Blackfin arch: add supporting for double fault debug handling

[safe/jmp/linux-2.6] / arch / blackfin / kernel / traps.c

diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index fd24e04..bd41fca 100644 (file)
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -68,7 +68,15 @@ void __init trap_init(void)
        CSYNC();
 }
 
-unsigned long saved_icplb_fault_addr, saved_dcplb_fault_addr;
+/*
+ * Used to save the RETX, SEQSTAT, I/D CPLB FAULT ADDR
+ * values across the transition from exception to IRQ5.
+ * We put these in L1, so they are going to be in a valid
+ * location during exception context
+ */
+__attribute__((l1_data))
+unsigned long saved_retx, saved_seqstat,
+       saved_icplb_fault_addr, saved_dcplb_fault_addr;
 
 static void decode_address(char *buf, unsigned long address)
 {
@@ -186,9 +194,27 @@ asmlinkage void double_fault_c(struct pt_regs *fp)
        console_verbose();
        oops_in_progress = 1;
        printk(KERN_EMERG "\n" KERN_EMERG "Double Fault\n");
-       dump_bfin_process(fp);
-       dump_bfin_mem(fp);
-       show_regs(fp);
+#ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT
+       if (((long)fp->seqstat &  SEQSTAT_EXCAUSE) == VEC_UNCOV) {
+               char buf[150];
+               decode_address(buf, saved_retx);
+               printk(KERN_EMERG "While handling exception (EXCAUSE = 0x%x) at %s:\n",
+                       (int)saved_seqstat & SEQSTAT_EXCAUSE, buf);
+               decode_address(buf, saved_dcplb_fault_addr);
+               printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %s\n", buf);
+               decode_address(buf, saved_icplb_fault_addr);
+               printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %s\n", buf);
+
+               decode_address(buf, fp->retx);
+               printk(KERN_NOTICE "The instruction at %s caused a double exception\n",
+                       buf);
+       } else
+#endif
+       {
+               dump_bfin_process(fp);
+               dump_bfin_mem(fp);
+               show_regs(fp);
+       }
        panic("Double Fault - unrecoverable event\n");
 
 }