
		i++;
	}
	pr_cont("\n");
	show_backtrace(task, regs, loglvl, user);
}

void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
{
	struct pt_regs regs;

	regs.csr_crmd = 0;
	if (sp) {
		regs.csr_era = 0;
		regs.regs[1] = 0;
		regs.regs[3] = (unsigned long)sp;
	} else {
		if (!task || task == current)
			prepare_frametrace(&regs);
		else {
			regs.csr_era = task->thread.reg01;
			regs.regs[1] = 0;
			regs.regs[3] = task->thread.reg03;
			regs.regs[22] = task->thread.reg22;
		}
	}

	show_stacktrace(task, &regs, loglvl, false);
}

static void show_code(unsigned int *pc, bool user)
{
	long i;
	unsigned int insn;

	printk("Code:");

	for(i = -3 ; i < 6 ; i++) {
		if (__get_inst(&insn, pc + i, user)) {
			pr_cont(" (Bad address in era)\n");
			break;
		}
		pr_cont("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
	}
	pr_cont("\n");
}

static void __show_regs(const struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);
	unsigned int excsubcode;
	unsigned int exccode;
	int i;

	show_regs_print_info(KERN_DEFAULT);

	/*
	 * Saved main processor registers
	 */
	for (i = 0; i < 32; ) {
		if ((i % 4) == 0)
			printk("$%2d   :", i);
		pr_cont(" %0*lx", field, regs->regs[i]);

		i++;
		if ((i % 4) == 0)
			pr_cont("\n");
	}

	/*
	 * Saved csr registers
	 */
	printk("era   : %0*lx %pS\n", field, regs->csr_era,
	       (void *) regs->csr_era);
	printk("ra    : %0*lx %pS\n", field, regs->regs[1],
	       (void *) regs->regs[1]);

	printk("CSR crmd: %08lx	", regs->csr_crmd);
	printk("CSR prmd: %08lx	", regs->csr_prmd);
	printk("CSR euen: %08lx	", regs->csr_euen);
	printk("CSR ecfg: %08lx	", regs->csr_ecfg);
	printk("CSR estat: %08lx	", regs->csr_estat);

	pr_cont("\n");

	exccode = ((regs->csr_estat) & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;
	excsubcode = ((regs->csr_estat) & CSR_ESTAT_ESUBCODE) >> CSR_ESTAT_ESUBCODE_SHIFT;
	printk("ExcCode : %x (SubCode %x)\n", exccode, excsubcode);

	if (exccode >= EXCCODE_TLBL && exccode <= EXCCODE_ALE)
		printk("BadVA : %0*lx\n", field, regs->csr_badvaddr);

	printk("PrId  : %08x (%s)\n", read_cpucfg(LOONGARCH_CPUCFG0),
	       cpu_family_string());
}

void show_regs(struct pt_regs *regs)
{
	__show_regs((struct pt_regs *)regs);
	dump_stack();
}

void show_registers(struct pt_regs *regs)
{
	__show_regs(regs);
	print_modules();
	printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
	       current->comm, current->pid, current_thread_info(), current);

	show_stacktrace(current, regs, KERN_DEFAULT, user_mode(regs));
	show_code((void *)regs->csr_era, user_mode(regs));
	printk("\n");
}

static DEFINE_RAW_SPINLOCK(die_lock);

void __noreturn die(const char *str, struct pt_regs *regs)
{
	static int die_counter;
	int sig = SIGSEGV;

	oops_enter();

	if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
		       SIGSEGV) == NOTIFY_STOP)
		sig = 0;

	console_verbose();
	raw_spin_lock_irq(&die_lock);
	bust_spinlocks(1);

	printk("%s[#%d]:\n", str, ++die_counter);
	show_registers(regs);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	raw_spin_unlock_irq(&die_lock);

	oops_exit();

	if (regs && kexec_should_crash(current))
		crash_kexec(regs);

	if (in_interrupt())
		panic("Fatal exception in interrupt");

	if (panic_on_oops)
		panic("Fatal exception");

	make_task_dead(sig);
}

static inline void setup_vint_size(unsigned int size)
{
	unsigned int vs;

	vs = ilog2(size/4);

	if (vs == 0 || vs > 7)
		panic("vint_size %d Not support yet", vs);

	csr_xchg32(vs<<CSR_ECFG_VS_SHIFT, CSR_ECFG_VS, LOONGARCH_CSR_ECFG);
}

/*
 * Send SIGFPE according to FCSR Cause bits, which must have already
 * been masked against Enable bits.  This is impotant as Inexact can
 * happen together with Overflow or Underflow, and `ptrace' can set
 * any bits.
 */
void force_fcsr_sig(unsigned long fcsr, void __user *fault_addr,
		     struct task_struct *tsk)
{
	int si_code = FPE_FLTUNK;

	if (fcsr & FPU_CSR_INV_X)
		si_code = FPE_FLTINV;
	else if (fcsr & FPU_CSR_DIV_X)
		si_code = FPE_FLTDIV;
	else if (fcsr & FPU_CSR_OVF_X)
		si_code = FPE_FLTOVF;
	else if (fcsr & FPU_CSR_UDF_X)
		si_code = FPE_FLTUND;
	else if (fcsr & FPU_CSR_INE_X)
		si_code = FPE_FLTRES;

	force_sig_fault(SIGFPE, si_code, fault_addr);
}

int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcsr)
{
	int si_code;

	switch (sig) {
	case 0:
		return 0;

	case SIGFPE:
		force_fcsr_sig(fcsr, fault_addr, current);
		return 1;

	case SIGBUS:
		force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr);
		return 1;

	case SIGSEGV:
		mmap_read_lock(current->mm);
		if (vma_lookup(current->mm, (unsigned long)fault_addr))
			si_code = SEGV_ACCERR;
		else
			si_code = SEGV_MAPERR;
		mmap_read_unlock(current->mm);
		force_sig_fault(SIGSEGV, si_code, fault_addr);
		return 1;

	default:
		force_sig(sig);
		return 1;
	}
}

/*
 * Delayed fp exceptions when doing a lazy ctx switch
 */
asmlinkage void noinstr do_fpe(struct pt_regs *regs, unsigned long fcsr)
{
	int sig;
	void __user *fault_addr;
	irqentry_state_t state = irqentry_enter(regs);

	if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
		       SIGFPE) == NOTIFY_STOP)
		goto out;

	/* Clear FCSR.Cause before enabling interrupts */
	write_fcsr(LOONGARCH_FCSR0, fcsr & ~mask_fcsr_x(fcsr));
	local_irq_enable();

	die_if_kernel("FP exception in kernel code", regs);

	sig = SIGFPE;
	fault_addr = (void __user *) regs->csr_era;

	/* Send a signal if required.  */
	process_fpemu_return(sig, fault_addr, fcsr);

out:
	local_irq_disable();
	irqentry_exit(regs, state);
}

asmlinkage void noinstr do_ade(struct pt_regs *regs)
{
	irqentry_state_t state = irqentry_enter(regs);

	die_if_kernel("Kernel ade access", regs);
	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)regs->csr_badvaddr);

	irqentry_exit(regs, state);
}

/* sysctl hooks */
int unaligned_enabled __read_mostly = 1;	/* Enabled by default */
int no_unaligned_warning __read_mostly = 1;	/* Only 1 warning by default */

asmlinkage void noinstr do_ale(struct pt_regs *regs)
{
	irqentry_state_t state = irqentry_enter(regs);

#ifndef CONFIG_ARCH_STRICT_ALIGN
	die_if_kernel("Kernel ale access", regs);
	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr);
#else
	unsigned int *pc;

	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, regs->csr_badvaddr);

	/*
	 * Did we catch a fault trying to load an instruction?
	 */
	if (regs->csr_badvaddr == regs->csr_era)
		goto sigbus;
	if (user_mode(regs) && !test_thread_flag(TIF_FIXADE))
		goto sigbus;
	if (!unaligned_enabled)
		goto sigbus;
	if (!no_unaligned_warning)
		show_registers(regs);

	pc = (unsigned int *)exception_era(regs);

	emulate_load_store_insn(regs, (void __user *)regs->csr_badvaddr, pc);

	goto out;

sigbus:
	die_if_kernel("Kernel ale access", regs);
	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr);
out:
#endif
	irqentry_exit(regs, state);
}

#ifdef CONFIG_GENERIC_BUG
int is_valid_bugaddr(unsigned long addr)
{
	return 1;
}
#endif /* CONFIG_GENERIC_BUG */

static void bug_handler(struct pt_regs *regs)
{
	switch (report_bug(regs->csr_era, regs)) {
	case BUG_TRAP_TYPE_BUG:
	case BUG_TRAP_TYPE_NONE:
		die_if_kernel("Oops - BUG", regs);
		force_sig(SIGTRAP);
		break;

	case BUG_TRAP_TYPE_WARN:
		/* Skip the BUG instruction and continue */
		regs->csr_era += LOONGARCH_INSN_SIZE;
		break;
	}
}

asmlinkage void noinstr do_bp(struct pt_regs *regs)
{
	bool user = user_mode(regs);
	unsigned int opcode, bcode;
	unsigned long era = exception_era(regs);
	irqentry_state_t state = irqentry_enter(regs);

	if (regs->csr_prmd & CSR_PRMD_PIE)
		local_irq_enable();

	current->thread.trap_nr = read_csr_excode();
	if (__get_inst(&opcode, (u32 *)era, user))
		goto out_sigsegv;

	bcode = (opcode & 0x7fff);

	/*
	 * notify the kprobe handlers, if instruction is likely to
	 * pertain to them.
	 */
	switch (bcode) {
	case BRK_KPROBE_BP:
		if (kprobe_breakpoint_handler(regs))
			goto out;
		else
			break;
	case BRK_KPROBE_SSTEPBP:
		if (kprobe_singlestep_handler(regs))
			goto out;
		else
			break;
	case BRK_UPROBE_BP:
		if (notify_die(DIE_UPROBE, "Uprobe", regs, bcode,
			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
			goto out;
		else
			break;
	case BRK_UPROBE_XOLBP:
		if (notify_die(DIE_UPROBE_XOL, "Uprobe_XOL", regs, bcode,
			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
			goto out;
		else
			break;
	default:
		if (notify_die(DIE_TRAP, "Break", regs, bcode,
			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
			goto out;
		else
			break;
	}

	switch (bcode) {
	case BRK_BUG:
		bug_handler(regs);
		break;
	case BRK_DIVZERO:
		die_if_kernel("Break instruction in kernel code", regs);
		force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->csr_era);
		break;
	case BRK_OVERFLOW:
		die_if_kernel("Break instruction in kernel code", regs);
		force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->csr_era);
		break;
	default:
		die_if_kernel("Break instruction in kernel code", regs);
		force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->csr_era);
		break;
	}

out:
	if (regs->csr_prmd & CSR_PRMD_PIE)
		local_irq_disable();

	irqentry_exit(regs, state);
	return;

out_sigsegv:
	force_sig(SIGSEGV);
	goto out;
}

asmlinkage void noinstr do_watch(struct pt_regs *regs)
{
	irqentry_state_t state = irqentry_enter(regs);

#ifndef CONFIG_HAVE_HW_BREAKPOINT
	pr_warn("Hardware watch point handler not implemented!\n");
#else
	if (test_tsk_thread_flag(current, TIF_SINGLESTEP)) {
		int llbit = (csr_read32(LOONGARCH_CSR_LLBCTL) & 0x1);
		unsigned long pc = instruction_pointer(regs);
		union loongarch_instruction *ip = (union loongarch_instruction *)pc;

		if (llbit) {
			/*
			 * When the ll-sc combo is encountered, it is regarded as an single
			 * instruction. So don't clear llbit and reset CSR.FWPS.Skip until
			 * the llsc execution is completed.
			 */
			csr_write32(CSR_FWPC_SKIP, LOONGARCH_CSR_FWPS);
			csr_write32(CSR_LLBCTL_KLO, LOONGARCH_CSR_LLBCTL);
			goto out;
		}

		if (pc == current->thread.single_step) {
			/*
			 * Certain insns are occasionally not skipped when CSR.FWPS.Skip is
			 * set, such as fld.d/fst.d. So singlestep needs to compare whether
			 * the csr_era is equal to the value of singlestep which last time set.
			 */
			if (!is_self_loop_ins(ip, regs)) {
				/*
				 * Check if the given instruction the target pc is equal to the
				 * current pc, If yes, then we should not set the CSR.FWPS.SKIP
				 * bit to break the original instruction stream.
				 */
				csr_write32(CSR_FWPC_SKIP, LOONGARCH_CSR_FWPS);
				goto out;
			}
		}
	} else {
		breakpoint_handler(regs);
		watchpoint_handler(regs);
	}

	force_sig(SIGTRAP);
out:
#endif
	irqentry_exit(regs, state);
}

asmlinkage void noinstr do_ri(struct pt_regs *regs)
{
	int status = SIGILL;
	unsigned int opcode = 0;
	unsigned int __user *era = (unsigned int __user *)exception_era(regs);
	irqentry_state_t state = irqentry_enter(regs);

	local_irq_enable();
	current->thread.trap_nr = read_csr_excode();

	if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
		       SIGILL) == NOTIFY_STOP)
		goto out;

	die_if_kernel("Reserved instruction in kernel code", regs);

	if (unlikely(get_user(opcode, era) < 0)) {
		status = SIGSEGV;
		current->thread.error_code = 1;
	}

	force_sig(status);

out:
	local_irq_disable();
	irqentry_exit(regs, state);
}

static void init_restore_fp(void)
{
	if (!used_math()) {
		/* First time FP context user. */
		init_fpu();
	} else {
		/* This task has formerly used the FP context */
		if (!is_fpu_owner())
			own_fpu_inatomic(1);
	}

	BUG_ON(!is_fp_enabled());
}

asmlinkage void noinstr do_fpu(struct pt_regs *regs)
{
	irqentry_state_t state = irqentry_enter(regs);

	local_irq_enable();
	die_if_kernel("do_fpu invoked from kernel context!", regs);

	preempt_disable();
	init_restore_fp();
	preempt_enable();

	local_irq_disable();
	irqentry_exit(regs, state);
}

asmlinkage void noinstr do_lsx(struct pt_regs *regs)
{
	irqentry_state_t state = irqentry_enter(regs);

	local_irq_enable();
	force_sig(SIGILL);
	local_irq_disable();

	irqentry_exit(regs, state);
}

asmlinkage void noinstr do_lasx(struct pt_regs *regs)
{
	irqentry_state_t state = irqentry_enter(regs);

	local_irq_enable();
	force_sig(SIGILL);
	local_irq_disable();

	irqentry_exit(regs, state);
}

asmlinkage void noinstr do_lbt(struct pt_regs *regs)
{
	irqentry_state_t state = irqentry_enter(regs);

	local_irq_enable();
	force_sig(SIGILL);
	local_irq_disable();

	irqentry_exit(regs, state);
}

asmlinkage void noinstr do_reserved(struct pt_regs *regs)
{
	irqentry_state_t state = irqentry_enter(regs);

	local_irq_enable();
	/*
	 * Game over - no way to handle this if it ever occurs.	Most probably
	 * caused by a fatal error after another hardware/software error.
	 */
	pr_err("Caught reserved exception %u on pid:%d [%s] - should not happen\n",
		read_csr_excode(), current->pid, current->comm);
	die_if_kernel("do_reserved exception", regs);
	force_sig(SIGUNUSED);

	local_irq_disable();

	irqentry_exit(regs, state);
}

asmlinkage void cache_parity_error(void)
{
	/* For the moment, report the problem and hang. */
	pr_err("Cache error exception:\n");
	pr_err("csr_merrctl == %08x\n", csr_read32(LOONGARCH_CSR_MERRCTL));
	pr_err("csr_merrera == %016llx\n", csr_read64(LOONGARCH_CSR_MERRERA));
	panic("Can't handle the cache error!");
}

asmlinkage void noinstr handle_loongarch_irq(struct pt_regs *regs)
{
	struct pt_regs *old_regs;

	irq_enter_rcu();
	old_regs = set_irq_regs(regs);
	handle_arch_irq(regs);
	set_irq_regs(old_regs);
	irq_exit_rcu();
}

asmlinkage void noinstr do_vint(struct pt_regs *regs, unsigned long sp)
{
	register int cpu;
	register unsigned long stack;
	irqentry_state_t state = irqentry_enter(regs);

	cpu = smp_processor_id();

	if (on_irq_stack(cpu, sp))
		handle_loongarch_irq(regs);
	else {
		stack = per_cpu(irq_stack, cpu) + IRQ_STACK_START;

		/* Save task's sp on IRQ stack for unwinding */
		*(unsigned long *)stack = sp;

		__asm__ __volatile__(
		"move	$s0, $sp		\n" /* Preserve sp */
		"move	$sp, %[stk]		\n" /* Switch stack */
		"move	$a0, %[regs]		\n"
		"bl	handle_loongarch_irq	\n"
		"move	$sp, $s0		\n" /* Restore sp */
		: /* No outputs */
		: [stk] "r" (stack), [regs] "r" (regs)
		: "$a0", "$a1", "$a2", "$a3", "$a4", "$a5", "$a6", "$a7", "$s0",
		  "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8",
		  "memory");
	}

	irqentry_exit(regs, state);
}

unsigned long eentry;
unsigned long tlbrentry;

long exception_handlers[VECSIZE * 128 / sizeof(long)] __aligned(SZ_64K);

static void configure_exception_vector(void)
{
	eentry    = (unsigned long)exception_handlers;
	tlbrentry = (unsigned long)exception_handlers + 80*VECSIZE;

	csr_write64(eentry, LOONGARCH_CSR_EENTRY);
	csr_write64(eentry, LOONGARCH_CSR_MERRENTRY);
	csr_write64(tlbrentry, LOONGARCH_CSR_TLBRENTRY);
}

void per_cpu_trap_init(int cpu)
{
	unsigned int i;

	setup_vint_size(VECSIZE);

	configure_exception_vector();

	if (!cpu_data[cpu].asid_cache)
		cpu_data[cpu].asid_cache = asid_first_version(cpu);

	mmgrab(&init_mm);
	current->active_mm = &init_mm;
	BUG_ON(current->mm);
	enter_lazy_tlb(&init_mm, current);

	/* Initialise exception handlers */
	if (cpu == 0)
		for (i = 0; i < 64; i++)
			set_handler(i * VECSIZE, handle_reserved, VECSIZE);

	tlb_init(cpu);
	cpu_cache_init();
}

/* Install CPU exception handler */
void set_handler(unsigned long offset, void *addr, unsigned long size)
{
	memcpy((void *)(eentry + offset), addr, size);
	local_flush_icache_range(eentry + offset, eentry + offset + size);
}

static const char panic_null_cerr[] =
	"Trying to set NULL cache error exception handler\n";

/*
 * Install uncached CPU exception handler.
 * This is suitable only for the cache error exception which is the only
 * exception handler that is being run uncached.
 */
void set_merr_handler(unsigned long offset, void *addr, unsigned long size)
{
	unsigned long uncached_eentry = TO_UNCACHE(__pa(eentry));

	if (!addr)
		panic(panic_null_cerr);

	memcpy((void *)(uncached_eentry + offset), addr, size);
}

void __init trap_init(void)
{
	long i;

	/* Set interrupt vector handler */
	for (i = EXCCODE_INT_START; i < EXCCODE_INT_END; i++)
		set_handler(i * VECSIZE, handle_vint, VECSIZE);

	set_handler(EXCCODE_ADE * VECSIZE, handle_ade, VECSIZE);
	set_handler(EXCCODE_ALE * VECSIZE, handle_ale, VECSIZE);
	set_handler(EXCCODE_SYS * VECSIZE, handle_sys, VECSIZE);
	set_handler(EXCCODE_BP * VECSIZE, handle_bp, VECSIZE);
	set_handler(EXCCODE_INE * VECSIZE, handle_ri, VECSIZE);
	set_handler(EXCCODE_IPE * VECSIZE, handle_ri, VECSIZE);
	set_handler(EXCCODE_FPDIS * VECSIZE, handle_fpu, VECSIZE);
	set_handler(EXCCODE_LSXDIS * VECSIZE, handle_lsx, VECSIZE);
	set_handler(EXCCODE_LASXDIS * VECSIZE, handle_lasx, VECSIZE);
	set_handler(EXCCODE_FPE * VECSIZE, handle_fpe, VECSIZE);
	set_handler(EXCCODE_BTDIS * VECSIZE, handle_lbt, VECSIZE);
	set_handler(EXCCODE_WATCH * VECSIZE, handle_watch, VECSIZE);

	cache_error_setup();

	local_flush_icache_range(eentry, eentry + 0x400);
}