Blackfin: decode hwerrcause/excause when crashing

Having to decode hwerrcause/excause values is a pain, so automate it.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

cpu/blackfin/traps.c

@@ -236,10 +236,45 @@ static void decode_address(char *buf, unsigned long address)
 		sprintf(buf, "<0x%p> /* unknown address */", address);
 }
 
+static char *strhwerrcause(uint16_t hwerrcause)
+{
+	switch (hwerrcause) {
+		case 0x02: return "system mmr error";
+		case 0x03: return "external memory addressing error";
+		case 0x12: return "performance monitor overflow";
+		case 0x18: return "raise 5 instruction";
+		default:   return "undef";
+	}
+}
+
+static char *strexcause(uint16_t excause)
+{
+	switch (excause) {
+		case 0x00 ... 0xf: return "custom exception";
+		case 0x10: return "single step";
+		case 0x11: return "trace buffer full";
+		case 0x21: return "undef inst";
+		case 0x22: return "illegal inst";
+		case 0x23: return "dcplb prot violation";
+		case 0x24: return "misaligned data";
+		case 0x25: return "unrecoverable event";
+		case 0x26: return "dcplb miss";
+		case 0x27: return "multiple dcplb hit";
+		case 0x28: return "emulation watchpoint";
+		case 0x2a: return "misaligned inst";
+		case 0x2b: return "icplb prot violation";
+		case 0x2c: return "icplb miss";
+		case 0x2d: return "multiple icplb hit";
+		case 0x2e: return "illegal use of supervisor resource";
+		default:   return "undef";
+	}
+}
+
 void dump(struct pt_regs *fp)
 {
 	char buf[150];
 	size_t i;
+	uint16_t hwerrcause, excause;
 
 	if (!ENABLE_DUMP)
 		return;
@@ -247,11 +282,14 @@ void dump(struct pt_regs *fp)
 	/* fp->ipend is garbage, so load it ourself */
 	fp->ipend = bfin_read_IPEND();
 
+	hwerrcause = (fp->seqstat & HWERRCAUSE) >> HWERRCAUSE_P;
+	excause = (fp->seqstat & EXCAUSE) >> EXCAUSE_P;
+
 	printf("SEQUENCER STATUS:\n");
 	printf(" SEQSTAT: %08lx  IPEND: %04lx  SYSCFG: %04lx\n",
 		fp->seqstat, fp->ipend, fp->syscfg);
-	printf("  HWERRCAUSE: 0x%lx\n", (fp->seqstat & HWERRCAUSE) >> HWERRCAUSE_P);
-	printf("  EXCAUSE   : 0x%lx\n", (fp->seqstat & EXCAUSE) >> EXCAUSE_P);
+	printf("  HWERRCAUSE: 0x%lx: %s\n", hwerrcause, strhwerrcause(hwerrcause));
+	printf("  EXCAUSE   : 0x%lx: %s\n", excause, strexcause(excause));
 	for (i = 6; i <= 15; ++i) {
 		if (fp->ipend & (1 << i)) {
 			decode_address(buf, bfin_read32(EVT0 + 4*i));