On 25 May 2017 at 09:57, Leo Yan <leo.yan@xxxxxxxxxx> wrote: > ARMv8 architecture reference manual (ARM DDI 0487A.k) Chapter H7 "The > Sample-based Profiling Extension" has description for sampling > registers, we can utilize these registers to check program counter > value with combined CPU exception level, secure state, etc. So this is > helpful for CPU lockup bugs, e.g. if one CPU has run into infinite loop > with IRQ disabled; the 'hang' CPU cannot switch context and handle any > interrupt, so it cannot handle SMP call for stack dump, etc. > > This patch series is to enable coresight debug module with sample-based > registers and register call back notifier for PCSR register dumping > when panic happens, so we can see below dumping info for panic; and > this patch series has considered the conditions for access permission > for debug registers self, so this can avoid access debug registers when > CPU power domain is off; the driver also try to figure out the CPU is > in secure or non-secure state. I have queued patches 1 to 7 to my tree. I can't do anything about patches 8 and 9 because they haven't been ack'ed. From here you can either chase them to get an ACK or send a separate patch to them directly. Thanks, Mathieu > > Patch 0001 is to document the dt binding; patch 0002 adds one detailed > document to describe the Coresight debug module implementation, the > clock and power domain impaction on the driver, some examples for usage. > > Patch 0003 is to document boot parameters used in kernel command line. > > Patch 0004 is to add file entries for MAINTAINERS. > > Patch 0005 is used to fix the func of_get_coresight_platform_data() > doesn't properly drop the reference to the CPU node pointer; and > patch 0006 is refactor to add new function of_coresight_get_cpu(). > > Patch 0007 is the driver for CPU debug module. > > Patch 0008 in this series are to enable debug unit on 96boards Hikey, > Patch 0009 is to enable debug on 96boards DB410c. Have verified on both > two boards. > > We can enable debugging with two methods, adding parameters into kernel > command line for build-in module: > coresight_cpu_debug.enable=1 > > Or we can wait the system has booted up to use debugfs nodes to enable > debugging: > # echo 1 > /sys/kernel/debug/coresight_cpu_debug/enable > > As result we can get below log after input command: > echo c > /proc/sysrq-trigger: > > ARM external debug module: > coresight-cpu-debug 850000.debug: CPU[0]: > coresight-cpu-debug 850000.debug: EDPRSR: 00000001 (Power:On DLK:Unlock) > coresight-cpu-debug 850000.debug: EDPCSR: [<ffff00000808e9bc>] handle_IPI+0x174/0x1d8 > coresight-cpu-debug 850000.debug: EDCIDSR: 00000000 > coresight-cpu-debug 850000.debug: EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0) > coresight-cpu-debug 852000.debug: CPU[1]: > coresight-cpu-debug 852000.debug: EDPRSR: 00000001 (Power:On DLK:Unlock) > coresight-cpu-debug 852000.debug: EDPCSR: [<ffff0000087fab34>] debug_notifier_call+0x23c/0x358 > coresight-cpu-debug 852000.debug: EDCIDSR: 00000000 > coresight-cpu-debug 852000.debug: EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0) > > [...] > > Changes from v12: > * Fix build warning for 'ARCH=arm' reported by kbuild test robot. > > Changes from v11: > * Dismissed checkpatch.pl warning about "quoted string split across > multiple lines" and "line over 80 characters". > > Changes from v10: > * Followed Liviu suggestion to improve readability of the documentation. > * ARM Juno DTS binding patch has been picked by Sudeep, so this patch > set has not included anymore. Great! > > Changes from v9: > * Used dev_xyz() to replace pr_xyz() for print log. > * Added DT binding patch for Juno shared by Suzuki. > > Changes from v8: > * According to Mathieu suggestions to split the doc into two patches, > one is for kernel parameter and another is for driver documentation. > * Add file entries to MAINTAINERS. > * According to Mathieu suggestions, refined functions > debug_enable_func()/debug_disable_func(). > > Changes from v7: > * Fix operator priority bug. > * Minor sequence adjustment for function debug_func_exit(). > > Changes from v6: > * According to Suzuki and Mathieu suggestions, refined debug module > driver to install panic notifier when insmod module; refined function > debug_force_cpu_powered_up() for CPU power state checking; some minor > fixing for output log, adding comments for memory barrier, code > alignment. > > Changes from v5: > * According to Suzuki and Mathieu suggestions, refined debug module > driver to drop unused structure members, refactored initialization > code to distinguish hardware implementation features, refactored > flow for forcing CPU powered up, supported pm_runtime operations. > * Added one new doc file: Documentation/trace/coresight-cpu-debug.txt, > which is used to describe detailed info for implementation, clock > and power domain impaction on debug module, and exmaples for common > usage. > * Removed "idle constraints" from debug driver. > > Changes from v4: > * This version is mainly credit to ARM colleagues many contribution > ideas for better quality (Thanks a lot Suzuki, Mike and Sudeep!). > * According to Suzuki suggestion, refined debug module driver to avoid > memory leak for drvdata struct, handle PCSAMPLE_MODE=1, use flag > drvdata.pc_has_offset to indicate if PCSR has offset, minor fixes. > * According to Mathieu suggestion, refined dt binding description. > * Changed driver to support module mode; > * According to Mike suggestion and very appreciate the pseudo code, > added support to force CPU powered up with register EDPRCR; > * According to discussions, added command line and debugfs nodes to > support enabling debugging for boot time, or later can dynamically > enable/disable debugging by debugfs. > * According to Rob Herring suggestion, one minor fixes in DT binding. > * According to Stephen Boyd suggestion, add const quality to structure > device_node. And used use of_cpu_device_node_get() to replace > of_get_cpu_node() in patch 0003. > > Changes from v3: > * Added Suzuki K Poulose's patch to fix issue for the func > of_get_coresight_platform_data() doesn't properly drop the reference > to the CPU node pointer. > * According to Suzuki suggestion, added code to handl the corner case > for ARMv8 CPU with aarch32 mode. > * According to Suzuki suggestion, changed compatible string to > "arm,coresight-cpu-debug". > * According to Mathieu suggestion, added "power-domains" as optional > properties. > > Changes from v2: > * According to Mathieu Poirier suggestion, applied some minor fixes. > * Added two extra patches for enabling debug module on Hikey. > > Changes from v1: > * According to Mike Leach suggestion, removed the binding for debug > module clocks which have been directly provided by CPU clocks. > * According to Mathieu Poirier suggestion, added function > of_coresight_get_cpu() and some minor refactors for debug module > driver. > > Changes from RFC: > * According to Mike Leach suggestion, added check for EDPRSR to avoid > lockup; added supporting EDVIDSR and EDCIDSR registers. > * According to Mark Rutland and Mathieu Poirier suggestion, rewrote > the documentation for DT binding. > * According to Mark and Mathieu suggestion, refined debug driver. > > Leo Yan (8): > coresight: bindings for CPU debug module > doc: Add documentation for Coresight CPU debug > doc: Add coresight_cpu_debug.enable to kernel-parameters.txt > MAINTAINERS: update file entries for Coresight subsystem > coresight: refactor with function of_coresight_get_cpu > coresight: add support for CPU debug module > arm64: dts: hi6220: register debug module > arm64: dts: qcom: msm8916: Add debug unit > > Suzuki K Poulose (1): > coresight: of_get_coresight_platform_data: Add missing of_node_put > > Documentation/admin-guide/kernel-parameters.txt | 7 + > .../bindings/arm/coresight-cpu-debug.txt | 49 ++ > Documentation/trace/coresight-cpu-debug.txt | 175 ++++++ > MAINTAINERS | 2 + > arch/arm64/boot/dts/hisilicon/hi6220.dtsi | 64 ++ > arch/arm64/boot/dts/qcom/msm8916.dtsi | 32 + > drivers/hwtracing/coresight/Kconfig | 14 + > drivers/hwtracing/coresight/Makefile | 1 + > drivers/hwtracing/coresight/coresight-cpu-debug.c | 700 +++++++++++++++++++++ > drivers/hwtracing/coresight/of_coresight.c | 40 +- > include/linux/coresight.h | 3 + > 11 files changed, 1075 insertions(+), 12 deletions(-) > create mode 100644 Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt > create mode 100644 Documentation/trace/coresight-cpu-debug.txt > create mode 100644 drivers/hwtracing/coresight/coresight-cpu-debug.c > > -- > 2.7.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
