Blackfin: bf54x: drop unused legacy MMR names
[linux-2.6.git] / arch / blackfin / kernel / traps.c
1 /*
2  * Main exception handling logic.
3  *
4  * Copyright 2004-2010 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later
7  */
8
9 #include <linux/bug.h>
10 #include <linux/uaccess.h>
11 #include <linux/module.h>
12 #include <asm/traps.h>
13 #include <asm/cplb.h>
14 #include <asm/blackfin.h>
15 #include <asm/irq_handler.h>
16 #include <linux/irq.h>
17 #include <asm/trace.h>
18 #include <asm/fixed_code.h>
19 #include <asm/pseudo_instructions.h>
20
21 #ifdef CONFIG_KGDB
22 # include <linux/kgdb.h>
23
24 # define CHK_DEBUGGER_TRAP() \
25         do { \
26                 kgdb_handle_exception(trapnr, sig, info.si_code, fp); \
27         } while (0)
28 # define CHK_DEBUGGER_TRAP_MAYBE() \
29         do { \
30                 if (kgdb_connected) \
31                         CHK_DEBUGGER_TRAP(); \
32         } while (0)
33 #else
34 # define CHK_DEBUGGER_TRAP() do { } while (0)
35 # define CHK_DEBUGGER_TRAP_MAYBE() do { } while (0)
36 #endif
37
38
39 #ifdef CONFIG_DEBUG_VERBOSE
40 #define verbose_printk(fmt, arg...) \
41         printk(fmt, ##arg)
42 #else
43 #define verbose_printk(fmt, arg...) \
44         ({ if (0) printk(fmt, ##arg); 0; })
45 #endif
46
47 #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
48 u32 last_seqstat;
49 #ifdef CONFIG_DEBUG_MMRS_MODULE
50 EXPORT_SYMBOL(last_seqstat);
51 #endif
52 #endif
53
54 /* Initiate the event table handler */
55 void __init trap_init(void)
56 {
57         CSYNC();
58         bfin_write_EVT3(trap);
59         CSYNC();
60 }
61
62 static int kernel_mode_regs(struct pt_regs *regs)
63 {
64         return regs->ipend & 0xffc0;
65 }
66
67 asmlinkage notrace void trap_c(struct pt_regs *fp)
68 {
69 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
70         int j;
71 #endif
72 #ifdef CONFIG_BFIN_PSEUDODBG_INSNS
73         int opcode;
74 #endif
75         unsigned int cpu = raw_smp_processor_id();
76         const char *strerror = NULL;
77         int sig = 0;
78         siginfo_t info;
79         unsigned long trapnr = fp->seqstat & SEQSTAT_EXCAUSE;
80
81         trace_buffer_save(j);
82 #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
83         last_seqstat = (u32)fp->seqstat;
84 #endif
85
86         /* Important - be very careful dereferncing pointers - will lead to
87          * double faults if the stack has become corrupt
88          */
89
90         /* trap_c() will be called for exceptions. During exceptions
91          * processing, the pc value should be set with retx value.
92          * With this change we can cleanup some code in signal.c- TODO
93          */
94         fp->orig_pc = fp->retx;
95         /* printk("exception: 0x%x, ipend=%x, reti=%x, retx=%x\n",
96                 trapnr, fp->ipend, fp->pc, fp->retx); */
97
98         /* send the appropriate signal to the user program */
99         switch (trapnr) {
100
101         /* This table works in conjuction with the one in ./mach-common/entry.S
102          * Some exceptions are handled there (in assembly, in exception space)
103          * Some are handled here, (in C, in interrupt space)
104          * Some, like CPLB, are handled in both, where the normal path is
105          * handled in assembly/exception space, and the error path is handled
106          * here
107          */
108
109         /* 0x00 - Linux Syscall, getting here is an error */
110         /* 0x01 - userspace gdb breakpoint, handled here */
111         case VEC_EXCPT01:
112                 info.si_code = TRAP_ILLTRAP;
113                 sig = SIGTRAP;
114                 CHK_DEBUGGER_TRAP_MAYBE();
115                 /* Check if this is a breakpoint in kernel space */
116                 if (kernel_mode_regs(fp))
117                         goto traps_done;
118                 else
119                         break;
120         /* 0x03 - User Defined, userspace stack overflow */
121         case VEC_EXCPT03:
122                 info.si_code = SEGV_STACKFLOW;
123                 sig = SIGSEGV;
124                 strerror = KERN_NOTICE EXC_0x03(KERN_NOTICE);
125                 CHK_DEBUGGER_TRAP_MAYBE();
126                 break;
127         /* 0x02 - KGDB initial connection and break signal trap */
128         case VEC_EXCPT02:
129 #ifdef CONFIG_KGDB
130                 info.si_code = TRAP_ILLTRAP;
131                 sig = SIGTRAP;
132                 CHK_DEBUGGER_TRAP();
133                 goto traps_done;
134 #endif
135         /* 0x04 - User Defined */
136         /* 0x05 - User Defined */
137         /* 0x06 - User Defined */
138         /* 0x07 - User Defined */
139         /* 0x08 - User Defined */
140         /* 0x09 - User Defined */
141         /* 0x0A - User Defined */
142         /* 0x0B - User Defined */
143         /* 0x0C - User Defined */
144         /* 0x0D - User Defined */
145         /* 0x0E - User Defined */
146         /* 0x0F - User Defined */
147         /* If we got here, it is most likely that someone was trying to use a
148          * custom exception handler, and it is not actually installed properly
149          */
150         case VEC_EXCPT04 ... VEC_EXCPT15:
151                 info.si_code = ILL_ILLPARAOP;
152                 sig = SIGILL;
153                 strerror = KERN_NOTICE EXC_0x04(KERN_NOTICE);
154                 CHK_DEBUGGER_TRAP_MAYBE();
155                 break;
156         /* 0x10 HW Single step, handled here */
157         case VEC_STEP:
158                 info.si_code = TRAP_STEP;
159                 sig = SIGTRAP;
160                 CHK_DEBUGGER_TRAP_MAYBE();
161                 /* Check if this is a single step in kernel space */
162                 if (kernel_mode_regs(fp))
163                         goto traps_done;
164                 else
165                         break;
166         /* 0x11 - Trace Buffer Full, handled here */
167         case VEC_OVFLOW:
168                 info.si_code = TRAP_TRACEFLOW;
169                 sig = SIGTRAP;
170                 strerror = KERN_NOTICE EXC_0x11(KERN_NOTICE);
171                 CHK_DEBUGGER_TRAP_MAYBE();
172                 break;
173         /* 0x12 - Reserved, Caught by default */
174         /* 0x13 - Reserved, Caught by default */
175         /* 0x14 - Reserved, Caught by default */
176         /* 0x15 - Reserved, Caught by default */
177         /* 0x16 - Reserved, Caught by default */
178         /* 0x17 - Reserved, Caught by default */
179         /* 0x18 - Reserved, Caught by default */
180         /* 0x19 - Reserved, Caught by default */
181         /* 0x1A - Reserved, Caught by default */
182         /* 0x1B - Reserved, Caught by default */
183         /* 0x1C - Reserved, Caught by default */
184         /* 0x1D - Reserved, Caught by default */
185         /* 0x1E - Reserved, Caught by default */
186         /* 0x1F - Reserved, Caught by default */
187         /* 0x20 - Reserved, Caught by default */
188         /* 0x21 - Undefined Instruction, handled here */
189         case VEC_UNDEF_I:
190 #ifdef CONFIG_BUG
191                 if (kernel_mode_regs(fp)) {
192                         switch (report_bug(fp->pc, fp)) {
193                         case BUG_TRAP_TYPE_NONE:
194                                 break;
195                         case BUG_TRAP_TYPE_WARN:
196                                 dump_bfin_trace_buffer();
197                                 fp->pc += 2;
198                                 goto traps_done;
199                         case BUG_TRAP_TYPE_BUG:
200                                 /* call to panic() will dump trace, and it is
201                                  * off at this point, so it won't be clobbered
202                                  */
203                                 panic("BUG()");
204                         }
205                 }
206 #endif
207 #ifdef CONFIG_BFIN_PSEUDODBG_INSNS
208                 /*
209                  * Support for the fake instructions, if the instruction fails,
210                  * then just execute a illegal opcode failure (like normal).
211                  * Don't support these instructions inside the kernel
212                  */
213                 if (!kernel_mode_regs(fp) && get_instruction(&opcode, (unsigned short *)fp->pc)) {
214                         if (execute_pseudodbg_assert(fp, opcode))
215                                 goto traps_done;
216                         if (execute_pseudodbg(fp, opcode))
217                                 goto traps_done;
218                 }
219 #endif
220                 info.si_code = ILL_ILLOPC;
221                 sig = SIGILL;
222                 strerror = KERN_NOTICE EXC_0x21(KERN_NOTICE);
223                 CHK_DEBUGGER_TRAP_MAYBE();
224                 break;
225         /* 0x22 - Illegal Instruction Combination, handled here */
226         case VEC_ILGAL_I:
227                 info.si_code = ILL_ILLPARAOP;
228                 sig = SIGILL;
229                 strerror = KERN_NOTICE EXC_0x22(KERN_NOTICE);
230                 CHK_DEBUGGER_TRAP_MAYBE();
231                 break;
232         /* 0x23 - Data CPLB protection violation, handled here */
233         case VEC_CPLB_VL:
234                 info.si_code = ILL_CPLB_VI;
235                 sig = SIGSEGV;
236                 strerror = KERN_NOTICE EXC_0x23(KERN_NOTICE);
237                 CHK_DEBUGGER_TRAP_MAYBE();
238                 break;
239         /* 0x24 - Data access misaligned, handled here */
240         case VEC_MISALI_D:
241                 info.si_code = BUS_ADRALN;
242                 sig = SIGBUS;
243                 strerror = KERN_NOTICE EXC_0x24(KERN_NOTICE);
244                 CHK_DEBUGGER_TRAP_MAYBE();
245                 break;
246         /* 0x25 - Unrecoverable Event, handled here */
247         case VEC_UNCOV:
248                 info.si_code = ILL_ILLEXCPT;
249                 sig = SIGILL;
250                 strerror = KERN_NOTICE EXC_0x25(KERN_NOTICE);
251                 CHK_DEBUGGER_TRAP_MAYBE();
252                 break;
253         /* 0x26 - Data CPLB Miss, normal case is handled in _cplb_hdr,
254                 error case is handled here */
255         case VEC_CPLB_M:
256                 info.si_code = BUS_ADRALN;
257                 sig = SIGBUS;
258                 strerror = KERN_NOTICE EXC_0x26(KERN_NOTICE);
259                 break;
260         /* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero, handled here */
261         case VEC_CPLB_MHIT:
262                 info.si_code = ILL_CPLB_MULHIT;
263                 sig = SIGSEGV;
264 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
265                 if (cpu_pda[cpu].dcplb_fault_addr < FIXED_CODE_START)
266                         strerror = KERN_NOTICE "NULL pointer access\n";
267                 else
268 #endif
269                         strerror = KERN_NOTICE EXC_0x27(KERN_NOTICE);
270                 CHK_DEBUGGER_TRAP_MAYBE();
271                 break;
272         /* 0x28 - Emulation Watchpoint, handled here */
273         case VEC_WATCH:
274                 info.si_code = TRAP_WATCHPT;
275                 sig = SIGTRAP;
276                 pr_debug(EXC_0x28(KERN_DEBUG));
277                 CHK_DEBUGGER_TRAP_MAYBE();
278                 /* Check if this is a watchpoint in kernel space */
279                 if (kernel_mode_regs(fp))
280                         goto traps_done;
281                 else
282                         break;
283 #ifdef CONFIG_BF535
284         /* 0x29 - Instruction fetch access error (535 only) */
285         case VEC_ISTRU_VL:      /* ADSP-BF535 only (MH) */
286                 info.si_code = BUS_OPFETCH;
287                 sig = SIGBUS;
288                 strerror = KERN_NOTICE "BF535: VEC_ISTRU_VL\n";
289                 CHK_DEBUGGER_TRAP_MAYBE();
290                 break;
291 #else
292         /* 0x29 - Reserved, Caught by default */
293 #endif
294         /* 0x2A - Instruction fetch misaligned, handled here */
295         case VEC_MISALI_I:
296                 info.si_code = BUS_ADRALN;
297                 sig = SIGBUS;
298                 strerror = KERN_NOTICE EXC_0x2A(KERN_NOTICE);
299                 CHK_DEBUGGER_TRAP_MAYBE();
300                 break;
301         /* 0x2B - Instruction CPLB protection violation, handled here */
302         case VEC_CPLB_I_VL:
303                 info.si_code = ILL_CPLB_VI;
304                 sig = SIGBUS;
305                 strerror = KERN_NOTICE EXC_0x2B(KERN_NOTICE);
306                 CHK_DEBUGGER_TRAP_MAYBE();
307                 break;
308         /* 0x2C - Instruction CPLB miss, handled in _cplb_hdr */
309         case VEC_CPLB_I_M:
310                 info.si_code = ILL_CPLB_MISS;
311                 sig = SIGBUS;
312                 strerror = KERN_NOTICE EXC_0x2C(KERN_NOTICE);
313                 break;
314         /* 0x2D - Instruction CPLB Multiple Hits, handled here */
315         case VEC_CPLB_I_MHIT:
316                 info.si_code = ILL_CPLB_MULHIT;
317                 sig = SIGSEGV;
318 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
319                 if (cpu_pda[cpu].icplb_fault_addr < FIXED_CODE_START)
320                         strerror = KERN_NOTICE "Jump to NULL address\n";
321                 else
322 #endif
323                         strerror = KERN_NOTICE EXC_0x2D(KERN_NOTICE);
324                 CHK_DEBUGGER_TRAP_MAYBE();
325                 break;
326         /* 0x2E - Illegal use of Supervisor Resource, handled here */
327         case VEC_ILL_RES:
328                 info.si_code = ILL_PRVOPC;
329                 sig = SIGILL;
330                 strerror = KERN_NOTICE EXC_0x2E(KERN_NOTICE);
331                 CHK_DEBUGGER_TRAP_MAYBE();
332                 break;
333         /* 0x2F - Reserved, Caught by default */
334         /* 0x30 - Reserved, Caught by default */
335         /* 0x31 - Reserved, Caught by default */
336         /* 0x32 - Reserved, Caught by default */
337         /* 0x33 - Reserved, Caught by default */
338         /* 0x34 - Reserved, Caught by default */
339         /* 0x35 - Reserved, Caught by default */
340         /* 0x36 - Reserved, Caught by default */
341         /* 0x37 - Reserved, Caught by default */
342         /* 0x38 - Reserved, Caught by default */
343         /* 0x39 - Reserved, Caught by default */
344         /* 0x3A - Reserved, Caught by default */
345         /* 0x3B - Reserved, Caught by default */
346         /* 0x3C - Reserved, Caught by default */
347         /* 0x3D - Reserved, Caught by default */
348         /* 0x3E - Reserved, Caught by default */
349         /* 0x3F - Reserved, Caught by default */
350         case VEC_HWERR:
351                 info.si_code = BUS_ADRALN;
352                 sig = SIGBUS;
353                 switch (fp->seqstat & SEQSTAT_HWERRCAUSE) {
354                 /* System MMR Error */
355                 case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR):
356                         info.si_code = BUS_ADRALN;
357                         sig = SIGBUS;
358                         strerror = KERN_NOTICE HWC_x2(KERN_NOTICE);
359                         break;
360                 /* External Memory Addressing Error */
361                 case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR):
362                         if (ANOMALY_05000310) {
363                                 static unsigned long anomaly_rets;
364
365                                 if ((fp->pc >= (L1_CODE_START + L1_CODE_LENGTH - 512)) &&
366                                     (fp->pc < (L1_CODE_START + L1_CODE_LENGTH))) {
367                                         /*
368                                          * A false hardware error will happen while fetching at
369                                          * the L1 instruction SRAM boundary.  Ignore it.
370                                          */
371                                         anomaly_rets = fp->rets;
372                                         goto traps_done;
373                                 } else if (fp->rets == anomaly_rets) {
374                                         /*
375                                          * While boundary code returns to a function, at the ret
376                                          * point, a new false hardware error might occur too based
377                                          * on tests.  Ignore it too.
378                                          */
379                                         goto traps_done;
380                                 } else if ((fp->rets >= (L1_CODE_START + L1_CODE_LENGTH - 512)) &&
381                                            (fp->rets < (L1_CODE_START + L1_CODE_LENGTH))) {
382                                         /*
383                                          * If boundary code calls a function, at the entry point,
384                                          * a new false hardware error maybe happen based on tests.
385                                          * Ignore it too.
386                                          */
387                                         goto traps_done;
388                                 } else
389                                         anomaly_rets = 0;
390                         }
391
392                         info.si_code = BUS_ADRERR;
393                         sig = SIGBUS;
394                         strerror = KERN_NOTICE HWC_x3(KERN_NOTICE);
395                         break;
396                 /* Performance Monitor Overflow */
397                 case (SEQSTAT_HWERRCAUSE_PERF_FLOW):
398                         strerror = KERN_NOTICE HWC_x12(KERN_NOTICE);
399                         break;
400                 /* RAISE 5 instruction */
401                 case (SEQSTAT_HWERRCAUSE_RAISE_5):
402                         printk(KERN_NOTICE HWC_x18(KERN_NOTICE));
403                         break;
404                 default:        /* Reserved */
405                         printk(KERN_NOTICE HWC_default(KERN_NOTICE));
406                         break;
407                 }
408                 CHK_DEBUGGER_TRAP_MAYBE();
409                 break;
410         /*
411          * We should be handling all known exception types above,
412          * if we get here we hit a reserved one, so panic
413          */
414         default:
415                 info.si_code = ILL_ILLPARAOP;
416                 sig = SIGILL;
417                 verbose_printk(KERN_EMERG "Caught Unhandled Exception, code = %08lx\n",
418                         (fp->seqstat & SEQSTAT_EXCAUSE));
419                 CHK_DEBUGGER_TRAP_MAYBE();
420                 break;
421         }
422
423         BUG_ON(sig == 0);
424
425         /* If the fault was caused by a kernel thread, or interrupt handler
426          * we will kernel panic, so the system reboots.
427          */
428         if (kernel_mode_regs(fp) || (current && !current->mm)) {
429                 console_verbose();
430                 oops_in_progress = 1;
431         }
432
433         if (sig != SIGTRAP) {
434                 if (strerror)
435                         verbose_printk(strerror);
436
437                 dump_bfin_process(fp);
438                 dump_bfin_mem(fp);
439                 show_regs(fp);
440
441                 /* Print out the trace buffer if it makes sense */
442 #ifndef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE
443                 if (trapnr == VEC_CPLB_I_M || trapnr == VEC_CPLB_M)
444                         verbose_printk(KERN_NOTICE "No trace since you do not have "
445                                "CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE enabled\n\n");
446                 else
447 #endif
448                         dump_bfin_trace_buffer();
449
450                 if (oops_in_progress) {
451                         /* Dump the current kernel stack */
452                         verbose_printk(KERN_NOTICE "Kernel Stack\n");
453                         show_stack(current, NULL);
454                         print_modules();
455 #ifndef CONFIG_ACCESS_CHECK
456                         verbose_printk(KERN_EMERG "Please turn on "
457                                "CONFIG_ACCESS_CHECK\n");
458 #endif
459                         panic("Kernel exception");
460                 } else {
461 #ifdef CONFIG_DEBUG_VERBOSE
462                         unsigned long *stack;
463                         /* Dump the user space stack */
464                         stack = (unsigned long *)rdusp();
465                         verbose_printk(KERN_NOTICE "Userspace Stack\n");
466                         show_stack(NULL, stack);
467 #endif
468                 }
469         }
470
471 #ifdef CONFIG_IPIPE
472         if (!ipipe_trap_notify(fp->seqstat & 0x3f, fp))
473 #endif
474         {
475                 info.si_signo = sig;
476                 info.si_errno = 0;
477                 switch (trapnr) {
478                 case VEC_CPLB_VL:
479                 case VEC_MISALI_D:
480                 case VEC_CPLB_M:
481                 case VEC_CPLB_MHIT:
482                         info.si_addr = (void __user *)cpu_pda[cpu].dcplb_fault_addr;
483                         break;
484                 default:
485                         info.si_addr = (void __user *)fp->pc;
486                         break;
487                 }
488                 force_sig_info(sig, &info, current);
489         }
490
491         if ((ANOMALY_05000461 && trapnr == VEC_HWERR && !access_ok(VERIFY_READ, fp->pc, 8)) ||
492             (ANOMALY_05000281 && trapnr == VEC_HWERR) ||
493             (ANOMALY_05000189 && (trapnr == VEC_CPLB_I_VL || trapnr == VEC_CPLB_VL)))
494                 fp->pc = SAFE_USER_INSTRUCTION;
495
496  traps_done:
497         trace_buffer_restore(j);
498 }
499
500 asmlinkage void double_fault_c(struct pt_regs *fp)
501 {
502 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
503         int j;
504         trace_buffer_save(j);
505 #endif
506
507         console_verbose();
508         oops_in_progress = 1;
509 #ifdef CONFIG_DEBUG_VERBOSE
510         printk(KERN_EMERG "Double Fault\n");
511 #ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT
512         if (((long)fp->seqstat &  SEQSTAT_EXCAUSE) == VEC_UNCOV) {
513                 unsigned int cpu = raw_smp_processor_id();
514                 char buf[150];
515                 decode_address(buf, cpu_pda[cpu].retx_doublefault);
516                 printk(KERN_EMERG "While handling exception (EXCAUSE = 0x%x) at %s:\n",
517                         (unsigned int)cpu_pda[cpu].seqstat_doublefault & SEQSTAT_EXCAUSE, buf);
518                 decode_address(buf, cpu_pda[cpu].dcplb_doublefault_addr);
519                 printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %s\n", buf);
520                 decode_address(buf, cpu_pda[cpu].icplb_doublefault_addr);
521                 printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %s\n", buf);
522
523                 decode_address(buf, fp->retx);
524                 printk(KERN_NOTICE "The instruction at %s caused a double exception\n", buf);
525         } else
526 #endif
527         {
528                 dump_bfin_process(fp);
529                 dump_bfin_mem(fp);
530                 show_regs(fp);
531                 dump_bfin_trace_buffer();
532         }
533 #endif
534         panic("Double Fault - unrecoverable event");
535
536 }
537
538
539 void panic_cplb_error(int cplb_panic, struct pt_regs *fp)
540 {
541         switch (cplb_panic) {
542         case CPLB_NO_UNLOCKED:
543                 printk(KERN_EMERG "All CPLBs are locked\n");
544                 break;
545         case CPLB_PROT_VIOL:
546                 return;
547         case CPLB_NO_ADDR_MATCH:
548                 return;
549         case CPLB_UNKNOWN_ERR:
550                 printk(KERN_EMERG "Unknown CPLB Exception\n");
551                 break;
552         }
553
554         oops_in_progress = 1;
555
556         dump_bfin_process(fp);
557         dump_bfin_mem(fp);
558         show_regs(fp);
559         dump_stack();
560         panic("Unrecoverable event");
561 }
562
563 #ifdef CONFIG_BUG
564 int is_valid_bugaddr(unsigned long addr)
565 {
566         unsigned int opcode;
567
568         if (!get_instruction(&opcode, (unsigned short *)addr))
569                 return 0;
570
571         return opcode == BFIN_BUG_OPCODE;
572 }
573 #endif
574
575 /* stub this out */
576 #ifndef CONFIG_DEBUG_VERBOSE
577 void show_regs(struct pt_regs *fp)
578 {
579
580 }
581 #endif