2 * Main exception handling logic.
4 * Copyright 2004-2010 Analog Devices Inc.
6 * Licensed under the GPL-2 or later
10 #include <linux/uaccess.h>
11 #include <linux/module.h>
12 #include <asm/traps.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>
22 # include <linux/kgdb.h>
24 # define CHK_DEBUGGER_TRAP() \
26 kgdb_handle_exception(trapnr, sig, info.si_code, fp); \
28 # define CHK_DEBUGGER_TRAP_MAYBE() \
31 CHK_DEBUGGER_TRAP(); \
34 # define CHK_DEBUGGER_TRAP() do { } while (0)
35 # define CHK_DEBUGGER_TRAP_MAYBE() do { } while (0)
39 #ifdef CONFIG_DEBUG_VERBOSE
40 #define verbose_printk(fmt, arg...) \
43 #define verbose_printk(fmt, arg...) \
44 ({ if (0) printk(fmt, ##arg); 0; })
47 #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
49 #ifdef CONFIG_DEBUG_MMRS_MODULE
50 EXPORT_SYMBOL(last_seqstat);
54 /* Initiate the event table handler */
55 void __init trap_init(void)
58 bfin_write_EVT3(trap);
62 static int kernel_mode_regs(struct pt_regs *regs)
64 return regs->ipend & 0xffc0;
67 asmlinkage notrace void trap_c(struct pt_regs *fp)
69 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
72 #ifdef CONFIG_BFIN_PSEUDODBG_INSNS
75 unsigned int cpu = raw_smp_processor_id();
76 const char *strerror = NULL;
79 unsigned long trapnr = fp->seqstat & SEQSTAT_EXCAUSE;
82 #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
83 last_seqstat = (u32)fp->seqstat;
86 /* Important - be very careful dereferncing pointers - will lead to
87 * double faults if the stack has become corrupt
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
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); */
98 /* send the appropriate signal to the user program */
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
109 /* 0x00 - Linux Syscall, getting here is an error */
110 /* 0x01 - userspace gdb breakpoint, handled here */
112 info.si_code = TRAP_ILLTRAP;
114 CHK_DEBUGGER_TRAP_MAYBE();
115 /* Check if this is a breakpoint in kernel space */
116 if (kernel_mode_regs(fp))
120 /* 0x03 - User Defined, userspace stack overflow */
122 info.si_code = SEGV_STACKFLOW;
124 strerror = KERN_NOTICE EXC_0x03(KERN_NOTICE);
125 CHK_DEBUGGER_TRAP_MAYBE();
127 /* 0x02 - KGDB initial connection and break signal trap */
130 info.si_code = TRAP_ILLTRAP;
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
150 case VEC_EXCPT04 ... VEC_EXCPT15:
151 info.si_code = ILL_ILLPARAOP;
153 strerror = KERN_NOTICE EXC_0x04(KERN_NOTICE);
154 CHK_DEBUGGER_TRAP_MAYBE();
156 /* 0x10 HW Single step, handled here */
158 info.si_code = TRAP_STEP;
160 CHK_DEBUGGER_TRAP_MAYBE();
161 /* Check if this is a single step in kernel space */
162 if (kernel_mode_regs(fp))
166 /* 0x11 - Trace Buffer Full, handled here */
168 info.si_code = TRAP_TRACEFLOW;
170 strerror = KERN_NOTICE EXC_0x11(KERN_NOTICE);
171 CHK_DEBUGGER_TRAP_MAYBE();
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 */
191 if (kernel_mode_regs(fp)) {
192 switch (report_bug(fp->pc, fp)) {
193 case BUG_TRAP_TYPE_NONE:
195 case BUG_TRAP_TYPE_WARN:
196 dump_bfin_trace_buffer();
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
207 #ifdef CONFIG_BFIN_PSEUDODBG_INSNS
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
213 if (!kernel_mode_regs(fp) && get_instruction(&opcode, (unsigned short *)fp->pc)) {
214 if (execute_pseudodbg_assert(fp, opcode))
218 info.si_code = ILL_ILLOPC;
220 strerror = KERN_NOTICE EXC_0x21(KERN_NOTICE);
221 CHK_DEBUGGER_TRAP_MAYBE();
223 /* 0x22 - Illegal Instruction Combination, handled here */
225 info.si_code = ILL_ILLPARAOP;
227 strerror = KERN_NOTICE EXC_0x22(KERN_NOTICE);
228 CHK_DEBUGGER_TRAP_MAYBE();
230 /* 0x23 - Data CPLB protection violation, handled here */
232 info.si_code = ILL_CPLB_VI;
234 strerror = KERN_NOTICE EXC_0x23(KERN_NOTICE);
235 CHK_DEBUGGER_TRAP_MAYBE();
237 /* 0x24 - Data access misaligned, handled here */
239 info.si_code = BUS_ADRALN;
241 strerror = KERN_NOTICE EXC_0x24(KERN_NOTICE);
242 CHK_DEBUGGER_TRAP_MAYBE();
244 /* 0x25 - Unrecoverable Event, handled here */
246 info.si_code = ILL_ILLEXCPT;
248 strerror = KERN_NOTICE EXC_0x25(KERN_NOTICE);
249 CHK_DEBUGGER_TRAP_MAYBE();
251 /* 0x26 - Data CPLB Miss, normal case is handled in _cplb_hdr,
252 error case is handled here */
254 info.si_code = BUS_ADRALN;
256 strerror = KERN_NOTICE EXC_0x26(KERN_NOTICE);
258 /* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero, handled here */
260 info.si_code = ILL_CPLB_MULHIT;
262 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
263 if (cpu_pda[cpu].dcplb_fault_addr < FIXED_CODE_START)
264 strerror = KERN_NOTICE "NULL pointer access\n";
267 strerror = KERN_NOTICE EXC_0x27(KERN_NOTICE);
268 CHK_DEBUGGER_TRAP_MAYBE();
270 /* 0x28 - Emulation Watchpoint, handled here */
272 info.si_code = TRAP_WATCHPT;
274 pr_debug(EXC_0x28(KERN_DEBUG));
275 CHK_DEBUGGER_TRAP_MAYBE();
276 /* Check if this is a watchpoint in kernel space */
277 if (kernel_mode_regs(fp))
282 /* 0x29 - Instruction fetch access error (535 only) */
283 case VEC_ISTRU_VL: /* ADSP-BF535 only (MH) */
284 info.si_code = BUS_OPFETCH;
286 strerror = KERN_NOTICE "BF535: VEC_ISTRU_VL\n";
287 CHK_DEBUGGER_TRAP_MAYBE();
290 /* 0x29 - Reserved, Caught by default */
292 /* 0x2A - Instruction fetch misaligned, handled here */
294 info.si_code = BUS_ADRALN;
296 strerror = KERN_NOTICE EXC_0x2A(KERN_NOTICE);
297 CHK_DEBUGGER_TRAP_MAYBE();
299 /* 0x2B - Instruction CPLB protection violation, handled here */
301 info.si_code = ILL_CPLB_VI;
303 strerror = KERN_NOTICE EXC_0x2B(KERN_NOTICE);
304 CHK_DEBUGGER_TRAP_MAYBE();
306 /* 0x2C - Instruction CPLB miss, handled in _cplb_hdr */
308 info.si_code = ILL_CPLB_MISS;
310 strerror = KERN_NOTICE EXC_0x2C(KERN_NOTICE);
312 /* 0x2D - Instruction CPLB Multiple Hits, handled here */
313 case VEC_CPLB_I_MHIT:
314 info.si_code = ILL_CPLB_MULHIT;
316 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
317 if (cpu_pda[cpu].icplb_fault_addr < FIXED_CODE_START)
318 strerror = KERN_NOTICE "Jump to NULL address\n";
321 strerror = KERN_NOTICE EXC_0x2D(KERN_NOTICE);
322 CHK_DEBUGGER_TRAP_MAYBE();
324 /* 0x2E - Illegal use of Supervisor Resource, handled here */
326 info.si_code = ILL_PRVOPC;
328 strerror = KERN_NOTICE EXC_0x2E(KERN_NOTICE);
329 CHK_DEBUGGER_TRAP_MAYBE();
331 /* 0x2F - Reserved, Caught by default */
332 /* 0x30 - Reserved, Caught by default */
333 /* 0x31 - Reserved, Caught by default */
334 /* 0x32 - Reserved, Caught by default */
335 /* 0x33 - Reserved, Caught by default */
336 /* 0x34 - Reserved, Caught by default */
337 /* 0x35 - Reserved, Caught by default */
338 /* 0x36 - Reserved, Caught by default */
339 /* 0x37 - Reserved, Caught by default */
340 /* 0x38 - Reserved, Caught by default */
341 /* 0x39 - Reserved, Caught by default */
342 /* 0x3A - Reserved, Caught by default */
343 /* 0x3B - Reserved, Caught by default */
344 /* 0x3C - Reserved, Caught by default */
345 /* 0x3D - Reserved, Caught by default */
346 /* 0x3E - Reserved, Caught by default */
347 /* 0x3F - Reserved, Caught by default */
349 info.si_code = BUS_ADRALN;
351 switch (fp->seqstat & SEQSTAT_HWERRCAUSE) {
352 /* System MMR Error */
353 case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR):
354 info.si_code = BUS_ADRALN;
356 strerror = KERN_NOTICE HWC_x2(KERN_NOTICE);
358 /* External Memory Addressing Error */
359 case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR):
360 if (ANOMALY_05000310) {
361 static unsigned long anomaly_rets;
363 if ((fp->pc >= (L1_CODE_START + L1_CODE_LENGTH - 512)) &&
364 (fp->pc < (L1_CODE_START + L1_CODE_LENGTH))) {
366 * A false hardware error will happen while fetching at
367 * the L1 instruction SRAM boundary. Ignore it.
369 anomaly_rets = fp->rets;
371 } else if (fp->rets == anomaly_rets) {
373 * While boundary code returns to a function, at the ret
374 * point, a new false hardware error might occur too based
375 * on tests. Ignore it too.
378 } else if ((fp->rets >= (L1_CODE_START + L1_CODE_LENGTH - 512)) &&
379 (fp->rets < (L1_CODE_START + L1_CODE_LENGTH))) {
381 * If boundary code calls a function, at the entry point,
382 * a new false hardware error maybe happen based on tests.
390 info.si_code = BUS_ADRERR;
392 strerror = KERN_NOTICE HWC_x3(KERN_NOTICE);
394 /* Performance Monitor Overflow */
395 case (SEQSTAT_HWERRCAUSE_PERF_FLOW):
396 strerror = KERN_NOTICE HWC_x12(KERN_NOTICE);
398 /* RAISE 5 instruction */
399 case (SEQSTAT_HWERRCAUSE_RAISE_5):
400 printk(KERN_NOTICE HWC_x18(KERN_NOTICE));
402 default: /* Reserved */
403 printk(KERN_NOTICE HWC_default(KERN_NOTICE));
406 CHK_DEBUGGER_TRAP_MAYBE();
409 * We should be handling all known exception types above,
410 * if we get here we hit a reserved one, so panic
413 info.si_code = ILL_ILLPARAOP;
415 verbose_printk(KERN_EMERG "Caught Unhandled Exception, code = %08lx\n",
416 (fp->seqstat & SEQSTAT_EXCAUSE));
417 CHK_DEBUGGER_TRAP_MAYBE();
423 /* If the fault was caused by a kernel thread, or interrupt handler
424 * we will kernel panic, so the system reboots.
426 if (kernel_mode_regs(fp) || (current && !current->mm)) {
428 oops_in_progress = 1;
431 if (sig != SIGTRAP) {
433 verbose_printk(strerror);
435 dump_bfin_process(fp);
439 /* Print out the trace buffer if it makes sense */
440 #ifndef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE
441 if (trapnr == VEC_CPLB_I_M || trapnr == VEC_CPLB_M)
442 verbose_printk(KERN_NOTICE "No trace since you do not have "
443 "CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE enabled\n\n");
446 dump_bfin_trace_buffer();
448 if (oops_in_progress) {
449 /* Dump the current kernel stack */
450 verbose_printk(KERN_NOTICE "Kernel Stack\n");
451 show_stack(current, NULL);
453 #ifndef CONFIG_ACCESS_CHECK
454 verbose_printk(KERN_EMERG "Please turn on "
455 "CONFIG_ACCESS_CHECK\n");
457 panic("Kernel exception");
459 #ifdef CONFIG_DEBUG_VERBOSE
460 unsigned long *stack;
461 /* Dump the user space stack */
462 stack = (unsigned long *)rdusp();
463 verbose_printk(KERN_NOTICE "Userspace Stack\n");
464 show_stack(NULL, stack);
470 if (!ipipe_trap_notify(fp->seqstat & 0x3f, fp))
480 info.si_addr = (void __user *)cpu_pda[cpu].dcplb_fault_addr;
483 info.si_addr = (void __user *)fp->pc;
486 force_sig_info(sig, &info, current);
489 if ((ANOMALY_05000461 && trapnr == VEC_HWERR && !access_ok(VERIFY_READ, fp->pc, 8)) ||
490 (ANOMALY_05000281 && trapnr == VEC_HWERR) ||
491 (ANOMALY_05000189 && (trapnr == VEC_CPLB_I_VL || trapnr == VEC_CPLB_VL)))
492 fp->pc = SAFE_USER_INSTRUCTION;
495 trace_buffer_restore(j);
498 asmlinkage void double_fault_c(struct pt_regs *fp)
500 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
502 trace_buffer_save(j);
506 oops_in_progress = 1;
507 #ifdef CONFIG_DEBUG_VERBOSE
508 printk(KERN_EMERG "Double Fault\n");
509 #ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT
510 if (((long)fp->seqstat & SEQSTAT_EXCAUSE) == VEC_UNCOV) {
511 unsigned int cpu = raw_smp_processor_id();
513 decode_address(buf, cpu_pda[cpu].retx_doublefault);
514 printk(KERN_EMERG "While handling exception (EXCAUSE = 0x%x) at %s:\n",
515 (unsigned int)cpu_pda[cpu].seqstat_doublefault & SEQSTAT_EXCAUSE, buf);
516 decode_address(buf, cpu_pda[cpu].dcplb_doublefault_addr);
517 printk(KERN_NOTICE " DCPLB_FAULT_ADDR: %s\n", buf);
518 decode_address(buf, cpu_pda[cpu].icplb_doublefault_addr);
519 printk(KERN_NOTICE " ICPLB_FAULT_ADDR: %s\n", buf);
521 decode_address(buf, fp->retx);
522 printk(KERN_NOTICE "The instruction at %s caused a double exception\n", buf);
526 dump_bfin_process(fp);
529 dump_bfin_trace_buffer();
532 panic("Double Fault - unrecoverable event");
537 void panic_cplb_error(int cplb_panic, struct pt_regs *fp)
539 switch (cplb_panic) {
540 case CPLB_NO_UNLOCKED:
541 printk(KERN_EMERG "All CPLBs are locked\n");
545 case CPLB_NO_ADDR_MATCH:
547 case CPLB_UNKNOWN_ERR:
548 printk(KERN_EMERG "Unknown CPLB Exception\n");
552 oops_in_progress = 1;
554 dump_bfin_process(fp);
558 panic("Unrecoverable event");
562 int is_valid_bugaddr(unsigned long addr)
566 if (!get_instruction(&opcode, (unsigned short *)addr))
569 return opcode == BFIN_BUG_OPCODE;
574 #ifndef CONFIG_DEBUG_VERBOSE
575 void show_regs(struct pt_regs *fp)