[PATCH v8 10/24] coresight: etm4x: allow etm4x to be built as a module
Tingwei Zhang
tingwei at codeaurora.org
Fri Aug 7 07:11:39 EDT 2020
From: Kim Phillips <kim.phillips at arm.com>
Allow to build coresight-etm4x 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-etm4x by the Makefile
- add an etm4_remove function, for module unload
- add a MODULE_DEVICE_TABLE for autoloading on boot
- protect etmdrvdata[] with mutex lock from racing
between module unload and CPU hotplug
Cc: Mathieu Poirier <mathieu.poirier at linaro.org>
Cc: Leo Yan <leo.yan at linaro.org>
Cc: Alexander Shishkin <alexander.shishkin at linux.intel.com>
Cc: Randy Dunlap <rdunlap at infradead.org>
Cc: Suzuki K Poulose <Suzuki.Poulose at arm.com>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Russell King <linux at armlinux.org.uk>
Signed-off-by: Kim Phillips <kim.phillips at arm.com>
Signed-off-by: Tingwei Zhang <tingwei at codeaurora.org>
Tested-by: Mike Leach <mike.leach at linaro.org>
---
drivers/hwtracing/coresight/Kconfig | 5 +-
drivers/hwtracing/coresight/Makefile | 4 +-
...resight-etm4x.c => coresight-etm4x-core.c} | 118 +++++++++++++-----
3 files changed, 92 insertions(+), 35 deletions(-)
rename drivers/hwtracing/coresight/{coresight-etm4x.c => coresight-etm4x-core.c} (95%)
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 8fd9fd139cf3..d6e107bbd30b 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -78,7 +78,7 @@ config CORESIGHT_SOURCE_ETM3X
module will be called coresight-etm3x.
config CORESIGHT_SOURCE_ETM4X
- bool "CoreSight Embedded Trace Macrocell 4.x driver"
+ tristate "CoreSight Embedded Trace Macrocell 4.x driver"
depends on ARM64
select CORESIGHT_LINKS_AND_SINKS
select PID_IN_CONTEXTIDR
@@ -88,6 +88,9 @@ config CORESIGHT_SOURCE_ETM4X
for instruction level tracing. Depending on the implemented version
data tracing may also be available.
+ To compile this driver as a module, choose M here: the
+ module will be called coresight-etm4x.
+
config CORESIGHT_STM
tristate "CoreSight System Trace Macrocell driver"
depends on (ARM && !(CPU_32v3 || CPU_32v4 || CPU_32v4T)) || ARM64
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index d619cfd0abd8..271dc255454f 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -14,8 +14,8 @@ obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \
obj-$(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_SOURCE_ETM4X) += coresight-etm4x.o
+coresight-etm4x-y := coresight-etm4x-core.o coresight-etm4x-sysfs.o
obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
similarity index 95%
rename from drivers/hwtracing/coresight/coresight-etm4x.c
rename to drivers/hwtracing/coresight/coresight-etm4x-core.c
index fddfd93b9a7b..ae9847e194a3 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -48,6 +48,7 @@ module_param(pm_save_enable, int, 0444);
MODULE_PARM_DESC(pm_save_enable,
"Save/restore state on power down: 1 = never, 2 = self-hosted");
+static DEFINE_PER_CPU(struct mutex, etmdrvdata_lock);
static struct etmv4_drvdata *etmdrvdata[NR_CPUS];
static void etm4_set_default_config(struct etmv4_config *config);
static int etm4_set_event_filters(struct etmv4_drvdata *drvdata,
@@ -1089,18 +1090,25 @@ void etm4_config_trace_mode(struct etmv4_config *config)
static int etm4_online_cpu(unsigned int cpu)
{
- if (!etmdrvdata[cpu])
+ mutex_lock(&per_cpu(etmdrvdata_lock, cpu));
+ if (!etmdrvdata[cpu]) {
+ mutex_unlock(&per_cpu(etmdrvdata_lock, cpu));
return 0;
+ }
if (etmdrvdata[cpu]->boot_enable && !etmdrvdata[cpu]->sticky_enable)
coresight_enable(etmdrvdata[cpu]->csdev);
+ mutex_unlock(&per_cpu(etmdrvdata_lock, cpu));
return 0;
}
static int etm4_starting_cpu(unsigned int cpu)
{
- if (!etmdrvdata[cpu])
+ mutex_lock(&per_cpu(etmdrvdata_lock, cpu));
+ if (!etmdrvdata[cpu]) {
+ mutex_unlock(&per_cpu(etmdrvdata_lock, cpu));
return 0;
+ }
spin_lock(&etmdrvdata[cpu]->spinlock);
if (!etmdrvdata[cpu]->os_unlock)
@@ -1109,18 +1117,23 @@ static int etm4_starting_cpu(unsigned int cpu)
if (local_read(&etmdrvdata[cpu]->mode))
etm4_enable_hw(etmdrvdata[cpu]);
spin_unlock(&etmdrvdata[cpu]->spinlock);
+ mutex_unlock(&per_cpu(etmdrvdata_lock, cpu));
return 0;
}
static int etm4_dying_cpu(unsigned int cpu)
{
- if (!etmdrvdata[cpu])
+ mutex_lock(&per_cpu(etmdrvdata_lock, cpu));
+ if (!etmdrvdata[cpu]) {
+ mutex_unlock(&per_cpu(etmdrvdata_lock, cpu));
return 0;
+ }
spin_lock(&etmdrvdata[cpu]->spinlock);
if (local_read(&etmdrvdata[cpu]->mode))
etm4_disable_hw(etmdrvdata[cpu]);
spin_unlock(&etmdrvdata[cpu]->spinlock);
+ mutex_unlock(&per_cpu(etmdrvdata_lock, cpu));
return 0;
}
@@ -1360,24 +1373,30 @@ static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
{
struct etmv4_drvdata *drvdata;
unsigned int cpu = smp_processor_id();
+ int ret = NOTIFY_OK;
+ mutex_lock(&per_cpu(etmdrvdata_lock, cpu));
if (!etmdrvdata[cpu])
- return NOTIFY_OK;
+ goto out;
drvdata = etmdrvdata[cpu];
if (!drvdata->save_state)
- return NOTIFY_OK;
+ goto out;
- if (WARN_ON_ONCE(drvdata->cpu != cpu))
- return NOTIFY_BAD;
+ if (WARN_ON_ONCE(drvdata->cpu != cpu)) {
+ ret = NOTIFY_BAD;
+ goto out;
+ }
switch (cmd) {
case CPU_PM_ENTER:
/* save the state if self-hosted coresight is in use */
if (local_read(&drvdata->mode))
- if (etm4_cpu_save(drvdata))
- return NOTIFY_BAD;
+ if (etm4_cpu_save(drvdata)) {
+ ret = NOTIFY_BAD;
+ goto out;
+ }
break;
case CPU_PM_EXIT:
/* fallthrough */
@@ -1386,10 +1405,12 @@ static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
etm4_cpu_restore(drvdata);
break;
default:
- return NOTIFY_DONE;
+ goto out;
}
- return NOTIFY_OK;
+out:
+ mutex_unlock(&per_cpu(etmdrvdata_lock, cpu));
+ return ret;
}
static struct notifier_block etm4_cpu_pm_nb = {
@@ -1430,7 +1451,7 @@ static int __init etm4_pm_setup(void)
return ret;
}
-static void __init etm4_pm_clear(void)
+static void etm4_pm_clear(void)
{
cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);
cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
@@ -1487,25 +1508,20 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
if (!desc.name)
return -ENOMEM;
- etmdrvdata[drvdata->cpu] = drvdata;
-
if (smp_call_function_single(drvdata->cpu,
etm4_init_arch_data, drvdata, 1))
dev_err(dev, "ETM arch init failed\n");
- if (etm4_arch_supported(drvdata->arch) == false) {
- ret = -EINVAL;
- goto err_arch_supported;
- }
+ if (etm4_arch_supported(drvdata->arch) == false)
+ return -EINVAL;
etm4_init_trace_id(drvdata);
etm4_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;
@@ -1515,17 +1531,19 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
desc.dev = dev;
desc.groups = coresight_etmv4_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;
}
+ mutex_lock(&per_cpu(etmdrvdata_lock, drvdata->cpu));
+ etmdrvdata[drvdata->cpu] = drvdata;
+ mutex_unlock(&per_cpu(etmdrvdata_lock, drvdata->cpu));
+
pm_runtime_put(&adev->dev);
dev_info(&drvdata->csdev->dev, "CPU%d: ETM v%d.%d initialized\n",
drvdata->cpu, drvdata->arch >> 4, drvdata->arch & 0xf);
@@ -1536,10 +1554,6 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
}
return 0;
-
-err_arch_supported:
- etmdrvdata[drvdata->cpu] = NULL;
- return ret;
}
static struct amba_cs_uci_id uci_id_etm4[] = {
@@ -1551,6 +1565,22 @@ static struct amba_cs_uci_id uci_id_etm4[] = {
}
};
+static int __exit etm4_remove(struct amba_device *adev)
+{
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+ etm_perf_symlink(drvdata->csdev, false);
+
+ mutex_lock(&per_cpu(etmdrvdata_lock, drvdata->cpu));
+ etmdrvdata[drvdata->cpu] = NULL;
+ mutex_unlock(&per_cpu(etmdrvdata_lock, drvdata->cpu));
+
+ coresight_unregister(drvdata->csdev);
+
+ return 0;
+}
+
+
static const struct amba_id etm4_ids[] = {
CS_AMBA_ID(0x000bb95d), /* Cortex-A53 */
CS_AMBA_ID(0x000bb95e), /* Cortex-A57 */
@@ -1568,18 +1598,26 @@ static const struct amba_id etm4_ids[] = {
{},
};
+MODULE_DEVICE_TABLE(amba, etm4_ids);
+
static struct amba_driver etm4x_driver = {
.drv = {
.name = "coresight-etm4x",
+ .owner = THIS_MODULE,
.suppress_bind_attrs = true,
},
.probe = etm4_probe,
+ .remove = etm4_remove,
.id_table = etm4_ids,
};
static int __init etm4x_init(void)
{
int ret;
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ mutex_init(&per_cpu(etmdrvdata_lock, cpu));
ret = etm4_pm_setup();
@@ -1595,4 +1633,20 @@ static int __init etm4x_init(void)
return ret;
}
-device_initcall(etm4x_init);
+
+static void __exit etm4x_exit(void)
+{
+ int cpu;
+
+ amba_driver_unregister(&etm4x_driver);
+ etm4_pm_clear();
+ for_each_possible_cpu(cpu)
+ mutex_destroy(&per_cpu(etmdrvdata_lock, cpu));
+}
+module_init(etm4x_init);
+module_exit(etm4x_exit);
+
+MODULE_AUTHOR("Pratik Patel <pratikp at codeaurora.org>");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier at linaro.org>");
+MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace v4 driver");
+MODULE_LICENSE("GPL v2");
--
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