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author | Kim Phillips <kim.phillips@arm.com> | 2020-09-28 10:34:57 -0600 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-28 19:47:41 +0200 |
commit | 97fe626ce64c8d0adf07d2700bd3c7c7089dd12f (patch) | |
tree | 8c287b4e2290fb293b5edcc04092a831a341f836 /drivers/hwtracing | |
parent | 716f5652a13122364a65e694386b9b26f5e98c51 (diff) | |
download | linux-97fe626ce64c8d0adf07d2700bd3c7c7089dd12f.tar.gz linux-97fe626ce64c8d0adf07d2700bd3c7c7089dd12f.tar.bz2 linux-97fe626ce64c8d0adf07d2700bd3c7c7089dd12f.zip |
coresight: etm3x: Allow etm3x to be built as a module
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>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200928163513.70169-10-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r-- | drivers/hwtracing/coresight/Kconfig | 5 | ||||
-rw-r--r-- | drivers/hwtracing/coresight/Makefile | 5 | ||||
-rw-r--r-- | drivers/hwtracing/coresight/coresight-etm3x-core.c (renamed from drivers/hwtracing/coresight/coresight-etm3x.c) | 154 |
3 files changed, 122 insertions, 42 deletions
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 index bf22dcfd3327..47f610b1c2b1 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -40,8 +40,6 @@ static int boot_enable; module_param_named(boot_enable, boot_enable, int, S_IRUGO); -/* The number of ETM/PTM currently registered */ -static int etm_count; static struct etm_drvdata *etmdrvdata[NR_CPUS]; static enum cpuhp_state hp_online; @@ -782,6 +780,42 @@ 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; @@ -823,39 +857,20 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) if (!desc.name) 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 +880,17 @@ 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 +900,40 @@ 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 +978,8 @@ 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 +988,39 @@ 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_hp_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"); |