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 per-CPU sink via the PM notifier.
There are no changes to the coresight_enable_helpers() function; the code movement is solely for compilation purposes.
Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 101 +++++++++++++++++++++------ include/linux/coresight.h | 4 ++ 2 files changed, 82 insertions(+), 23 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 04e8c3b862494abb2a5a46d385f0ff4cad93b71f..ef9dbba285710fe508580ee2726e22bcc654014e 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -393,6 +393,25 @@ static void coresight_disable_helper(struct coresight_device *csdev, void *data) helper_ops(csdev)->disable(csdev, data); }
+static int coresight_enable_helpers(struct coresight_device *csdev, + enum cs_mode mode, void *data) +{ + int i, ret = 0; + struct coresight_device *helper; + + for (i = 0; i < csdev->pdata->nr_outconns; ++i) { + helper = csdev->pdata->out_conns[i]->dest_dev; + if (!helper || !coresight_is_helper(helper)) + continue; + + ret = coresight_enable_helper(helper, mode, data); + if (ret) + return ret; + } + + return 0; +} + static void coresight_disable_helpers(struct coresight_device *csdev, void *data) { int i; @@ -480,6 +499,43 @@ static void coresight_restore_source(struct coresight_device *csdev) source_ops(csdev)->restore(csdev); }
+static int coresight_save_percpu_sink(struct coresight_device *csdev) +{ + int ret; + + if (csdev && sink_ops(csdev)->save) { + ret = sink_ops(csdev)->save(csdev); + if (ret) + return ret; + + coresight_disable_helpers(csdev, NULL); + } + + /* Return success if callback is not supported */ + return 0; +} + +static int coresight_restore_percpu_sink(struct coresight_device *csdev, + struct coresight_path *path, + enum cs_mode mode) +{ + int ret = 0; + + if (csdev && sink_ops(csdev)->restore) { + ret = coresight_enable_helpers(csdev, mode, path); + if (ret) + return ret; + + ret = sink_ops(csdev)->restore(csdev); + if (ret) { + coresight_disable_helpers(csdev, path); + return ret; + } + } + + return ret; +} + /* * 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 @@ -553,25 +609,6 @@ void coresight_disable_path(struct coresight_path *path) } EXPORT_SYMBOL_GPL(coresight_disable_path);
-static int coresight_enable_helpers(struct coresight_device *csdev, - enum cs_mode mode, void *data) -{ - int i, ret = 0; - struct coresight_device *helper; - - for (i = 0; i < csdev->pdata->nr_outconns; ++i) { - helper = csdev->pdata->out_conns[i]->dest_dev; - if (!helper || !coresight_is_helper(helper)) - continue; - - ret = coresight_enable_helper(helper, mode, data); - if (ret) - return ret; - } - - return 0; -} - static int _coresight_enable_path(struct coresight_path *path, enum cs_mode mode, void *sink_data, bool in_idle) @@ -1670,9 +1707,12 @@ EXPORT_SYMBOL_GPL(coresight_alloc_device_name); static int coresight_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, void *v) { + int ret; unsigned int cpu = smp_processor_id(); struct coresight_device *source = per_cpu(csdev_source, cpu); struct coresight_path *path; + struct coresight_device *sink; + enum cs_mode mode;
if (!coresight_need_save_restore_source(source)) return NOTIFY_OK; @@ -1685,18 +1725,33 @@ static int coresight_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, if (WARN_ON(!path)) return NOTIFY_BAD;
+ sink = coresight_get_sink(path); + mode = coresight_get_mode(source); + switch (cmd) { case CPU_PM_ENTER: if (coresight_save_source(source)) return NOTIFY_BAD;
- coresight_disable_path_from(path, NULL, true); + ret = 0; + if (coresight_is_percpu_sink(sink)) + ret = coresight_save_percpu_sink(sink); + else + coresight_disable_path_from(path, NULL, true); + + if (ret) { + coresight_restore_source(source); + return NOTIFY_BAD; + } break; case CPU_PM_EXIT: case CPU_PM_ENTER_FAILED: - if (_coresight_enable_path(path, - coresight_get_mode(source), - NULL, true)) + if (coresight_is_percpu_sink(sink)) + ret = coresight_restore_percpu_sink(sink, path, mode); + else + ret = _coresight_enable_path(path, mode, NULL, true); + + if (ret) return NOTIFY_BAD;
coresight_restore_source(source); diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 462876b5a870f3e93ad2a1807a9045d5eb115ccd..21bb99f9684747d7a610aa7185e1ba5f987248d9 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -363,6 +363,8 @@ enum cs_mode { * @alloc_buffer: initialises perf's ring buffer for trace collection. * @free_buffer: release memory allocated in @get_config. * @update_buffer: update buffer pointers after a trace session. + * @save: save context for a sink. + * @restore: restore context for a sink. */ struct coresight_ops_sink { int (*enable)(struct coresight_device *csdev, enum cs_mode mode, @@ -375,6 +377,8 @@ struct coresight_ops_sink { unsigned long (*update_buffer)(struct coresight_device *csdev, struct perf_output_handle *handle, void *sink_config); + int (*save)(struct coresight_device *csdev); + int (*restore)(struct coresight_device *csdev); };
/**