Messages in this thread | | | From | Mike Leach <> | Date | Fri, 16 Jul 2021 11:25:47 +0100 | Subject | Re: [PATCH v8 00/10] CoreSight configuration management; ETM strobing |
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HI Mathieu,
Below my change notes for the patches changed between v7 and v8 in this set.
Regards
Mike
0001, 0003, 0004, 0006, 0007, 0008, 0010 - no change
0002 - coresight-syscfg.c top of file - mutex declaration removed. cscfg_add_csdev_cfg() Spinlock replaces mutex cscfg_load_feat_csdev() Spinlock replaces mutex cscsg_list_add_csdev() Init spinlock coresight.h struct coresight_device {} Add spinlock cscfg_csdev_lock alongside the csdev feature and config lists that it protects.
0005 - coresight-syscfg.c cscfg_csdev_reset_feats() Spinlock replaces mutex.
cscfg_csdev_enable_active_config() Spinlock replaces mutex. In enable flag to avoid race with disable. cscfg_csdev_disable_active_config() Spinlock replaces mutex. In enable flag to avoid race with enable.
coresight.h struct coresight_device {} In enable flag introduced to control possible race between enable and disable. E.g. if we are enabling a config, but a power event tries to shut down the CPU/ETM causing a disable call. We don’t want to hold the cscfg_csdev_lock spinlock throughout the entire enable process - especially as the programming call will claim the internal driver spinlock when writing internal driver data, but we need to ensure that if there is a condition that permits a disable call out of normal sequence then we are able to see it and handle it.
0009 - KConfig add in dependency on CONFIGFS_FS to eliminate problem highlighted by the kernel bot tests. This had configured coresight as Y, but configfs as M - meaning link issues for configfs code introduced in this set.
On Tue, 13 Jul 2021 at 10:43, Branislav Rankov <branislav.rankov@arm.com> wrote: > > Hi Mathieu, > > On 7/12/21 5:44 PM, Mathieu Poirier wrote: > > Good morning Mike, > > > > On Wed, Jul 07, 2021 at 02:29:53PM +0100, Mike Leach wrote: > >> This patchset introduces initial concepts in CoreSight system > >> configuration management support. to allow more detailed and complex > >> programming to be applied to CoreSight systems during trace capture. > >> > >> Configurations consist of 2 elements:- > >> 1) Features - programming combinations for devices, applied to a class of > >> device on the system (all ETMv4), or individual devices. > >> 2) Configurations - a set of programmed features used when the named > >> configuration is selected. > >> > >> Features and configurations are declared as a data table, a set of register, > >> resource and parameter requirements. Features and configurations are loaded > >> into the system by the virtual cs_syscfg device. This then matches features > >> to any registered devices and loads the feature into them. > >> > >> Individual device classes that support feature and configuration register > >> with cs_syscfg. > >> > >> Once loaded a configuration can be enabled for a specific trace run. > >> Configurations are registered with the perf cs_etm event as entries in > >> cs_etm/events. These can be selected on the perf command line as follows:- > >> > >> perf record -e cs_etm/<config_name>/ ... > >> > >> This patch set has one pre-loaded configuration and feature. > >> A named "strobing" feature is provided for ETMv4. > >> A named "autofdo" configuration is provided. This configuration enables > >> strobing on any ETM in used. > >> > >> Thus the command: > >> perf record -e cs_etm/autofdo/ ... > >> > >> will trace the supplied application while enabling the "autofdo" configuation > >> on each ETM as it is enabled by perf. This in turn will enable strobing for > >> the ETM - with default parameters. Parameters can be adjusted using configfs. > >> > >> The sink used in the trace run will be automatically selected. > >> > >> A configuration can supply up to 15 of preset parameter values, which will > >> subsitute in parameter values for any feature used in the configuration. > >> > >> Selection of preset values as follows > >> perf record -e cs_etm/autofdo,preset=1/ ... > >> > >> (valid presets 1-N, where N is the number supplied in the configuration, not > >> exceeding 15. preset=0 is the same as not selecting a preset.) > >> > >> Applies to & tested against coresight/next (5.13-rc6 base) > >> > >> Changes since v7: > >> > >> Fixed kernel test robot issue - config with CORESIGHT=y & CONFIGFS_FS=m causes > >> build error. Altered CORESIGHT config to select CONFIGFS_FS. > >> Reported-by: kernel test robot <lkp@intel.com> > >> > >> Replaced mutex use to protect loaded config lists in coresight devices with per > >> device spinlock to remove issue when disable called in interrupt context. > >> Reported-by: Branislav Rankov <branislav.rankov@arm.com> > >> > > > > Can you indicate which patches have changed so I don't have to review the whole > > thing again? It is also common practice to remove the RB tag when patches > > have changed enough to mandate another review. In this case all patches still > > bare my RB tags. > > > > Branislav reported the problem but he is not a recipient. I would like to have > > a confirmation from him that this set fixes the problem he observed before I > > start looking at it. > > I have tested this series and the issue I reported is fixed. > > > > Thanks, > > Mathieu > > > >> > >> Changes since v6: > >> Fixed kernel test robot issues- > >> Reported-by: kernel test robot <lkp@intel.com> > >> > >> Changes since v5: > >> > >> 1) Fix code style issues from auto-build reports, as > >> Reported-by: kernel test robot <lkp@intel.com> > >> 2) Update comments to get consistent docs for API functions. > >> 3) remove unused #define from autofdo example. > >> 4) fix perf code style issues from patch 4 (Mathieu) > >> 5) fix configfs code style issues from patch 9. (Mathieu) > >> > >> Changes since v4: (based on comments from Matthieu and Suzuki). > >> No large functional changes - primarily code improvements and naming schema. > >> 1) Updated entire set to ensure a consistent naming scheme was used for > >> variables and struct members that refer to the key objects in the system. > >> Suffixes _desc used for all references to feature and configuraion descriptors, > >> suffix _csdev used for all references to load feature and configs in the csdev > >> instances. (Mathieu & Suzuki). > >> 2) Dropped the 'configurations' sub dir in cs_etm perf directories as superfluous > >> with the configfs containing the same information. (Mathieu). > >> 3) Simplified perf handling code (suzuki) > >> 4) Multiple simplifications and improvements for code readability (Matthieu > >> and Suzuki) > >> > >> Changes since v3: (Primarily based on comments from Matthieu) > >> 1) Locking mechanisms simplified. > >> 2) Removed the possibility to enable features independently from > >> configurations.Only configurations can be enabled now. Simplifies programming > >> logic. > >> 3) Configuration now uses an activate->enable mechanism. This means that perf > >> will activate a selected configuration at the start of a session (during > >> setup_aux), and disable at the end of a session (around free_aux) > >> The active configuration and associated features will be programmed into the > >> CoreSight device instances when they are enabled. This locks the configuration > >> into the system while in use. Parameters cannot be altered while this is > >> in place. This mechanism will be extended in future for dynamic load / unload > >> of configurations to prevent removal while in use. > >> 4) Removed the custom bus / driver as un-necessary. A single device is > >> registered to own perf fs elements and configfs. > >> 5) Various other minor issues addressed. > >> > >> Changes since v2: > >> 1) Added documentation file. > >> 2) Altered cs_syscfg driver to no longer be coresight_device based, and moved > >> to its own custom bus to remove it from the main coresight bus. (Mathieu) > >> 3) Added configfs support to inspect and control loaded configurations and > >> features. Allows listing of preset values (Yabin Cui) > >> 4) Dropped sysfs support for adjusting feature parameters on the per device > >> basis, in favour of a single point adjustment in configfs that is pushed to all > >> device instances. > >> 5) Altered how the config and preset command line options are handled in perf > >> and the drivers. (Mathieu and Suzuki). > >> 6) Fixes for various issues and technical points (Mathieu, Yabin) > >> > >> Changes since v1: > >> 1) Moved preloaded configurations and features out of individual drivers. > >> 2) Added cs_syscfg driver to manage configurations and features. Individual > >> drivers register with cs_syscfg indicating support for config, and provide > >> matching information that the system uses to load features into the drivers. > >> This allows individual drivers to be updated on an as needed basis - and > >> removes the need to consider devices that cannot benefit from configuration - > >> static replicators, funnels, tpiu. > >> 3) Added perf selection of configuarations. > >> 4) Rebased onto the coresight module loading set. > >> > >> To follow in future revisions / sets:- > >> a) load of additional config and features by loadable module. > >> b) load of additional config and features by configfs > >> c) enhanced resource management for ETMv4 and checking features have sufficient > >> resources to be enabled. > >> d) ECT and CTI support for configuration and features. > >> > >> Mike Leach (10): > >> coresight: syscfg: Initial coresight system configuration > >> coresight: syscfg: Add registration and feature loading for cs devices > >> coresight: config: Add configuration and feature generic functions > >> coresight: etm-perf: update to handle configuration selection > >> coresight: syscfg: Add API to activate and enable configurations > >> coresight: etm-perf: Update to activate selected configuration > >> coresight: etm4x: Add complex configuration handlers to etmv4 > >> coresight: config: Add preloaded configurations > >> coresight: syscfg: Add initial configfs support > >> Documentation: coresight: Add documentation for CoreSight config > >> > >> .../trace/coresight/coresight-config.rst | 244 ++++++ > >> Documentation/trace/coresight/coresight.rst | 16 + > >> drivers/hwtracing/coresight/Kconfig | 1 + > >> drivers/hwtracing/coresight/Makefile | 7 +- > >> .../hwtracing/coresight/coresight-cfg-afdo.c | 153 ++++ > >> .../coresight/coresight-cfg-preload.c | 31 + > >> .../coresight/coresight-cfg-preload.h | 13 + > >> .../hwtracing/coresight/coresight-config.c | 275 ++++++ > >> .../hwtracing/coresight/coresight-config.h | 253 ++++++ > >> drivers/hwtracing/coresight/coresight-core.c | 12 +- > >> .../hwtracing/coresight/coresight-etm-perf.c | 150 +++- > >> .../hwtracing/coresight/coresight-etm-perf.h | 12 +- > >> .../hwtracing/coresight/coresight-etm4x-cfg.c | 182 ++++ > >> .../hwtracing/coresight/coresight-etm4x-cfg.h | 30 + > >> .../coresight/coresight-etm4x-core.c | 38 +- > >> .../coresight/coresight-etm4x-sysfs.c | 3 + > >> .../coresight/coresight-syscfg-configfs.c | 396 +++++++++ > >> .../coresight/coresight-syscfg-configfs.h | 45 + > >> .../hwtracing/coresight/coresight-syscfg.c | 829 ++++++++++++++++++ > >> .../hwtracing/coresight/coresight-syscfg.h | 81 ++ > >> include/linux/coresight.h | 11 + > >> 21 files changed, 2746 insertions(+), 36 deletions(-) > >> create mode 100644 Documentation/trace/coresight/coresight-config.rst > >> create mode 100644 drivers/hwtracing/coresight/coresight-cfg-afdo.c > >> create mode 100644 drivers/hwtracing/coresight/coresight-cfg-preload.c > >> create mode 100644 drivers/hwtracing/coresight/coresight-cfg-preload.h > >> create mode 100644 drivers/hwtracing/coresight/coresight-config.c > >> create mode 100644 drivers/hwtracing/coresight/coresight-config.h > >> create mode 100644 drivers/hwtracing/coresight/coresight-etm4x-cfg.c > >> create mode 100644 drivers/hwtracing/coresight/coresight-etm4x-cfg.h > >> create mode 100644 drivers/hwtracing/coresight/coresight-syscfg-configfs.c > >> create mode 100644 drivers/hwtracing/coresight/coresight-syscfg-configfs.h > >> create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.c > >> create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.h > >> > >> -- > >> 2.17.1 > >> > > _______________________________________________ > > CoreSight mailing list > > CoreSight@lists.linaro.org > > https://lists.linaro.org/mailman/listinfo/coresight > >
-- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
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