1 files changed, 84 insertions, 48 deletions

diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index 8bbfef31666b..c90f16825f98 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -39,6 +39,7 @@
 #include <linux/irq.h>
 #include <asm/trace.h>
 #include <asm/fixed_code.h>
+#include <asm/dma.h>
 
 #ifdef CONFIG_KGDB
 # include <linux/debugger.h>
@@ -171,7 +172,7 @@ asmlinkage void double_fault_c(struct pt_regs *fp)
         oops_in_progress = 1;
         printk(KERN_EMERG "\n" KERN_EMERG "Double Fault\n");
         dump_bfin_process(fp);
-        dump_bfin_mem((void *)fp->retx);
+        dump_bfin_mem(fp);
         show_regs(fp);
         panic("Double Fault - unrecoverable event\n");
 
@@ -196,6 +197,10 @@ asmlinkage void trap_c(struct pt_regs *fp)
          * we will kernel panic, so the system reboots.
          * If KGDB is enabled, don't set this for kernel breakpoints
         */
+
+        /* TODO: check to see if we are in some sort of deferred HWERR
+         * that we should be able to recover from, not kernel panic
+         */
         if ((bfin_read_IPEND() & 0xFFC0)
 #ifdef CONFIG_KGDB
                 && trapnr != VEC_EXCPT02
@@ -478,11 +483,7 @@ asmlinkage void trap_c(struct pt_regs *fp)
         if (sig != SIGTRAP) {
                 unsigned long stack;
                 dump_bfin_process(fp);
-                /* Is it an interrupt, or an exception? */
-                if (trapnr == VEC_HWERR)
-                        dump_bfin_mem((void *)fp->pc);
-                else
-                        dump_bfin_mem((void *)fp->retx);
+                dump_bfin_mem(fp);
                 show_regs(fp);
 
                 /* Print out the trace buffer if it makes sense */
@@ -644,8 +645,10 @@ void dump_bfin_process(struct pt_regs *fp)
         if (oops_in_progress)
                 printk(KERN_EMERG "Kernel OOPS in progress\n");
 
-        if (context & 0x0020)
-                printk(KERN_NOTICE "Deferred excecption or HW Error context\n");
+        if (context & 0x0020 && (fp->seqstat & SEQSTAT_EXCAUSE) == VEC_HWERR)
+                printk(KERN_NOTICE "HW Error context\n");
+        else if (context & 0x0020)
+                printk(KERN_NOTICE "Defered Exception context\n");
         else if (context & 0x3FC0)
                 printk(KERN_NOTICE "Interrupt context\n");
         else if (context & 0x4000)
@@ -673,49 +676,82 @@ void dump_bfin_process(struct pt_regs *fp)
                      "No Valid process in current context\n");
 }
 
-void dump_bfin_mem(void *retaddr)
+void dump_bfin_mem(struct pt_regs *fp)
 {
+        unsigned short *addr, *erraddr, val = 0, err = 0;
+        char sti = 0, buf[6];
 
-        if (retaddr >= (void *)FIXED_CODE_START  && retaddr < (void *)physical_mem_end
-#if L1_CODE_LENGTH != 0
-            /* FIXME: Copy the code out of L1 Instruction SRAM through dma
-               memcpy.  */
-            && !(retaddr >= (void *)L1_CODE_START
-                 && retaddr < (void *)(L1_CODE_START + L1_CODE_LENGTH))
-#endif
-        ) {
-                int i = ((unsigned int)retaddr & 0xFFFFFFF0) - 32;
-                unsigned short x = 0;
-                printk(KERN_NOTICE "return address: [0x%p]; contents of:", retaddr);
-                for (; i < ((unsigned int)retaddr & 0xFFFFFFF0) + 32; i += 2) {
-                        if (!(i & 0xF))
-                                printk("\n" KERN_NOTICE "0x%08x: ", i);
-
-                        if (get_user(x, (unsigned short *)i))
-                                break;
+        if (unlikely((fp->seqstat & SEQSTAT_EXCAUSE) == VEC_HWERR))
+                erraddr = (void *)fp->pc;
+        else
+                erraddr = (void *)fp->retx;
+
+        printk(KERN_NOTICE "return address: [0x%p]; contents of:", erraddr);
+
+        for (addr = (unsigned short *)((unsigned long)erraddr & ~0xF) - 0x10;
+             addr < (unsigned short *)((unsigned long)erraddr & ~0xF) + 0x10;
+             addr++) {
+                if (!((unsigned long)addr & 0xF))
+                        printk("\n" KERN_NOTICE "0x%p: ", addr);
+
+                if (get_user(val, addr)) {
+                        if (addr >= (unsigned short *)L1_CODE_START &&
+                            addr < (unsigned short *)(L1_CODE_START + L1_CODE_LENGTH)) {
+                                dma_memcpy(&val, addr, sizeof(val));
+                                sprintf(buf, "%04x", val);
+                        } else if (addr >= (unsigned short *)FIXED_CODE_START &&
+                                addr <= (unsigned short *)memory_start) {
+                                val = bfin_read16(addr);
+                                sprintf(buf, "%04x", val);
+                        } else {
+                                val = 0;
+                                sprintf(buf, "????");
+                        }
+                } else
+                        sprintf(buf, "%04x", val);
+
+                if (addr == erraddr) {
+                        printk("[%s]", buf);
+                        err = val;
+                } else
+                        printk(" %s ", buf);
+
+                /* Do any previous instructions turn on interrupts? */
+                if (addr <= erraddr &&                          /* in the past */
+                    ((val >= 0x0040 && val <= 0x0047) ||        /* STI instruction */
+                      val == 0x017b))                           /* [SP++] = RETI */
+                        sti = 1;
+        }
+
+        printk("\n");
+
+        /* Hardware error interrupts can be deferred */
+        if (unlikely(sti && (fp->seqstat & SEQSTAT_EXCAUSE) == VEC_HWERR &&
+            oops_in_progress)){
+                printk(KERN_NOTICE "Looks like this was a deferred error - sorry\n");
 #ifndef CONFIG_DEBUG_HWERR
-                        /* If one of the last few instructions was a STI
-                         * it is likely that the error occured awhile ago
-                         * and we just noticed. This only happens in kernel
-                         * context, which should mean an oops is happening
-                         */
-                        if (oops_in_progress && x >= 0x0040 && x <= 0x0047 && i <= 0)
-                                printk(KERN_EMERG "\n"
-                                        KERN_EMERG "WARNING : You should reconfigure"
-                                        " the kernel to turn on\n"
-                                        KERN_EMERG " 'Hardware error interrupt debugging'\n"
-                                        KERN_EMERG " The rest of this error is meanless\n");
-#endif
-                        if (i == (unsigned int)retaddr)
-                                printk("[%04x]", x);
-                        else
-                                printk(" %04x ", x);
+                printk(KERN_NOTICE "The remaining message may be meaningless\n"
+                        KERN_NOTICE "You should enable CONFIG_DEBUG_HWERR to get a"
+                         " better idea where it came from\n");
+#else
+                /* If we are handling only one peripheral interrupt
+                 * and current mm and pid are valid, and the last error
+                 * was in that user space process's text area
+                 * print it out - because that is where the problem exists
+                 */
+                if ((!(((fp)->ipend & ~0x30) & (((fp)->ipend & ~0x30) - 1))) &&
+                     (current->pid && current->mm)) {
+                        /* And the last RETI points to the current userspace context */
+                        if ((fp + 1)->pc >= current->mm->start_code &&
+                            (fp + 1)->pc <= current->mm->end_code) {
+                                printk(KERN_NOTICE "It might be better to look around here : \n");
+                                printk(KERN_NOTICE "-------------------------------------------\n");
+                                show_regs(fp + 1);
+                                printk(KERN_NOTICE "-------------------------------------------\n");
+                        }
                 }
-                printk("\n");
-        } else
-                printk("\n" KERN_NOTICE
-                        "Cannot look at the [PC] <%p> for it is"
-                        " in unreadable memory - sorry\n", retaddr);
+#endif
+        }
 }
 
 void show_regs(struct pt_regs *fp)
@@ -885,7 +921,7 @@ void panic_cplb_error(int cplb_panic, struct pt_regs *fp)
         printk(KERN_EMERG "DCPLB_FAULT_ADDR=%p\n", (void *)bfin_read_DCPLB_FAULT_ADDR());
         printk(KERN_EMERG "ICPLB_FAULT_ADDR=%p\n", (void *)bfin_read_ICPLB_FAULT_ADDR());
         dump_bfin_process(fp);
-        dump_bfin_mem((void *)fp->retx);
+        dump_bfin_mem(fp);
         show_regs(fp);
         dump_stack();
         panic("Unrecoverable event\n");