Hi,
On Wed, 5 Aug 2020 at 12:05, Suzuki K Poulose suzuki.poulose@arm.com wrote:
On 08/05/2020 03:54 AM, Tingwei Zhang wrote:
From: Kim Phillips kim.phillips@arm.com
Allow to build coresight-etm3x as a module, for ease of development.
- Kconfig becomes a tristate, to allow =m
- append -core to source file name to allow module to be called coresight-etm3x by the Makefile
- add an etm_remove function, for module unload
- add a MODULE_DEVICE_TABLE for autoloading on boot
Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Leo Yan leo.yan@linaro.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Randy Dunlap rdunlap@infradead.org Cc: Suzuki K Poulose Suzuki.Poulose@arm.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Russell King linux@armlinux.org.uk Signed-off-by: Kim Phillips kim.phillips@arm.com Signed-off-by: Tingwei Zhang tingwei@codeaurora.org Reviewed-by: Mike Leach mike.leach@linaro.org
drivers/hwtracing/coresight/Kconfig | 5 +++- drivers/hwtracing/coresight/Makefile | 3 ++- ...resight-etm3x.c => coresight-etm3x-core.c} | 27 ++++++++++++++++++- 3 files changed, 32 insertions(+), 3 deletions(-) rename drivers/hwtracing/coresight/{coresight-etm3x.c => coresight-etm3x-core.c} (97%)
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig index 6433f835fc97..8fd9fd139cf3 100644 --- a/drivers/hwtracing/coresight/Kconfig +++ b/drivers/hwtracing/coresight/Kconfig @@ -65,7 +65,7 @@ config CORESIGHT_SINK_ETBV10 special enhancement or added features.
config CORESIGHT_SOURCE_ETM3X
bool "CoreSight Embedded Trace Macrocell 3.x driver"
tristate "CoreSight Embedded Trace Macrocell 3.x driver" depends on !ARM64 select CORESIGHT_LINKS_AND_SINKS help@@ -74,6 +74,9 @@ config CORESIGHT_SOURCE_ETM3X This is primarily useful for instruction level tracing. Depending the ETM version data tracing may also be available.
To compile this driver as a module, choose M here: themodule will be called coresight-etm3x.- config CORESIGHT_SOURCE_ETM4X bool "CoreSight Embedded Trace Macrocell 4.x driver" depends on ARM64
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index 19497d1d92bf..d619cfd0abd8 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -11,7 +11,8 @@ obj-$(CONFIG_CORESIGHT_SINK_TPIU) += coresight-tpiu.o obj-$(CONFIG_CORESIGHT_SINK_ETBV10) += coresight-etb10.o obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \ coresight-replicator.o -obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o coresight-etm-cp14.o \ +obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o +coresight-etm3x-y := coresight-etm3x-core.o coresight-etm-cp14.o \ coresight-etm3x-sysfs.o obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \ coresight-etm4x-sysfs.o diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c similarity index 97% rename from drivers/hwtracing/coresight/coresight-etm3x.c rename to drivers/hwtracing/coresight/coresight-etm3x-core.c index bf22dcfd3327..82b333c40006 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -895,6 +895,23 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) return ret; }
+static int __exit etm_remove(struct amba_device *adev) +{
struct etm_drvdata *drvdata = dev_get_drvdata(&adev->dev);etm_perf_symlink(drvdata->csdev, false);if (--etm_count == 0) {Could there be multiple instances of remove running in parallel ? I believe we need some sort of a protection here to avoid racing.
Or even better, I would recommend leaving the notifiers registered at module_init and removed at the cleanup of the module, just like we are doing for etm4x driver, and get rid of this silly scheme.
I would agree that this needs addressing but this is an independent problem that could be better served by a separate patchset, rather than add feature creep to this set. The same schema is used in the CTI driver as well and needs fixing there.
Like here :
https://lkml.kernel.org/r/20200729051310.18436-1-saiprakash.ranjan@codeauror...
This conflicts with the init / exit fns created for module loading in the etm4x part of this set..
A decision needs to be made on which set gets applied first - my view is that the module set could go first, then a set fixing the PM registration issues for all three affected drivers to be applied next.
The change to making all the drivers module loadable provides the init functions needed to initalise the PM outside the probe functions, just like the patch mentioned above and makes a change to all three drivers easy to create.
Regards
Mike
Cheers Suzuki