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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Author: Huacai Chen <chenhuacai@loongson.cn>
4 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
5 */
6#include <linux/bitfield.h>
7#include <linux/bitops.h>
8#include <linux/bug.h>
9#include <linux/compiler.h>
10#include <linux/context_tracking.h>
11#include <linux/entry-common.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/kexec.h>
15#include <linux/module.h>
16#include <linux/extable.h>
17#include <linux/mm.h>
18#include <linux/sched/mm.h>
19#include <linux/sched/debug.h>
20#include <linux/smp.h>
21#include <linux/spinlock.h>
22#include <linux/kallsyms.h>
23#include <linux/memblock.h>
24#include <linux/interrupt.h>
25#include <linux/ptrace.h>
26#include <linux/kgdb.h>
27#include <linux/kdebug.h>
28#include <linux/notifier.h>
29#include <linux/irq.h>
30#include <linux/perf_event.h>
31
32#include <asm/addrspace.h>
33#include <asm/bootinfo.h>
34#include <asm/branch.h>
35#include <asm/break.h>
36#include <asm/cpu.h>
37#include <asm/exception.h>
38#include <asm/fpu.h>
39#include <asm/lbt.h>
40#include <asm/inst.h>
41#include <asm/kgdb.h>
42#include <asm/loongarch.h>
43#include <asm/mmu_context.h>
44#include <asm/pgtable.h>
45#include <asm/ptrace.h>
46#include <asm/sections.h>
47#include <asm/siginfo.h>
48#include <asm/stacktrace.h>
49#include <asm/tlb.h>
50#include <asm/types.h>
51#include <asm/unwind.h>
52#include <asm/uprobes.h>
53
54#include "access-helper.h"
55
56static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
57 const char *loglvl, bool user)
58{
59 unsigned long addr;
60 struct unwind_state state;
61 struct pt_regs *pregs = (struct pt_regs *)regs;
62
63 if (!task)
64 task = current;
65
66 printk("%sCall Trace:", loglvl);
67 for (unwind_start(&state, task, pregs);
68 !unwind_done(&state); unwind_next_frame(&state)) {
69 addr = unwind_get_return_address(&state);
70 print_ip_sym(loglvl, addr);
71 }
72 printk("%s\n", loglvl);
73}
74
75static void show_stacktrace(struct task_struct *task,
76 const struct pt_regs *regs, const char *loglvl, bool user)
77{
78 int i;
79 const int field = 2 * sizeof(unsigned long);
80 unsigned long stackdata;
81 unsigned long *sp = (unsigned long *)regs->regs[3];
82
83 printk("%sStack :", loglvl);
84 i = 0;
85 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
86 if (i && ((i % (64 / field)) == 0)) {
87 pr_cont("\n");
88 printk("%s ", loglvl);
89 }
90 if (i > 39) {
91 pr_cont(" ...");
92 break;
93 }
94
95 if (__get_addr(&stackdata, sp++, user)) {
96 pr_cont(" (Bad stack address)");
97 break;
98 }
99
100 pr_cont(" %0*lx", field, stackdata);
101 i++;
102 }
103 pr_cont("\n");
104 show_backtrace(task, regs, loglvl, user);
105}
106
107void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
108{
109 struct pt_regs regs;
110
111 regs.csr_crmd = 0;
112 if (sp) {
113 regs.csr_era = 0;
114 regs.regs[1] = 0;
115 regs.regs[3] = (unsigned long)sp;
116 } else {
117 if (!task || task == current)
118 prepare_frametrace(®s);
119 else {
120 regs.csr_era = task->thread.reg01;
121 regs.regs[1] = 0;
122 regs.regs[3] = task->thread.reg03;
123 regs.regs[22] = task->thread.reg22;
124 }
125 }
126
127 show_stacktrace(task, ®s, loglvl, false);
128}
129
130static void show_code(unsigned int *pc, bool user)
131{
132 long i;
133 unsigned int insn;
134
135 printk("Code:");
136
137 for(i = -3 ; i < 6 ; i++) {
138 if (__get_inst(&insn, pc + i, user)) {
139 pr_cont(" (Bad address in era)\n");
140 break;
141 }
142 pr_cont("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
143 }
144 pr_cont("\n");
145}
146
147static void print_bool_fragment(const char *key, unsigned long val, bool first)
148{
149 /* e.g. "+PG", "-DA" */
150 pr_cont("%s%c%s", first ? "" : " ", val ? '+' : '-', key);
151}
152
153static void print_plv_fragment(const char *key, int val)
154{
155 /* e.g. "PLV0", "PPLV3" */
156 pr_cont("%s%d", key, val);
157}
158
159static void print_memory_type_fragment(const char *key, unsigned long val)
160{
161 const char *humanized_type;
162
163 switch (val) {
164 case 0:
165 humanized_type = "SUC";
166 break;
167 case 1:
168 humanized_type = "CC";
169 break;
170 case 2:
171 humanized_type = "WUC";
172 break;
173 default:
174 pr_cont(" %s=Reserved(%lu)", key, val);
175 return;
176 }
177
178 /* e.g. " DATM=WUC" */
179 pr_cont(" %s=%s", key, humanized_type);
180}
181
182static void print_intr_fragment(const char *key, unsigned long val)
183{
184 /* e.g. "LIE=0-1,3,5-7" */
185 pr_cont("%s=%*pbl", key, EXCCODE_INT_NUM, &val);
186}
187
188static void print_crmd(unsigned long x)
189{
190 printk(" CRMD: %08lx (", x);
191 print_plv_fragment("PLV", (int) FIELD_GET(CSR_CRMD_PLV, x));
192 print_bool_fragment("IE", FIELD_GET(CSR_CRMD_IE, x), false);
193 print_bool_fragment("DA", FIELD_GET(CSR_CRMD_DA, x), false);
194 print_bool_fragment("PG", FIELD_GET(CSR_CRMD_PG, x), false);
195 print_memory_type_fragment("DACF", FIELD_GET(CSR_CRMD_DACF, x));
196 print_memory_type_fragment("DACM", FIELD_GET(CSR_CRMD_DACM, x));
197 print_bool_fragment("WE", FIELD_GET(CSR_CRMD_WE, x), false);
198 pr_cont(")\n");
199}
200
201static void print_prmd(unsigned long x)
202{
203 printk(" PRMD: %08lx (", x);
204 print_plv_fragment("PPLV", (int) FIELD_GET(CSR_PRMD_PPLV, x));
205 print_bool_fragment("PIE", FIELD_GET(CSR_PRMD_PIE, x), false);
206 print_bool_fragment("PWE", FIELD_GET(CSR_PRMD_PWE, x), false);
207 pr_cont(")\n");
208}
209
210static void print_euen(unsigned long x)
211{
212 printk(" EUEN: %08lx (", x);
213 print_bool_fragment("FPE", FIELD_GET(CSR_EUEN_FPEN, x), true);
214 print_bool_fragment("SXE", FIELD_GET(CSR_EUEN_LSXEN, x), false);
215 print_bool_fragment("ASXE", FIELD_GET(CSR_EUEN_LASXEN, x), false);
216 print_bool_fragment("BTE", FIELD_GET(CSR_EUEN_LBTEN, x), false);
217 pr_cont(")\n");
218}
219
220static void print_ecfg(unsigned long x)
221{
222 printk(" ECFG: %08lx (", x);
223 print_intr_fragment("LIE", FIELD_GET(CSR_ECFG_IM, x));
224 pr_cont(" VS=%d)\n", (int) FIELD_GET(CSR_ECFG_VS, x));
225}
226
227static const char *humanize_exc_name(unsigned int ecode, unsigned int esubcode)
228{
229 /*
230 * LoongArch users and developers are probably more familiar with
231 * those names found in the ISA manual, so we are going to print out
232 * the latter. This will require some mapping.
233 */
234 switch (ecode) {
235 case EXCCODE_RSV: return "INT";
236 case EXCCODE_TLBL: return "PIL";
237 case EXCCODE_TLBS: return "PIS";
238 case EXCCODE_TLBI: return "PIF";
239 case EXCCODE_TLBM: return "PME";
240 case EXCCODE_TLBNR: return "PNR";
241 case EXCCODE_TLBNX: return "PNX";
242 case EXCCODE_TLBPE: return "PPI";
243 case EXCCODE_ADE:
244 switch (esubcode) {
245 case EXSUBCODE_ADEF: return "ADEF";
246 case EXSUBCODE_ADEM: return "ADEM";
247 }
248 break;
249 case EXCCODE_ALE: return "ALE";
250 case EXCCODE_BCE: return "BCE";
251 case EXCCODE_SYS: return "SYS";
252 case EXCCODE_BP: return "BRK";
253 case EXCCODE_INE: return "INE";
254 case EXCCODE_IPE: return "IPE";
255 case EXCCODE_FPDIS: return "FPD";
256 case EXCCODE_LSXDIS: return "SXD";
257 case EXCCODE_LASXDIS: return "ASXD";
258 case EXCCODE_FPE:
259 switch (esubcode) {
260 case EXCSUBCODE_FPE: return "FPE";
261 case EXCSUBCODE_VFPE: return "VFPE";
262 }
263 break;
264 case EXCCODE_WATCH:
265 switch (esubcode) {
266 case EXCSUBCODE_WPEF: return "WPEF";
267 case EXCSUBCODE_WPEM: return "WPEM";
268 }
269 break;
270 case EXCCODE_BTDIS: return "BTD";
271 case EXCCODE_BTE: return "BTE";
272 case EXCCODE_GSPR: return "GSPR";
273 case EXCCODE_HVC: return "HVC";
274 case EXCCODE_GCM:
275 switch (esubcode) {
276 case EXCSUBCODE_GCSC: return "GCSC";
277 case EXCSUBCODE_GCHC: return "GCHC";
278 }
279 break;
280 /*
281 * The manual did not mention the EXCCODE_SE case, but print out it
282 * nevertheless.
283 */
284 case EXCCODE_SE: return "SE";
285 }
286
287 return "???";
288}
289
290static void print_estat(unsigned long x)
291{
292 unsigned int ecode = FIELD_GET(CSR_ESTAT_EXC, x);
293 unsigned int esubcode = FIELD_GET(CSR_ESTAT_ESUBCODE, x);
294
295 printk("ESTAT: %08lx [%s] (", x, humanize_exc_name(ecode, esubcode));
296 print_intr_fragment("IS", FIELD_GET(CSR_ESTAT_IS, x));
297 pr_cont(" ECode=%d EsubCode=%d)\n", (int) ecode, (int) esubcode);
298}
299
300static void __show_regs(const struct pt_regs *regs)
301{
302 const int field = 2 * sizeof(unsigned long);
303 unsigned int exccode = FIELD_GET(CSR_ESTAT_EXC, regs->csr_estat);
304
305 show_regs_print_info(KERN_DEFAULT);
306
307 /* Print saved GPRs except $zero (substituting with PC/ERA) */
308#define GPR_FIELD(x) field, regs->regs[x]
309 printk("pc %0*lx ra %0*lx tp %0*lx sp %0*lx\n",
310 field, regs->csr_era, GPR_FIELD(1), GPR_FIELD(2), GPR_FIELD(3));
311 printk("a0 %0*lx a1 %0*lx a2 %0*lx a3 %0*lx\n",
312 GPR_FIELD(4), GPR_FIELD(5), GPR_FIELD(6), GPR_FIELD(7));
313 printk("a4 %0*lx a5 %0*lx a6 %0*lx a7 %0*lx\n",
314 GPR_FIELD(8), GPR_FIELD(9), GPR_FIELD(10), GPR_FIELD(11));
315 printk("t0 %0*lx t1 %0*lx t2 %0*lx t3 %0*lx\n",
316 GPR_FIELD(12), GPR_FIELD(13), GPR_FIELD(14), GPR_FIELD(15));
317 printk("t4 %0*lx t5 %0*lx t6 %0*lx t7 %0*lx\n",
318 GPR_FIELD(16), GPR_FIELD(17), GPR_FIELD(18), GPR_FIELD(19));
319 printk("t8 %0*lx u0 %0*lx s9 %0*lx s0 %0*lx\n",
320 GPR_FIELD(20), GPR_FIELD(21), GPR_FIELD(22), GPR_FIELD(23));
321 printk("s1 %0*lx s2 %0*lx s3 %0*lx s4 %0*lx\n",
322 GPR_FIELD(24), GPR_FIELD(25), GPR_FIELD(26), GPR_FIELD(27));
323 printk("s5 %0*lx s6 %0*lx s7 %0*lx s8 %0*lx\n",
324 GPR_FIELD(28), GPR_FIELD(29), GPR_FIELD(30), GPR_FIELD(31));
325
326 /* The slot for $zero is reused as the syscall restart flag */
327 if (regs->regs[0])
328 printk("syscall restart flag: %0*lx\n", GPR_FIELD(0));
329
330 if (user_mode(regs)) {
331 printk(" ra: %0*lx\n", GPR_FIELD(1));
332 printk(" ERA: %0*lx\n", field, regs->csr_era);
333 } else {
334 printk(" ra: %0*lx %pS\n", GPR_FIELD(1), (void *) regs->regs[1]);
335 printk(" ERA: %0*lx %pS\n", field, regs->csr_era, (void *) regs->csr_era);
336 }
337#undef GPR_FIELD
338
339 /* Print saved important CSRs */
340 print_crmd(regs->csr_crmd);
341 print_prmd(regs->csr_prmd);
342 print_euen(regs->csr_euen);
343 print_ecfg(regs->csr_ecfg);
344 print_estat(regs->csr_estat);
345
346 if (exccode >= EXCCODE_TLBL && exccode <= EXCCODE_ALE)
347 printk(" BADV: %0*lx\n", field, regs->csr_badvaddr);
348
349 printk(" PRID: %08x (%s, %s)\n", read_cpucfg(LOONGARCH_CPUCFG0),
350 cpu_family_string(), cpu_full_name_string());
351}
352
353void show_regs(struct pt_regs *regs)
354{
355 __show_regs((struct pt_regs *)regs);
356 dump_stack();
357}
358
359void show_registers(struct pt_regs *regs)
360{
361 __show_regs(regs);
362 print_modules();
363 printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
364 current->comm, current->pid, current_thread_info(), current);
365
366 show_stacktrace(current, regs, KERN_DEFAULT, user_mode(regs));
367 show_code((void *)regs->csr_era, user_mode(regs));
368 printk("\n");
369}
370
371static DEFINE_RAW_SPINLOCK(die_lock);
372
373void die(const char *str, struct pt_regs *regs)
374{
375 int ret;
376 static int die_counter;
377
378 oops_enter();
379
380 ret = notify_die(DIE_OOPS, str, regs, 0,
381 current->thread.trap_nr, SIGSEGV);
382
383 console_verbose();
384 raw_spin_lock_irq(&die_lock);
385 bust_spinlocks(1);
386
387 printk("%s[#%d]:\n", str, ++die_counter);
388 show_registers(regs);
389 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
390 raw_spin_unlock_irq(&die_lock);
391
392 oops_exit();
393
394 if (ret == NOTIFY_STOP)
395 return;
396
397 if (regs && kexec_should_crash(current))
398 crash_kexec(regs);
399
400 if (in_interrupt())
401 panic("Fatal exception in interrupt");
402
403 if (panic_on_oops)
404 panic("Fatal exception");
405
406 make_task_dead(SIGSEGV);
407}
408
409static inline void setup_vint_size(unsigned int size)
410{
411 unsigned int vs;
412
413 vs = ilog2(size/4);
414
415 if (vs == 0 || vs > 7)
416 panic("vint_size %d Not support yet", vs);
417
418 csr_xchg32(vs<<CSR_ECFG_VS_SHIFT, CSR_ECFG_VS, LOONGARCH_CSR_ECFG);
419}
420
421/*
422 * Send SIGFPE according to FCSR Cause bits, which must have already
423 * been masked against Enable bits. This is impotant as Inexact can
424 * happen together with Overflow or Underflow, and `ptrace' can set
425 * any bits.
426 */
427static void force_fcsr_sig(unsigned long fcsr,
428 void __user *fault_addr, struct task_struct *tsk)
429{
430 int si_code = FPE_FLTUNK;
431
432 if (fcsr & FPU_CSR_INV_X)
433 si_code = FPE_FLTINV;
434 else if (fcsr & FPU_CSR_DIV_X)
435 si_code = FPE_FLTDIV;
436 else if (fcsr & FPU_CSR_OVF_X)
437 si_code = FPE_FLTOVF;
438 else if (fcsr & FPU_CSR_UDF_X)
439 si_code = FPE_FLTUND;
440 else if (fcsr & FPU_CSR_INE_X)
441 si_code = FPE_FLTRES;
442
443 force_sig_fault(SIGFPE, si_code, fault_addr);
444}
445
446static int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcsr)
447{
448 int si_code;
449
450 switch (sig) {
451 case 0:
452 return 0;
453
454 case SIGFPE:
455 force_fcsr_sig(fcsr, fault_addr, current);
456 return 1;
457
458 case SIGBUS:
459 force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr);
460 return 1;
461
462 case SIGSEGV:
463 mmap_read_lock(current->mm);
464 if (vma_lookup(current->mm, (unsigned long)fault_addr))
465 si_code = SEGV_ACCERR;
466 else
467 si_code = SEGV_MAPERR;
468 mmap_read_unlock(current->mm);
469 force_sig_fault(SIGSEGV, si_code, fault_addr);
470 return 1;
471
472 default:
473 force_sig(sig);
474 return 1;
475 }
476}
477
478/*
479 * Delayed fp exceptions when doing a lazy ctx switch
480 */
481asmlinkage void noinstr do_fpe(struct pt_regs *regs, unsigned long fcsr)
482{
483 int sig;
484 void __user *fault_addr;
485 irqentry_state_t state = irqentry_enter(regs);
486
487 if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
488 SIGFPE) == NOTIFY_STOP)
489 goto out;
490
491 /* Clear FCSR.Cause before enabling interrupts */
492 write_fcsr(LOONGARCH_FCSR0, fcsr & ~mask_fcsr_x(fcsr));
493 local_irq_enable();
494
495 die_if_kernel("FP exception in kernel code", regs);
496
497 sig = SIGFPE;
498 fault_addr = (void __user *) regs->csr_era;
499
500 /* Send a signal if required. */
501 process_fpemu_return(sig, fault_addr, fcsr);
502
503out:
504 local_irq_disable();
505 irqentry_exit(regs, state);
506}
507
508asmlinkage void noinstr do_ade(struct pt_regs *regs)
509{
510 irqentry_state_t state = irqentry_enter(regs);
511
512 die_if_kernel("Kernel ade access", regs);
513 force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)regs->csr_badvaddr);
514
515 irqentry_exit(regs, state);
516}
517
518/* sysctl hooks */
519int unaligned_enabled __read_mostly = 1; /* Enabled by default */
520int no_unaligned_warning __read_mostly = 1; /* Only 1 warning by default */
521
522asmlinkage void noinstr do_ale(struct pt_regs *regs)
523{
524 irqentry_state_t state = irqentry_enter(regs);
525
526#ifndef CONFIG_ARCH_STRICT_ALIGN
527 die_if_kernel("Kernel ale access", regs);
528 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr);
529#else
530 unsigned int *pc;
531
532 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, regs->csr_badvaddr);
533
534 /*
535 * Did we catch a fault trying to load an instruction?
536 */
537 if (regs->csr_badvaddr == regs->csr_era)
538 goto sigbus;
539 if (user_mode(regs) && !test_thread_flag(TIF_FIXADE))
540 goto sigbus;
541 if (!unaligned_enabled)
542 goto sigbus;
543 if (!no_unaligned_warning)
544 show_registers(regs);
545
546 pc = (unsigned int *)exception_era(regs);
547
548 emulate_load_store_insn(regs, (void __user *)regs->csr_badvaddr, pc);
549
550 goto out;
551
552sigbus:
553 die_if_kernel("Kernel ale access", regs);
554 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr);
555out:
556#endif
557 irqentry_exit(regs, state);
558}
559
560#ifdef CONFIG_GENERIC_BUG
561int is_valid_bugaddr(unsigned long addr)
562{
563 return 1;
564}
565#endif /* CONFIG_GENERIC_BUG */
566
567static void bug_handler(struct pt_regs *regs)
568{
569 switch (report_bug(regs->csr_era, regs)) {
570 case BUG_TRAP_TYPE_BUG:
571 case BUG_TRAP_TYPE_NONE:
572 die_if_kernel("Oops - BUG", regs);
573 force_sig(SIGTRAP);
574 break;
575
576 case BUG_TRAP_TYPE_WARN:
577 /* Skip the BUG instruction and continue */
578 regs->csr_era += LOONGARCH_INSN_SIZE;
579 break;
580 }
581}
582
583asmlinkage void noinstr do_bce(struct pt_regs *regs)
584{
585 bool user = user_mode(regs);
586 unsigned long era = exception_era(regs);
587 u64 badv = 0, lower = 0, upper = ULONG_MAX;
588 union loongarch_instruction insn;
589 irqentry_state_t state = irqentry_enter(regs);
590
591 if (regs->csr_prmd & CSR_PRMD_PIE)
592 local_irq_enable();
593
594 current->thread.trap_nr = read_csr_excode();
595
596 die_if_kernel("Bounds check error in kernel code", regs);
597
598 /*
599 * Pull out the address that failed bounds checking, and the lower /
600 * upper bound, by minimally looking at the faulting instruction word
601 * and reading from the correct register.
602 */
603 if (__get_inst(&insn.word, (u32 *)era, user))
604 goto bad_era;
605
606 switch (insn.reg3_format.opcode) {
607 case asrtle_op:
608 if (insn.reg3_format.rd != 0)
609 break; /* not asrtle */
610 badv = regs->regs[insn.reg3_format.rj];
611 upper = regs->regs[insn.reg3_format.rk];
612 break;
613
614 case asrtgt_op:
615 if (insn.reg3_format.rd != 0)
616 break; /* not asrtgt */
617 badv = regs->regs[insn.reg3_format.rj];
618 lower = regs->regs[insn.reg3_format.rk];
619 break;
620
621 case ldleb_op:
622 case ldleh_op:
623 case ldlew_op:
624 case ldled_op:
625 case stleb_op:
626 case stleh_op:
627 case stlew_op:
628 case stled_op:
629 case fldles_op:
630 case fldled_op:
631 case fstles_op:
632 case fstled_op:
633 badv = regs->regs[insn.reg3_format.rj];
634 upper = regs->regs[insn.reg3_format.rk];
635 break;
636
637 case ldgtb_op:
638 case ldgth_op:
639 case ldgtw_op:
640 case ldgtd_op:
641 case stgtb_op:
642 case stgth_op:
643 case stgtw_op:
644 case stgtd_op:
645 case fldgts_op:
646 case fldgtd_op:
647 case fstgts_op:
648 case fstgtd_op:
649 badv = regs->regs[insn.reg3_format.rj];
650 lower = regs->regs[insn.reg3_format.rk];
651 break;
652 }
653
654 force_sig_bnderr((void __user *)badv, (void __user *)lower, (void __user *)upper);
655
656out:
657 if (regs->csr_prmd & CSR_PRMD_PIE)
658 local_irq_disable();
659
660 irqentry_exit(regs, state);
661 return;
662
663bad_era:
664 /*
665 * Cannot pull out the instruction word, hence cannot provide more
666 * info than a regular SIGSEGV in this case.
667 */
668 force_sig(SIGSEGV);
669 goto out;
670}
671
672asmlinkage void noinstr do_bp(struct pt_regs *regs)
673{
674 bool user = user_mode(regs);
675 unsigned int opcode, bcode;
676 unsigned long era = exception_era(regs);
677 irqentry_state_t state = irqentry_enter(regs);
678
679 if (regs->csr_prmd & CSR_PRMD_PIE)
680 local_irq_enable();
681
682 if (__get_inst(&opcode, (u32 *)era, user))
683 goto out_sigsegv;
684
685 bcode = (opcode & 0x7fff);
686
687 /*
688 * notify the kprobe handlers, if instruction is likely to
689 * pertain to them.
690 */
691 switch (bcode) {
692 case BRK_KDB:
693 if (kgdb_breakpoint_handler(regs))
694 goto out;
695 else
696 break;
697 case BRK_KPROBE_BP:
698 if (kprobe_breakpoint_handler(regs))
699 goto out;
700 else
701 break;
702 case BRK_KPROBE_SSTEPBP:
703 if (kprobe_singlestep_handler(regs))
704 goto out;
705 else
706 break;
707 case BRK_UPROBE_BP:
708 if (uprobe_breakpoint_handler(regs))
709 goto out;
710 else
711 break;
712 case BRK_UPROBE_XOLBP:
713 if (uprobe_singlestep_handler(regs))
714 goto out;
715 else
716 break;
717 default:
718 current->thread.trap_nr = read_csr_excode();
719 if (notify_die(DIE_TRAP, "Break", regs, bcode,
720 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
721 goto out;
722 else
723 break;
724 }
725
726 switch (bcode) {
727 case BRK_BUG:
728 bug_handler(regs);
729 break;
730 case BRK_DIVZERO:
731 die_if_kernel("Break instruction in kernel code", regs);
732 force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->csr_era);
733 break;
734 case BRK_OVERFLOW:
735 die_if_kernel("Break instruction in kernel code", regs);
736 force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->csr_era);
737 break;
738 default:
739 die_if_kernel("Break instruction in kernel code", regs);
740 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->csr_era);
741 break;
742 }
743
744out:
745 if (regs->csr_prmd & CSR_PRMD_PIE)
746 local_irq_disable();
747
748 irqentry_exit(regs, state);
749 return;
750
751out_sigsegv:
752 force_sig(SIGSEGV);
753 goto out;
754}
755
756asmlinkage void noinstr do_watch(struct pt_regs *regs)
757{
758 irqentry_state_t state = irqentry_enter(regs);
759
760#ifndef CONFIG_HAVE_HW_BREAKPOINT
761 pr_warn("Hardware watch point handler not implemented!\n");
762#else
763 if (kgdb_breakpoint_handler(regs))
764 goto out;
765
766 if (test_tsk_thread_flag(current, TIF_SINGLESTEP)) {
767 int llbit = (csr_read32(LOONGARCH_CSR_LLBCTL) & 0x1);
768 unsigned long pc = instruction_pointer(regs);
769 union loongarch_instruction *ip = (union loongarch_instruction *)pc;
770
771 if (llbit) {
772 /*
773 * When the ll-sc combo is encountered, it is regarded as an single
774 * instruction. So don't clear llbit and reset CSR.FWPS.Skip until
775 * the llsc execution is completed.
776 */
777 csr_write32(CSR_FWPC_SKIP, LOONGARCH_CSR_FWPS);
778 csr_write32(CSR_LLBCTL_KLO, LOONGARCH_CSR_LLBCTL);
779 goto out;
780 }
781
782 if (pc == current->thread.single_step) {
783 /*
784 * Certain insns are occasionally not skipped when CSR.FWPS.Skip is
785 * set, such as fld.d/fst.d. So singlestep needs to compare whether
786 * the csr_era is equal to the value of singlestep which last time set.
787 */
788 if (!is_self_loop_ins(ip, regs)) {
789 /*
790 * Check if the given instruction the target pc is equal to the
791 * current pc, If yes, then we should not set the CSR.FWPS.SKIP
792 * bit to break the original instruction stream.
793 */
794 csr_write32(CSR_FWPC_SKIP, LOONGARCH_CSR_FWPS);
795 goto out;
796 }
797 }
798 } else {
799 breakpoint_handler(regs);
800 watchpoint_handler(regs);
801 }
802
803 force_sig(SIGTRAP);
804out:
805#endif
806 irqentry_exit(regs, state);
807}
808
809asmlinkage void noinstr do_ri(struct pt_regs *regs)
810{
811 int status = SIGILL;
812 unsigned int __maybe_unused opcode;
813 unsigned int __user *era = (unsigned int __user *)exception_era(regs);
814 irqentry_state_t state = irqentry_enter(regs);
815
816 local_irq_enable();
817 current->thread.trap_nr = read_csr_excode();
818
819 if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
820 SIGILL) == NOTIFY_STOP)
821 goto out;
822
823 die_if_kernel("Reserved instruction in kernel code", regs);
824
825 if (unlikely(get_user(opcode, era) < 0)) {
826 status = SIGSEGV;
827 current->thread.error_code = 1;
828 }
829
830 force_sig(status);
831
832out:
833 local_irq_disable();
834 irqentry_exit(regs, state);
835}
836
837static void init_restore_fp(void)
838{
839 if (!used_math()) {
840 /* First time FP context user. */
841 init_fpu();
842 } else {
843 /* This task has formerly used the FP context */
844 if (!is_fpu_owner())
845 own_fpu_inatomic(1);
846 }
847
848 BUG_ON(!is_fp_enabled());
849}
850
851static void init_restore_lsx(void)
852{
853 enable_lsx();
854
855 if (!thread_lsx_context_live()) {
856 /* First time LSX context user */
857 init_restore_fp();
858 init_lsx_upper();
859 set_thread_flag(TIF_LSX_CTX_LIVE);
860 } else {
861 if (!is_simd_owner()) {
862 if (is_fpu_owner()) {
863 restore_lsx_upper(current);
864 } else {
865 __own_fpu();
866 restore_lsx(current);
867 }
868 }
869 }
870
871 set_thread_flag(TIF_USEDSIMD);
872
873 BUG_ON(!is_fp_enabled());
874 BUG_ON(!is_lsx_enabled());
875}
876
877static void init_restore_lasx(void)
878{
879 enable_lasx();
880
881 if (!thread_lasx_context_live()) {
882 /* First time LASX context user */
883 init_restore_lsx();
884 init_lasx_upper();
885 set_thread_flag(TIF_LASX_CTX_LIVE);
886 } else {
887 if (is_fpu_owner() || is_simd_owner()) {
888 init_restore_lsx();
889 restore_lasx_upper(current);
890 } else {
891 __own_fpu();
892 enable_lsx();
893 restore_lasx(current);
894 }
895 }
896
897 set_thread_flag(TIF_USEDSIMD);
898
899 BUG_ON(!is_fp_enabled());
900 BUG_ON(!is_lsx_enabled());
901 BUG_ON(!is_lasx_enabled());
902}
903
904asmlinkage void noinstr do_fpu(struct pt_regs *regs)
905{
906 irqentry_state_t state = irqentry_enter(regs);
907
908 local_irq_enable();
909 die_if_kernel("do_fpu invoked from kernel context!", regs);
910 BUG_ON(is_lsx_enabled());
911 BUG_ON(is_lasx_enabled());
912
913 preempt_disable();
914 init_restore_fp();
915 preempt_enable();
916
917 local_irq_disable();
918 irqentry_exit(regs, state);
919}
920
921asmlinkage void noinstr do_lsx(struct pt_regs *regs)
922{
923 irqentry_state_t state = irqentry_enter(regs);
924
925 local_irq_enable();
926 if (!cpu_has_lsx) {
927 force_sig(SIGILL);
928 goto out;
929 }
930
931 die_if_kernel("do_lsx invoked from kernel context!", regs);
932 BUG_ON(is_lasx_enabled());
933
934 preempt_disable();
935 init_restore_lsx();
936 preempt_enable();
937
938out:
939 local_irq_disable();
940 irqentry_exit(regs, state);
941}
942
943asmlinkage void noinstr do_lasx(struct pt_regs *regs)
944{
945 irqentry_state_t state = irqentry_enter(regs);
946
947 local_irq_enable();
948 if (!cpu_has_lasx) {
949 force_sig(SIGILL);
950 goto out;
951 }
952
953 die_if_kernel("do_lasx invoked from kernel context!", regs);
954
955 preempt_disable();
956 init_restore_lasx();
957 preempt_enable();
958
959out:
960 local_irq_disable();
961 irqentry_exit(regs, state);
962}
963
964static void init_restore_lbt(void)
965{
966 if (!thread_lbt_context_live()) {
967 /* First time LBT context user */
968 init_lbt();
969 set_thread_flag(TIF_LBT_CTX_LIVE);
970 } else {
971 if (!is_lbt_owner())
972 own_lbt_inatomic(1);
973 }
974
975 BUG_ON(!is_lbt_enabled());
976}
977
978asmlinkage void noinstr do_lbt(struct pt_regs *regs)
979{
980 irqentry_state_t state = irqentry_enter(regs);
981
982 /*
983 * BTD (Binary Translation Disable exception) can be triggered
984 * during FP save/restore if TM (Top Mode) is on, which may
985 * cause irq_enable during 'switch_to'. To avoid this situation
986 * (including the user using 'MOVGR2GCSR' to turn on TM, which
987 * will not trigger the BTE), we need to check PRMD first.
988 */
989 if (regs->csr_prmd & CSR_PRMD_PIE)
990 local_irq_enable();
991
992 if (!cpu_has_lbt) {
993 force_sig(SIGILL);
994 goto out;
995 }
996 BUG_ON(is_lbt_enabled());
997
998 preempt_disable();
999 init_restore_lbt();
1000 preempt_enable();
1001
1002out:
1003 if (regs->csr_prmd & CSR_PRMD_PIE)
1004 local_irq_disable();
1005
1006 irqentry_exit(regs, state);
1007}
1008
1009asmlinkage void noinstr do_reserved(struct pt_regs *regs)
1010{
1011 irqentry_state_t state = irqentry_enter(regs);
1012
1013 local_irq_enable();
1014 /*
1015 * Game over - no way to handle this if it ever occurs. Most probably
1016 * caused by a fatal error after another hardware/software error.
1017 */
1018 pr_err("Caught reserved exception %u on pid:%d [%s] - should not happen\n",
1019 read_csr_excode(), current->pid, current->comm);
1020 die_if_kernel("do_reserved exception", regs);
1021 force_sig(SIGUNUSED);
1022
1023 local_irq_disable();
1024
1025 irqentry_exit(regs, state);
1026}
1027
1028asmlinkage void cache_parity_error(void)
1029{
1030 /* For the moment, report the problem and hang. */
1031 pr_err("Cache error exception:\n");
1032 pr_err("csr_merrctl == %08x\n", csr_read32(LOONGARCH_CSR_MERRCTL));
1033 pr_err("csr_merrera == %016lx\n", csr_read64(LOONGARCH_CSR_MERRERA));
1034 panic("Can't handle the cache error!");
1035}
1036
1037asmlinkage void noinstr handle_loongarch_irq(struct pt_regs *regs)
1038{
1039 struct pt_regs *old_regs;
1040
1041 irq_enter_rcu();
1042 old_regs = set_irq_regs(regs);
1043 handle_arch_irq(regs);
1044 set_irq_regs(old_regs);
1045 irq_exit_rcu();
1046}
1047
1048asmlinkage void noinstr do_vint(struct pt_regs *regs, unsigned long sp)
1049{
1050 register int cpu;
1051 register unsigned long stack;
1052 irqentry_state_t state = irqentry_enter(regs);
1053
1054 cpu = smp_processor_id();
1055
1056 if (on_irq_stack(cpu, sp))
1057 handle_loongarch_irq(regs);
1058 else {
1059 stack = per_cpu(irq_stack, cpu) + IRQ_STACK_START;
1060
1061 /* Save task's sp on IRQ stack for unwinding */
1062 *(unsigned long *)stack = sp;
1063
1064 __asm__ __volatile__(
1065 "move $s0, $sp \n" /* Preserve sp */
1066 "move $sp, %[stk] \n" /* Switch stack */
1067 "move $a0, %[regs] \n"
1068 "bl handle_loongarch_irq \n"
1069 "move $sp, $s0 \n" /* Restore sp */
1070 : /* No outputs */
1071 : [stk] "r" (stack), [regs] "r" (regs)
1072 : "$a0", "$a1", "$a2", "$a3", "$a4", "$a5", "$a6", "$a7", "$s0",
1073 "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8",
1074 "memory");
1075 }
1076
1077 irqentry_exit(regs, state);
1078}
1079
1080unsigned long eentry;
1081unsigned long tlbrentry;
1082
1083long exception_handlers[VECSIZE * 128 / sizeof(long)] __aligned(SZ_64K);
1084
1085static void configure_exception_vector(void)
1086{
1087 eentry = (unsigned long)exception_handlers;
1088 tlbrentry = (unsigned long)exception_handlers + 80*VECSIZE;
1089
1090 csr_write64(eentry, LOONGARCH_CSR_EENTRY);
1091 csr_write64(eentry, LOONGARCH_CSR_MERRENTRY);
1092 csr_write64(tlbrentry, LOONGARCH_CSR_TLBRENTRY);
1093}
1094
1095void per_cpu_trap_init(int cpu)
1096{
1097 unsigned int i;
1098
1099 setup_vint_size(VECSIZE);
1100
1101 configure_exception_vector();
1102
1103 if (!cpu_data[cpu].asid_cache)
1104 cpu_data[cpu].asid_cache = asid_first_version(cpu);
1105
1106 mmgrab(&init_mm);
1107 current->active_mm = &init_mm;
1108 BUG_ON(current->mm);
1109 enter_lazy_tlb(&init_mm, current);
1110
1111 /* Initialise exception handlers */
1112 if (cpu == 0)
1113 for (i = 0; i < 64; i++)
1114 set_handler(i * VECSIZE, handle_reserved, VECSIZE);
1115
1116 tlb_init(cpu);
1117 cpu_cache_init();
1118}
1119
1120/* Install CPU exception handler */
1121void set_handler(unsigned long offset, void *addr, unsigned long size)
1122{
1123 memcpy((void *)(eentry + offset), addr, size);
1124 local_flush_icache_range(eentry + offset, eentry + offset + size);
1125}
1126
1127static const char panic_null_cerr[] =
1128 "Trying to set NULL cache error exception handler\n";
1129
1130/*
1131 * Install uncached CPU exception handler.
1132 * This is suitable only for the cache error exception which is the only
1133 * exception handler that is being run uncached.
1134 */
1135void set_merr_handler(unsigned long offset, void *addr, unsigned long size)
1136{
1137 unsigned long uncached_eentry = TO_UNCACHE(__pa(eentry));
1138
1139 if (!addr)
1140 panic(panic_null_cerr);
1141
1142 memcpy((void *)(uncached_eentry + offset), addr, size);
1143}
1144
1145void __init trap_init(void)
1146{
1147 long i;
1148
1149 /* Set interrupt vector handler */
1150 for (i = EXCCODE_INT_START; i <= EXCCODE_INT_END; i++)
1151 set_handler(i * VECSIZE, handle_vint, VECSIZE);
1152
1153 set_handler(EXCCODE_ADE * VECSIZE, handle_ade, VECSIZE);
1154 set_handler(EXCCODE_ALE * VECSIZE, handle_ale, VECSIZE);
1155 set_handler(EXCCODE_BCE * VECSIZE, handle_bce, VECSIZE);
1156 set_handler(EXCCODE_SYS * VECSIZE, handle_sys, VECSIZE);
1157 set_handler(EXCCODE_BP * VECSIZE, handle_bp, VECSIZE);
1158 set_handler(EXCCODE_INE * VECSIZE, handle_ri, VECSIZE);
1159 set_handler(EXCCODE_IPE * VECSIZE, handle_ri, VECSIZE);
1160 set_handler(EXCCODE_FPDIS * VECSIZE, handle_fpu, VECSIZE);
1161 set_handler(EXCCODE_LSXDIS * VECSIZE, handle_lsx, VECSIZE);
1162 set_handler(EXCCODE_LASXDIS * VECSIZE, handle_lasx, VECSIZE);
1163 set_handler(EXCCODE_FPE * VECSIZE, handle_fpe, VECSIZE);
1164 set_handler(EXCCODE_BTDIS * VECSIZE, handle_lbt, VECSIZE);
1165 set_handler(EXCCODE_WATCH * VECSIZE, handle_watch, VECSIZE);
1166
1167 cache_error_setup();
1168
1169 local_flush_icache_range(eentry, eentry + 0x400);
1170}