Commit 7ebd0ec6 authored by Mike Leach's avatar Mike Leach Committed by Mathieu Poirier
Browse files

coresight: configfs: Allow configfs to activate configuration 



Adds configfs attributes to allow a configuration to be enabled for use
when sysfs is used to control CoreSight.

perf retains independent enabling of configurations.

Signed-off-by: default avatarMike Leach <mike.leach@linaro.org>
Link: https://lore.kernel.org/r/20211124200038.28662-6-mike.leach@linaro.org


Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
parent ede5bab8

drivers/hwtracing/coresight/coresight-etm4x-core.c

+10 −1
Original line number Diff line number Diff line
@@ -722,7 +722,16 @@ static int etm4_enable_sysfs(struct coresight_device *csdev) 
{

	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

	struct etm4_enable_arg arg = { };

	int ret;

	unsigned long cfg_hash;

	int ret, preset;



	/* enable any config activated by configfs */

	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);

	if (cfg_hash) {

		ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);

		if (ret)

			return ret;

	}



	spin_lock(&drvdata->spinlock);

drivers/hwtracing/coresight/coresight-syscfg-configfs.c

+67 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 


#include <linux/configfs.h>



#include "coresight-config.h"

#include "coresight-syscfg-configfs.h"



/* create a default ci_type. */
@@ -87,9 +88,75 @@ static ssize_t cscfg_cfg_values_show(struct config_item *item, char *page) 
}

CONFIGFS_ATTR_RO(cscfg_cfg_, values);



static ssize_t cscfg_cfg_enable_show(struct config_item *item, char *page)

{

	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),

							 struct cscfg_fs_config, group);



	return scnprintf(page, PAGE_SIZE, "%d\n", fs_config->active);

}



static ssize_t cscfg_cfg_enable_store(struct config_item *item,

					const char *page, size_t count)

{

	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),

							 struct cscfg_fs_config, group);

	int err;

	bool val;



	err = kstrtobool(page, &val);

	if (!err)

		err = cscfg_config_sysfs_activate(fs_config->config_desc, val);

	if (!err) {

		fs_config->active = val;

		if (val)

			cscfg_config_sysfs_set_preset(fs_config->preset);

	}

	return err ? err : count;

}

CONFIGFS_ATTR(cscfg_cfg_, enable);



static ssize_t cscfg_cfg_preset_show(struct config_item *item, char *page)

{

	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),

							 struct cscfg_fs_config, group);



	return scnprintf(page, PAGE_SIZE, "%d\n", fs_config->preset);

}



static ssize_t cscfg_cfg_preset_store(struct config_item *item,

					     const char *page, size_t count)

{

	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),

							 struct cscfg_fs_config, group);

	int preset, err;



	err = kstrtoint(page, 0, &preset);

	if (!err) {

		/*

		 * presets start at 1, and go up to max (15),

		 * but the config may provide fewer.

		 */

		if ((preset < 1) || (preset > fs_config->config_desc->nr_presets))

			err = -EINVAL;

	}



	if (!err) {

		/* set new value */

		fs_config->preset = preset;

		/* set on system if active */

		if (fs_config->active)

			cscfg_config_sysfs_set_preset(fs_config->preset);

	}

	return err ? err : count;

}

CONFIGFS_ATTR(cscfg_cfg_, preset);



static struct configfs_attribute *cscfg_config_view_attrs[] = {

	&cscfg_cfg_attr_description,

	&cscfg_cfg_attr_feature_refs,

	&cscfg_cfg_attr_enable,

	&cscfg_cfg_attr_preset,

	NULL,

};

drivers/hwtracing/coresight/coresight-syscfg-configfs.h

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
struct cscfg_fs_config {

	struct cscfg_config_desc *config_desc;

	struct config_group group;

	bool active;

	int preset;

};



/* container for feature view */

drivers/hwtracing/coresight/coresight-syscfg.c

+100 −26
Original line number Diff line number Diff line
@@ -745,30 +745,20 @@ void cscfg_csdev_reset_feats(struct coresight_device *csdev) 
}

EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats);



/**

 * cscfg_activate_config -  Mark a configuration descriptor as active.

 *

 * This will be seen when csdev devices are enabled in the system.

 * Only activated configurations can be enabled on individual devices.

 * Activation protects the configuration from alteration or removal while

 * active.

 *

 * 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.

/*

 * This activate configuration for either perf or sysfs. Perf can have multiple

 * active configs, selected per event, sysfs is limited to one.

 *

 * Increments the configuration descriptor active count and the global active

 * count.

 *

 * @cfg_hash: Hash value of the selected configuration name.

 */

int cscfg_activate_config(unsigned long cfg_hash)

static int _cscfg_activate_config(unsigned long cfg_hash)

{

	struct cscfg_config_desc *config_desc;

	int err = -EINVAL;



	mutex_lock(&cscfg_mutex);



	list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {

		if ((unsigned long)config_desc->event_ea->var == cfg_hash) {

			/* must ensure that config cannot be unloaded in use */
@@ -792,6 +782,101 @@ int cscfg_activate_config(unsigned long cfg_hash) 
			break;

		}

	}

	return err;

}



static void _cscfg_deactivate_config(unsigned long cfg_hash)

{

	struct cscfg_config_desc *config_desc;



	list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {

		if ((unsigned long)config_desc->event_ea->var == cfg_hash) {

			atomic_dec(&config_desc->active_cnt);

			atomic_dec(&cscfg_mgr->sys_active_cnt);

			cscfg_owner_put(config_desc->load_owner);

			dev_dbg(cscfg_device(), "Deactivate config %s.\n", config_desc->name);

			break;

		}

	}

}



/*

 * called from configfs to set/clear the active configuration for use when

 * using sysfs to control trace.

 */

int cscfg_config_sysfs_activate(struct cscfg_config_desc *config_desc, bool activate)

{

	unsigned long cfg_hash;

	int err = 0;



	mutex_lock(&cscfg_mutex);



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



	if (activate) {

		/* cannot be a current active value to activate this */

		if (cscfg_mgr->sysfs_active_config) {

			err = -EBUSY;

			goto exit_unlock;

		}

		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) {

			_cscfg_deactivate_config(cfg_hash);

			cscfg_mgr->sysfs_active_config = 0;

		} else

			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);

	cscfg_mgr->sysfs_active_preset = preset;

	mutex_unlock(&cscfg_mutex);

}



/*

 * Used by a device to get the config and preset selected as active in configfs,

 * when using sysfs to control trace.

 */

void cscfg_config_sysfs_get_active_cfg(unsigned long *cfg_hash, int *preset)

{

	mutex_lock(&cscfg_mutex);

	*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);



/**

 * cscfg_activate_config -  Mark a configuration descriptor as active.

 *

 * This will be seen when csdev devices are enabled in the system.

 * Only activated configurations can be enabled on individual devices.

 * Activation protects the configuration from alteration or removal while

 * active.

 *

 * 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)

{

	int err = 0;



	mutex_lock(&cscfg_mutex);

	err = _cscfg_activate_config(cfg_hash);

	mutex_unlock(&cscfg_mutex);



	return err;
@@ -807,19 +892,8 @@ EXPORT_SYMBOL_GPL(cscfg_activate_config); 
 */

void cscfg_deactivate_config(unsigned long cfg_hash)

{

	struct cscfg_config_desc *config_desc;



	mutex_lock(&cscfg_mutex);



	list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {

		if ((unsigned long)config_desc->event_ea->var == cfg_hash) {

			atomic_dec(&config_desc->active_cnt);

			atomic_dec(&cscfg_mgr->sys_active_cnt);

			cscfg_owner_put(config_desc->load_owner);

			dev_dbg(cscfg_device(), "Deactivate config %s.\n", config_desc->name);

			break;

		}

	}

	_cscfg_deactivate_config(cfg_hash);

	mutex_unlock(&cscfg_mutex);

}

EXPORT_SYMBOL_GPL(cscfg_deactivate_config);

drivers/hwtracing/coresight/coresight-syscfg.h

+7 −1
Original line number Diff line number Diff line
@@ -28,6 +28,8 @@ 
 * @load_order_list:    Ordered list of owners for dynamically loaded configurations.

 * @sys_active_cnt:	Total number of active config descriptor references.

 * @cfgfs_subsys:	configfs subsystem used to manage configurations.

 * @sysfs_active_config:Active config hash used if CoreSight controlled from sysfs.

 * @sysfs_active_preset:Active preset index used if CoreSight controlled from sysfs.

 */

struct cscfg_manager {

	struct device dev;
@@ -37,6 +39,8 @@ struct cscfg_manager { 
	struct list_head load_order_list;

	atomic_t sys_active_cnt;

	struct configfs_subsystem cfgfs_subsys;

	u32 sysfs_active_config;

	int sysfs_active_preset;

};



/* get reference to dev in cscfg_manager */
@@ -88,7 +92,8 @@ int cscfg_preload(void *owner_handle); 
const struct cscfg_feature_desc *cscfg_get_named_feat_desc(const char *name);

int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc,

				int param_idx, u64 value);



int cscfg_config_sysfs_activate(struct cscfg_config_desc *cfg_desc, bool activate);

void cscfg_config_sysfs_set_preset(int preset);



/* syscfg manager external API */

int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs,
@@ -104,5 +109,6 @@ void cscfg_csdev_reset_feats(struct coresight_device *csdev); 
int cscfg_csdev_enable_active_config(struct coresight_device *csdev,

				     unsigned long cfg_hash, int preset);

void cscfg_csdev_disable_active_config(struct coresight_device *csdev);

void cscfg_config_sysfs_get_active_cfg(unsigned long *cfg_hash, int *preset);



#endif /* CORESIGHT_SYSCFG_H */