1 /* MN10300 Exception handling
2 *
3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Modified by David Howells (dhowells@redhat.com)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
11 */
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/errno.h>
16 #include <linux/ptrace.h>
17 #include <linux/timer.h>
18 #include <linux/mm.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <linux/spinlock.h>
23 #include <linux/interrupt.h>
24 #include <linux/kallsyms.h>
25 #include <linux/pci.h>
26 #include <linux/kdebug.h>
27 #include <linux/bug.h>
28 #include <linux/irq.h>
29 #include <asm/processor.h>
30 #include <asm/system.h>
31 #include <asm/uaccess.h>
32 #include <asm/io.h>
33 #include <asm/atomic.h>
34 #include <asm/smp.h>
35 #include <asm/pgalloc.h>
36 #include <asm/cacheflush.h>
37 #include <asm/cpu-regs.h>
38 #include <asm/busctl-regs.h>
39 #include <unit/leds.h>
40 #include <asm/fpu.h>
41 #include <asm/gdb-stub.h>
42 #include <asm/sections.h>
43
44 #if (CONFIG_INTERRUPT_VECTOR_BASE & 0xffffff)
45 #error "INTERRUPT_VECTOR_BASE not aligned to 16MiB boundary!"
46 #endif
47
48 struct pt_regs *__frame; /* current frame pointer */
49 EXPORT_SYMBOL(__frame);
50
51 int kstack_depth_to_print = 24;
52
53 spinlock_t die_lock = __SPIN_LOCK_UNLOCKED(die_lock);
54
55 ATOMIC_NOTIFIER_HEAD(mn10300_die_chain);
56
57 /*
58 * These constants are for searching for possible module text
59 * segments. MODULE_RANGE is a guess of how much space is likely
60 * to be vmalloced.
61 */
62 #define MODULE_RANGE (8 * 1024 * 1024)
63
64 #define DO_ERROR(signr, prologue, str, name) \
65 asmlinkage void name(struct pt_regs *regs, u32 intcode) \
66 { \
67 prologue; \
68 if (die_if_no_fixup(str, regs, intcode)) \
69 return; \
70 force_sig(signr, current); \
71 }
72
73 #define DO_EINFO(signr, prologue, str, name, sicode) \
74 asmlinkage void name(struct pt_regs *regs, u32 intcode) \
75 { \
76 siginfo_t info; \
77 prologue; \
78 if (die_if_no_fixup(str, regs, intcode)) \
79 return; \
80 info.si_signo = signr; \
81 if (signr == SIGILL && sicode == ILL_ILLOPC) { \
82 uint8_t opcode; \
83 if (get_user(opcode, (uint8_t __user *)regs->pc) == 0) \
84 if (opcode == 0xff) \
85 info.si_signo = SIGTRAP; \
86 } \
87 info.si_errno = 0; \
88 info.si_code = sicode; \
89 info.si_addr = (void *) regs->pc; \
90 force_sig_info(info.si_signo, &info, current); \
91 }
92
93 DO_ERROR(SIGTRAP, {}, "trap", trap);
94 DO_ERROR(SIGSEGV, {}, "ibreak", ibreak);
95 DO_ERROR(SIGSEGV, {}, "obreak", obreak);
96 DO_EINFO(SIGSEGV, {}, "access error", access_error, SEGV_ACCERR);
97 DO_EINFO(SIGSEGV, {}, "insn access error", insn_acc_error, SEGV_ACCERR);
98 DO_EINFO(SIGSEGV, {}, "data access error", data_acc_error, SEGV_ACCERR);
99 DO_EINFO(SIGILL, {}, "privileged opcode", priv_op, ILL_PRVOPC);
100 DO_EINFO(SIGILL, {}, "invalid opcode", invalid_op, ILL_ILLOPC);
101 DO_EINFO(SIGILL, {}, "invalid ex opcode", invalid_exop, ILL_ILLOPC);
102 DO_EINFO(SIGBUS, {}, "invalid address", mem_error, BUS_ADRERR);
103 DO_EINFO(SIGBUS, {}, "bus error", bus_error, BUS_ADRERR);
104 DO_EINFO(SIGILL, {}, "FPU invalid opcode", fpu_invalid_op, ILL_COPROC);
105
106 DO_ERROR(SIGTRAP,
107 #ifndef CONFIG_MN10300_USING_JTAG
108 DCR &= ~0x0001,
109 #else
110 {},
111 #endif
112 "single step", istep);
113
114 /*
115 * handle NMI
116 */
117 asmlinkage void nmi(struct pt_regs *regs, enum exception_code code)
118 {
119 /* see if gdbstub wants to deal with it */
120 #ifdef CONFIG_GDBSTUB
121 if (gdbstub_intercept(regs, code))
122 return;
123 #endif
124
125 printk(KERN_WARNING "--- Register Dump ---\n");
126 show_registers(regs);
127 printk(KERN_WARNING "---------------------\n");
128 }
129
130 /*
131 * show a stack trace from the specified stack pointer
132 */
133 void show_trace(unsigned long *sp)
134 {
135 unsigned long *stack, addr, module_start, module_end;
136 int i;
137
138 printk(KERN_EMERG "\nCall Trace:");
139
140 stack = sp;
141 i = 0;
142 module_start = VMALLOC_START;
143 module_end = VMALLOC_END;
144
145 while (((long) stack & (THREAD_SIZE - 1)) != 0) {
146 addr = *stack++;
147 if (__kernel_text_address(addr)) {
148 #if 1
149 printk(" [<%08lx>]", addr);
150 print_symbol(" %s", addr);
151 printk("\n");
152 #else
153 if ((i % 6) == 0)
154 printk(KERN_EMERG " ");
155 printk("[<%08lx>] ", addr);
156 i++;
157 #endif
158 }
159 }
160
161 printk("\n");
162 }
163
164 /*
165 * show the raw stack from the specified stack pointer
166 */
167 void show_stack(struct task_struct *task, unsigned long *sp)
168 {
169 unsigned long *stack;
170 int i;
171
172 if (!sp)
173 sp = (unsigned long *) &sp;
174
175 stack = sp;
176 printk(KERN_EMERG "Stack:");
177 for (i = 0; i < kstack_depth_to_print; i++) {
178 if (((long) stack & (THREAD_SIZE - 1)) == 0)
179 break;
180 if ((i % 8) == 0)
181 printk(KERN_EMERG " ");
182 printk("%08lx ", *stack++);
183 }
184
185 show_trace(sp);
186 }
187
188 /*
189 * the architecture-independent dump_stack generator
190 */
191 void dump_stack(void)
192 {
193 unsigned long stack;
194
195 show_stack(current, &stack);
196 }
197 EXPORT_SYMBOL(dump_stack);
198
199 /*
200 * dump the register file in the specified exception frame
201 */
202 void show_registers_only(struct pt_regs *regs)
203 {
204 unsigned long ssp;
205
206 ssp = (unsigned long) regs + sizeof(*regs);
207
208 printk(KERN_EMERG "PC: %08lx EPSW: %08lx SSP: %08lx mode: %s\n",
209 regs->pc, regs->epsw, ssp, user_mode(regs) ? "User" : "Super");
210 printk(KERN_EMERG "d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
211 regs->d0, regs->d1, regs->d2, regs->d3);
212 printk(KERN_EMERG "a0: %08lx a1: %08lx a2: %08lx a3: %08lx\n",
213 regs->a0, regs->a1, regs->a2, regs->a3);
214 printk(KERN_EMERG "e0: %08lx e1: %08lx e2: %08lx e3: %08lx\n",
215 regs->e0, regs->e1, regs->e2, regs->e3);
216 printk(KERN_EMERG "e4: %08lx e5: %08lx e6: %08lx e7: %08lx\n",
217 regs->e4, regs->e5, regs->e6, regs->e7);
218 printk(KERN_EMERG "lar: %08lx lir: %08lx mdr: %08lx usp: %08lx\n",
219 regs->lar, regs->lir, regs->mdr, regs->sp);
220 printk(KERN_EMERG "cvf: %08lx crl: %08lx crh: %08lx drq: %08lx\n",
221 regs->mcvf, regs->mcrl, regs->mcrh, regs->mdrq);
222 printk(KERN_EMERG "threadinfo=%p task=%p)\n",
223 current_thread_info(), current);
224
225 if ((unsigned long) current >= 0x90000000UL &&
226 (unsigned long) current < 0x94000000UL)
227 printk(KERN_EMERG "Process %s (pid: %d)\n",
228 current->comm, current->pid);
229
230 printk(KERN_EMERG "CPUP: %04hx\n", CPUP);
231 printk(KERN_EMERG "TBR: %08x\n", TBR);
232 printk(KERN_EMERG "DEAR: %08x\n", DEAR);
233 printk(KERN_EMERG "sISR: %08x\n", sISR);
234 printk(KERN_EMERG "NMICR: %04hx\n", NMICR);
235 printk(KERN_EMERG "BCBERR: %08x\n", BCBERR);
236 printk(KERN_EMERG "BCBEAR: %08x\n", BCBEAR);
237 printk(KERN_EMERG "MMUFCR: %08x\n", MMUFCR);
238 printk(KERN_EMERG "IPTEU : %08x IPTEL2: %08x\n", IPTEU, IPTEL2);
239 printk(KERN_EMERG "DPTEU: %08x DPTEL2: %08x\n", DPTEU, DPTEL2);
240 }
241
242 /*
243 * dump the registers and the stack
244 */
245 void show_registers(struct pt_regs *regs)
246 {
247 unsigned long sp;
248 int i;
249
250 show_registers_only(regs);
251
252 if (!user_mode(regs))
253 sp = (unsigned long) regs + sizeof(*regs);
254 else
255 sp = regs->sp;
256
257 /* when in-kernel, we also print out the stack and code at the
258 * time of the fault..
259 */
260 if (!user_mode(regs)) {
261 printk(KERN_EMERG "\n");
262 show_stack(current, (unsigned long *) sp);
263
264 #if 0
265 printk(KERN_EMERG "\nCode: ");
266 if (regs->pc < PAGE_OFFSET)
267 goto bad;
268
269 for (i = 0; i < 20; i++) {
270 unsigned char c;
271 if (__get_user(c, &((unsigned char *) regs->pc)[i]))
272 goto bad;
273 printk("%02x ", c);
274 }
275 #else
276 i = 0;
277 #endif
278 }
279
280 printk("\n");
281 return;
282
283 #if 0
284 bad:
285 printk(KERN_EMERG " Bad PC value.");
286 break;
287 #endif
288 }
289
290 /*
291 *
292 */
293 void show_trace_task(struct task_struct *tsk)
294 {
295 unsigned long sp = tsk->thread.sp;
296
297 /* User space on another CPU? */
298 if ((sp ^ (unsigned long) tsk) & (PAGE_MASK << 1))
299 return;
300
301 show_trace((unsigned long *) sp);
302 }
303
304 /*
305 * note the untimely death of part of the kernel
306 */
307 void die(const char *str, struct pt_regs *regs, enum exception_code code)
308 {
309 console_verbose();
310 spin_lock_irq(&die_lock);
311 printk(KERN_EMERG "\n%s: %04x\n",
312 str, code & 0xffff);
313 show_registers(regs);
314
315 if (regs->pc >= 0x02000000 && regs->pc < 0x04000000 &&
316 (regs->epsw & (EPSW_IM | EPSW_IE)) != (EPSW_IM | EPSW_IE)) {
317 printk(KERN_EMERG "Exception in usermode interrupt handler\n");
318 printk(KERN_EMERG "\nPlease connect to kernel debugger !!\n");
319 asm volatile ("0: bra 0b");
320 }
321
322 spin_unlock_irq(&die_lock);
323 do_exit(SIGSEGV);
324 }
325
326 /*
327 * see if there's a fixup handler we can force a jump to when an exception
328 * happens due to something kernel code did
329 */
330 int die_if_no_fixup(const char *str, struct pt_regs *regs,
331 enum exception_code code)
332 {
333 if (user_mode(regs))
334 return 0;
335
336 peripheral_leds_display_exception(code);
337
338 switch (code) {
339 /* see if we can fixup the kernel accessing memory */
340 case EXCEP_ITLBMISS:
341 case EXCEP_DTLBMISS:
342 case EXCEP_IAERROR:
343 case EXCEP_DAERROR:
344 case EXCEP_MEMERR:
345 case EXCEP_MISALIGN:
346 case EXCEP_BUSERROR:
347 case EXCEP_ILLDATACC:
348 case EXCEP_IOINSACC:
349 case EXCEP_PRIVINSACC:
350 case EXCEP_PRIVDATACC:
351 case EXCEP_DATINSACC:
352 if (fixup_exception(regs))
353 return 1;
354 case EXCEP_UNIMPINS:
355 if (regs->pc && *(uint8_t *)regs->pc == 0xff)
356 if (notify_die(DIE_BREAKPOINT, str, regs, code, 0, 0))
357 return 1;
358 break;
359 default:
360 break;
361 }
362
363 /* see if gdbstub wants to deal with it */
364 #ifdef CONFIG_GDBSTUB
365 if (gdbstub_intercept(regs, code))
366 return 1;
367 #endif
368
369 if (notify_die(DIE_GPF, str, regs, code, 0, 0))
370 return 1;
371
372 /* make the process die as the last resort */
373 die(str, regs, code);
374 }
375
376 /*
377 * handle unsupported syscall instructions (syscall 1-15)
378 */
379 static asmlinkage void unsupported_syscall(struct pt_regs *regs,
380 enum exception_code code)
381 {
382 struct task_struct *tsk = current;
383 siginfo_t info;
384
385 /* catch a kernel BUG() */
386 if (code == EXCEP_SYSCALL15 && !user_mode(regs)) {
387 if (report_bug(regs->pc, regs) == BUG_TRAP_TYPE_BUG) {
388 #ifdef CONFIG_GDBSTUB
389 gdbstub_intercept(regs, code);
390 #endif
391 }
392 }
393
394 regs->pc -= 2; /* syscall return addr is _after_ the instruction */
395
396 die_if_no_fixup("An unsupported syscall insn was used by the kernel\n",
397 regs, code);
398
399 info.si_signo = SIGILL;
400 info.si_errno = ENOSYS;
401 info.si_code = ILL_ILLTRP;
402 info.si_addr = (void *) regs->pc;
403 force_sig_info(SIGILL, &info, tsk);
404 }
405
406 /*
407 * display the register file when the stack pointer gets clobbered
408 */
409 asmlinkage void do_double_fault(struct pt_regs *regs)
410 {
411 struct task_struct *tsk = current;
412
413 strcpy(tsk->comm, "emergency tsk");
414 tsk->pid = 0;
415 console_verbose();
416 printk(KERN_EMERG "--- double fault ---\n");
417 show_registers(regs);
418 }
419
420 /*
421 * asynchronous bus error (external, usually I/O DMA)
422 */
423 asmlinkage void io_bus_error(u32 bcberr, u32 bcbear, struct pt_regs *regs)
424 {
425 console_verbose();
426
427 printk(KERN_EMERG "Asynchronous I/O Bus Error\n");
428 printk(KERN_EMERG "==========================\n");
429
430 if (bcberr & BCBERR_BEME)
431 printk(KERN_EMERG "- Multiple recorded errors\n");
432
433 printk(KERN_EMERG "- Faulting Buses:%s%s%s\n",
434 bcberr & BCBERR_BEMR_CI ? " CPU-Ins-Fetch" : "",
435 bcberr & BCBERR_BEMR_CD ? " CPU-Data" : "",
436 bcberr & BCBERR_BEMR_DMA ? " DMA" : "");
437
438 printk(KERN_EMERG "- %s %s access made to %s at address %08x\n",
439 bcberr & BCBERR_BEBST ? "Burst" : "Single",
440 bcberr & BCBERR_BERW ? "Read" : "Write",
441 bcberr & BCBERR_BESB_MON ? "Monitor Space" :
442 bcberr & BCBERR_BESB_IO ? "Internal CPU I/O Space" :
443 bcberr & BCBERR_BESB_EX ? "External I/O Bus" :
444 bcberr & BCBERR_BESB_OPEX ? "External Memory Bus" :
445 "On Chip Memory",
446 bcbear
447 );
448
449 printk(KERN_EMERG "- Detected by the %s\n",
450 bcberr&BCBERR_BESD ? "Bus Control Unit" : "Slave Bus");
451
452 #ifdef CONFIG_PCI
453 #define BRIDGEREGB(X) (*(volatile __u8 *)(0xBE040000 + (X)))
454 #define BRIDGEREGW(X) (*(volatile __u16 *)(0xBE040000 + (X)))
455 #define BRIDGEREGL(X) (*(volatile __u32 *)(0xBE040000 + (X)))
456
457 printk(KERN_EMERG "- PCI Memory Paging Reg: %08x\n",
458 *(volatile __u32 *) (0xBFFFFFF4));
459 printk(KERN_EMERG "- PCI Bridge Base Address 0: %08x\n",
460 BRIDGEREGL(PCI_BASE_ADDRESS_0));
461 printk(KERN_EMERG "- PCI Bridge AMPCI Base Address: %08x\n",
462 BRIDGEREGL(0x48));
463 printk(KERN_EMERG "- PCI Bridge Command: %04hx\n",
464 BRIDGEREGW(PCI_COMMAND));
465 printk(KERN_EMERG "- PCI Bridge Status: %04hx\n",
466 BRIDGEREGW(PCI_STATUS));
467 printk(KERN_EMERG "- PCI Bridge Int Status: %08hx\n",
468 BRIDGEREGL(0x4c));
469 #endif
470
471 printk(KERN_EMERG "\n");
472 show_registers(regs);
473
474 panic("Halted due to asynchronous I/O Bus Error\n");
475 }
476
477 /*
478 * handle an exception for which a handler has not yet been installed
479 */
480 asmlinkage void uninitialised_exception(struct pt_regs *regs,
481 enum exception_code code)
482 {
483
484 /* see if gdbstub wants to deal with it */
485 #ifdef CONFIG_GDBSTUB
486 if (gdbstub_intercept(regs, code))
487 return;
488 #endif
489
490 peripheral_leds_display_exception(code);
491 printk(KERN_EMERG "Uninitialised Exception 0x%04x\n", code & 0xFFFF);
492 show_registers(regs);
493
494 for (;;)
495 continue;
496 }
497
498 /*
499 * set an interrupt stub to jump to a handler
500 * ! NOTE: this does *not* flush the caches
501 */
502 void __init __set_intr_stub(enum exception_code code, void *handler)
503 {
504 unsigned long addr;
505 u8 *vector = (u8 *)(CONFIG_INTERRUPT_VECTOR_BASE + code);
506
507 addr = (unsigned long) handler - (unsigned long) vector;
508 vector[0] = 0xdc; /* JMP handler */
509 vector[1] = addr;
510 vector[2] = addr >> 8;
511 vector[3] = addr >> 16;
512 vector[4] = addr >> 24;
513 vector[5] = 0xcb;
514 vector[6] = 0xcb;
515 vector[7] = 0xcb;
516 }
517
518 /*
519 * set an interrupt stub to jump to a handler
520 */
521 void __init set_intr_stub(enum exception_code code, void *handler)
522 {
523 unsigned long addr;
524 u8 *vector = (u8 *)(CONFIG_INTERRUPT_VECTOR_BASE + code);
525
526 addr = (unsigned long) handler - (unsigned long) vector;
527 vector[0] = 0xdc; /* JMP handler */
528 vector[1] = addr;
529 vector[2] = addr >> 8;
530 vector[3] = addr >> 16;
531 vector[4] = addr >> 24;
532 vector[5] = 0xcb;
533 vector[6] = 0xcb;
534 vector[7] = 0xcb;
535
536 mn10300_dcache_flush_inv();
537 mn10300_icache_inv();
538 }
539
540 /*
541 * set an interrupt stub to invoke the JTAG unit and then jump to a handler
542 */
543 void __init set_jtag_stub(enum exception_code code, void *handler)
544 {
545 unsigned long addr;
546 u8 *vector = (u8 *)(CONFIG_INTERRUPT_VECTOR_BASE + code);
547
548 addr = (unsigned long) handler - ((unsigned long) vector + 1);
549 vector[0] = 0xff; /* PI to jump into JTAG debugger */
550 vector[1] = 0xdc; /* jmp handler */
551 vector[2] = addr;
552 vector[3] = addr >> 8;
553 vector[4] = addr >> 16;
554 vector[5] = addr >> 24;
555 vector[6] = 0xcb;
556 vector[7] = 0xcb;
557
558 mn10300_dcache_flush_inv();
559 flush_icache_range((unsigned long) vector, (unsigned long) vector + 8);
560 }
561
562 /*
563 * initialise the exception table
564 */
565 void __init trap_init(void)
566 {
567 set_excp_vector(EXCEP_TRAP, trap);
568 set_excp_vector(EXCEP_ISTEP, istep);
569 set_excp_vector(EXCEP_IBREAK, ibreak);
570 set_excp_vector(EXCEP_OBREAK, obreak);
571
572 set_excp_vector(EXCEP_PRIVINS, priv_op);
573 set_excp_vector(EXCEP_UNIMPINS, invalid_op);
574 set_excp_vector(EXCEP_UNIMPEXINS, invalid_exop);
575 set_excp_vector(EXCEP_MEMERR, mem_error);
576 set_excp_vector(EXCEP_MISALIGN, misalignment);
577 set_excp_vector(EXCEP_BUSERROR, bus_error);
578 set_excp_vector(EXCEP_ILLINSACC, insn_acc_error);
579 set_excp_vector(EXCEP_ILLDATACC, data_acc_error);
580 set_excp_vector(EXCEP_IOINSACC, insn_acc_error);
581 set_excp_vector(EXCEP_PRIVINSACC, insn_acc_error);
582 set_excp_vector(EXCEP_PRIVDATACC, data_acc_error);
583 set_excp_vector(EXCEP_DATINSACC, insn_acc_error);
584 set_excp_vector(EXCEP_FPU_DISABLED, fpu_disabled);
585 set_excp_vector(EXCEP_FPU_UNIMPINS, fpu_invalid_op);
586 set_excp_vector(EXCEP_FPU_OPERATION, fpu_exception);
587
588 set_excp_vector(EXCEP_NMI, nmi);
589
590 set_excp_vector(EXCEP_SYSCALL1, unsupported_syscall);
591 set_excp_vector(EXCEP_SYSCALL2, unsupported_syscall);
592 set_excp_vector(EXCEP_SYSCALL3, unsupported_syscall);
593 set_excp_vector(EXCEP_SYSCALL4, unsupported_syscall);
594 set_excp_vector(EXCEP_SYSCALL5, unsupported_syscall);
595 set_excp_vector(EXCEP_SYSCALL6, unsupported_syscall);
596 set_excp_vector(EXCEP_SYSCALL7, unsupported_syscall);
597 set_excp_vector(EXCEP_SYSCALL8, unsupported_syscall);
598 set_excp_vector(EXCEP_SYSCALL9, unsupported_syscall);
599 set_excp_vector(EXCEP_SYSCALL10, unsupported_syscall);
600 set_excp_vector(EXCEP_SYSCALL11, unsupported_syscall);
601 set_excp_vector(EXCEP_SYSCALL12, unsupported_syscall);
602 set_excp_vector(EXCEP_SYSCALL13, unsupported_syscall);
603 set_excp_vector(EXCEP_SYSCALL14, unsupported_syscall);
604 set_excp_vector(EXCEP_SYSCALL15, unsupported_syscall);
605 }
606
607 /*
608 * determine if a program counter value is a valid bug address
609 */
610 int is_valid_bugaddr(unsigned long pc)
611 {
612 return pc >= PAGE_OFFSET;
613 }
614
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