Use a new function coresight_init_dev() for device structure allocation and initialization. This makes it easier to extend with additional initialization operations in the future.

Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 46f247f73cf64a97b9353b84ba5b76b991676f5f..5452de9367d450de399a2107016c3fddb894fc82 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -1322,20 +1322,16 @@ void coresight_release_platform_data(struct device *dev, devm_kfree(dev, pdata); }

-struct coresight_device *coresight_register(struct coresight_desc *desc) +static struct coresight_device * +coresight_init_device(struct coresight_desc *desc) { - int ret; struct coresight_device *csdev; - bool registered = false;

csdev = kzalloc_obj(*csdev); - if (!csdev) { - ret = -ENOMEM; - goto err_out; - } + if (!csdev) + return ERR_PTR(-ENOMEM);

csdev->pdata = desc->pdata; - csdev->type = desc->type; csdev->subtype = desc->subtype; csdev->ops = desc->ops; @@ -1348,6 +1344,21 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) csdev->dev.release = coresight_device_release; csdev->dev.bus = &coresight_bustype;

+ return csdev; +} + +struct coresight_device *coresight_register(struct coresight_desc *desc) +{ + int ret; + struct coresight_device *csdev; + bool registered = false; + + csdev = coresight_init_device(desc); + if (IS_ERR(csdev)) { + ret = PTR_ERR(csdev); + goto err_out; + } + if (csdev->type == CORESIGHT_DEV_TYPE_SINK || csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) { raw_spin_lock_init(&csdev->perf_sink_id_map.lock);

The CPU ID can be fetched directly from the coresight_device structure, so the .cpu_id() callback is no longer needed.

Remove the .cpu_id() callback from source ops and update callers accordingly.

Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 8 ++++---- drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +- drivers/hwtracing/coresight/coresight-etm3x-core.c | 8 -------- drivers/hwtracing/coresight/coresight-etm4x-core.c | 8 -------- drivers/hwtracing/coresight/coresight-sysfs.c | 4 ++-- include/linux/coresight.h | 3 --- 6 files changed, 7 insertions(+), 26 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 89911fc27128b2bb78c8ba704f2af5a5d4efe83c..6907da35ed02fa58f8d30f5576627a6ce3b88362 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -787,7 +787,7 @@ static int _coresight_build_path(struct coresight_device *csdev, goto out;

if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) && - sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) { + sink == per_cpu(csdev_sink, csdev->cpu)) { if (_coresight_build_path(sink, source, sink, path) == 0) { found = true; goto out; @@ -1014,7 +1014,7 @@ coresight_find_default_sink(struct coresight_device *csdev) /* look for a default sink if we have not found for this device */ if (!csdev->def_sink) { if (coresight_is_percpu_source(csdev)) - csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev)); + csdev->def_sink = per_cpu(csdev_sink, csdev->cpu); if (!csdev->def_sink) csdev->def_sink = coresight_find_sink(csdev, &depth); } @@ -1752,10 +1752,10 @@ int coresight_etm_get_trace_id(struct coresight_device *csdev, enum cs_mode mode { int cpu, trace_id;

- if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE || !source_ops(csdev)->cpu_id) + if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) return -EINVAL;

- cpu = source_ops(csdev)->cpu_id(csdev); + cpu = csdev->cpu; switch (mode) { case CS_MODE_SYSFS: trace_id = coresight_trace_id_get_cpu_id(cpu); diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index f85dedf89a3f9e85d568ca4c320fa6fa6d9059ff..cae6738e9906c35d291e4b0f3feae37306b95c06 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -824,7 +824,7 @@ static void etm_addr_filters_sync(struct perf_event *event) int etm_perf_symlink(struct coresight_device *csdev, bool link) { char entry[sizeof("cpu9999999")]; - int ret = 0, cpu = source_ops(csdev)->cpu_id(csdev); + int ret = 0, cpu = csdev->cpu; struct device *pmu_dev = etm_pmu.dev; struct device *cs_dev = &csdev->dev;

diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c index eb665db1a37d9970f7f55395c0aa23b98a7f3118..ab47f69e923fb191b48b82367dce465c79b3a93d 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -466,13 +466,6 @@ static void etm_enable_sysfs_smp_call(void *info) coresight_set_mode(csdev, CS_MODE_DISABLED); }

-static int etm_cpu_id(struct coresight_device *csdev) -{ - struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); - - return drvdata->cpu; -} - void etm_release_trace_id(struct etm_drvdata *drvdata) { coresight_trace_id_put_cpu_id(drvdata->cpu); @@ -684,7 +677,6 @@ static void etm_disable(struct coresight_device *csdev, }

static const struct coresight_ops_source etm_source_ops = { - .cpu_id = etm_cpu_id, .enable = etm_enable, .disable = etm_disable, }; diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index b1e0254a534027d7ede8591e56be28745d0b9974..66a8058098376264d3f8c5815763a75ebffb352e 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -227,13 +227,6 @@ static void etm4_cs_unlock(struct etmv4_drvdata *drvdata, CS_UNLOCK(csa->base); }

-static int etm4_cpu_id(struct coresight_device *csdev) -{ - struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); - - return drvdata->cpu; -} - void etm4_release_trace_id(struct etmv4_drvdata *drvdata) { coresight_trace_id_put_cpu_id(drvdata->cpu); @@ -1201,7 +1194,6 @@ static void etm4_pause_perf(struct coresight_device *csdev) }

static const struct coresight_ops_source etm4_source_ops = { - .cpu_id = etm4_cpu_id, .enable = etm4_enable, .disable = etm4_disable, .resume_perf = etm4_resume_perf, diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index d2a6ed8bcc74d64dccc735463f14790b4e80d101..3b1e7152dd108408d837c404ce607ba511ca14a6 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -232,7 +232,7 @@ int coresight_enable_sysfs(struct coresight_device *csdev) * be a single session per tracer (when working from sysFS) * a per-cpu variable will do just fine. */ - cpu = source_ops(csdev)->cpu_id(csdev); + cpu = csdev->cpu; per_cpu(tracer_path, cpu) = path; break; case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE: @@ -282,7 +282,7 @@ void coresight_disable_sysfs(struct coresight_device *csdev)

switch (csdev->subtype.source_subtype) { case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC: - cpu = source_ops(csdev)->cpu_id(csdev); + cpu = csdev->cpu; path = per_cpu(tracer_path, cpu); per_cpu(tracer_path, cpu) = NULL; break; diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 687190ca11ddeaa83193caa3903a480bac3060d1..e9c20ceb9016fa3db256b8c1147c1fd2027b7b0d 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -395,15 +395,12 @@ struct coresight_ops_link { /** * struct coresight_ops_source - basic operations for a source * Operations available for sources. - * @cpu_id: returns the value of the CPU number this component - * is associated to. * @enable: enables tracing for a source. * @disable: disables tracing for a source. * @resume_perf: resumes tracing for a source in perf session. * @pause_perf: pauses tracing for a source in perf session. */ struct coresight_ops_source { - int (*cpu_id)(struct coresight_device *csdev); int (*enable)(struct coresight_device *csdev, struct perf_event *event, enum cs_mode mode, struct coresight_path *path); void (*disable)(struct coresight_device *csdev,

Move the per-CPU source pointer from ETM perf to the core layer, as this will be used for not only perf session and also for CPU PM notifiers.

Provides coresight_{set|clear|get}_percpu_source() helpers to access the per-CPU source pointer. Add a raw spinlock to protect exclusive access.

Device registration and unregistration call the set and clear helpers for init and teardown the pointers.

Update callers to invoke coresight_get_percpu_source() for retrieving the pointer.

Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 32 ++++++++++++++++++++++++ drivers/hwtracing/coresight/coresight-etm-perf.c | 21 +++++++--------- drivers/hwtracing/coresight/coresight-priv.h | 1 + 3 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 6907da35ed02fa58f8d30f5576627a6ce3b88362..93acbd36c9c0efcc311c5374463b2ae9a4e6e49b 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -35,6 +35,9 @@ DEFINE_MUTEX(coresight_mutex); static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);

+static DEFINE_RAW_SPINLOCK(coresight_dev_lock); +static DEFINE_PER_CPU(struct coresight_device *, csdev_source); + /** * struct coresight_node - elements of a path, from source to sink * @csdev: Address of an element. @@ -82,6 +85,33 @@ struct coresight_device *coresight_get_percpu_sink(int cpu) } EXPORT_SYMBOL_GPL(coresight_get_percpu_sink);

+static void coresight_set_percpu_source(struct coresight_device *csdev) +{ + if (!csdev || !coresight_is_percpu_source(csdev)) + return; + + guard(raw_spinlock_irqsave)(&coresight_dev_lock); + per_cpu(csdev_source, csdev->cpu) = csdev; +} + +static void coresight_clear_percpu_source(struct coresight_device *csdev) +{ + if (!csdev || !coresight_is_percpu_source(csdev)) + return; + + guard(raw_spinlock_irqsave)(&coresight_dev_lock); + per_cpu(csdev_source, csdev->cpu) = NULL; +} + +struct coresight_device *coresight_get_percpu_source(int cpu) +{ + if (WARN_ON(cpu < 0)) + return NULL; + + guard(raw_spinlock_irqsave)(&coresight_dev_lock); + return per_cpu(csdev_source, cpu); +} + static struct coresight_device *coresight_get_source(struct coresight_path *path) { struct coresight_device *csdev; @@ -1422,6 +1452,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) if (ret) goto out_unlock;

+ coresight_set_percpu_source(csdev); mutex_unlock(&coresight_mutex);

if (cti_assoc_ops && cti_assoc_ops->add) @@ -1451,6 +1482,7 @@ void coresight_unregister(struct coresight_device *csdev) cti_assoc_ops->remove(csdev);

mutex_lock(&coresight_mutex); + coresight_clear_percpu_source(csdev); etm_perf_del_symlink_sink(csdev); coresight_remove_conns(csdev); coresight_clear_default_sink(csdev); diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index cae6738e9906c35d291e4b0f3feae37306b95c06..a2c1c876099d1f5dacf039d733b78827296d9c2e 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -49,7 +49,6 @@ struct etm_ctxt { };

static DEFINE_PER_CPU(struct etm_ctxt, etm_ctxt); -static DEFINE_PER_CPU(struct coresight_device *, csdev_src);

GEN_PMU_FORMAT_ATTR(cycacc); GEN_PMU_FORMAT_ATTR(timestamp); @@ -356,7 +355,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, struct coresight_path *path; struct coresight_device *csdev;

- csdev = per_cpu(csdev_src, cpu); + csdev = coresight_get_percpu_source(cpu); /* * If there is no ETM associated with this CPU clear it from * the mask and continue with the rest. If ever we try to trace @@ -479,10 +478,11 @@ static void etm_event_start(struct perf_event *event, int flags) struct etm_event_data *event_data; struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt); struct perf_output_handle *handle = &ctxt->handle; - struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu); + struct coresight_device *sink, *csdev; struct coresight_path *path; u64 hw_id;

+ csdev = coresight_get_percpu_source(cpu); if (!csdev) goto fail;

@@ -630,12 +630,14 @@ static void etm_event_stop(struct perf_event *event, int mode) { int cpu = smp_processor_id(); unsigned long size; - struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu); + struct coresight_device *sink, *csdev; struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt); struct perf_output_handle *handle = &ctxt->handle; struct etm_event_data *event_data; struct coresight_path *path;

+ csdev = coresight_get_percpu_source(cpu); + if (mode & PERF_EF_PAUSE) return etm_event_pause(event, csdev, ctxt);

@@ -833,17 +835,12 @@ int etm_perf_symlink(struct coresight_device *csdev, bool link) if (!etm_perf_up) return -EPROBE_DEFER;

- if (link) { + if (link) ret = sysfs_create_link(&pmu_dev->kobj, &cs_dev->kobj, entry); - if (ret) - return ret; - per_cpu(csdev_src, cpu) = csdev; - } else { + else sysfs_remove_link(&pmu_dev->kobj, entry); - per_cpu(csdev_src, cpu) = NULL; - }

- return 0; + return ret; } EXPORT_SYMBOL_GPL(etm_perf_symlink);

diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 1ea882dffd703b2873e41b4ce0c2564d2ce9bbad..c96d63657f9334be890cca2320abbb8cbd807802 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -248,6 +248,7 @@ void coresight_add_helper(struct coresight_device *csdev,

void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev); struct coresight_device *coresight_get_percpu_sink(int cpu); +struct coresight_device *coresight_get_percpu_source(int cpu); void coresight_disable_source(struct coresight_device *csdev, void *data); void coresight_pause_source(struct coresight_device *csdev); int coresight_resume_source(struct coresight_device *csdev);

Hook the CPU save and restore callbacks when the self-hosted state is enabled (pm_save_enable == PARAM_PM_SAVE_SELF_HOSTED) so they can be invoked by the core layer.

The CPU PM notifier in the ETMv4 driver is no longer needed, remove it along with its registration and unregistration code.

Reviewed-by: James Clark james.clark@linaro.org Tested-by: James Clark james.clark@linaro.org Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-etm4x-core.c | 57 +++++----------------- 1 file changed, 11 insertions(+), 46 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 66a8058098376264d3f8c5815763a75ebffb352e..6ed0ee95c78c24bcb6c636d9ebf2ae463c748b22 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1200,7 +1200,7 @@ static const struct coresight_ops_source etm4_source_ops = { .pause_perf = etm4_pause_perf, };

-static const struct coresight_ops etm4_cs_ops = { +static struct coresight_ops etm4_cs_ops = { .trace_id = coresight_etm_get_trace_id, .source_ops = &etm4_source_ops, }; @@ -2000,8 +2000,9 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata) return ret; }

-static int etm4_cpu_save(struct etmv4_drvdata *drvdata) +static int etm4_cpu_save(struct coresight_device *csdev) { + struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); int ret = 0;

if (pm_save_enable != PARAM_PM_SAVE_SELF_HOSTED) @@ -2117,8 +2118,10 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata) etm4_cs_lock(drvdata, csa); }

-static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) +static void etm4_cpu_restore(struct coresight_device *csdev) { + struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + if (pm_save_enable != PARAM_PM_SAVE_SELF_HOSTED) return;

@@ -2126,55 +2129,17 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) __etm4_cpu_restore(drvdata); }

-static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, - void *v) -{ - struct etmv4_drvdata *drvdata; - unsigned int cpu = smp_processor_id(); - - if (!etmdrvdata[cpu]) - return NOTIFY_OK; - - drvdata = etmdrvdata[cpu]; - - if (WARN_ON_ONCE(drvdata->cpu != cpu)) - return NOTIFY_BAD; - - switch (cmd) { - case CPU_PM_ENTER: - if (etm4_cpu_save(drvdata)) - return NOTIFY_BAD; - break; - case CPU_PM_EXIT: - case CPU_PM_ENTER_FAILED: - etm4_cpu_restore(drvdata); - break; - default: - return NOTIFY_DONE; - } - - return NOTIFY_OK; -} - -static struct notifier_block etm4_cpu_pm_nb = { - .notifier_call = etm4_cpu_pm_notify, -}; - /* Setup PM. Deals with error conditions and counts */ static int __init etm4_pm_setup(void) { int ret;

- ret = cpu_pm_register_notifier(&etm4_cpu_pm_nb); - if (ret) - return ret; - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, "arm/coresight4:starting", etm4_starting_cpu, etm4_dying_cpu);

if (ret) - goto unregister_notifier; + return ret;

ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "arm/coresight4:online", @@ -2188,15 +2153,11 @@ static int __init etm4_pm_setup(void)

/* failed dyn state - remove others */ cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); - -unregister_notifier: - cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); return ret; }

static void etm4_pm_clear(void) { - cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); if (hp_online) { cpuhp_remove_state_nocalls(hp_online); @@ -2308,6 +2269,10 @@ static int etm4_probe(struct device *dev) sizeof(struct etmv4_save_state), GFP_KERNEL); if (!drvdata->save_state) return -ENOMEM; + + /* Setup CPU PM callbacks */ + etm4_cs_ops.pm_save_disable = etm4_cpu_save; + etm4_cs_ops.pm_restore_enable = etm4_cpu_restore; }

raw_spin_lock_init(&drvdata->spinlock);

To support dynamically enabling and disabling the CoreSight path during CPU idle, cscfg_config_sysfs_get_active_cfg() may be called by the ETM driver in an atomic context. However, the function currently acquires a mutex, which is a sleepable lock, and this is not allowed in atomic context.

To make cscfg_config_sysfs_get_active_cfg() called in the idle flow, replace the mutex with a raw spinlock to protect the active variables.

Acquire the raw spinlock with IRQ-safe to avoid lockdep complaint.

Reviewed-by: James Clark james.clark@linaro.org Tested-by: James Clark james.clark@linaro.org Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-syscfg.c | 21 ++++++++++----------- drivers/hwtracing/coresight/coresight-syscfg.h | 2 ++ 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index d7f5037953d6ba7fb7f83a8012a1abc5ffd0a147..7e070787e18b47bc4be17b0f9821267268600513 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -953,19 +953,21 @@ int cscfg_config_sysfs_activate(struct cscfg_config_desc *config_desc, bool acti unsigned long cfg_hash; int err = 0;

- mutex_lock(&cscfg_mutex); + guard(mutex)(&cscfg_mutex);

cfg_hash = (unsigned long)config_desc->event_ea->var;

+ guard(raw_spinlock_irqsave)(&cscfg_mgr->sysfs_store_lock); + if (activate) { /* cannot be a current active value to activate this */ if (cscfg_mgr->sysfs_active_config) { err = -EBUSY; - goto exit_unlock; + } else { + err = _cscfg_activate_config(cfg_hash); + if (!err) + cscfg_mgr->sysfs_active_config = cfg_hash; } - err = _cscfg_activate_config(cfg_hash); - if (!err) - cscfg_mgr->sysfs_active_config = cfg_hash; } else { /* disable if matching current value */ if (cscfg_mgr->sysfs_active_config == cfg_hash) { @@ -975,17 +977,14 @@ int cscfg_config_sysfs_activate(struct cscfg_config_desc *config_desc, bool acti err = -EINVAL; }

-exit_unlock: - mutex_unlock(&cscfg_mutex); return err; }

/* set the sysfs preset value */ void cscfg_config_sysfs_set_preset(int preset) { - mutex_lock(&cscfg_mutex); + guard(raw_spinlock_irqsave)(&cscfg_mgr->sysfs_store_lock); cscfg_mgr->sysfs_active_preset = preset; - mutex_unlock(&cscfg_mutex); }

/* @@ -994,10 +993,9 @@ void cscfg_config_sysfs_set_preset(int preset) */ void cscfg_config_sysfs_get_active_cfg(unsigned long *cfg_hash, int *preset) { - mutex_lock(&cscfg_mutex); + guard(raw_spinlock_irqsave)(&cscfg_mgr->sysfs_store_lock); *preset = cscfg_mgr->sysfs_active_preset; *cfg_hash = cscfg_mgr->sysfs_active_config; - mutex_unlock(&cscfg_mutex); } EXPORT_SYMBOL_GPL(cscfg_config_sysfs_get_active_cfg);

@@ -1201,6 +1199,7 @@ static int cscfg_create_device(void) INIT_LIST_HEAD(&cscfg_mgr->load_order_list); atomic_set(&cscfg_mgr->sys_active_cnt, 0); cscfg_mgr->load_state = CSCFG_NONE; + raw_spin_lock_init(&cscfg_mgr->sysfs_store_lock);

/* setup the device */ dev = cscfg_device(); diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h index 66e2db890d8203853a0c3c907b48aa66dd8014e6..658e93c3705f1cb3ba3523d0bc27ac704697dd70 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.h +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -42,6 +42,7 @@ enum cscfg_load_ops { * @sysfs_active_config:Active config hash used if CoreSight controlled from sysfs. * @sysfs_active_preset:Active preset index used if CoreSight controlled from sysfs. * @load_state: A multi-stage load/unload operation is in progress. + * @sysfs_store_lock: Exclusive access sysfs stored variables. */ struct cscfg_manager { struct device dev; @@ -54,6 +55,7 @@ struct cscfg_manager { u32 sysfs_active_config; int sysfs_active_preset; enum cscfg_load_ops load_state; + raw_spinlock_t sysfs_store_lock; };

/* get reference to dev in cscfg_manager */

Add parameters @from and @to for path enabling and disabling, allowing finer-grained control of a path. The range is [@from..@to], where both @from and @to are inclusive, introduce coresight_path_nodes_in_order() to validate the given range if is ordered.

The helpers coresight_path_{first|last}_node() are provided for conveniently fetching the first and last nodes on the path.

A minor refactoring removes the local variable "source" from coresight_enable_path_from_to(), deferring reading the source until it is needed.

Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 95 ++++++++++++++++++++++------ 1 file changed, 77 insertions(+), 18 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 1d6a4c5b3b97b13d06356b01b5acd161c8d607de..ae75c3ce117db5f194f9debd9b329695e0fb0cde 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -62,6 +62,24 @@ static LIST_HEAD(coresight_dev_idx_list);

static const struct cti_assoc_op *cti_assoc_ops;

+static struct coresight_node * +coresight_path_first_node(struct coresight_path *path) +{ + if (list_empty(&path->path_list)) + return NULL; + + return list_first_entry(&path->path_list, struct coresight_node, link); +} + +static struct coresight_node * +coresight_path_last_node(struct coresight_path *path) +{ + if (list_empty(&path->path_list)) + return NULL; + + return list_last_entry(&path->path_list, struct coresight_node, link); +} + void coresight_set_cti_ops(const struct cti_assoc_op *cti_op) { cti_assoc_ops = cti_op; @@ -448,19 +466,41 @@ int coresight_resume_source(struct coresight_device *csdev) EXPORT_SYMBOL_GPL(coresight_resume_source);

/* - * coresight_disable_path_from : Disable components in the given path beyond - * @nd in the list. If @nd is NULL, all the components, except the SOURCE are - * disabled. + * Callers must fetch nodes from the path and pass @from and @to to the path + * enable/disable functions. Walk the path from @from to locate @to. If @to + * is found, it indicates @from and @to are in order. Otherwise, they are out + * of order. */ -static void coresight_disable_path_from(struct coresight_path *path, - struct coresight_node *nd) +static bool coresight_path_nodes_in_order(struct coresight_path *path, + struct coresight_node *from, + struct coresight_node *to) +{ + struct coresight_node *nd; + + if (WARN_ON_ONCE(!from || !to)) + return false; + + nd = from; + list_for_each_entry_from(nd, &path->path_list, link) { + if (nd == to) + return true; + } + + return false; +} + +static void coresight_disable_path_from_to(struct coresight_path *path, + struct coresight_node *from, + struct coresight_node *to) { u32 type; struct coresight_device *csdev, *parent, *child; + struct coresight_node *nd;

- if (!nd) - nd = list_first_entry(&path->path_list, struct coresight_node, link); + if (!coresight_path_nodes_in_order(path, from, to)) + return;

+ nd = from; list_for_each_entry_from(nd, &path->path_list, link) { csdev = nd->csdev; type = csdev->type; @@ -494,12 +534,18 @@ static void coresight_disable_path_from(struct coresight_path *path,

/* Disable all helpers adjacent along the path last */ coresight_disable_helpers(csdev, path); + + /* Iterate up to and including @to */ + if (nd == to) + break; } }

void coresight_disable_path(struct coresight_path *path) { - coresight_disable_path_from(path, NULL); + coresight_disable_path_from_to(path, + coresight_path_first_node(path), + coresight_path_last_node(path)); } EXPORT_SYMBOL_GPL(coresight_disable_path);

@@ -523,19 +569,20 @@ static int coresight_enable_helpers(struct coresight_device *csdev, return 0; }

-int coresight_enable_path(struct coresight_path *path, enum cs_mode mode) +static int coresight_enable_path_from_to(struct coresight_path *path, + enum cs_mode mode, + struct coresight_node *from, + struct coresight_node *to) { int ret = 0; u32 type; - struct coresight_node *nd, *last; + struct coresight_node *nd; struct coresight_device *csdev, *parent, *child; - struct coresight_device *source;

- source = coresight_get_source(path); - - last = list_last_entry(&path->path_list, struct coresight_node, link); + if (!coresight_path_nodes_in_order(path, from, to)) + return -EINVAL;

- nd = last; + nd = to; list_for_each_entry_from_reverse(nd, &path->path_list, link) { csdev = nd->csdev; type = csdev->type; @@ -575,7 +622,8 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode) case CORESIGHT_DEV_TYPE_LINK: parent = list_prev_entry(nd, link)->csdev; child = list_next_entry(nd, link)->csdev; - ret = coresight_enable_link(csdev, parent, child, source); + ret = coresight_enable_link(csdev, parent, child, + coresight_get_source(path)); if (ret) goto err_disable_helpers; break; @@ -583,6 +631,10 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode) ret = -EINVAL; goto err_disable_helpers; } + + /* Iterate down to and including @from */ + if (nd == from) + break; }

out: @@ -591,14 +643,21 @@ int coresight_enable_path(struct coresight_path *path, enum cs_mode mode) coresight_disable_helpers(csdev, path); err_disable_path: /* No device is actually enabled */ - if (nd == last) + if (nd == to) goto out;

nd = list_next_entry(nd, link); - coresight_disable_path_from(path, nd); + coresight_disable_path_from_to(path, nd, to); goto out; }

+int coresight_enable_path(struct coresight_path *path, enum cs_mode mode) +{ + return coresight_enable_path_from_to(path, mode, + coresight_path_first_node(path), + coresight_path_last_node(path)); +} + struct coresight_device *coresight_get_sink(struct coresight_path *path) { struct coresight_device *csdev;

Introduce the coresight_enable_source() helper for enabling source device.

Add validation to ensure the device is a source before proceeding with further operations.

Reviewed-by: James Clark james.clark@linaro.org Tested-by: James Clark james.clark@linaro.org Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 18 ++++++++++++++++-- drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +- drivers/hwtracing/coresight/coresight-priv.h | 3 +++ drivers/hwtracing/coresight/coresight-sysfs.c | 2 +- 4 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 9bbc31389f16b51d399924d44b52b1614f6ffe81..aaa525f6d5a66a974bdcca3a42447ac26ad39733 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -439,11 +439,25 @@ static void coresight_disable_helpers(struct coresight_device *csdev, }

/* - * coresight_disable_source() only disables the source, but do nothing for - * the associated helpers, which are controlled as part of the path. + * coresight_enable_source() and coresight_disable_source() only enable and + * disable the source, but do nothing for the associated helpers, which are + * controlled as part of the path. */ +int coresight_enable_source(struct coresight_device *csdev, + struct perf_event *event, enum cs_mode mode, + struct coresight_path *path) +{ + if (!coresight_is_device_source(csdev)) + return -EINVAL; + + return source_ops(csdev)->enable(csdev, event, mode, path); +} + void coresight_disable_source(struct coresight_device *csdev, void *data) { + if (!coresight_is_device_source(csdev)) + return; + source_ops(csdev)->disable(csdev, data); } EXPORT_SYMBOL_GPL(coresight_disable_source); diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index a2c1c876099d1f5dacf039d733b78827296d9c2e..6783396635b7a62328483ad5d8837c9a59990e50 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -533,7 +533,7 @@ static void etm_event_start(struct perf_event *event, int flags) goto fail_end_stop;

/* Finally enable the tracer */ - if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF, path)) + if (coresight_enable_source(csdev, event, CS_MODE_PERF, path)) goto fail_disable_path;

/* diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index c96d63657f9334be890cca2320abbb8cbd807802..51ff1718502d6a5bf86b16e0723d7cdfdecc1848 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -249,6 +249,9 @@ void coresight_add_helper(struct coresight_device *csdev, void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev); struct coresight_device *coresight_get_percpu_sink(int cpu); struct coresight_device *coresight_get_percpu_source(int cpu); +int coresight_enable_source(struct coresight_device *csdev, + struct perf_event *event, enum cs_mode mode, + struct coresight_path *path); void coresight_disable_source(struct coresight_device *csdev, void *data); void coresight_pause_source(struct coresight_device *csdev); int coresight_resume_source(struct coresight_device *csdev); diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index 2546f3ef82f810fd04a119cecd2093b8150112b6..de1cc05433f565eb7cb91e386f79939857dadcd5 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -66,7 +66,7 @@ static int coresight_enable_source_sysfs(struct coresight_device *csdev, */ lockdep_assert_held(&coresight_mutex); if (coresight_get_mode(csdev) != CS_MODE_SYSFS) { - ret = source_ops(csdev)->enable(csdev, NULL, mode, path); + ret = coresight_enable_source(csdev, NULL, mode, path); if (ret) return ret; }

Set and clear the path pointer on the target CPU during ETM enable and disable operations to avoid race conditions when retrieving the pointer in CPU PM callbacks.

Tested-by: James Clark james.clark@linaro.org Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Reviewed-by: James Clark james.clark@linaro.org Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-etm4x-core.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 4a9b226781a5c2ab6efcadf08614de58bcd4043a..1f100e8bbcc775a1bdc5f8b27ff15dbcaf030a63 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -234,6 +234,7 @@ void etm4_release_trace_id(struct etmv4_drvdata *drvdata)

struct etm4_enable_arg { struct etmv4_drvdata *drvdata; + struct coresight_path *path; int rc; };

@@ -621,8 +622,12 @@ static void etm4_enable_sysfs_smp_call(void *info) arg->rc = etm4_enable_hw(arg->drvdata);

/* The tracer didn't start */ - if (arg->rc) + if (arg->rc) { coresight_set_mode(csdev, CS_MODE_DISABLED); + return; + } + + csdev->path = arg->path; }

/* @@ -890,9 +895,13 @@ static int etm4_enable_perf(struct coresight_device *csdev,

out: /* Failed to start tracer; roll back to DISABLED mode */ - if (ret) + if (ret) { coresight_set_mode(csdev, CS_MODE_DISABLED); - return ret; + return ret; + } + + csdev->path = path; + return 0; }

static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_path *path) @@ -922,6 +931,7 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa * ensures that register writes occur when cpu is powered. */ arg.drvdata = drvdata; + arg.path = path; ret = smp_call_function_single(drvdata->cpu, etm4_enable_sysfs_smp_call, &arg, 1); if (!ret) @@ -1063,6 +1073,7 @@ static void etm4_disable_sysfs_smp_call(void *info)

etm4_disable_hw(drvdata);

+ drvdata->csdev->path = NULL; coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED); }

@@ -1092,6 +1103,7 @@ static int etm4_disable_perf(struct coresight_device *csdev, /* TRCVICTLR::SSSTATUS, bit[9] */ filters->ssstatus = (control & BIT(9));

+ drvdata->csdev->path = NULL; coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED);

/*

Since the path pointer is stored in the source's structure, retrieve it directly when disabling the path.

As a result, the global variables used for caching path pointers are no longer needed. Remove them to simplify the code.

Tested-by: James Clark james.clark@linaro.org Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Reviewed-by: James Clark james.clark@linaro.org Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-sysfs.c | 79 +++------------------------ 1 file changed, 9 insertions(+), 70 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index de1cc05433f565eb7cb91e386f79939857dadcd5..9e94505bccf4ac91207f2f5393ae57ae077d61d6 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -12,19 +12,6 @@ #include "coresight-priv.h" #include "coresight-trace-id.h"

-/* - * Use IDR to map the hash of the source's device name - * to the pointer of path for the source. The idr is for - * the sources which aren't associated with CPU. - */ -static DEFINE_IDR(path_idr); - -/* - * When operating Coresight drivers from the sysFS interface, only a single - * path can exist from a tracer (associated to a CPU) to a sink. - */ -static DEFINE_PER_CPU(struct coresight_path *, tracer_path); - ssize_t coresight_simple_show_pair(struct device *_dev, struct device_attribute *attr, char *buf) { @@ -170,11 +157,10 @@ static int coresight_validate_source_sysfs(struct coresight_device *csdev,

int coresight_enable_sysfs(struct coresight_device *csdev) { - int cpu, ret = 0; + int ret = 0; struct coresight_device *sink; struct coresight_path *path; enum coresight_dev_subtype_source subtype; - u32 hash;

subtype = csdev->subtype.source_subtype;

@@ -226,35 +212,6 @@ int coresight_enable_sysfs(struct coresight_device *csdev) if (ret) goto err_source;

- switch (subtype) { - case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC: - /* - * When working from sysFS it is important to keep track - * of the paths that were created so that they can be - * undone in 'coresight_disable()'. Since there can only - * be a single session per tracer (when working from sysFS) - * a per-cpu variable will do just fine. - */ - cpu = csdev->cpu; - per_cpu(tracer_path, cpu) = path; - break; - case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE: - case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM: - case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS: - /* - * Use the hash of source's device name as ID - * and map the ID to the pointer of the path. - */ - hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev))); - ret = idr_alloc_u32(&path_idr, path, &hash, hash, GFP_KERNEL); - if (ret) - goto err_source; - break; - default: - /* We can't be here */ - break; - } - out: mutex_unlock(&coresight_mutex); return ret; @@ -270,9 +227,8 @@ EXPORT_SYMBOL_GPL(coresight_enable_sysfs);

void coresight_disable_sysfs(struct coresight_device *csdev) { - int cpu, ret; - struct coresight_path *path = NULL; - u32 hash; + int ret; + struct coresight_path *path;

mutex_lock(&coresight_mutex);

@@ -280,32 +236,15 @@ void coresight_disable_sysfs(struct coresight_device *csdev) if (ret) goto out;

+ /* + * coresight_disable_source_sysfs() clears the 'csdev->path' pointer + * when disabling the source. Retrieve the path pointer here. + */ + path = csdev->path; + if (!coresight_disable_source_sysfs(csdev, NULL)) goto out;

- switch (csdev->subtype.source_subtype) { - case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC: - cpu = csdev->cpu; - path = per_cpu(tracer_path, cpu); - per_cpu(tracer_path, cpu) = NULL; - break; - case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE: - case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM: - case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS: - hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev))); - /* Find the path by the hash. */ - path = idr_find(&path_idr, hash); - if (path == NULL) { - pr_err("Path is not found for %s\n", dev_name(&csdev->dev)); - goto out; - } - idr_remove(&path_idr, hash); - break; - default: - /* We can't be here */ - break; - } - coresight_disable_path(path); coresight_release_path(path);

Unlike a system level's sink, the per-CPU sink may lose power during CPU idle states. Currently, this refers specifically to TRBE as the sink.

This commit registers save and restore callbacks for the sink via the PM notifier.

Tested-by: James Clark james.clark@linaro.org Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Reviewed-by: James Clark james.clark@linaro.org Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 5060ccbc8f4c82eb14ec081ec05709391a585a11..6b18a278f44f3b45d083db15ab09f2eae1c69a0f 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -1816,11 +1816,17 @@ static bool coresight_pm_is_needed(struct coresight_path *path)

static int coresight_pm_device_save(struct coresight_device *csdev) { + if (!csdev || !coresight_ops(csdev)->pm_save_disable) + return 0; + return coresight_ops(csdev)->pm_save_disable(csdev); }

static void coresight_pm_device_restore(struct coresight_device *csdev) { + if (!csdev || !coresight_ops(csdev)->pm_restore_enable) + return; + coresight_ops(csdev)->pm_restore_enable(csdev); }

@@ -1840,7 +1846,17 @@ static int coresight_pm_save(struct coresight_path *path) to = list_prev_entry(coresight_path_last_node(path), link); coresight_disable_path_from_to(path, from, to);

+ ret = coresight_pm_device_save(coresight_get_sink(path)); + if (ret) + goto failed_out; + return 0; + +failed_out: + coresight_enable_path_from_to(path, coresight_get_mode(source), + from, to); + coresight_pm_device_restore(source); + return ret; }

static void coresight_pm_restore(struct coresight_path *path) @@ -1848,6 +1864,8 @@ static void coresight_pm_restore(struct coresight_path *path) struct coresight_device *source; struct coresight_node *from, *to;

+ coresight_pm_device_restore(coresight_get_sink(path)); + source = coresight_get_source(path); from = coresight_path_first_node(path); /* Up to the node before sink to avoid latency */

Except for system tracers (e.g. STM), other sources treat multiple enables as equivalent to a single enable. The device mode already tracks the binary state, so it is redundant to operate refcount.

Refactor to maintain the refcount only for system sources. This simplifies future CPU PM handling without refcount logic.

Tested-by: James Clark james.clark@linaro.org Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Reviewed-by: James Clark james.clark@linaro.org Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-sysfs.c | 35 +++++++++++++++------------ 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index 9e94505bccf4ac91207f2f5393ae57ae077d61d6..04c1425eb37d69c6feb8e49446fc58ee57a5e82e 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -58,7 +58,17 @@ static int coresight_enable_source_sysfs(struct coresight_device *csdev, return ret; }

- csdev->refcnt++; + /* + * There could be multiple applications driving the software + * source. So keep the refcount for each such user when the + * source is already enabled. + * + * No need to increment the reference counter for other source + * types, as multiple enables are the same as a single enable. + */ + if (csdev->subtype.source_subtype == + CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) + csdev->refcnt++;

return 0; } @@ -80,7 +90,10 @@ static bool coresight_disable_source_sysfs(struct coresight_device *csdev, if (coresight_get_mode(csdev) != CS_MODE_SYSFS) return false;

- csdev->refcnt--; + if (csdev->subtype.source_subtype == + CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) + csdev->refcnt--; + if (csdev->refcnt == 0) { coresight_disable_source(csdev, data); return true; @@ -159,10 +172,7 @@ int coresight_enable_sysfs(struct coresight_device *csdev) { int ret = 0; struct coresight_device *sink; - struct coresight_path *path; - enum coresight_dev_subtype_source subtype; - - subtype = csdev->subtype.source_subtype; + struct coresight_path *path = NULL;

mutex_lock(&coresight_mutex);

@@ -176,16 +186,8 @@ int coresight_enable_sysfs(struct coresight_device *csdev) * coresight_enable_source() so can still race with Perf mode which * doesn't hold coresight_mutex. */ - if (coresight_get_mode(csdev) == CS_MODE_SYSFS) { - /* - * There could be multiple applications driving the software - * source. So keep the refcount for each such user when the - * source is already enabled. - */ - if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) - csdev->refcnt++; - goto out; - } + if (coresight_get_mode(csdev) == CS_MODE_SYSFS) + goto enable_source;

sink = coresight_find_activated_sysfs_sink(csdev); if (!sink) { @@ -208,6 +210,7 @@ int coresight_enable_sysfs(struct coresight_device *csdev) if (ret) goto err_path;

+enable_source: ret = coresight_enable_source_sysfs(csdev, CS_MODE_SYSFS, path); if (ret) goto err_source;

This commit moves CPU hotplug callbacks from ETMv4 driver to core layer. The motivation is the core layer can control all components on an activated path rather but not only managing tracer in ETMv4 driver.

The perf event layer will disable CoreSight PMU event 'cs_etm' when hotplug off a CPU. That means a perf mode will be always converted to disabled mode in CPU hotplug. Arm CoreSight CPU hotplug callbacks only need to handle the Sysfs mode and ignore the perf mode.

The core layer disables and releases the active path when hotplug-off a CPU. When hotplug-in a CPU, it does not re-enable the path, in this case, users need to re-enable the trace via Sysfs interface.

Tested-by: James Clark james.clark@linaro.org Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Reviewed-by: James Clark james.clark@linaro.org Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 36 ++++++++++++++++++- drivers/hwtracing/coresight/coresight-etm3x-core.c | 40 ---------------------- drivers/hwtracing/coresight/coresight-etm4x-core.c | 37 -------------------- 3 files changed, 35 insertions(+), 78 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 6b18a278f44f3b45d083db15ab09f2eae1c69a0f..5a90ec7cf0b845284223fa0b0a175a770804c868 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -1904,13 +1904,47 @@ static struct notifier_block coresight_cpu_pm_nb = { .notifier_call = coresight_cpu_pm_notify, };

+static int coresight_dying_cpu(unsigned int cpu) +{ + struct coresight_path *path = coresight_get_local_cpu_path(); + struct coresight_device *source = coresight_get_source(path); + + if (!path || !source) + return 0; + + /* + * The perf event layer will disable PMU events in the CPU hotplug. + * CoreSight driver should never handle the CS_MODE_PERF case. + */ + if (coresight_get_mode(source) != CS_MODE_SYSFS) + return 0; + + coresight_disable_source(source, NULL); + coresight_disable_path(path); + coresight_release_path(path); + return 0; +} + static int __init coresight_pm_setup(void) { - return cpu_pm_register_notifier(&coresight_cpu_pm_nb); + int ret; + + ret = cpu_pm_register_notifier(&coresight_cpu_pm_nb); + if (ret) + return ret; + + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, + "arm/coresight-core:starting", + NULL, coresight_dying_cpu); + if (ret) + cpu_pm_unregister_notifier(&coresight_cpu_pm_nb); + + return ret; }

static void coresight_pm_cleanup(void) { + cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); cpu_pm_unregister_notifier(&coresight_cpu_pm_nb); }

diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c index c6fe8b25b855a4119110fee4162f55c0154c3d05..862ad0786699c41433eae8683406b3c1340a6cb6 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -699,35 +699,6 @@ static int etm_online_cpu(unsigned int cpu) return 0; }

-static int etm_starting_cpu(unsigned int cpu) -{ - if (!etmdrvdata[cpu]) - return 0; - - spin_lock(&etmdrvdata[cpu]->spinlock); - if (!etmdrvdata[cpu]->os_unlock) { - etm_os_unlock(etmdrvdata[cpu]); - etmdrvdata[cpu]->os_unlock = true; - } - - if (coresight_get_mode(etmdrvdata[cpu]->csdev)) - etm_enable_hw(etmdrvdata[cpu]); - spin_unlock(&etmdrvdata[cpu]->spinlock); - return 0; -} - -static int etm_dying_cpu(unsigned int cpu) -{ - if (!etmdrvdata[cpu]) - return 0; - - spin_lock(&etmdrvdata[cpu]->spinlock); - if (coresight_get_mode(etmdrvdata[cpu]->csdev)) - etm_disable_hw(etmdrvdata[cpu]); - spin_unlock(&etmdrvdata[cpu]->spinlock); - return 0; -} - static bool etm_arch_supported(u8 arch) { switch (arch) { @@ -795,13 +766,6 @@ static int __init etm_hp_setup(void) { int ret;

- ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, - "arm/coresight:starting", - etm_starting_cpu, etm_dying_cpu); - - if (ret) - return ret; - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "arm/coresight:online", etm_online_cpu, NULL); @@ -812,15 +776,11 @@ static int __init etm_hp_setup(void) 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; diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 2870c162fdc1c119f05ee5d92c1f6c71aa1cfb5f..1d7bfa21d7c205ae1b903bd62bc6d675d0fa949d 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1834,33 +1834,6 @@ static int etm4_online_cpu(unsigned int cpu) return 0; }

-static int etm4_starting_cpu(unsigned int cpu) -{ - if (!etmdrvdata[cpu]) - return 0; - - raw_spin_lock(&etmdrvdata[cpu]->spinlock); - if (!etmdrvdata[cpu]->os_unlock) - etm4_os_unlock(etmdrvdata[cpu]); - - if (coresight_get_mode(etmdrvdata[cpu]->csdev)) - etm4_enable_hw(etmdrvdata[cpu]); - raw_spin_unlock(&etmdrvdata[cpu]->spinlock); - return 0; -} - -static int etm4_dying_cpu(unsigned int cpu) -{ - if (!etmdrvdata[cpu]) - return 0; - - raw_spin_lock(&etmdrvdata[cpu]->spinlock); - if (coresight_get_mode(etmdrvdata[cpu]->csdev)) - etm4_disable_hw(etmdrvdata[cpu]); - raw_spin_unlock(&etmdrvdata[cpu]->spinlock); - return 0; -} - static int etm4_cpu_save(struct coresight_device *csdev) { int i, ret = 0; @@ -2110,13 +2083,6 @@ static int __init etm4_pm_setup(void) { int ret;

- ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, - "arm/coresight4:starting", - etm4_starting_cpu, etm4_dying_cpu); - - if (ret) - return ret; - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "arm/coresight4:online", etm4_online_cpu, NULL); @@ -2127,14 +2093,11 @@ static int __init etm4_pm_setup(void) return 0; }

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

static void etm4_pm_clear(void) { - cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); if (hp_online) { cpuhp_remove_state_nocalls(hp_online); hp_online = 0;