Blackfin arch: add supporting for double fault debug handling

[pandora-kernel.git] / arch / blackfin / kernel / setup.c

diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c
index 7a82d10..8e639dc 100644 (file)
--- a/arch/blackfin/kernel/setup.c
+++ b/arch/blackfin/kernel/setup.c
@@ -52,7 +52,8 @@ EXPORT_SYMBOL(mtd_size);
 #endif
 
 char __initdata command_line[COMMAND_LINE_SIZE];
-unsigned int __initdata *__retx;
+void __initdata *init_retx, *init_saved_retx, *init_saved_seqstat,
+       *init_saved_icplb_fault_addr, *init_saved_dcplb_fault_addr;
 
 /* boot memmap, for parsing "memmap=" */
 #define BFIN_MEMMAP_MAX                128 /* number of entries in bfin_memmap */
@@ -782,16 +783,25 @@ void __init setup_arch(char **cmdline_p)
 
        _bfin_swrst = bfin_read_SWRST();
 
-       /* If we double fault, reset the system - otherwise we hang forever */
-       bfin_write_SWRST(DOUBLE_FAULT);
+#ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT
+       bfin_write_SWRST(_bfin_swrst & ~DOUBLE_FAULT);
+#endif
+#ifdef CONFIG_DEBUG_DOUBLEFAULT_RESET
+       bfin_write_SWRST(_bfin_swrst | DOUBLE_FAULT);
+#endif
 
-       if (_bfin_swrst & RESET_DOUBLE)
-               /*
-                * don't decode the address, since you don't know if this
-                * kernel's symbol map is the same as the crashing kernel
-                */
-               printk(KERN_INFO "Recovering from Double Fault event at %pF\n", __retx);
-       else if (_bfin_swrst & RESET_WDOG)
+       if (_bfin_swrst & RESET_DOUBLE) {
+               printk(KERN_EMERG "Recovering from DOUBLE FAULT event\n");
+#ifdef CONFIG_DEBUG_DOUBLEFAULT
+               /* We assume the crashing kernel, and the current symbol table match */
+               printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
+                       (int)init_saved_seqstat & SEQSTAT_EXCAUSE, init_saved_retx);
+               printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr);
+               printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr);
+#endif
+               printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
+                       init_retx);
+       } else if (_bfin_swrst & RESET_WDOG)
                printk(KERN_INFO "Recovering from Watchdog event\n");
        else if (_bfin_swrst & RESET_SOFTWARE)
                printk(KERN_NOTICE "Reset caused by Software reset\n");