[Blackfin] arch: change the trace buffer control start/stop logic in the exception handlers

To save/restore the trace buffer control so that if we take an exception
after turning off the trace buffer at a higher level we dont inadvertently
turn the trace buffer back on

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

1 files changed, 20 insertions, 15 deletions

diff --git a/include/asm-blackfin/trace.h b/include/asm-blackfin/trace.h
index 6313aace9d59..ef18afbc2101 100644
--- a/include/asm-blackfin/trace.h
+++ b/include/asm-blackfin/trace.h
@@ -46,42 +46,47 @@ extern unsigned long software_trace_buff[];
 
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
 
-#define TRACE_BUFFER_START(preg, dreg) trace_buffer_start(preg, dreg)
-#define TRACE_BUFFER_STOP(preg, dreg)  trace_buffer_stop(preg, dreg)
-
 #define trace_buffer_stop(preg, dreg)   \
         preg.L = LO(TBUFCTL);           \
         preg.H = HI(TBUFCTL);           \
         dreg = 0x1;                     \
         [preg] = dreg;
 
-#define trace_buffer_start(preg, dreg)  \
-        preg.L = LO(TBUFCTL);           \
-        preg.H = HI(TBUFCTL);           \
-        dreg = BFIN_TRACE_ON;           \
-        [preg] = dreg;
-
 #define trace_buffer_init(preg, dreg) \
         preg.L = LO(TBUFCTL);         \
         preg.H = HI(TBUFCTL);         \
         dreg = BFIN_TRACE_INIT;       \
         [preg] = dreg;
 
+#define trace_buffer_save(preg, dreg) \
+        preg.L = LO(TBUFCTL); \
+        preg.H = HI(TBUFCTL); \
+        dreg = [preg]; \
+        [sp++] = dreg; \
+        dreg = 0x1; \
+        [preg] = dreg;
+
+#define trace_buffer_restore(preg, dreg) \
+        preg.L = LO(TBUFCTL); \
+        preg.H = HI(TBUFCTL); \
+        dreg = [sp--]; \
+        [preg] = dreg;
+
 #else /* CONFIG_DEBUG_BFIN_HWTRACE_ON */
 
 #define trace_buffer_stop(preg, dreg)
-#define trace_buffer_start(preg, dreg)
 #define trace_buffer_init(preg, dreg)
+#define trace_buffer_save(preg, dreg)
+#define trace_buffer_restore(preg, dreg)
 
 #endif /* CONFIG_DEBUG_BFIN_HWTRACE_ON */
 
 #ifdef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE
-# define DEBUG_START_HWTRACE(preg, dreg) trace_buffer_start(preg, dreg)
-# define DEBUG_STOP_HWTRACE(preg, dreg) trace_buffer_stop(preg, dreg)
-
+# define DEBUG_HWTRACE_SAVE(preg, dreg)    trace_buffer_save(preg, dreg)
+# define DEBUG_HWTRACE_RESTORE(preg, dreg) trace_buffer_restore(preg, dreg)
 #else
-# define DEBUG_START_HWTRACE(preg, dreg)
-# define DEBUG_STOP_HWTRACE(preg, dreg)
+# define DEBUG_HWTRACE_SAVE(preg, dreg)
+# define DEBUG_HWTRACE_RESTORE(preg, dreg)
 #endif
 
 #endif /* __ASSEMBLY__ */