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From: Tingwei Zhang <tingwei@codeaurora.org>
To: Mathieu Poirier <mathieu.poirier@linaro.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Mike Leach <mike.leach@linaro.org>
Cc: tsoni@codeaurora.org,
	Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
	Kim Phillips <kim.phillips@arm.com>,
	Mao Jinlong <jinlmao@codeaurora.org>,
	Suzuki K Poulose <Suzuki.Poulose@arm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	coresight@lists.linaro.org, Randy Dunlap <rdunlap@infradead.org>,
	Mian Yousaf Kaukab <ykaukab@suse.de>,
	Russell King <linux@armlinux.org.uk>,
	linux-kernel@vger.kernel.org,
	Tingwei Zhang <tingwei@codeaurora.org>,
	Leo Yan <leo.yan@linaro.org>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v11 09/24] coresight: etm3x: allow etm3x to be built as a module
Date: Tue, 15 Sep 2020 18:41:01 +0800	[thread overview]
Message-ID: <20200915104116.16789-10-tingwei@codeaurora.org> (raw)
In-Reply-To: <20200915104116.16789-1-tingwei@codeaurora.org>

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%)

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);
+
+	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();
-	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 */
+	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");
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


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  parent reply	other threads:[~2020-09-15 10:47 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-15 10:40 [PATCH v11 00/24] coresight: allow to build coresight as modules Tingwei Zhang
2020-09-15 10:40 ` [PATCH v11 01/24] coresight: cpu_debug: add module name in Kconfig Tingwei Zhang
2020-09-15 10:40 ` [PATCH v11 02/24] coresight: cpu_debug: define MODULE_DEVICE_TABLE Tingwei Zhang
2020-09-15 10:40 ` [PATCH v11 03/24] coresight: use IS_ENABLED for CONFIGs that may be modules Tingwei Zhang
2020-09-15 10:40 ` [PATCH v11 04/24] coresight: add coresight prefix to barrier_pkt Tingwei Zhang
2020-09-15 10:40 ` [PATCH v11 05/24] coresight: export global symbols Tingwei Zhang
2020-09-15 10:40 ` [PATCH v11 06/24] coresight: add try_get_module() in coresight_grab_device() Tingwei Zhang
2020-09-15 11:08   ` Suzuki K Poulose
2020-09-15 10:40 ` [PATCH v11 07/24] coresight: stm: allow to build coresight-stm as a module Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 08/24] coresight: etm: perf: Fix warning caused by etm_setup_aux failure Tingwei Zhang
2020-09-15 10:41 ` Tingwei Zhang [this message]
2020-09-15 18:09   ` [PATCH v11 09/24] coresight: etm3x: allow etm3x to be built as a module Mathieu Poirier
2020-09-22 21:42     ` Mathieu Poirier
2020-09-23  0:23       ` Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 10/24] coresight: etm4x: allow etm4x " Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 11/24] coresight: etb: allow etb " Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 12/24] coresight: tpiu: allow tpiu " Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 13/24] coresight: tmc: allow tmc " Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 14/24] coresight: allow funnel driver to be built as module Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 15/24] coresight: allow replicator " Tingwei Zhang
2020-09-15 11:25   ` Suzuki K Poulose
2020-09-15 10:41 ` [PATCH v11 16/24] coresight: cti: add function to register cti associate ops Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 17/24] coresight: cti: Fix remove sysfs link error Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 18/24] coresight: cti: Fix bug clearing sysfs links on callback Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 19/24] coresight: cti: don't disable ect device if it's not enabled Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 20/24] coresight: cti: increase reference count when enabling cti Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 21/24] coresight: cti: allow cti to be built as a module Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 22/24] coresight: tmc-etr: add function to register catu ops Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 23/24] coresight: catu: allow catu drivers to be built as modules Tingwei Zhang
2020-09-15 10:41 ` [PATCH v11 24/24] coresight: allow the coresight core driver to be built as a module Tingwei Zhang

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