Blackfin arch: Add ability to expend the hardware trace buffer

[powerpc.git] / arch / blackfin / Kconfig

diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 9ce675e..a7a6e0c 100644 (file)
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -1024,8 +1024,89 @@ config DEBUG_HUNT_FOR_ZERO
          Enabling this option will take up an extra entry in CPLB table.
          Otherwise, there is no extra overhead.
 
+config DEBUG_BFIN_HWTRACE_ON
+       bool "Turn on Blackfin's Hardware Trace"
+       default y
+       help
+         All Blackfins include a Trace Unit which stores a history of the last
+         16 changes in program flow taken by the program sequencer. The history
+         allows the user to recreate the program sequencer’s recent path. This
+         can be handy when an application dies - we print out the execution
+         path of how it got to the offending instruction.
+
+         By turning this off, you may save a tiny amount of power.
+
+choice
+       prompt "Omit loop Tracing"
+       default DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
+       depends on DEBUG_BFIN_HWTRACE_ON
+       help
+         The trace buffer can be configured to omit recording of changes in
+         program flow that match either the last entry or one of the last
+         two entries. Omitting one of these entries from the record prevents
+         the trace buffer from overflowing because of any sort of loop (for, do
+         while, etc) in the program.
+
+         Because zero-overhead Hardware loops are not recorded in the trace buffer,
+         this feature can be used to prevent trace overflow from loops that
+         are nested four deep.
+
+config DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
+       bool "Trace all Loops"
+       help
+         The trace buffer records all changes of flow 
+
+config DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
+       bool "Compress single-level loops"
+       help
+         The trace buffer does not record single loops - helpful if trace 
+         is spinning on a while or do loop.
+
+config DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
+       bool "Compress two-level loops"
+       help
+         The trace buffer does not record loops two levels deep. Helpful if
+         the trace is spinning in a nested loop
+
+endchoice
+
+config DEBUG_BFIN_HWTRACE_COMPRESSION
+       int
+       depends on DEBUG_BFIN_HWTRACE_ON
+       default 0 if DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
+       default 1 if DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
+       default 2 if DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
+
+
+config DEBUG_BFIN_HWTRACE_EXPAND
+       bool "Expand Trace Buffer greater than 16 entries"
+       depends on DEBUG_BFIN_HWTRACE_ON
+       default n
+       help
+         By selecting this option, every time the 16 hardware entries in
+         the Blackfin's HW Trace buffer are full, the kernel will move them
+         into a software buffer, for dumping when there is an issue. This 
+         has a great impact on performance, (an interrupt every 16 change of 
+         flows) and should normally be turned off, except in those nasty
+         debugging sessions
+
+config DEBUG_BFIN_HWTRACE_EXPAND_LEN
+       int "Size of Trace buffer (in power of 2k)"
+       range 0 4
+       depends on DEBUG_BFIN_HWTRACE_EXPAND
+       default 1
+       help
+         This sets the size of the software buffer that the trace information
+         is kept in.
+         0 for (2^0)  1k, or 256 entries,
+         1 for (2^1)  2k, or 512 entries,
+         2 for (2^2)  4k, or 1024 entries,
+         3 for (2^3)  8k, or 2048 entries,
+         4 for (2^4) 16k, or 4096 entries
+
 config DEBUG_BFIN_NO_KERN_HWTRACE
        bool "Trace user apps (turn off hwtrace in kernel)"
+       depends on DEBUG_BFIN_HWTRACE_ON
        default n
        help
          Some pieces of the kernel contain a lot of flow changes which can