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.
Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com Reviewed-by: James Clark james.clark@linaro.org Tested-by: James Clark james.clark@linaro.org Tested-by: Jie Gan jie.gan@oss.qualcomm.com Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 38 ++++++++++++++++++++++++ drivers/hwtracing/coresight/coresight-etm-perf.c | 14 +++------ drivers/hwtracing/coresight/coresight-priv.h | 1 + 3 files changed, 43 insertions(+), 10 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 6b098c3cab0b8a710863bceb2c5f9584ad0bd8af..995a4a1bab3d983141237f453b6f630e73e69e5e 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 +85,39 @@ 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); + + /* Expect no device to be set yet */ + WARN_ON(per_cpu(csdev_source, csdev->cpu)); + 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); + + /* The per-CPU pointer should contain the same csdev */ + WARN_ON(per_cpu(csdev_source, csdev->cpu) != csdev); + 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); +} + struct coresight_device *coresight_get_source(struct coresight_path *path) { struct coresight_device *csdev; @@ -1452,6 +1488,7 @@ 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) @@ -1481,6 +1518,7 @@ 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 bab85f7dac4757173912639ea016cdc32e5616fb..b9e556818c3c6873ed53e5a1b8052443dd7740d0 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); @@ -386,7 +385,7 @@ 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 @@ -864,17 +863,12 @@ 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 75029744561f7744225c7b866eee60e0f7cf9e10..4d6f5bc1df9cc5dfd974a8b27820328e7916f169 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -249,6 +249,7 @@ 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_source(struct coresight_path *path); +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);