Re: [PATCH v11 09/24] coresight: etm3x: allow etm3x to be built as a module

On Tue, Sep 15, 2020 at 12:09:18PM -0600, Mathieu Poirier wrote:

On Tue, Sep 15, 2020 at 06:41:01PM +0800, 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
• delay advertising the per-cpu etmdrvdata
• protect etmdrvdata[] by modifying it on relevant CPU

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 | 5 +- ...resight-etm3x.c => coresight-etm3x-core.c} | 148 ++++++++++++++---- 3 files changed, 122 insertions(+), 36 deletions(-) rename drivers/hwtracing/coresight/{coresight-etm3x.c => coresight-etm3x-core.c} (90%)

I got tired of waiting for a V12 and Mike has based his work on complex configuration on your patchset. So I did the corrections and applied this set to my tree. With a little luck Greg won't mind the late submission and things will work out fine.

You owe me a beer. If Greg accepts my pull request, you owe him one too.

Mathieu

...

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: 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 index 19497d1d92bf..86b4648844b4 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -11,8 +11,9 @@ 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 \

• 			coresight-etm3x-sysfs.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-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \ coresight-etm4x-sysfs.o obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c similarity index 90% rename from drivers/hwtracing/coresight/coresight-etm3x.c rename to drivers/hwtracing/coresight/coresight-etm3x-core.c index bf22dcfd3327..56eba0b5c71f 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -782,6 +782,42 @@ static void etm_init_trace_id(struct etm_drvdata *drvdata) drvdata->traceid = coresight_get_trace_id(drvdata->cpu); } +static int __init etm_hp_setup(void) +{

• int ret;
• ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING,

• 			     "arm/coresight:starting",
  

• 			     etm_starting_cpu, etm_dying_cpu);
  

Indentation problem.

...

• if (ret)

• return ret;
  

• ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,

• 				   "arm/coresight:online",
  

• 				   etm_online_cpu, NULL);
  

• /* HP dyn state ID returned in ret on success */
• if (ret > 0) {

• hp_online = ret;
  

• return 0;
  

• }
• /* failed dyn state - remove others */
• cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
• return ret;

+}

+static void etm_hp_clear(void) +{

• cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
• if (hp_online) {

• cpuhp_remove_state_nocalls(hp_online);
  

• hp_online = 0;
  

• }

+}

static int etm_probe(struct amba_device *adev, const struct amba_id *id) { int ret; @@ -824,38 +860,23 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) return -ENOMEM; cpus_read_lock();

Locking is no longer needed.

...

• etmdrvdata[drvdata->cpu] = drvdata;

if (smp_call_function_single(drvdata->cpu, etm_init_arch_data, drvdata, 1)) dev_err(dev, "ETM arch init failed\n");

• if (!etm_count++) {

• cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING,
  

• 				     "arm/coresight:starting",
  

• 				     etm_starting_cpu, etm_dying_cpu);
  

• ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
  

• 					   "arm/coresight:online",
  

• 					   etm_online_cpu, NULL);
  

• if (ret < 0)
  

• 	goto err_arch_supported;
  

• hp_online = ret;
  

• } cpus_read_unlock();

• if (etm_arch_supported(drvdata->arch) == false) {

• ret = -EINVAL;
  

• goto err_arch_supported;
  

• }

• if (etm_arch_supported(drvdata->arch) == false)

• return -EINVAL;
  

etm_init_trace_id(drvdata); etm_set_default(&drvdata->config); pdata = coresight_get_platform_data(dev);

• if (IS_ERR(pdata)) {

• ret = PTR_ERR(pdata);
  

• goto err_arch_supported;
  

• }

• if (IS_ERR(pdata))

• return PTR_ERR(pdata);
  

• adev->dev.platform_data = pdata;

desc.type = CORESIGHT_DEV_TYPE_SOURCE; @@ -865,17 +886,17 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) desc.dev = dev; desc.groups = coresight_etm_groups; drvdata->csdev = coresight_register(&desc);

• if (IS_ERR(drvdata->csdev)) {

• ret = PTR_ERR(drvdata->csdev);
  

• goto err_arch_supported;
  

• }

• if (IS_ERR(drvdata->csdev))

• return PTR_ERR(drvdata->csdev);
  

ret = etm_perf_symlink(drvdata->csdev, true); if (ret) { coresight_unregister(drvdata->csdev);

• goto err_arch_supported;
  

• return ret;
  

  }

• etmdrvdata[drvdata->cpu] = drvdata;
• pm_runtime_put(&adev->dev); dev_info(&drvdata->csdev->dev, "%s initialized\n", (char *)coresight_get_uci_data(id));

@@ -885,14 +906,40 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) } return 0; +} -err_arch_supported:

• if (--etm_count == 0) {

• cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
  

• if (hp_online)
  

• 	cpuhp_remove_state_nocalls(hp_online);
  

• }
• return ret;

+static void __exit clear_etmdrvdata(void *info) +{

• int cpu = *(int *)info;
• etmdrvdata[cpu] = NULL;

+}

+static int __exit etm_remove(struct amba_device *adev) +{

• struct etm_drvdata *drvdata = dev_get_drvdata(&adev->dev);
• etm_perf_symlink(drvdata->csdev, false);
• /*

• * Taking hotplug lock here to avoid racing between etm_remove and
  

• * CPU hotplug call backs.
  

• */
  

• cpus_read_lock();
• /*

• * The readers for etmdrvdata[] are CPU hotplug call backs
  

• * and PM notification call backs. Change etmdrvdata[i] on
  

• * CPU i ensures these call backs has consistent view
  

• * inside one call back function.
  

• */
  

• if (smp_call_function_single(drvdata->cpu, clear_etmdrvdata, &drvdata->cpu, 1))

• etmdrvdata[drvdata->cpu] = NULL;
  

• cpus_read_unlock();
• coresight_unregister(drvdata->csdev);
• return 0;

} #ifdef CONFIG_PM @@ -937,6 +984,8 @@ 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 +994,39 @@ 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);

+static int __init etm_init(void) +{

• int ret;
• ret = etm_hp_setup();
• /* etm_pm_setup() does its own cleanup - exit on error */

Copy/paste error --> s/etm_pm_setup/etm_hp_setup

...

• if (ret)

• return ret;
  

• ret = amba_driver_register(&etm_driver);
• if (ret) {

• pr_err("Error registering etm3x driver\n");
  

• etm_hp_clear();
  

• }
• return ret;

+}

+static void __exit etm_exit(void) +{

• amba_driver_unregister(&etm_driver);
• etm_hp_clear();

+}

+module_init(etm_init); +module_exit(etm_exit);

+MODULE_AUTHOR("Pratik Patel pratikp@codeaurora.org"); +MODULE_AUTHOR("Mathieu Poirier mathieu.poirier@linaro.org"); +MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace driver");

+MODULE_LICENSE("GPL v2");

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