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Merge remote-tracking branch 'spi/topic/rspi' into spi-pdata
[deliverable/linux.git] / arch / mips / kernel / traps.c
1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
7 * Copyright (C) 1995, 1996 Paul M. Antoine
8 * Copyright (C) 1998 Ulf Carlsson
9 * Copyright (C) 1999 Silicon Graphics, Inc.
10 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11 * Copyright (C) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
12 * Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved.
13 */
14 #include <linux/bug.h>
15 #include <linux/compiler.h>
16 #include <linux/context_tracking.h>
17 #include <linux/kexec.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/mm.h>
22 #include <linux/sched.h>
23 #include <linux/smp.h>
24 #include <linux/spinlock.h>
25 #include <linux/kallsyms.h>
26 #include <linux/bootmem.h>
27 #include <linux/interrupt.h>
28 #include <linux/ptrace.h>
29 #include <linux/kgdb.h>
30 #include <linux/kdebug.h>
31 #include <linux/kprobes.h>
32 #include <linux/notifier.h>
33 #include <linux/kdb.h>
34 #include <linux/irq.h>
35 #include <linux/perf_event.h>
36
37 #include <asm/bootinfo.h>
38 #include <asm/branch.h>
39 #include <asm/break.h>
40 #include <asm/cop2.h>
41 #include <asm/cpu.h>
42 #include <asm/dsp.h>
43 #include <asm/fpu.h>
44 #include <asm/fpu_emulator.h>
45 #include <asm/idle.h>
46 #include <asm/mipsregs.h>
47 #include <asm/mipsmtregs.h>
48 #include <asm/module.h>
49 #include <asm/pgtable.h>
50 #include <asm/ptrace.h>
51 #include <asm/sections.h>
52 #include <asm/tlbdebug.h>
53 #include <asm/traps.h>
54 #include <asm/uaccess.h>
55 #include <asm/watch.h>
56 #include <asm/mmu_context.h>
57 #include <asm/types.h>
58 #include <asm/stacktrace.h>
59 #include <asm/uasm.h>
60
61 extern void check_wait(void);
62 extern asmlinkage void rollback_handle_int(void);
63 extern asmlinkage void handle_int(void);
64 extern u32 handle_tlbl[];
65 extern u32 handle_tlbs[];
66 extern u32 handle_tlbm[];
67 extern asmlinkage void handle_adel(void);
68 extern asmlinkage void handle_ades(void);
69 extern asmlinkage void handle_ibe(void);
70 extern asmlinkage void handle_dbe(void);
71 extern asmlinkage void handle_sys(void);
72 extern asmlinkage void handle_bp(void);
73 extern asmlinkage void handle_ri(void);
74 extern asmlinkage void handle_ri_rdhwr_vivt(void);
75 extern asmlinkage void handle_ri_rdhwr(void);
76 extern asmlinkage void handle_cpu(void);
77 extern asmlinkage void handle_ov(void);
78 extern asmlinkage void handle_tr(void);
79 extern asmlinkage void handle_fpe(void);
80 extern asmlinkage void handle_mdmx(void);
81 extern asmlinkage void handle_watch(void);
82 extern asmlinkage void handle_mt(void);
83 extern asmlinkage void handle_dsp(void);
84 extern asmlinkage void handle_mcheck(void);
85 extern asmlinkage void handle_reserved(void);
86
87 void (*board_be_init)(void);
88 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
89 void (*board_nmi_handler_setup)(void);
90 void (*board_ejtag_handler_setup)(void);
91 void (*board_bind_eic_interrupt)(int irq, int regset);
92 void (*board_ebase_setup)(void);
93 void(*board_cache_error_setup)(void);
94
95 static void show_raw_backtrace(unsigned long reg29)
96 {
97 unsigned long *sp = (unsigned long *)(reg29 & ~3);
98 unsigned long addr;
99
100 printk("Call Trace:");
101 #ifdef CONFIG_KALLSYMS
102 printk("\n");
103 #endif
104 while (!kstack_end(sp)) {
105 unsigned long __user *p =
106 (unsigned long __user *)(unsigned long)sp++;
107 if (__get_user(addr, p)) {
108 printk(" (Bad stack address)");
109 break;
110 }
111 if (__kernel_text_address(addr))
112 print_ip_sym(addr);
113 }
114 printk("\n");
115 }
116
117 #ifdef CONFIG_KALLSYMS
118 int raw_show_trace;
119 static int __init set_raw_show_trace(char *str)
120 {
121 raw_show_trace = 1;
122 return 1;
123 }
124 __setup("raw_show_trace", set_raw_show_trace);
125 #endif
126
127 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
128 {
129 unsigned long sp = regs->regs[29];
130 unsigned long ra = regs->regs[31];
131 unsigned long pc = regs->cp0_epc;
132
133 if (!task)
134 task = current;
135
136 if (raw_show_trace || !__kernel_text_address(pc)) {
137 show_raw_backtrace(sp);
138 return;
139 }
140 printk("Call Trace:\n");
141 do {
142 print_ip_sym(pc);
143 pc = unwind_stack(task, &sp, pc, &ra);
144 } while (pc);
145 printk("\n");
146 }
147
148 /*
149 * This routine abuses get_user()/put_user() to reference pointers
150 * with at least a bit of error checking ...
151 */
152 static void show_stacktrace(struct task_struct *task,
153 const struct pt_regs *regs)
154 {
155 const int field = 2 * sizeof(unsigned long);
156 long stackdata;
157 int i;
158 unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
159
160 printk("Stack :");
161 i = 0;
162 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
163 if (i && ((i % (64 / field)) == 0))
164 printk("\n ");
165 if (i > 39) {
166 printk(" ...");
167 break;
168 }
169
170 if (__get_user(stackdata, sp++)) {
171 printk(" (Bad stack address)");
172 break;
173 }
174
175 printk(" %0*lx", field, stackdata);
176 i++;
177 }
178 printk("\n");
179 show_backtrace(task, regs);
180 }
181
182 void show_stack(struct task_struct *task, unsigned long *sp)
183 {
184 struct pt_regs regs;
185 if (sp) {
186 regs.regs[29] = (unsigned long)sp;
187 regs.regs[31] = 0;
188 regs.cp0_epc = 0;
189 } else {
190 if (task && task != current) {
191 regs.regs[29] = task->thread.reg29;
192 regs.regs[31] = 0;
193 regs.cp0_epc = task->thread.reg31;
194 #ifdef CONFIG_KGDB_KDB
195 } else if (atomic_read(&kgdb_active) != -1 &&
196 kdb_current_regs) {
197 memcpy(&regs, kdb_current_regs, sizeof(regs));
198 #endif /* CONFIG_KGDB_KDB */
199 } else {
200 prepare_frametrace(&regs);
201 }
202 }
203 show_stacktrace(task, &regs);
204 }
205
206 static void show_code(unsigned int __user *pc)
207 {
208 long i;
209 unsigned short __user *pc16 = NULL;
210
211 printk("\nCode:");
212
213 if ((unsigned long)pc & 1)
214 pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
215 for(i = -3 ; i < 6 ; i++) {
216 unsigned int insn;
217 if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
218 printk(" (Bad address in epc)\n");
219 break;
220 }
221 printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
222 }
223 }
224
225 static void __show_regs(const struct pt_regs *regs)
226 {
227 const int field = 2 * sizeof(unsigned long);
228 unsigned int cause = regs->cp0_cause;
229 int i;
230
231 show_regs_print_info(KERN_DEFAULT);
232
233 /*
234 * Saved main processor registers
235 */
236 for (i = 0; i < 32; ) {
237 if ((i % 4) == 0)
238 printk("$%2d :", i);
239 if (i == 0)
240 printk(" %0*lx", field, 0UL);
241 else if (i == 26 || i == 27)
242 printk(" %*s", field, "");
243 else
244 printk(" %0*lx", field, regs->regs[i]);
245
246 i++;
247 if ((i % 4) == 0)
248 printk("\n");
249 }
250
251 #ifdef CONFIG_CPU_HAS_SMARTMIPS
252 printk("Acx : %0*lx\n", field, regs->acx);
253 #endif
254 printk("Hi : %0*lx\n", field, regs->hi);
255 printk("Lo : %0*lx\n", field, regs->lo);
256
257 /*
258 * Saved cp0 registers
259 */
260 printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
261 (void *) regs->cp0_epc);
262 printk(" %s\n", print_tainted());
263 printk("ra : %0*lx %pS\n", field, regs->regs[31],
264 (void *) regs->regs[31]);
265
266 printk("Status: %08x ", (uint32_t) regs->cp0_status);
267
268 if (cpu_has_3kex) {
269 if (regs->cp0_status & ST0_KUO)
270 printk("KUo ");
271 if (regs->cp0_status & ST0_IEO)
272 printk("IEo ");
273 if (regs->cp0_status & ST0_KUP)
274 printk("KUp ");
275 if (regs->cp0_status & ST0_IEP)
276 printk("IEp ");
277 if (regs->cp0_status & ST0_KUC)
278 printk("KUc ");
279 if (regs->cp0_status & ST0_IEC)
280 printk("IEc ");
281 } else if (cpu_has_4kex) {
282 if (regs->cp0_status & ST0_KX)
283 printk("KX ");
284 if (regs->cp0_status & ST0_SX)
285 printk("SX ");
286 if (regs->cp0_status & ST0_UX)
287 printk("UX ");
288 switch (regs->cp0_status & ST0_KSU) {
289 case KSU_USER:
290 printk("USER ");
291 break;
292 case KSU_SUPERVISOR:
293 printk("SUPERVISOR ");
294 break;
295 case KSU_KERNEL:
296 printk("KERNEL ");
297 break;
298 default:
299 printk("BAD_MODE ");
300 break;
301 }
302 if (regs->cp0_status & ST0_ERL)
303 printk("ERL ");
304 if (regs->cp0_status & ST0_EXL)
305 printk("EXL ");
306 if (regs->cp0_status & ST0_IE)
307 printk("IE ");
308 }
309 printk("\n");
310
311 printk("Cause : %08x\n", cause);
312
313 cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
314 if (1 <= cause && cause <= 5)
315 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
316
317 printk("PrId : %08x (%s)\n", read_c0_prid(),
318 cpu_name_string());
319 }
320
321 /*
322 * FIXME: really the generic show_regs should take a const pointer argument.
323 */
324 void show_regs(struct pt_regs *regs)
325 {
326 __show_regs((struct pt_regs *)regs);
327 }
328
329 void show_registers(struct pt_regs *regs)
330 {
331 const int field = 2 * sizeof(unsigned long);
332
333 __show_regs(regs);
334 print_modules();
335 printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
336 current->comm, current->pid, current_thread_info(), current,
337 field, current_thread_info()->tp_value);
338 if (cpu_has_userlocal) {
339 unsigned long tls;
340
341 tls = read_c0_userlocal();
342 if (tls != current_thread_info()->tp_value)
343 printk("*HwTLS: %0*lx\n", field, tls);
344 }
345
346 show_stacktrace(current, regs);
347 show_code((unsigned int __user *) regs->cp0_epc);
348 printk("\n");
349 }
350
351 static int regs_to_trapnr(struct pt_regs *regs)
352 {
353 return (regs->cp0_cause >> 2) & 0x1f;
354 }
355
356 static DEFINE_RAW_SPINLOCK(die_lock);
357
358 void __noreturn die(const char *str, struct pt_regs *regs)
359 {
360 static int die_counter;
361 int sig = SIGSEGV;
362 #ifdef CONFIG_MIPS_MT_SMTC
363 unsigned long dvpret;
364 #endif /* CONFIG_MIPS_MT_SMTC */
365
366 oops_enter();
367
368 if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV) == NOTIFY_STOP)
369 sig = 0;
370
371 console_verbose();
372 raw_spin_lock_irq(&die_lock);
373 #ifdef CONFIG_MIPS_MT_SMTC
374 dvpret = dvpe();
375 #endif /* CONFIG_MIPS_MT_SMTC */
376 bust_spinlocks(1);
377 #ifdef CONFIG_MIPS_MT_SMTC
378 mips_mt_regdump(dvpret);
379 #endif /* CONFIG_MIPS_MT_SMTC */
380
381 printk("%s[#%d]:\n", str, ++die_counter);
382 show_registers(regs);
383 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
384 raw_spin_unlock_irq(&die_lock);
385
386 oops_exit();
387
388 if (in_interrupt())
389 panic("Fatal exception in interrupt");
390
391 if (panic_on_oops) {
392 printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
393 ssleep(5);
394 panic("Fatal exception");
395 }
396
397 if (regs && kexec_should_crash(current))
398 crash_kexec(regs);
399
400 do_exit(sig);
401 }
402
403 extern struct exception_table_entry __start___dbe_table[];
404 extern struct exception_table_entry __stop___dbe_table[];
405
406 __asm__(
407 " .section __dbe_table, \"a\"\n"
408 " .previous \n");
409
410 /* Given an address, look for it in the exception tables. */
411 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
412 {
413 const struct exception_table_entry *e;
414
415 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
416 if (!e)
417 e = search_module_dbetables(addr);
418 return e;
419 }
420
421 asmlinkage void do_be(struct pt_regs *regs)
422 {
423 const int field = 2 * sizeof(unsigned long);
424 const struct exception_table_entry *fixup = NULL;
425 int data = regs->cp0_cause & 4;
426 int action = MIPS_BE_FATAL;
427 enum ctx_state prev_state;
428
429 prev_state = exception_enter();
430 /* XXX For now. Fixme, this searches the wrong table ... */
431 if (data && !user_mode(regs))
432 fixup = search_dbe_tables(exception_epc(regs));
433
434 if (fixup)
435 action = MIPS_BE_FIXUP;
436
437 if (board_be_handler)
438 action = board_be_handler(regs, fixup != NULL);
439
440 switch (action) {
441 case MIPS_BE_DISCARD:
442 goto out;
443 case MIPS_BE_FIXUP:
444 if (fixup) {
445 regs->cp0_epc = fixup->nextinsn;
446 goto out;
447 }
448 break;
449 default:
450 break;
451 }
452
453 /*
454 * Assume it would be too dangerous to continue ...
455 */
456 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
457 data ? "Data" : "Instruction",
458 field, regs->cp0_epc, field, regs->regs[31]);
459 if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs), SIGBUS)
460 == NOTIFY_STOP)
461 goto out;
462
463 die_if_kernel("Oops", regs);
464 force_sig(SIGBUS, current);
465
466 out:
467 exception_exit(prev_state);
468 }
469
470 /*
471 * ll/sc, rdhwr, sync emulation
472 */
473
474 #define OPCODE 0xfc000000
475 #define BASE 0x03e00000
476 #define RT 0x001f0000
477 #define OFFSET 0x0000ffff
478 #define LL 0xc0000000
479 #define SC 0xe0000000
480 #define SPEC0 0x00000000
481 #define SPEC3 0x7c000000
482 #define RD 0x0000f800
483 #define FUNC 0x0000003f
484 #define SYNC 0x0000000f
485 #define RDHWR 0x0000003b
486
487 /* microMIPS definitions */
488 #define MM_POOL32A_FUNC 0xfc00ffff
489 #define MM_RDHWR 0x00006b3c
490 #define MM_RS 0x001f0000
491 #define MM_RT 0x03e00000
492
493 /*
494 * The ll_bit is cleared by r*_switch.S
495 */
496
497 unsigned int ll_bit;
498 struct task_struct *ll_task;
499
500 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
501 {
502 unsigned long value, __user *vaddr;
503 long offset;
504
505 /*
506 * analyse the ll instruction that just caused a ri exception
507 * and put the referenced address to addr.
508 */
509
510 /* sign extend offset */
511 offset = opcode & OFFSET;
512 offset <<= 16;
513 offset >>= 16;
514
515 vaddr = (unsigned long __user *)
516 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
517
518 if ((unsigned long)vaddr & 3)
519 return SIGBUS;
520 if (get_user(value, vaddr))
521 return SIGSEGV;
522
523 preempt_disable();
524
525 if (ll_task == NULL || ll_task == current) {
526 ll_bit = 1;
527 } else {
528 ll_bit = 0;
529 }
530 ll_task = current;
531
532 preempt_enable();
533
534 regs->regs[(opcode & RT) >> 16] = value;
535
536 return 0;
537 }
538
539 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
540 {
541 unsigned long __user *vaddr;
542 unsigned long reg;
543 long offset;
544
545 /*
546 * analyse the sc instruction that just caused a ri exception
547 * and put the referenced address to addr.
548 */
549
550 /* sign extend offset */
551 offset = opcode & OFFSET;
552 offset <<= 16;
553 offset >>= 16;
554
555 vaddr = (unsigned long __user *)
556 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
557 reg = (opcode & RT) >> 16;
558
559 if ((unsigned long)vaddr & 3)
560 return SIGBUS;
561
562 preempt_disable();
563
564 if (ll_bit == 0 || ll_task != current) {
565 regs->regs[reg] = 0;
566 preempt_enable();
567 return 0;
568 }
569
570 preempt_enable();
571
572 if (put_user(regs->regs[reg], vaddr))
573 return SIGSEGV;
574
575 regs->regs[reg] = 1;
576
577 return 0;
578 }
579
580 /*
581 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
582 * opcodes are supposed to result in coprocessor unusable exceptions if
583 * executed on ll/sc-less processors. That's the theory. In practice a
584 * few processors such as NEC's VR4100 throw reserved instruction exceptions
585 * instead, so we're doing the emulation thing in both exception handlers.
586 */
587 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
588 {
589 if ((opcode & OPCODE) == LL) {
590 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
591 1, regs, 0);
592 return simulate_ll(regs, opcode);
593 }
594 if ((opcode & OPCODE) == SC) {
595 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
596 1, regs, 0);
597 return simulate_sc(regs, opcode);
598 }
599
600 return -1; /* Must be something else ... */
601 }
602
603 /*
604 * Simulate trapping 'rdhwr' instructions to provide user accessible
605 * registers not implemented in hardware.
606 */
607 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
608 {
609 struct thread_info *ti = task_thread_info(current);
610
611 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
612 1, regs, 0);
613 switch (rd) {
614 case 0: /* CPU number */
615 regs->regs[rt] = smp_processor_id();
616 return 0;
617 case 1: /* SYNCI length */
618 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
619 current_cpu_data.icache.linesz);
620 return 0;
621 case 2: /* Read count register */
622 regs->regs[rt] = read_c0_count();
623 return 0;
624 case 3: /* Count register resolution */
625 switch (current_cpu_data.cputype) {
626 case CPU_20KC:
627 case CPU_25KF:
628 regs->regs[rt] = 1;
629 break;
630 default:
631 regs->regs[rt] = 2;
632 }
633 return 0;
634 case 29:
635 regs->regs[rt] = ti->tp_value;
636 return 0;
637 default:
638 return -1;
639 }
640 }
641
642 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
643 {
644 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
645 int rd = (opcode & RD) >> 11;
646 int rt = (opcode & RT) >> 16;
647
648 simulate_rdhwr(regs, rd, rt);
649 return 0;
650 }
651
652 /* Not ours. */
653 return -1;
654 }
655
656 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
657 {
658 if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
659 int rd = (opcode & MM_RS) >> 16;
660 int rt = (opcode & MM_RT) >> 21;
661 simulate_rdhwr(regs, rd, rt);
662 return 0;
663 }
664
665 /* Not ours. */
666 return -1;
667 }
668
669 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
670 {
671 if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
672 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
673 1, regs, 0);
674 return 0;
675 }
676
677 return -1; /* Must be something else ... */
678 }
679
680 asmlinkage void do_ov(struct pt_regs *regs)
681 {
682 enum ctx_state prev_state;
683 siginfo_t info;
684
685 prev_state = exception_enter();
686 die_if_kernel("Integer overflow", regs);
687
688 info.si_code = FPE_INTOVF;
689 info.si_signo = SIGFPE;
690 info.si_errno = 0;
691 info.si_addr = (void __user *) regs->cp0_epc;
692 force_sig_info(SIGFPE, &info, current);
693 exception_exit(prev_state);
694 }
695
696 int process_fpemu_return(int sig, void __user *fault_addr)
697 {
698 if (sig == SIGSEGV || sig == SIGBUS) {
699 struct siginfo si = {0};
700 si.si_addr = fault_addr;
701 si.si_signo = sig;
702 if (sig == SIGSEGV) {
703 if (find_vma(current->mm, (unsigned long)fault_addr))
704 si.si_code = SEGV_ACCERR;
705 else
706 si.si_code = SEGV_MAPERR;
707 } else {
708 si.si_code = BUS_ADRERR;
709 }
710 force_sig_info(sig, &si, current);
711 return 1;
712 } else if (sig) {
713 force_sig(sig, current);
714 return 1;
715 } else {
716 return 0;
717 }
718 }
719
720 /*
721 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
722 */
723 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
724 {
725 enum ctx_state prev_state;
726 siginfo_t info = {0};
727
728 prev_state = exception_enter();
729 if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs), SIGFPE)
730 == NOTIFY_STOP)
731 goto out;
732 die_if_kernel("FP exception in kernel code", regs);
733
734 if (fcr31 & FPU_CSR_UNI_X) {
735 int sig;
736 void __user *fault_addr = NULL;
737
738 /*
739 * Unimplemented operation exception. If we've got the full
740 * software emulator on-board, let's use it...
741 *
742 * Force FPU to dump state into task/thread context. We're
743 * moving a lot of data here for what is probably a single
744 * instruction, but the alternative is to pre-decode the FP
745 * register operands before invoking the emulator, which seems
746 * a bit extreme for what should be an infrequent event.
747 */
748 /* Ensure 'resume' not overwrite saved fp context again. */
749 lose_fpu(1);
750
751 /* Run the emulator */
752 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
753 &fault_addr);
754
755 /*
756 * We can't allow the emulated instruction to leave any of
757 * the cause bit set in $fcr31.
758 */
759 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
760
761 /* Restore the hardware register state */
762 own_fpu(1); /* Using the FPU again. */
763
764 /* If something went wrong, signal */
765 process_fpemu_return(sig, fault_addr);
766
767 goto out;
768 } else if (fcr31 & FPU_CSR_INV_X)
769 info.si_code = FPE_FLTINV;
770 else if (fcr31 & FPU_CSR_DIV_X)
771 info.si_code = FPE_FLTDIV;
772 else if (fcr31 & FPU_CSR_OVF_X)
773 info.si_code = FPE_FLTOVF;
774 else if (fcr31 & FPU_CSR_UDF_X)
775 info.si_code = FPE_FLTUND;
776 else if (fcr31 & FPU_CSR_INE_X)
777 info.si_code = FPE_FLTRES;
778 else
779 info.si_code = __SI_FAULT;
780 info.si_signo = SIGFPE;
781 info.si_errno = 0;
782 info.si_addr = (void __user *) regs->cp0_epc;
783 force_sig_info(SIGFPE, &info, current);
784
785 out:
786 exception_exit(prev_state);
787 }
788
789 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
790 const char *str)
791 {
792 siginfo_t info;
793 char b[40];
794
795 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
796 if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
797 return;
798 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
799
800 if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
801 return;
802
803 /*
804 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
805 * insns, even for trap and break codes that indicate arithmetic
806 * failures. Weird ...
807 * But should we continue the brokenness??? --macro
808 */
809 switch (code) {
810 case BRK_OVERFLOW:
811 case BRK_DIVZERO:
812 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
813 die_if_kernel(b, regs);
814 if (code == BRK_DIVZERO)
815 info.si_code = FPE_INTDIV;
816 else
817 info.si_code = FPE_INTOVF;
818 info.si_signo = SIGFPE;
819 info.si_errno = 0;
820 info.si_addr = (void __user *) regs->cp0_epc;
821 force_sig_info(SIGFPE, &info, current);
822 break;
823 case BRK_BUG:
824 die_if_kernel("Kernel bug detected", regs);
825 force_sig(SIGTRAP, current);
826 break;
827 case BRK_MEMU:
828 /*
829 * Address errors may be deliberately induced by the FPU
830 * emulator to retake control of the CPU after executing the
831 * instruction in the delay slot of an emulated branch.
832 *
833 * Terminate if exception was recognized as a delay slot return
834 * otherwise handle as normal.
835 */
836 if (do_dsemulret(regs))
837 return;
838
839 die_if_kernel("Math emu break/trap", regs);
840 force_sig(SIGTRAP, current);
841 break;
842 default:
843 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
844 die_if_kernel(b, regs);
845 force_sig(SIGTRAP, current);
846 }
847 }
848
849 asmlinkage void do_bp(struct pt_regs *regs)
850 {
851 unsigned int opcode, bcode;
852 enum ctx_state prev_state;
853 unsigned long epc;
854 u16 instr[2];
855
856 prev_state = exception_enter();
857 if (get_isa16_mode(regs->cp0_epc)) {
858 /* Calculate EPC. */
859 epc = exception_epc(regs);
860 if (cpu_has_mmips) {
861 if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)) ||
862 (__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2)))))
863 goto out_sigsegv;
864 opcode = (instr[0] << 16) | instr[1];
865 } else {
866 /* MIPS16e mode */
867 if (__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)))
868 goto out_sigsegv;
869 bcode = (instr[0] >> 6) & 0x3f;
870 do_trap_or_bp(regs, bcode, "Break");
871 goto out;
872 }
873 } else {
874 if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
875 goto out_sigsegv;
876 }
877
878 /*
879 * There is the ancient bug in the MIPS assemblers that the break
880 * code starts left to bit 16 instead to bit 6 in the opcode.
881 * Gas is bug-compatible, but not always, grrr...
882 * We handle both cases with a simple heuristics. --macro
883 */
884 bcode = ((opcode >> 6) & ((1 << 20) - 1));
885 if (bcode >= (1 << 10))
886 bcode >>= 10;
887
888 /*
889 * notify the kprobe handlers, if instruction is likely to
890 * pertain to them.
891 */
892 switch (bcode) {
893 case BRK_KPROBE_BP:
894 if (notify_die(DIE_BREAK, "debug", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
895 goto out;
896 else
897 break;
898 case BRK_KPROBE_SSTEPBP:
899 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
900 goto out;
901 else
902 break;
903 default:
904 break;
905 }
906
907 do_trap_or_bp(regs, bcode, "Break");
908
909 out:
910 exception_exit(prev_state);
911 return;
912
913 out_sigsegv:
914 force_sig(SIGSEGV, current);
915 goto out;
916 }
917
918 asmlinkage void do_tr(struct pt_regs *regs)
919 {
920 u32 opcode, tcode = 0;
921 enum ctx_state prev_state;
922 u16 instr[2];
923 unsigned long epc = msk_isa16_mode(exception_epc(regs));
924
925 prev_state = exception_enter();
926 if (get_isa16_mode(regs->cp0_epc)) {
927 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
928 __get_user(instr[1], (u16 __user *)(epc + 2)))
929 goto out_sigsegv;
930 opcode = (instr[0] << 16) | instr[1];
931 /* Immediate versions don't provide a code. */
932 if (!(opcode & OPCODE))
933 tcode = (opcode >> 12) & ((1 << 4) - 1);
934 } else {
935 if (__get_user(opcode, (u32 __user *)epc))
936 goto out_sigsegv;
937 /* Immediate versions don't provide a code. */
938 if (!(opcode & OPCODE))
939 tcode = (opcode >> 6) & ((1 << 10) - 1);
940 }
941
942 do_trap_or_bp(regs, tcode, "Trap");
943
944 out:
945 exception_exit(prev_state);
946 return;
947
948 out_sigsegv:
949 force_sig(SIGSEGV, current);
950 goto out;
951 }
952
953 asmlinkage void do_ri(struct pt_regs *regs)
954 {
955 unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
956 unsigned long old_epc = regs->cp0_epc;
957 unsigned long old31 = regs->regs[31];
958 enum ctx_state prev_state;
959 unsigned int opcode = 0;
960 int status = -1;
961
962 prev_state = exception_enter();
963 if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs), SIGILL)
964 == NOTIFY_STOP)
965 goto out;
966
967 die_if_kernel("Reserved instruction in kernel code", regs);
968
969 if (unlikely(compute_return_epc(regs) < 0))
970 goto out;
971
972 if (get_isa16_mode(regs->cp0_epc)) {
973 unsigned short mmop[2] = { 0 };
974
975 if (unlikely(get_user(mmop[0], epc) < 0))
976 status = SIGSEGV;
977 if (unlikely(get_user(mmop[1], epc) < 0))
978 status = SIGSEGV;
979 opcode = (mmop[0] << 16) | mmop[1];
980
981 if (status < 0)
982 status = simulate_rdhwr_mm(regs, opcode);
983 } else {
984 if (unlikely(get_user(opcode, epc) < 0))
985 status = SIGSEGV;
986
987 if (!cpu_has_llsc && status < 0)
988 status = simulate_llsc(regs, opcode);
989
990 if (status < 0)
991 status = simulate_rdhwr_normal(regs, opcode);
992
993 if (status < 0)
994 status = simulate_sync(regs, opcode);
995 }
996
997 if (status < 0)
998 status = SIGILL;
999
1000 if (unlikely(status > 0)) {
1001 regs->cp0_epc = old_epc; /* Undo skip-over. */
1002 regs->regs[31] = old31;
1003 force_sig(status, current);
1004 }
1005
1006 out:
1007 exception_exit(prev_state);
1008 }
1009
1010 /*
1011 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1012 * emulated more than some threshold number of instructions, force migration to
1013 * a "CPU" that has FP support.
1014 */
1015 static void mt_ase_fp_affinity(void)
1016 {
1017 #ifdef CONFIG_MIPS_MT_FPAFF
1018 if (mt_fpemul_threshold > 0 &&
1019 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1020 /*
1021 * If there's no FPU present, or if the application has already
1022 * restricted the allowed set to exclude any CPUs with FPUs,
1023 * we'll skip the procedure.
1024 */
1025 if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
1026 cpumask_t tmask;
1027
1028 current->thread.user_cpus_allowed
1029 = current->cpus_allowed;
1030 cpus_and(tmask, current->cpus_allowed,
1031 mt_fpu_cpumask);
1032 set_cpus_allowed_ptr(current, &tmask);
1033 set_thread_flag(TIF_FPUBOUND);
1034 }
1035 }
1036 #endif /* CONFIG_MIPS_MT_FPAFF */
1037 }
1038
1039 /*
1040 * No lock; only written during early bootup by CPU 0.
1041 */
1042 static RAW_NOTIFIER_HEAD(cu2_chain);
1043
1044 int __ref register_cu2_notifier(struct notifier_block *nb)
1045 {
1046 return raw_notifier_chain_register(&cu2_chain, nb);
1047 }
1048
1049 int cu2_notifier_call_chain(unsigned long val, void *v)
1050 {
1051 return raw_notifier_call_chain(&cu2_chain, val, v);
1052 }
1053
1054 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1055 void *data)
1056 {
1057 struct pt_regs *regs = data;
1058
1059 die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1060 "instruction", regs);
1061 force_sig(SIGILL, current);
1062
1063 return NOTIFY_OK;
1064 }
1065
1066 asmlinkage void do_cpu(struct pt_regs *regs)
1067 {
1068 enum ctx_state prev_state;
1069 unsigned int __user *epc;
1070 unsigned long old_epc, old31;
1071 unsigned int opcode;
1072 unsigned int cpid;
1073 int status;
1074 unsigned long __maybe_unused flags;
1075
1076 prev_state = exception_enter();
1077 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1078
1079 if (cpid != 2)
1080 die_if_kernel("do_cpu invoked from kernel context!", regs);
1081
1082 switch (cpid) {
1083 case 0:
1084 epc = (unsigned int __user *)exception_epc(regs);
1085 old_epc = regs->cp0_epc;
1086 old31 = regs->regs[31];
1087 opcode = 0;
1088 status = -1;
1089
1090 if (unlikely(compute_return_epc(regs) < 0))
1091 goto out;
1092
1093 if (get_isa16_mode(regs->cp0_epc)) {
1094 unsigned short mmop[2] = { 0 };
1095
1096 if (unlikely(get_user(mmop[0], epc) < 0))
1097 status = SIGSEGV;
1098 if (unlikely(get_user(mmop[1], epc) < 0))
1099 status = SIGSEGV;
1100 opcode = (mmop[0] << 16) | mmop[1];
1101
1102 if (status < 0)
1103 status = simulate_rdhwr_mm(regs, opcode);
1104 } else {
1105 if (unlikely(get_user(opcode, epc) < 0))
1106 status = SIGSEGV;
1107
1108 if (!cpu_has_llsc && status < 0)
1109 status = simulate_llsc(regs, opcode);
1110
1111 if (status < 0)
1112 status = simulate_rdhwr_normal(regs, opcode);
1113 }
1114
1115 if (status < 0)
1116 status = SIGILL;
1117
1118 if (unlikely(status > 0)) {
1119 regs->cp0_epc = old_epc; /* Undo skip-over. */
1120 regs->regs[31] = old31;
1121 force_sig(status, current);
1122 }
1123
1124 goto out;
1125
1126 case 3:
1127 /*
1128 * Old (MIPS I and MIPS II) processors will set this code
1129 * for COP1X opcode instructions that replaced the original
1130 * COP3 space. We don't limit COP1 space instructions in
1131 * the emulator according to the CPU ISA, so we want to
1132 * treat COP1X instructions consistently regardless of which
1133 * code the CPU chose. Therefore we redirect this trap to
1134 * the FP emulator too.
1135 *
1136 * Then some newer FPU-less processors use this code
1137 * erroneously too, so they are covered by this choice
1138 * as well.
1139 */
1140 if (raw_cpu_has_fpu)
1141 break;
1142 /* Fall through. */
1143
1144 case 1:
1145 if (used_math()) /* Using the FPU again. */
1146 own_fpu(1);
1147 else { /* First time FPU user. */
1148 init_fpu();
1149 set_used_math();
1150 }
1151
1152 if (!raw_cpu_has_fpu) {
1153 int sig;
1154 void __user *fault_addr = NULL;
1155 sig = fpu_emulator_cop1Handler(regs,
1156 &current->thread.fpu,
1157 0, &fault_addr);
1158 if (!process_fpemu_return(sig, fault_addr))
1159 mt_ase_fp_affinity();
1160 }
1161
1162 goto out;
1163
1164 case 2:
1165 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1166 goto out;
1167 }
1168
1169 force_sig(SIGILL, current);
1170
1171 out:
1172 exception_exit(prev_state);
1173 }
1174
1175 asmlinkage void do_mdmx(struct pt_regs *regs)
1176 {
1177 enum ctx_state prev_state;
1178
1179 prev_state = exception_enter();
1180 force_sig(SIGILL, current);
1181 exception_exit(prev_state);
1182 }
1183
1184 /*
1185 * Called with interrupts disabled.
1186 */
1187 asmlinkage void do_watch(struct pt_regs *regs)
1188 {
1189 enum ctx_state prev_state;
1190 u32 cause;
1191
1192 prev_state = exception_enter();
1193 /*
1194 * Clear WP (bit 22) bit of cause register so we don't loop
1195 * forever.
1196 */
1197 cause = read_c0_cause();
1198 cause &= ~(1 << 22);
1199 write_c0_cause(cause);
1200
1201 /*
1202 * If the current thread has the watch registers loaded, save
1203 * their values and send SIGTRAP. Otherwise another thread
1204 * left the registers set, clear them and continue.
1205 */
1206 if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1207 mips_read_watch_registers();
1208 local_irq_enable();
1209 force_sig(SIGTRAP, current);
1210 } else {
1211 mips_clear_watch_registers();
1212 local_irq_enable();
1213 }
1214 exception_exit(prev_state);
1215 }
1216
1217 asmlinkage void do_mcheck(struct pt_regs *regs)
1218 {
1219 const int field = 2 * sizeof(unsigned long);
1220 int multi_match = regs->cp0_status & ST0_TS;
1221 enum ctx_state prev_state;
1222
1223 prev_state = exception_enter();
1224 show_regs(regs);
1225
1226 if (multi_match) {
1227 printk("Index : %0x\n", read_c0_index());
1228 printk("Pagemask: %0x\n", read_c0_pagemask());
1229 printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
1230 printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1231 printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1232 printk("\n");
1233 dump_tlb_all();
1234 }
1235
1236 show_code((unsigned int __user *) regs->cp0_epc);
1237
1238 /*
1239 * Some chips may have other causes of machine check (e.g. SB1
1240 * graduation timer)
1241 */
1242 panic("Caught Machine Check exception - %scaused by multiple "
1243 "matching entries in the TLB.",
1244 (multi_match) ? "" : "not ");
1245 }
1246
1247 asmlinkage void do_mt(struct pt_regs *regs)
1248 {
1249 int subcode;
1250
1251 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1252 >> VPECONTROL_EXCPT_SHIFT;
1253 switch (subcode) {
1254 case 0:
1255 printk(KERN_DEBUG "Thread Underflow\n");
1256 break;
1257 case 1:
1258 printk(KERN_DEBUG "Thread Overflow\n");
1259 break;
1260 case 2:
1261 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1262 break;
1263 case 3:
1264 printk(KERN_DEBUG "Gating Storage Exception\n");
1265 break;
1266 case 4:
1267 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1268 break;
1269 case 5:
1270 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1271 break;
1272 default:
1273 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1274 subcode);
1275 break;
1276 }
1277 die_if_kernel("MIPS MT Thread exception in kernel", regs);
1278
1279 force_sig(SIGILL, current);
1280 }
1281
1282
1283 asmlinkage void do_dsp(struct pt_regs *regs)
1284 {
1285 if (cpu_has_dsp)
1286 panic("Unexpected DSP exception");
1287
1288 force_sig(SIGILL, current);
1289 }
1290
1291 asmlinkage void do_reserved(struct pt_regs *regs)
1292 {
1293 /*
1294 * Game over - no way to handle this if it ever occurs. Most probably
1295 * caused by a new unknown cpu type or after another deadly
1296 * hard/software error.
1297 */
1298 show_regs(regs);
1299 panic("Caught reserved exception %ld - should not happen.",
1300 (regs->cp0_cause & 0x7f) >> 2);
1301 }
1302
1303 static int __initdata l1parity = 1;
1304 static int __init nol1parity(char *s)
1305 {
1306 l1parity = 0;
1307 return 1;
1308 }
1309 __setup("nol1par", nol1parity);
1310 static int __initdata l2parity = 1;
1311 static int __init nol2parity(char *s)
1312 {
1313 l2parity = 0;
1314 return 1;
1315 }
1316 __setup("nol2par", nol2parity);
1317
1318 /*
1319 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1320 * it different ways.
1321 */
1322 static inline void parity_protection_init(void)
1323 {
1324 switch (current_cpu_type()) {
1325 case CPU_24K:
1326 case CPU_34K:
1327 case CPU_74K:
1328 case CPU_1004K:
1329 {
1330 #define ERRCTL_PE 0x80000000
1331 #define ERRCTL_L2P 0x00800000
1332 unsigned long errctl;
1333 unsigned int l1parity_present, l2parity_present;
1334
1335 errctl = read_c0_ecc();
1336 errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1337
1338 /* probe L1 parity support */
1339 write_c0_ecc(errctl | ERRCTL_PE);
1340 back_to_back_c0_hazard();
1341 l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1342
1343 /* probe L2 parity support */
1344 write_c0_ecc(errctl|ERRCTL_L2P);
1345 back_to_back_c0_hazard();
1346 l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1347
1348 if (l1parity_present && l2parity_present) {
1349 if (l1parity)
1350 errctl |= ERRCTL_PE;
1351 if (l1parity ^ l2parity)
1352 errctl |= ERRCTL_L2P;
1353 } else if (l1parity_present) {
1354 if (l1parity)
1355 errctl |= ERRCTL_PE;
1356 } else if (l2parity_present) {
1357 if (l2parity)
1358 errctl |= ERRCTL_L2P;
1359 } else {
1360 /* No parity available */
1361 }
1362
1363 printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1364
1365 write_c0_ecc(errctl);
1366 back_to_back_c0_hazard();
1367 errctl = read_c0_ecc();
1368 printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1369
1370 if (l1parity_present)
1371 printk(KERN_INFO "Cache parity protection %sabled\n",
1372 (errctl & ERRCTL_PE) ? "en" : "dis");
1373
1374 if (l2parity_present) {
1375 if (l1parity_present && l1parity)
1376 errctl ^= ERRCTL_L2P;
1377 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1378 (errctl & ERRCTL_L2P) ? "en" : "dis");
1379 }
1380 }
1381 break;
1382
1383 case CPU_5KC:
1384 case CPU_5KE:
1385 case CPU_LOONGSON1:
1386 write_c0_ecc(0x80000000);
1387 back_to_back_c0_hazard();
1388 /* Set the PE bit (bit 31) in the c0_errctl register. */
1389 printk(KERN_INFO "Cache parity protection %sabled\n",
1390 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1391 break;
1392 case CPU_20KC:
1393 case CPU_25KF:
1394 /* Clear the DE bit (bit 16) in the c0_status register. */
1395 printk(KERN_INFO "Enable cache parity protection for "
1396 "MIPS 20KC/25KF CPUs.\n");
1397 clear_c0_status(ST0_DE);
1398 break;
1399 default:
1400 break;
1401 }
1402 }
1403
1404 asmlinkage void cache_parity_error(void)
1405 {
1406 const int field = 2 * sizeof(unsigned long);
1407 unsigned int reg_val;
1408
1409 /* For the moment, report the problem and hang. */
1410 printk("Cache error exception:\n");
1411 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1412 reg_val = read_c0_cacheerr();
1413 printk("c0_cacheerr == %08x\n", reg_val);
1414
1415 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1416 reg_val & (1<<30) ? "secondary" : "primary",
1417 reg_val & (1<<31) ? "data" : "insn");
1418 printk("Error bits: %s%s%s%s%s%s%s\n",
1419 reg_val & (1<<29) ? "ED " : "",
1420 reg_val & (1<<28) ? "ET " : "",
1421 reg_val & (1<<26) ? "EE " : "",
1422 reg_val & (1<<25) ? "EB " : "",
1423 reg_val & (1<<24) ? "EI " : "",
1424 reg_val & (1<<23) ? "E1 " : "",
1425 reg_val & (1<<22) ? "E0 " : "");
1426 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1427
1428 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1429 if (reg_val & (1<<22))
1430 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1431
1432 if (reg_val & (1<<23))
1433 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1434 #endif
1435
1436 panic("Can't handle the cache error!");
1437 }
1438
1439 /*
1440 * SDBBP EJTAG debug exception handler.
1441 * We skip the instruction and return to the next instruction.
1442 */
1443 void ejtag_exception_handler(struct pt_regs *regs)
1444 {
1445 const int field = 2 * sizeof(unsigned long);
1446 unsigned long depc, old_epc, old_ra;
1447 unsigned int debug;
1448
1449 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1450 depc = read_c0_depc();
1451 debug = read_c0_debug();
1452 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1453 if (debug & 0x80000000) {
1454 /*
1455 * In branch delay slot.
1456 * We cheat a little bit here and use EPC to calculate the
1457 * debug return address (DEPC). EPC is restored after the
1458 * calculation.
1459 */
1460 old_epc = regs->cp0_epc;
1461 old_ra = regs->regs[31];
1462 regs->cp0_epc = depc;
1463 compute_return_epc(regs);
1464 depc = regs->cp0_epc;
1465 regs->cp0_epc = old_epc;
1466 regs->regs[31] = old_ra;
1467 } else
1468 depc += 4;
1469 write_c0_depc(depc);
1470
1471 #if 0
1472 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1473 write_c0_debug(debug | 0x100);
1474 #endif
1475 }
1476
1477 /*
1478 * NMI exception handler.
1479 * No lock; only written during early bootup by CPU 0.
1480 */
1481 static RAW_NOTIFIER_HEAD(nmi_chain);
1482
1483 int register_nmi_notifier(struct notifier_block *nb)
1484 {
1485 return raw_notifier_chain_register(&nmi_chain, nb);
1486 }
1487
1488 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1489 {
1490 raw_notifier_call_chain(&nmi_chain, 0, regs);
1491 bust_spinlocks(1);
1492 printk("NMI taken!!!!\n");
1493 die("NMI", regs);
1494 }
1495
1496 #define VECTORSPACING 0x100 /* for EI/VI mode */
1497
1498 unsigned long ebase;
1499 unsigned long exception_handlers[32];
1500 unsigned long vi_handlers[64];
1501
1502 void __init *set_except_vector(int n, void *addr)
1503 {
1504 unsigned long handler = (unsigned long) addr;
1505 unsigned long old_handler;
1506
1507 #ifdef CONFIG_CPU_MICROMIPS
1508 /*
1509 * Only the TLB handlers are cache aligned with an even
1510 * address. All other handlers are on an odd address and
1511 * require no modification. Otherwise, MIPS32 mode will
1512 * be entered when handling any TLB exceptions. That
1513 * would be bad...since we must stay in microMIPS mode.
1514 */
1515 if (!(handler & 0x1))
1516 handler |= 1;
1517 #endif
1518 old_handler = xchg(&exception_handlers[n], handler);
1519
1520 if (n == 0 && cpu_has_divec) {
1521 #ifdef CONFIG_CPU_MICROMIPS
1522 unsigned long jump_mask = ~((1 << 27) - 1);
1523 #else
1524 unsigned long jump_mask = ~((1 << 28) - 1);
1525 #endif
1526 u32 *buf = (u32 *)(ebase + 0x200);
1527 unsigned int k0 = 26;
1528 if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1529 uasm_i_j(&buf, handler & ~jump_mask);
1530 uasm_i_nop(&buf);
1531 } else {
1532 UASM_i_LA(&buf, k0, handler);
1533 uasm_i_jr(&buf, k0);
1534 uasm_i_nop(&buf);
1535 }
1536 local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1537 }
1538 return (void *)old_handler;
1539 }
1540
1541 static void do_default_vi(void)
1542 {
1543 show_regs(get_irq_regs());
1544 panic("Caught unexpected vectored interrupt.");
1545 }
1546
1547 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1548 {
1549 unsigned long handler;
1550 unsigned long old_handler = vi_handlers[n];
1551 int srssets = current_cpu_data.srsets;
1552 u16 *h;
1553 unsigned char *b;
1554
1555 BUG_ON(!cpu_has_veic && !cpu_has_vint);
1556 BUG_ON((n < 0) && (n > 9));
1557
1558 if (addr == NULL) {
1559 handler = (unsigned long) do_default_vi;
1560 srs = 0;
1561 } else
1562 handler = (unsigned long) addr;
1563 vi_handlers[n] = handler;
1564
1565 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1566
1567 if (srs >= srssets)
1568 panic("Shadow register set %d not supported", srs);
1569
1570 if (cpu_has_veic) {
1571 if (board_bind_eic_interrupt)
1572 board_bind_eic_interrupt(n, srs);
1573 } else if (cpu_has_vint) {
1574 /* SRSMap is only defined if shadow sets are implemented */
1575 if (srssets > 1)
1576 change_c0_srsmap(0xf << n*4, srs << n*4);
1577 }
1578
1579 if (srs == 0) {
1580 /*
1581 * If no shadow set is selected then use the default handler
1582 * that does normal register saving and standard interrupt exit
1583 */
1584 extern char except_vec_vi, except_vec_vi_lui;
1585 extern char except_vec_vi_ori, except_vec_vi_end;
1586 extern char rollback_except_vec_vi;
1587 char *vec_start = using_rollback_handler() ?
1588 &rollback_except_vec_vi : &except_vec_vi;
1589 #ifdef CONFIG_MIPS_MT_SMTC
1590 /*
1591 * We need to provide the SMTC vectored interrupt handler
1592 * not only with the address of the handler, but with the
1593 * Status.IM bit to be masked before going there.
1594 */
1595 extern char except_vec_vi_mori;
1596 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1597 const int mori_offset = &except_vec_vi_mori - vec_start + 2;
1598 #else
1599 const int mori_offset = &except_vec_vi_mori - vec_start;
1600 #endif
1601 #endif /* CONFIG_MIPS_MT_SMTC */
1602 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1603 const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1604 const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1605 #else
1606 const int lui_offset = &except_vec_vi_lui - vec_start;
1607 const int ori_offset = &except_vec_vi_ori - vec_start;
1608 #endif
1609 const int handler_len = &except_vec_vi_end - vec_start;
1610
1611 if (handler_len > VECTORSPACING) {
1612 /*
1613 * Sigh... panicing won't help as the console
1614 * is probably not configured :(
1615 */
1616 panic("VECTORSPACING too small");
1617 }
1618
1619 set_handler(((unsigned long)b - ebase), vec_start,
1620 #ifdef CONFIG_CPU_MICROMIPS
1621 (handler_len - 1));
1622 #else
1623 handler_len);
1624 #endif
1625 #ifdef CONFIG_MIPS_MT_SMTC
1626 BUG_ON(n > 7); /* Vector index %d exceeds SMTC maximum. */
1627
1628 h = (u16 *)(b + mori_offset);
1629 *h = (0x100 << n);
1630 #endif /* CONFIG_MIPS_MT_SMTC */
1631 h = (u16 *)(b + lui_offset);
1632 *h = (handler >> 16) & 0xffff;
1633 h = (u16 *)(b + ori_offset);
1634 *h = (handler & 0xffff);
1635 local_flush_icache_range((unsigned long)b,
1636 (unsigned long)(b+handler_len));
1637 }
1638 else {
1639 /*
1640 * In other cases jump directly to the interrupt handler. It
1641 * is the handler's responsibility to save registers if required
1642 * (eg hi/lo) and return from the exception using "eret".
1643 */
1644 u32 insn;
1645
1646 h = (u16 *)b;
1647 /* j handler */
1648 #ifdef CONFIG_CPU_MICROMIPS
1649 insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
1650 #else
1651 insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
1652 #endif
1653 h[0] = (insn >> 16) & 0xffff;
1654 h[1] = insn & 0xffff;
1655 h[2] = 0;
1656 h[3] = 0;
1657 local_flush_icache_range((unsigned long)b,
1658 (unsigned long)(b+8));
1659 }
1660
1661 return (void *)old_handler;
1662 }
1663
1664 void *set_vi_handler(int n, vi_handler_t addr)
1665 {
1666 return set_vi_srs_handler(n, addr, 0);
1667 }
1668
1669 extern void tlb_init(void);
1670
1671 /*
1672 * Timer interrupt
1673 */
1674 int cp0_compare_irq;
1675 EXPORT_SYMBOL_GPL(cp0_compare_irq);
1676 int cp0_compare_irq_shift;
1677
1678 /*
1679 * Performance counter IRQ or -1 if shared with timer
1680 */
1681 int cp0_perfcount_irq;
1682 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1683
1684 static int noulri;
1685
1686 static int __init ulri_disable(char *s)
1687 {
1688 pr_info("Disabling ulri\n");
1689 noulri = 1;
1690
1691 return 1;
1692 }
1693 __setup("noulri", ulri_disable);
1694
1695 void per_cpu_trap_init(bool is_boot_cpu)
1696 {
1697 unsigned int cpu = smp_processor_id();
1698 unsigned int status_set = ST0_CU0;
1699 unsigned int hwrena = cpu_hwrena_impl_bits;
1700 #ifdef CONFIG_MIPS_MT_SMTC
1701 int secondaryTC = 0;
1702 int bootTC = (cpu == 0);
1703
1704 /*
1705 * Only do per_cpu_trap_init() for first TC of Each VPE.
1706 * Note that this hack assumes that the SMTC init code
1707 * assigns TCs consecutively and in ascending order.
1708 */
1709
1710 if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1711 ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1712 secondaryTC = 1;
1713 #endif /* CONFIG_MIPS_MT_SMTC */
1714
1715 /*
1716 * Disable coprocessors and select 32-bit or 64-bit addressing
1717 * and the 16/32 or 32/32 FPR register model. Reset the BEV
1718 * flag that some firmware may have left set and the TS bit (for
1719 * IP27). Set XX for ISA IV code to work.
1720 */
1721 #ifdef CONFIG_64BIT
1722 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1723 #endif
1724 if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
1725 status_set |= ST0_XX;
1726 if (cpu_has_dsp)
1727 status_set |= ST0_MX;
1728
1729 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1730 status_set);
1731
1732 if (cpu_has_mips_r2)
1733 hwrena |= 0x0000000f;
1734
1735 if (!noulri && cpu_has_userlocal)
1736 hwrena |= (1 << 29);
1737
1738 if (hwrena)
1739 write_c0_hwrena(hwrena);
1740
1741 #ifdef CONFIG_MIPS_MT_SMTC
1742 if (!secondaryTC) {
1743 #endif /* CONFIG_MIPS_MT_SMTC */
1744
1745 if (cpu_has_veic || cpu_has_vint) {
1746 unsigned long sr = set_c0_status(ST0_BEV);
1747 write_c0_ebase(ebase);
1748 write_c0_status(sr);
1749 /* Setting vector spacing enables EI/VI mode */
1750 change_c0_intctl(0x3e0, VECTORSPACING);
1751 }
1752 if (cpu_has_divec) {
1753 if (cpu_has_mipsmt) {
1754 unsigned int vpflags = dvpe();
1755 set_c0_cause(CAUSEF_IV);
1756 evpe(vpflags);
1757 } else
1758 set_c0_cause(CAUSEF_IV);
1759 }
1760
1761 /*
1762 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1763 *
1764 * o read IntCtl.IPTI to determine the timer interrupt
1765 * o read IntCtl.IPPCI to determine the performance counter interrupt
1766 */
1767 if (cpu_has_mips_r2) {
1768 cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
1769 cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
1770 cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
1771 if (cp0_perfcount_irq == cp0_compare_irq)
1772 cp0_perfcount_irq = -1;
1773 } else {
1774 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1775 cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
1776 cp0_perfcount_irq = -1;
1777 }
1778
1779 #ifdef CONFIG_MIPS_MT_SMTC
1780 }
1781 #endif /* CONFIG_MIPS_MT_SMTC */
1782
1783 if (!cpu_data[cpu].asid_cache)
1784 cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1785
1786 atomic_inc(&init_mm.mm_count);
1787 current->active_mm = &init_mm;
1788 BUG_ON(current->mm);
1789 enter_lazy_tlb(&init_mm, current);
1790
1791 #ifdef CONFIG_MIPS_MT_SMTC
1792 if (bootTC) {
1793 #endif /* CONFIG_MIPS_MT_SMTC */
1794 /* Boot CPU's cache setup in setup_arch(). */
1795 if (!is_boot_cpu)
1796 cpu_cache_init();
1797 tlb_init();
1798 #ifdef CONFIG_MIPS_MT_SMTC
1799 } else if (!secondaryTC) {
1800 /*
1801 * First TC in non-boot VPE must do subset of tlb_init()
1802 * for MMU countrol registers.
1803 */
1804 write_c0_pagemask(PM_DEFAULT_MASK);
1805 write_c0_wired(0);
1806 }
1807 #endif /* CONFIG_MIPS_MT_SMTC */
1808 TLBMISS_HANDLER_SETUP();
1809 }
1810
1811 /* Install CPU exception handler */
1812 void set_handler(unsigned long offset, void *addr, unsigned long size)
1813 {
1814 #ifdef CONFIG_CPU_MICROMIPS
1815 memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
1816 #else
1817 memcpy((void *)(ebase + offset), addr, size);
1818 #endif
1819 local_flush_icache_range(ebase + offset, ebase + offset + size);
1820 }
1821
1822 static char panic_null_cerr[] =
1823 "Trying to set NULL cache error exception handler";
1824
1825 /*
1826 * Install uncached CPU exception handler.
1827 * This is suitable only for the cache error exception which is the only
1828 * exception handler that is being run uncached.
1829 */
1830 void set_uncached_handler(unsigned long offset, void *addr,
1831 unsigned long size)
1832 {
1833 unsigned long uncached_ebase = CKSEG1ADDR(ebase);
1834
1835 if (!addr)
1836 panic(panic_null_cerr);
1837
1838 memcpy((void *)(uncached_ebase + offset), addr, size);
1839 }
1840
1841 static int __initdata rdhwr_noopt;
1842 static int __init set_rdhwr_noopt(char *str)
1843 {
1844 rdhwr_noopt = 1;
1845 return 1;
1846 }
1847
1848 __setup("rdhwr_noopt", set_rdhwr_noopt);
1849
1850 void __init trap_init(void)
1851 {
1852 extern char except_vec3_generic;
1853 extern char except_vec4;
1854 extern char except_vec3_r4000;
1855 unsigned long i;
1856
1857 check_wait();
1858
1859 #if defined(CONFIG_KGDB)
1860 if (kgdb_early_setup)
1861 return; /* Already done */
1862 #endif
1863
1864 if (cpu_has_veic || cpu_has_vint) {
1865 unsigned long size = 0x200 + VECTORSPACING*64;
1866 ebase = (unsigned long)
1867 __alloc_bootmem(size, 1 << fls(size), 0);
1868 } else {
1869 #ifdef CONFIG_KVM_GUEST
1870 #define KVM_GUEST_KSEG0 0x40000000
1871 ebase = KVM_GUEST_KSEG0;
1872 #else
1873 ebase = CKSEG0;
1874 #endif
1875 if (cpu_has_mips_r2)
1876 ebase += (read_c0_ebase() & 0x3ffff000);
1877 }
1878
1879 if (cpu_has_mmips) {
1880 unsigned int config3 = read_c0_config3();
1881
1882 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
1883 write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
1884 else
1885 write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
1886 }
1887
1888 if (board_ebase_setup)
1889 board_ebase_setup();
1890 per_cpu_trap_init(true);
1891
1892 /*
1893 * Copy the generic exception handlers to their final destination.
1894 * This will be overriden later as suitable for a particular
1895 * configuration.
1896 */
1897 set_handler(0x180, &except_vec3_generic, 0x80);
1898
1899 /*
1900 * Setup default vectors
1901 */
1902 for (i = 0; i <= 31; i++)
1903 set_except_vector(i, handle_reserved);
1904
1905 /*
1906 * Copy the EJTAG debug exception vector handler code to it's final
1907 * destination.
1908 */
1909 if (cpu_has_ejtag && board_ejtag_handler_setup)
1910 board_ejtag_handler_setup();
1911
1912 /*
1913 * Only some CPUs have the watch exceptions.
1914 */
1915 if (cpu_has_watch)
1916 set_except_vector(23, handle_watch);
1917
1918 /*
1919 * Initialise interrupt handlers
1920 */
1921 if (cpu_has_veic || cpu_has_vint) {
1922 int nvec = cpu_has_veic ? 64 : 8;
1923 for (i = 0; i < nvec; i++)
1924 set_vi_handler(i, NULL);
1925 }
1926 else if (cpu_has_divec)
1927 set_handler(0x200, &except_vec4, 0x8);
1928
1929 /*
1930 * Some CPUs can enable/disable for cache parity detection, but does
1931 * it different ways.
1932 */
1933 parity_protection_init();
1934
1935 /*
1936 * The Data Bus Errors / Instruction Bus Errors are signaled
1937 * by external hardware. Therefore these two exceptions
1938 * may have board specific handlers.
1939 */
1940 if (board_be_init)
1941 board_be_init();
1942
1943 set_except_vector(0, using_rollback_handler() ? rollback_handle_int
1944 : handle_int);
1945 set_except_vector(1, handle_tlbm);
1946 set_except_vector(2, handle_tlbl);
1947 set_except_vector(3, handle_tlbs);
1948
1949 set_except_vector(4, handle_adel);
1950 set_except_vector(5, handle_ades);
1951
1952 set_except_vector(6, handle_ibe);
1953 set_except_vector(7, handle_dbe);
1954
1955 set_except_vector(8, handle_sys);
1956 set_except_vector(9, handle_bp);
1957 set_except_vector(10, rdhwr_noopt ? handle_ri :
1958 (cpu_has_vtag_icache ?
1959 handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1960 set_except_vector(11, handle_cpu);
1961 set_except_vector(12, handle_ov);
1962 set_except_vector(13, handle_tr);
1963
1964 if (current_cpu_type() == CPU_R6000 ||
1965 current_cpu_type() == CPU_R6000A) {
1966 /*
1967 * The R6000 is the only R-series CPU that features a machine
1968 * check exception (similar to the R4000 cache error) and
1969 * unaligned ldc1/sdc1 exception. The handlers have not been
1970 * written yet. Well, anyway there is no R6000 machine on the
1971 * current list of targets for Linux/MIPS.
1972 * (Duh, crap, there is someone with a triple R6k machine)
1973 */
1974 //set_except_vector(14, handle_mc);
1975 //set_except_vector(15, handle_ndc);
1976 }
1977
1978
1979 if (board_nmi_handler_setup)
1980 board_nmi_handler_setup();
1981
1982 if (cpu_has_fpu && !cpu_has_nofpuex)
1983 set_except_vector(15, handle_fpe);
1984
1985 set_except_vector(22, handle_mdmx);
1986
1987 if (cpu_has_mcheck)
1988 set_except_vector(24, handle_mcheck);
1989
1990 if (cpu_has_mipsmt)
1991 set_except_vector(25, handle_mt);
1992
1993 set_except_vector(26, handle_dsp);
1994
1995 if (board_cache_error_setup)
1996 board_cache_error_setup();
1997
1998 if (cpu_has_vce)
1999 /* Special exception: R4[04]00 uses also the divec space. */
2000 set_handler(0x180, &except_vec3_r4000, 0x100);
2001 else if (cpu_has_4kex)
2002 set_handler(0x180, &except_vec3_generic, 0x80);
2003 else
2004 set_handler(0x080, &except_vec3_generic, 0x80);
2005
2006 local_flush_icache_range(ebase, ebase + 0x400);
2007
2008 sort_extable(__start___dbe_table, __stop___dbe_table);
2009
2010 cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
2011 }
Linux kernel - Deliverables
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