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>
23 # include <linux/kgdb.h>
25 # define CHK_DEBUGGER_TRAP() \
27 kgdb_handle_exception(trapnr, sig, info.si_code, fp); \
29 # define CHK_DEBUGGER_TRAP_MAYBE() \
32 CHK_DEBUGGER_TRAP(); \
35 # define CHK_DEBUGGER_TRAP() do { } while (0)
36 # define CHK_DEBUGGER_TRAP_MAYBE() do { } while (0)
40 #ifdef CONFIG_DEBUG_VERBOSE
41 #define verbose_printk(fmt, arg...) \
44 #define verbose_printk(fmt, arg...) \
45 ({ if (0) printk(fmt, ##arg); 0; })
48 #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
50 #ifdef CONFIG_DEBUG_MMRS_MODULE
51 EXPORT_SYMBOL(last_seqstat
);
55 /* Initiate the event table handler */
56 void __init
trap_init(void)
59 bfin_write_EVT3(trap
);
63 static int kernel_mode_regs(struct pt_regs
*regs
)
65 return regs
->ipend
& 0xffc0;
68 asmlinkage notrace
void trap_c(struct pt_regs
*fp
)
70 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
73 #ifdef CONFIG_BFIN_PSEUDODBG_INSNS
76 unsigned int cpu
= raw_smp_processor_id();
77 const char *strerror
= NULL
;
80 unsigned long trapnr
= fp
->seqstat
& SEQSTAT_EXCAUSE
;
83 #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
84 last_seqstat
= (u32
)fp
->seqstat
;
87 /* Important - be very careful dereferncing pointers - will lead to
88 * double faults if the stack has become corrupt
91 /* trap_c() will be called for exceptions. During exceptions
92 * processing, the pc value should be set with retx value.
93 * With this change we can cleanup some code in signal.c- TODO
95 fp
->orig_pc
= fp
->retx
;
96 /* printk("exception: 0x%x, ipend=%x, reti=%x, retx=%x\n",
97 trapnr, fp->ipend, fp->pc, fp->retx); */
99 /* send the appropriate signal to the user program */
102 /* This table works in conjunction with the one in ./mach-common/entry.S
103 * Some exceptions are handled there (in assembly, in exception space)
104 * Some are handled here, (in C, in interrupt space)
105 * Some, like CPLB, are handled in both, where the normal path is
106 * handled in assembly/exception space, and the error path is handled
110 /* 0x00 - Linux Syscall, getting here is an error */
111 /* 0x01 - userspace gdb breakpoint, handled here */
113 info
.si_code
= TRAP_ILLTRAP
;
115 CHK_DEBUGGER_TRAP_MAYBE();
116 /* Check if this is a breakpoint in kernel space */
117 if (kernel_mode_regs(fp
))
121 /* 0x03 - User Defined, userspace stack overflow */
123 info
.si_code
= SEGV_STACKFLOW
;
125 strerror
= KERN_NOTICE
EXC_0x03(KERN_NOTICE
);
126 CHK_DEBUGGER_TRAP_MAYBE();
128 /* 0x02 - KGDB initial connection and break signal trap */
131 info
.si_code
= TRAP_ILLTRAP
;
136 /* 0x04 - User Defined */
137 /* 0x05 - User Defined */
138 /* 0x06 - User Defined */
139 /* 0x07 - User Defined */
140 /* 0x08 - User Defined */
141 /* 0x09 - User Defined */
142 /* 0x0A - User Defined */
143 /* 0x0B - User Defined */
144 /* 0x0C - User Defined */
145 /* 0x0D - User Defined */
146 /* 0x0E - User Defined */
147 /* 0x0F - User Defined */
148 /* If we got here, it is most likely that someone was trying to use a
149 * custom exception handler, and it is not actually installed properly
151 case VEC_EXCPT04
... VEC_EXCPT15
:
152 info
.si_code
= ILL_ILLPARAOP
;
154 strerror
= KERN_NOTICE
EXC_0x04(KERN_NOTICE
);
155 CHK_DEBUGGER_TRAP_MAYBE();
157 /* 0x10 HW Single step, handled here */
159 info
.si_code
= TRAP_STEP
;
161 CHK_DEBUGGER_TRAP_MAYBE();
162 /* Check if this is a single step in kernel space */
163 if (kernel_mode_regs(fp
))
167 /* 0x11 - Trace Buffer Full, handled here */
169 info
.si_code
= TRAP_TRACEFLOW
;
171 strerror
= KERN_NOTICE
EXC_0x11(KERN_NOTICE
);
172 CHK_DEBUGGER_TRAP_MAYBE();
174 /* 0x12 - Reserved, Caught by default */
175 /* 0x13 - Reserved, Caught by default */
176 /* 0x14 - Reserved, Caught by default */
177 /* 0x15 - Reserved, Caught by default */
178 /* 0x16 - Reserved, Caught by default */
179 /* 0x17 - Reserved, Caught by default */
180 /* 0x18 - Reserved, Caught by default */
181 /* 0x19 - Reserved, Caught by default */
182 /* 0x1A - Reserved, Caught by default */
183 /* 0x1B - Reserved, Caught by default */
184 /* 0x1C - Reserved, Caught by default */
185 /* 0x1D - Reserved, Caught by default */
186 /* 0x1E - Reserved, Caught by default */
187 /* 0x1F - Reserved, Caught by default */
188 /* 0x20 - Reserved, Caught by default */
189 /* 0x21 - Undefined Instruction, handled here */
192 if (kernel_mode_regs(fp
)) {
193 switch (report_bug(fp
->pc
, fp
)) {
194 case BUG_TRAP_TYPE_NONE
:
196 case BUG_TRAP_TYPE_WARN
:
197 dump_bfin_trace_buffer();
200 case BUG_TRAP_TYPE_BUG
:
201 /* call to panic() will dump trace, and it is
202 * off at this point, so it won't be clobbered
208 #ifdef CONFIG_BFIN_PSEUDODBG_INSNS
210 * Support for the fake instructions, if the instruction fails,
211 * then just execute a illegal opcode failure (like normal).
212 * Don't support these instructions inside the kernel
214 if (!kernel_mode_regs(fp
) && get_instruction(&opcode
, (unsigned short *)fp
->pc
)) {
215 if (execute_pseudodbg_assert(fp
, opcode
))
217 if (execute_pseudodbg(fp
, opcode
))
221 info
.si_code
= ILL_ILLOPC
;
223 strerror
= KERN_NOTICE
EXC_0x21(KERN_NOTICE
);
224 CHK_DEBUGGER_TRAP_MAYBE();
226 /* 0x22 - Illegal Instruction Combination, handled here */
228 info
.si_code
= ILL_ILLPARAOP
;
230 strerror
= KERN_NOTICE
EXC_0x22(KERN_NOTICE
);
231 CHK_DEBUGGER_TRAP_MAYBE();
233 /* 0x23 - Data CPLB protection violation, handled here */
235 info
.si_code
= ILL_CPLB_VI
;
237 strerror
= KERN_NOTICE
EXC_0x23(KERN_NOTICE
);
238 CHK_DEBUGGER_TRAP_MAYBE();
240 /* 0x24 - Data access misaligned, handled here */
242 info
.si_code
= BUS_ADRALN
;
244 strerror
= KERN_NOTICE
EXC_0x24(KERN_NOTICE
);
245 CHK_DEBUGGER_TRAP_MAYBE();
247 /* 0x25 - Unrecoverable Event, handled here */
249 info
.si_code
= ILL_ILLEXCPT
;
251 strerror
= KERN_NOTICE
EXC_0x25(KERN_NOTICE
);
252 CHK_DEBUGGER_TRAP_MAYBE();
254 /* 0x26 - Data CPLB Miss, normal case is handled in _cplb_hdr,
255 error case is handled here */
257 info
.si_code
= BUS_ADRALN
;
259 strerror
= KERN_NOTICE
EXC_0x26(KERN_NOTICE
);
261 /* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero, handled here */
263 info
.si_code
= ILL_CPLB_MULHIT
;
265 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
266 if (cpu_pda
[cpu
].dcplb_fault_addr
< FIXED_CODE_START
)
267 strerror
= KERN_NOTICE
"NULL pointer access\n";
270 strerror
= KERN_NOTICE
EXC_0x27(KERN_NOTICE
);
271 CHK_DEBUGGER_TRAP_MAYBE();
273 /* 0x28 - Emulation Watchpoint, handled here */
275 info
.si_code
= TRAP_WATCHPT
;
277 pr_debug(EXC_0x28(KERN_DEBUG
));
278 CHK_DEBUGGER_TRAP_MAYBE();
279 /* Check if this is a watchpoint in kernel space */
280 if (kernel_mode_regs(fp
))
285 /* 0x29 - Instruction fetch access error (535 only) */
286 case VEC_ISTRU_VL
: /* ADSP-BF535 only (MH) */
287 info
.si_code
= BUS_OPFETCH
;
289 strerror
= KERN_NOTICE
"BF535: VEC_ISTRU_VL\n";
290 CHK_DEBUGGER_TRAP_MAYBE();
293 /* 0x29 - Reserved, Caught by default */
295 /* 0x2A - Instruction fetch misaligned, handled here */
297 info
.si_code
= BUS_ADRALN
;
299 strerror
= KERN_NOTICE
EXC_0x2A(KERN_NOTICE
);
300 CHK_DEBUGGER_TRAP_MAYBE();
302 /* 0x2B - Instruction CPLB protection violation, handled here */
304 info
.si_code
= ILL_CPLB_VI
;
306 strerror
= KERN_NOTICE
EXC_0x2B(KERN_NOTICE
);
307 CHK_DEBUGGER_TRAP_MAYBE();
309 /* 0x2C - Instruction CPLB miss, handled in _cplb_hdr */
311 info
.si_code
= ILL_CPLB_MISS
;
313 strerror
= KERN_NOTICE
EXC_0x2C(KERN_NOTICE
);
315 /* 0x2D - Instruction CPLB Multiple Hits, handled here */
316 case VEC_CPLB_I_MHIT
:
317 info
.si_code
= ILL_CPLB_MULHIT
;
319 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
320 if (cpu_pda
[cpu
].icplb_fault_addr
< FIXED_CODE_START
)
321 strerror
= KERN_NOTICE
"Jump to NULL address\n";
324 strerror
= KERN_NOTICE
EXC_0x2D(KERN_NOTICE
);
325 CHK_DEBUGGER_TRAP_MAYBE();
327 /* 0x2E - Illegal use of Supervisor Resource, handled here */
329 info
.si_code
= ILL_PRVOPC
;
331 strerror
= KERN_NOTICE
EXC_0x2E(KERN_NOTICE
);
332 CHK_DEBUGGER_TRAP_MAYBE();
334 /* 0x2F - Reserved, Caught by default */
335 /* 0x30 - Reserved, Caught by default */
336 /* 0x31 - Reserved, Caught by default */
337 /* 0x32 - Reserved, Caught by default */
338 /* 0x33 - Reserved, Caught by default */
339 /* 0x34 - Reserved, Caught by default */
340 /* 0x35 - Reserved, Caught by default */
341 /* 0x36 - Reserved, Caught by default */
342 /* 0x37 - Reserved, Caught by default */
343 /* 0x38 - Reserved, Caught by default */
344 /* 0x39 - Reserved, Caught by default */
345 /* 0x3A - Reserved, Caught by default */
346 /* 0x3B - Reserved, Caught by default */
347 /* 0x3C - Reserved, Caught by default */
348 /* 0x3D - Reserved, Caught by default */
349 /* 0x3E - Reserved, Caught by default */
350 /* 0x3F - Reserved, Caught by default */
352 info
.si_code
= BUS_ADRALN
;
354 switch (fp
->seqstat
& SEQSTAT_HWERRCAUSE
) {
355 /* System MMR Error */
356 case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR
):
357 info
.si_code
= BUS_ADRALN
;
359 strerror
= KERN_NOTICE
HWC_x2(KERN_NOTICE
);
361 /* External Memory Addressing Error */
362 case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR
):
363 if (ANOMALY_05000310
) {
364 static unsigned long anomaly_rets
;
366 if ((fp
->pc
>= (L1_CODE_START
+ L1_CODE_LENGTH
- 512)) &&
367 (fp
->pc
< (L1_CODE_START
+ L1_CODE_LENGTH
))) {
369 * A false hardware error will happen while fetching at
370 * the L1 instruction SRAM boundary. Ignore it.
372 anomaly_rets
= fp
->rets
;
374 } else if (fp
->rets
== anomaly_rets
) {
376 * While boundary code returns to a function, at the ret
377 * point, a new false hardware error might occur too based
378 * on tests. Ignore it too.
381 } else if ((fp
->rets
>= (L1_CODE_START
+ L1_CODE_LENGTH
- 512)) &&
382 (fp
->rets
< (L1_CODE_START
+ L1_CODE_LENGTH
))) {
384 * If boundary code calls a function, at the entry point,
385 * a new false hardware error maybe happen based on tests.
393 info
.si_code
= BUS_ADRERR
;
395 strerror
= KERN_NOTICE
HWC_x3(KERN_NOTICE
);
397 /* Performance Monitor Overflow */
398 case (SEQSTAT_HWERRCAUSE_PERF_FLOW
):
399 strerror
= KERN_NOTICE
HWC_x12(KERN_NOTICE
);
401 /* RAISE 5 instruction */
402 case (SEQSTAT_HWERRCAUSE_RAISE_5
):
403 printk(KERN_NOTICE
HWC_x18(KERN_NOTICE
));
405 default: /* Reserved */
406 printk(KERN_NOTICE
HWC_default(KERN_NOTICE
));
409 CHK_DEBUGGER_TRAP_MAYBE();
412 * We should be handling all known exception types above,
413 * if we get here we hit a reserved one, so panic
416 info
.si_code
= ILL_ILLPARAOP
;
418 verbose_printk(KERN_EMERG
"Caught Unhandled Exception, code = %08lx\n",
419 (fp
->seqstat
& SEQSTAT_EXCAUSE
));
420 CHK_DEBUGGER_TRAP_MAYBE();
426 /* If the fault was caused by a kernel thread, or interrupt handler
427 * we will kernel panic, so the system reboots.
429 if (kernel_mode_regs(fp
) || (current
&& !current
->mm
)) {
431 oops_in_progress
= 1;
434 if (sig
!= SIGTRAP
) {
436 verbose_printk(strerror
);
438 dump_bfin_process(fp
);
442 /* Print out the trace buffer if it makes sense */
443 #ifndef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE
444 if (trapnr
== VEC_CPLB_I_M
|| trapnr
== VEC_CPLB_M
)
445 verbose_printk(KERN_NOTICE
"No trace since you do not have "
446 "CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE enabled\n\n");
449 dump_bfin_trace_buffer();
451 if (oops_in_progress
) {
452 /* Dump the current kernel stack */
453 verbose_printk(KERN_NOTICE
"Kernel Stack\n");
454 show_stack(current
, NULL
);
456 #ifndef CONFIG_ACCESS_CHECK
457 verbose_printk(KERN_EMERG
"Please turn on "
458 "CONFIG_ACCESS_CHECK\n");
460 panic("Kernel exception");
462 #ifdef CONFIG_DEBUG_VERBOSE
463 unsigned long *stack
;
464 /* Dump the user space stack */
465 stack
= (unsigned long *)rdusp();
466 verbose_printk(KERN_NOTICE
"Userspace Stack\n");
467 show_stack(NULL
, stack
);
473 if (!ipipe_trap_notify(fp
->seqstat
& 0x3f, fp
))
483 info
.si_addr
= (void __user
*)cpu_pda
[cpu
].dcplb_fault_addr
;
486 info
.si_addr
= (void __user
*)fp
->pc
;
489 force_sig_info(sig
, &info
, current
);
492 if ((ANOMALY_05000461
&& trapnr
== VEC_HWERR
&& !access_ok(VERIFY_READ
, fp
->pc
, 8)) ||
493 (ANOMALY_05000281
&& trapnr
== VEC_HWERR
) ||
494 (ANOMALY_05000189
&& (trapnr
== VEC_CPLB_I_VL
|| trapnr
== VEC_CPLB_VL
)))
495 fp
->pc
= SAFE_USER_INSTRUCTION
;
498 trace_buffer_restore(j
);
501 asmlinkage
void double_fault_c(struct pt_regs
*fp
)
503 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
505 trace_buffer_save(j
);
509 oops_in_progress
= 1;
510 #ifdef CONFIG_DEBUG_VERBOSE
511 printk(KERN_EMERG
"Double Fault\n");
512 #ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT
513 if (((long)fp
->seqstat
& SEQSTAT_EXCAUSE
) == VEC_UNCOV
) {
514 unsigned int cpu
= raw_smp_processor_id();
516 decode_address(buf
, cpu_pda
[cpu
].retx_doublefault
);
517 printk(KERN_EMERG
"While handling exception (EXCAUSE = 0x%x) at %s:\n",
518 (unsigned int)cpu_pda
[cpu
].seqstat_doublefault
& SEQSTAT_EXCAUSE
, buf
);
519 decode_address(buf
, cpu_pda
[cpu
].dcplb_doublefault_addr
);
520 printk(KERN_NOTICE
" DCPLB_FAULT_ADDR: %s\n", buf
);
521 decode_address(buf
, cpu_pda
[cpu
].icplb_doublefault_addr
);
522 printk(KERN_NOTICE
" ICPLB_FAULT_ADDR: %s\n", buf
);
524 decode_address(buf
, fp
->retx
);
525 printk(KERN_NOTICE
"The instruction at %s caused a double exception\n", buf
);
529 dump_bfin_process(fp
);
532 dump_bfin_trace_buffer();
535 panic("Double Fault - unrecoverable event");
540 void panic_cplb_error(int cplb_panic
, struct pt_regs
*fp
)
542 switch (cplb_panic
) {
543 case CPLB_NO_UNLOCKED
:
544 printk(KERN_EMERG
"All CPLBs are locked\n");
548 case CPLB_NO_ADDR_MATCH
:
550 case CPLB_UNKNOWN_ERR
:
551 printk(KERN_EMERG
"Unknown CPLB Exception\n");
555 oops_in_progress
= 1;
557 dump_bfin_process(fp
);
561 panic("Unrecoverable event");
565 int is_valid_bugaddr(unsigned long addr
)
569 if (!get_instruction(&opcode
, (unsigned short *)addr
))
572 return opcode
== BFIN_BUG_OPCODE
;
577 #ifndef CONFIG_DEBUG_VERBOSE
578 void show_regs(struct pt_regs
*fp
)