Blackfin: print out the faulting insn in the trace output

Print out the faulting instruction so when people send traces as part of
bug reports, we have a better idea of what is going on.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/arch/blackfin/kernel/trace.c b/arch/blackfin/kernel/trace.c
index 6e37a8765bc0..5aa0d5e4e704 100644
--- a/arch/blackfin/kernel/trace.c
+++ b/arch/blackfin/kernel/trace.c
@@ -19,6 +19,7 @@
 #include <asm/trace.h>
 #include <asm/fixed_code.h>
 #include <asm/traps.h>
+#include <asm/irq_handler.h>
 
 void decode_address(char *buf, unsigned long address)
 {
@@ -260,9 +261,10 @@ static void decode_instruction(unsigned short *address)
 void dump_bfin_trace_buffer(void)
 {
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
-        int tflags, i = 0;
+        int tflags, i = 0, fault = 0;
         char buf[150];
         unsigned short *addr;
+        unsigned int cpu = raw_smp_processor_id();
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
         int j, index;
 #endif
@@ -277,8 +279,21 @@ void dump_bfin_trace_buffer(void)
 
         if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
                 for (; bfin_read_TBUFSTAT() & TBUFCNT; i++) {
-                        decode_address(buf, (unsigned long)bfin_read_TBUF());
+                        addr = (unsigned short *)bfin_read_TBUF();
+                        decode_address(buf, (unsigned long)addr);
                         pr_notice("%4i Target : %s\n", i, buf);
+                        /* Normally, the faulting instruction doesn't go into
+                         * the trace buffer, (since it doesn't commit), so
+                         * we print out the fault address here
+                         */
+                        if (!fault && addr == (unsigned short *)trap &&
+                                (cpu_pda[cpu].seqstat & SEQSTAT_EXCAUSE) > VEC_EXCPT15) {
+                                decode_address(buf, cpu_pda[cpu].icplb_fault_addr);
+                                pr_notice("      FAULT : %s ", buf);
+                                decode_instruction((unsigned short *)cpu_pda[cpu].icplb_fault_addr);
+                                pr_cont("\n");
+                                fault = 1;
+                        }
                         addr = (unsigned short *)bfin_read_TBUF();
                         decode_address(buf, (unsigned long)addr);
                         pr_notice("     Source : %s ", buf);