On Thu, Aug 13, 2020 at 04:47:41AM +0800, Mathieu Poirier wrote:

On Fri, Aug 07, 2020 at 07:11:38PM +0800, Tingwei Zhang wrote:

quoted

From: Kim Phillips <redacted>

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 <redacted>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Randy Dunlap <redacted>
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 <redacted>
Signed-off-by: Tingwei Zhang <redacted>
Reviewed-by: Mike Leach <redacted>
---
 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%)

quoted

diff --git a/drivers/hwtracing/coresight/Kconfig

b/drivers/hwtracing/coresight/Kconfig

quoted

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

quoted

 	  the ETM version data tracing may also be available.
 
+	  To compile this driver as a module, choose M here: the
+	  module 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

quoted

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 \

quoted

+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

quoted

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)

quoted

 	return ret;
 }
 
+static int __exit etm_remove(struct amba_device *adev)
+{

Not sure adding __exit does anything special here since all the code is
removed by the kernel anyway.  The same comment goes for the other drivers
in
this set.

We still need to remove any reference in other part of Kernel to etm device.
For example, we remove ETM module but keep coresight module. ETM-perf and
coresight-core still could access ETM device structure if etm_perf_symlink()
and coresigh_unregister() are not called in etm_remove. We need clean any
reference to ETM device structure up.

Thanks,
Tingwei

quoted

+	struct etm_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+	etm_perf_symlink(drvdata->csdev, false);
+
+	if (--etm_count == 0) {
+

cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);

quoted

+		if (hp_online)
+			cpuhp_remove_state_nocalls(hp_online);
+	}
+
+	coresight_unregister(drvdata->csdev);
+
+	return 0;
+}
+
 #ifdef CONFIG_PM
 static int etm_runtime_suspend(struct device *dev)
 {

@@ -937,6 +954,8 @@ static const struct amba_id etm_ids[] = {
 	{ 0, 0},
 };
 
+MODULE_DEVICE_TABLE(amba, etm_ids);
+
 static struct amba_driver etm_driver = {
 	.drv = {
 		.name	= "coresight-etm3x",

@@ -945,6 +964,12 @@ static struct amba_driver etm_driver = {
 		.suppress_bind_attrs = true,
 	},
 	.probe		= etm_probe,
+	.remove         = etm_remove,
 	.id_table	= etm_ids,
 };
-builtin_amba_driver(etm_driver);
+module_amba_driver(etm_driver);
+
+MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
+MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace driver");

That should be "Arm CoreSight Embedded Trace Macrocell 3.x driver"

With the above: 

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

quoted

+MODULE_LICENSE("GPL v2");
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora

Forum,

quoted

a Linux Foundation Collaborative Project

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