From 518039bc24cbb9ce34665814fe120eac50bedd9a Mon Sep 17 00:00:00 2001 From: Robin Getz Date: Wed, 25 Jul 2007 11:03:28 +0800 Subject: Blackfin arch: Add ability to expend the hardware trace buffer Add ability to expend the hardware trace buffer via a configurable software buffer - so you can have lots of history when a crash occurs. The interesting way we do printk in the traps.c confusese the checking script Signed-off-by: Robin Getz Signed-off-by: Bryan Wu --- arch/blackfin/Kconfig | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) (limited to 'arch/blackfin/Kconfig') diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig index 9ce675e80260..a7a6e0c5827d 100644 --- 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 -- cgit v1.2.3-59-g8ed1b