On 1/28/21 5:09 PM, Mike Leach wrote:
Configurations are first activated, then when any coresight device is
enabled, the active configurations are checked and any matching
one is enabled.
This patch provides the activation / enable API.
Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
---
.../hwtracing/coresight/coresight-config.h | 2 +
.../hwtracing/coresight/coresight-syscfg.c | 127 ++++++++++++++++++
.../hwtracing/coresight/coresight-syscfg.h | 10 +-
include/linux/coresight.h | 2 +
4 files changed, 140 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h
index 98380b496046..26396b70c826 100644
--- a/drivers/hwtracing/coresight/coresight-config.h
+++ b/drivers/hwtracing/coresight/coresight-config.h
@@ -156,6 +156,7 @@ struct cscfg_config_feat_ref {
* @presets: Array of preset values.
* @id_ea: Extended attribute for perf configid value
* @event_ea: Extended attribute for perf event value
+ * @active_cnt: ref count for activate on this configuration.
*/
struct cscfg_config_desc {
const char *name;
@@ -168,6 +169,7 @@ struct cscfg_config_desc {
const u64 *presets; /* nr_presets * nr_total_params */
struct dev_ext_attribute *id_ea;
struct dev_ext_attribute *event_ea;
+ atomic_t active_cnt;
};
/**
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c
index a070f135eca3..d79cf5b36758 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg.c
+++ b/drivers/hwtracing/coresight/coresight-syscfg.c
@@ -298,6 +298,7 @@ static int cscfg_load_config(struct cscfg_config_desc *cfg_desc)
return err;
list_add(&cfg_desc->item, &cscfg_mgr->data.config_desc_list);
+ atomic_set(&cfg_desc->active_cnt, 0);
return 0;
}
@@ -477,6 +478,131 @@ void cscfg_unregister_csdev(struct coresight_device *csdev)
}
EXPORT_SYMBOL_GPL(cscfg_unregister_csdev);
+void cscfg_csdev_reset_feats(struct coresight_device *csdev)
+{
+ struct cscfg_feature_csdev *feat;
+
+ mutex_lock(&cscfg_csdev_mutex);
+ if (list_empty(&csdev->feature_csdev_list))
+ goto unlock_exit;
+
+ list_for_each_entry(feat, &csdev->feature_csdev_list, node)
+ cscfg_reset_feat(feat);
+
+unlock_exit:
+ mutex_unlock(&cscfg_csdev_mutex);
+}
+EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats);
+
+/**
+ * Mark a config descriptor as active.
+ * This will be seen when csdev devices are activated in the system.
+ *
+ * Selection by hash value - generated from the configuration name when it
+ * was loaded and added to the cs_etm/configurations file system for selection
+ * by perf.
+ *
+ * @cfg_hash: Hash value of the selected configuration name.
+ */
+int cscfg_activate_config(unsigned long cfg_hash)
+{
+ struct cscfg_config_desc *curr_item, *match_item = 0;
nit: s/0/NULL
+
+ mutex_lock(&cscfg_mutex);
+
+ list_for_each_entry(curr_item, &cscfg_mgr->data.config_desc_list, item) {
+ if ((unsigned long)curr_item->id_ea->var == cfg_hash) {
+ match_item = curr_item;
+ atomic_inc(&cscfg_mgr->data.sys_active_cnt);
+ break;
+ }
+ }
+ mutex_unlock(&cscfg_mutex);
+
+ if (!match_item)
+ return -EINVAL;
+
+ dev_dbg(to_device_cscfg(), "Activate config %s.\n", match_item->name);
+
+ /* mark the descriptors as active so enable config will use them */
+ mutex_lock(&cscfg_csdev_mutex);
+ atomic_inc(&match_item->active_cnt);
+ mutex_unlock(&cscfg_csdev_mutex);
Is there a guarantee that this item is active and present in the list after
we dropped the mutex above ? We could certainly nest the mutex as long as
we follow the order everywhere to prevent such a race.
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cscfg_activate_config);
+
+void cscfg_deactivate_config(unsigned long cfg_hash)
+{
+ struct cscfg_config_desc *curr_item, *match_item = 0;
+
+ mutex_lock(&cscfg_mutex);
+
+ list_for_each_entry(curr_item, &cscfg_mgr->data.config_desc_list, item) {
+ if ((unsigned long)curr_item->id_ea->var == cfg_hash) {
+ match_item = curr_item;
+ break;
+ }
+ }
+ mutex_unlock(&cscfg_mutex);
+ if (!match_item)
+ return;
+
+ dev_dbg(to_device_cscfg(), "Deactivate config %s.\n", match_item->name);
+
+ mutex_lock(&cscfg_csdev_mutex);
+ atomic_dec(&match_item->active_cnt);
+ mutex_unlock(&cscfg_csdev_mutex);
+
+ atomic_dec(&cscfg_mgr->data.sys_active_cnt);
+}
+EXPORT_SYMBOL_GPL(cscfg_deactivate_config);
+
+/* Find and program any active config for the supplied device.*/
+int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
+ unsigned long id_hash, int preset)
+{
+ struct cscfg_config_csdev *cfg = NULL, *item;
+ const struct cscfg_config_desc *desc;
+ int err = 0;
+
+ /* quickly check global count */
+ if (!atomic_read(&cscfg_mgr->data.sys_active_cnt))
+ return 0;
+
+ mutex_lock(&cscfg_csdev_mutex);
+ list_for_each_entry(item, &csdev->config_csdev_list, node) {
+ desc = item->desc;
+ if ((atomic_read(&desc->active_cnt)) &&
+ ((unsigned long)desc->id_ea->var == id_hash)) {
+ cfg = item;
+ break;
+ }
+ }
+ if (cfg) {
+ err = cscfg_csdev_enable_config(cfg, preset);
+ if (!err)
+ csdev->active_cfg_ctxt = (void *)cfg;
+ }
+ mutex_unlock(&cscfg_csdev_mutex);
+ return err;
+}
+EXPORT_SYMBOL_GPL(cscfg_csdev_enable_active_config);
+
+/* save and disable the active config for the device */
+void cscfg_csdev_disable_active_config(struct coresight_device *csdev)
+{
+ struct cscfg_config_csdev *cfg;
+
+ mutex_lock(&cscfg_csdev_mutex);
+ cfg = (struct cscfg_config_csdev *)csdev->active_cfg_ctxt;
+ if (cfg)
+ cscfg_csdev_disable_config(cfg);
+ mutex_unlock(&cscfg_csdev_mutex);
+}
+EXPORT_SYMBOL_GPL(cscfg_csdev_disable_active_config);
+
/* Initialise system configuration management device. */
struct device *to_device_cscfg(void)
@@ -546,6 +672,7 @@ int __init cscfg_init(void)
INIT_LIST_HEAD(&cscfg_mgr->data.feat_desc_list);
INIT_LIST_HEAD(&cscfg_mgr->data.config_desc_list);
cscfg_mgr->data.nr_csdev = 0;
+ atomic_set(&cscfg_mgr->data.sys_active_cnt, 0);
dev_info(to_device_cscfg(), "CoreSight Configuration manager initialised");
return 0;
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h
index ebf5e1491d86..301e26e1e98f 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg.h
+++ b/drivers/hwtracing/coresight/coresight-syscfg.h
@@ -17,13 +17,15 @@
* @csdev_list: List of coresight devices registered with the configuration manager.
* @feat_desc_list: List of feature descriptors to load into registered devices.
nit: Is this aligned ? (It is from Patch 1, though).
* @config_desc_list: List of system configuration descriptors to load into registered devices.
- * @nr_csdev: Number of registered devices with the cscfg system
+ * @nr_csdev: Number of registered devices with the cscfg system
Spurious change ?
+ * @sys_active_cnt: Total number of active config descriptor references.
*/
struct cscfg_api_data {
struct list_head csdev_desc_list;
struct list_head feat_desc_list;
struct list_head config_desc_list;
int nr_csdev;
+ atomic_t sys_active_cnt;
};
/**
@@ -53,6 +55,12 @@ int cscfg_register_csdev(struct coresight_device *csdev,
struct cscfg_match_desc *info,
struct cscfg_csdev_feat_ops *ops);
void cscfg_unregister_csdev(struct coresight_device *csdev);
+int cscfg_activate_config(unsigned long cfg_hash);
+void cscfg_deactivate_config(unsigned long cfg_hash);
+void cscfg_csdev_reset_feats(struct coresight_device *csdev);
+int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
+ unsigned long id_hash, int preset);
+void cscfg_csdev_disable_active_config(struct coresight_device *csdev);
/**
* System configuration manager device.
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index d0126ed326a6..3941854e8280 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -221,6 +221,7 @@ struct coresight_sysfs_link {
* @has_conns_grp: Have added a "connections" group for sysfs links.
* @feature_csdev_list: List of complex feature programming added to the device.
* @config_csdev_list: List of system configurations added to the device.
+ * @active_cfg_ctxt: Context information for current active congfig.
*/
struct coresight_device {
struct coresight_platform_data *pdata;
@@ -245,6 +246,7 @@ struct coresight_device {
/* system configuration and feature lists */
struct list_head feature_csdev_list;
struct list_head config_csdev_list;
+ void *active_cfg_ctxt;
};
Suzuki