Update the load API to permit the runtime loading and unloading of new configurations and features.

On load, configurations and features are tagged with a "load owner" that is used to determine sets that were loaded together in a given API call.

To unload the API uses the load owner to unload all elements previously loaded by that owner.

The API also records the order in which different owners loaded their elements into the system. Later loading configurations can use previously loaded features, creating load dependencies. Therefore unload is enforced strictly in the reverse order to load.

A load owner will be an additional loadable module, or a configuration created or loaded via configfs.

Signed-off-by: Mike Leach mike.leach@linaro.org Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org --- .../coresight/coresight-cfg-preload.c | 9 +- .../hwtracing/coresight/coresight-config.h | 9 +- .../coresight/coresight-syscfg-configfs.c | 20 +++ .../coresight/coresight-syscfg-configfs.h | 2 + .../hwtracing/coresight/coresight-syscfg.c | 154 +++++++++++++++++- .../hwtracing/coresight/coresight-syscfg.h | 30 +++- 6 files changed, 216 insertions(+), 8 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cfg-preload.c b/drivers/hwtracing/coresight/coresight-cfg-preload.c index 751af3710d56..e237a4edfa09 100644 --- a/drivers/hwtracing/coresight/coresight-cfg-preload.c +++ b/drivers/hwtracing/coresight/coresight-cfg-preload.c @@ -24,8 +24,13 @@ static struct cscfg_config_desc *preload_cfgs[] = { NULL };

+static struct cscfg_load_owner_info preload_owner = { + .type = CSCFG_OWNER_PRELOAD, +}; + /* preload called on initialisation */ -int cscfg_preload(void) +int cscfg_preload(void *owner_handle) { - return cscfg_load_config_sets(preload_cfgs, preload_feats); + preload_owner.owner_handle = owner_handle; + return cscfg_load_config_sets(preload_cfgs, preload_feats, &preload_owner); } diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h index 25eb6c632692..9bd44b940add 100644 --- a/drivers/hwtracing/coresight/coresight-config.h +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -97,6 +97,8 @@ struct cscfg_regval_desc { * @params_desc: array of parameters used. * @nr_regs: number of registers used. * @regs_desc: array of registers used. + * @load_owner: handle to load owner for dynamic load and unload of features. + * @fs_group: reference to configfs group for dynamic unload. */ struct cscfg_feature_desc { const char *name; @@ -107,6 +109,8 @@ struct cscfg_feature_desc { struct cscfg_parameter_desc *params_desc; int nr_regs; struct cscfg_regval_desc *regs_desc; + void *load_owner; + struct config_group *fs_group; };

/** @@ -128,7 +132,8 @@ struct cscfg_feature_desc { * @presets: Array of preset values. * @event_ea: Extended attribute for perf event value * @active_cnt: ref count for activate on this configuration. - * + * @load_owner: handle to load owner for dynamic load and unload of configs. + * @fs_group: reference to configfs group for dynamic unload. */ struct cscfg_config_desc { const char *name; @@ -141,6 +146,8 @@ struct cscfg_config_desc { const u64 *presets; /* nr_presets * nr_total_params */ struct dev_ext_attribute *event_ea; atomic_t active_cnt; + void *load_owner; + struct config_group *fs_group; };

/** diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c index c547816b9000..345a62f1b728 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c +++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c @@ -334,9 +334,19 @@ int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc) if (IS_ERR(new_group)) return PTR_ERR(new_group); err = configfs_register_group(&cscfg_configs_grp, new_group); + if (!err) + config_desc->fs_group = new_group; return err; }

+void cscfg_configfs_del_config(struct cscfg_config_desc *config_desc) +{ + if (config_desc->fs_group) { + configfs_unregister_group(config_desc->fs_group); + config_desc->fs_group = NULL; + } +} + static struct config_item_type cscfg_features_type = { .ct_owner = THIS_MODULE, }; @@ -358,9 +368,19 @@ int cscfg_configfs_add_feature(struct cscfg_feature_desc *feat_desc) if (IS_ERR(new_group)) return PTR_ERR(new_group); err = configfs_register_group(&cscfg_features_grp, new_group); + if (!err) + feat_desc->fs_group = new_group; return err; }

+void cscfg_configfs_del_feature(struct cscfg_feature_desc *feat_desc) +{ + if (feat_desc->fs_group) { + configfs_unregister_group(feat_desc->fs_group); + feat_desc->fs_group = NULL; + } +} + int cscfg_configfs_init(struct cscfg_manager *cscfg_mgr) { struct configfs_subsystem *subsys; diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.h b/drivers/hwtracing/coresight/coresight-syscfg-configfs.h index 7d6ffe35ca4c..ea1e54d29f7f 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg-configfs.h +++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.h @@ -41,5 +41,7 @@ int cscfg_configfs_init(struct cscfg_manager *cscfg_mgr); void cscfg_configfs_release(struct cscfg_manager *cscfg_mgr); int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc); int cscfg_configfs_add_feature(struct cscfg_feature_desc *feat_desc); +void cscfg_configfs_del_config(struct cscfg_config_desc *config_desc); +void cscfg_configfs_del_feature(struct cscfg_feature_desc *feat_desc);

#endif /* CORESIGHT_SYSCFG_CONFIGFS_H */ diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index fc0760f55c53..9bb0b0913a9a 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -249,6 +249,13 @@ static int cscfg_check_feat_for_cfg(struct cscfg_config_desc *config_desc) static int cscfg_load_feat(struct cscfg_feature_desc *feat_desc) { int err; + struct cscfg_feature_desc *feat_desc_exist; + + /* new feature must have unique name */ + list_for_each_entry(feat_desc_exist, &cscfg_mgr->feat_desc_list, item) { + if (!strcmp(feat_desc_exist->name, feat_desc->name)) + return -EEXIST; + }

/* add feature to any matching registered devices */ err = cscfg_add_feat_to_csdevs(feat_desc); @@ -266,6 +273,13 @@ static int cscfg_load_feat(struct cscfg_feature_desc *feat_desc) static int cscfg_load_config(struct cscfg_config_desc *config_desc) { int err; + struct cscfg_config_desc *config_desc_exist; + + /* new configuration must have a unique name */ + list_for_each_entry(config_desc_exist, &cscfg_mgr->config_desc_list, item) { + if (!strcmp(config_desc_exist->name, config_desc->name)) + return -EEXIST; + }

/* validate features are present */ err = cscfg_check_feat_for_cfg(config_desc); @@ -353,6 +367,72 @@ int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc, return err; }

+static void cscfg_remove_owned_csdev_configs(struct coresight_device *csdev, void *load_owner) +{ + struct cscfg_config_csdev *config_csdev, *tmp; + + if (list_empty(&csdev->config_csdev_list)) + return; + + list_for_each_entry_safe(config_csdev, tmp, &csdev->config_csdev_list, node) { + if (config_csdev->config_desc->load_owner == load_owner) + list_del(&config_csdev->node); + } +} + +static void cscfg_remove_owned_csdev_features(struct coresight_device *csdev, void *load_owner) +{ + struct cscfg_feature_csdev *feat_csdev, *tmp; + + if (list_empty(&csdev->feature_csdev_list)) + return; + + list_for_each_entry_safe(feat_csdev, tmp, &csdev->feature_csdev_list, node) { + if (feat_csdev->feat_desc->load_owner == load_owner) + list_del(&feat_csdev->node); + } +} + +/* + * removal is relatively easy - just remove from all lists, anything that + * matches the owner. Memory for the descriptors will be managed by the owner, + * memory for the csdev items is devm_ allocated with the individual csdev + * devices. + */ +static void cscfg_unload_owned_cfgs_feats(void *load_owner) +{ + struct cscfg_config_desc *config_desc, *cfg_tmp; + struct cscfg_feature_desc *feat_desc, *feat_tmp; + struct cscfg_registered_csdev *csdev_item; + + /* remove from each csdev instance feature and config lists */ + list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) { + /* + * for each csdev, check the loaded lists and remove if + * referenced descriptor is owned + */ + cscfg_remove_owned_csdev_configs(csdev_item->csdev, load_owner); + cscfg_remove_owned_csdev_features(csdev_item->csdev, load_owner); + } + + /* remove from the config descriptor lists */ + list_for_each_entry_safe(config_desc, cfg_tmp, &cscfg_mgr->config_desc_list, item) { + if (config_desc->load_owner == load_owner) { + cscfg_configfs_del_config(config_desc); + etm_perf_del_symlink_cscfg(config_desc); + list_del(&config_desc->item); + } + } + + /* remove from the feature descriptor lists */ + list_for_each_entry_safe(feat_desc, feat_tmp, &cscfg_mgr->feat_desc_list, item) { + if (feat_desc->load_owner == load_owner) { + cscfg_configfs_del_feature(feat_desc); + list_del(&feat_desc->item); + } + } +} + /** * cscfg_load_config_sets - API function to load feature and config sets. * @@ -360,13 +440,22 @@ int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc, * descriptors and load into the system. * Features are loaded first to ensure configuration dependencies can be met. * + * To facilitate dynamic loading and unloading, features and configurations + * have a "load_owner", to allow later unload by the same owner. An owner may + * be a loadable module or configuration dynamically created via configfs. + * As later loaded configurations can use earlier loaded features, creating load + * dependencies, a load order list is maintained. Unload is strictly in the + * reverse order to load. + * * @config_descs: 0 terminated array of configuration descriptors. * @feat_descs: 0 terminated array of feature descriptors. + * @owner_info: Information on the owner of this set. */ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs, - struct cscfg_feature_desc **feat_descs) + struct cscfg_feature_desc **feat_descs, + struct cscfg_load_owner_info *owner_info) { - int err, i = 0; + int err = 0, i = 0;

mutex_lock(&cscfg_mutex);

@@ -379,8 +468,10 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs, if (err) { pr_err("coresight-syscfg: Failed to load feature %s\n", feat_descs[i]->name); + cscfg_unload_owned_cfgs_feats(owner_info); goto exit_unlock; } + feat_descs[i]->load_owner = owner_info; i++; } } @@ -395,18 +486,74 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs, if (err) { pr_err("coresight-syscfg: Failed to load configuration %s\n", config_descs[i]->name); + cscfg_unload_owned_cfgs_feats(owner_info); goto exit_unlock; } + config_descs[i]->load_owner = owner_info; i++; } }

+ /* add the load owner to the load order list */ + list_add_tail(&owner_info->item, &cscfg_mgr->load_order_list); + exit_unlock: mutex_unlock(&cscfg_mutex); return err; } EXPORT_SYMBOL_GPL(cscfg_load_config_sets);

+/** + * cscfg_unload_config_sets - unload a set of configurations by owner. + * + * Dynamic unload of configuration and feature sets is done on the basis of + * the load owner of that set. Later loaded configurations can depend on + * features loaded earlier. + * + * Therefore, unload is only possible if:- + * 1) no configurations are active. + * 2) the set being unloaded was the last to be loaded to maintain dependencies. + * + * @owner_info: Information on owner for set being unloaded. + */ +int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info) +{ + int err = 0; + struct cscfg_load_owner_info *load_list_item = NULL; + + mutex_lock(&cscfg_mutex); + + /* cannot unload if anything is active */ + if (atomic_read(&cscfg_mgr->sys_active_cnt)) { + err = -EBUSY; + goto exit_unlock; + } + + /* cannot unload if not last loaded in load order */ + if (!list_empty(&cscfg_mgr->load_order_list)) { + load_list_item = list_last_entry(&cscfg_mgr->load_order_list, + struct cscfg_load_owner_info, item); + if (load_list_item != owner_info) + load_list_item = NULL; + } + + if (!load_list_item) { + err = -EINVAL; + goto exit_unlock; + } + + /* unload all belonging to load_owner */ + cscfg_unload_owned_cfgs_feats(owner_info); + + /* remove from load order list */ + list_del(&load_list_item->item); + +exit_unlock: + mutex_unlock(&cscfg_mutex); + return err; +} +EXPORT_SYMBOL_GPL(cscfg_unload_config_sets); + /* Handle coresight device registration and add configs and features to devices */

/* iterate through config lists and load matching configs to device */ @@ -826,10 +973,11 @@ int __init cscfg_init(void) INIT_LIST_HEAD(&cscfg_mgr->csdev_desc_list); INIT_LIST_HEAD(&cscfg_mgr->feat_desc_list); INIT_LIST_HEAD(&cscfg_mgr->config_desc_list); + INIT_LIST_HEAD(&cscfg_mgr->load_order_list); atomic_set(&cscfg_mgr->sys_active_cnt, 0);

/* preload built-in configurations */ - err = cscfg_preload(); + err = cscfg_preload(THIS_MODULE); if (err) goto exit_err;

diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h index 8d018efd6ead..e2b2bdab31aa 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.h +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -25,6 +25,7 @@ * @csdev_desc_list: List of coresight devices registered with the configuration manager. * @feat_desc_list: List of feature descriptors to load into registered devices. * @config_desc_list: List of system configuration descriptors to load into registered devices. + * @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. */ @@ -33,6 +34,7 @@ struct cscfg_manager { struct list_head csdev_desc_list; struct list_head feat_desc_list; struct list_head config_desc_list; + struct list_head load_order_list; atomic_t sys_active_cnt; struct configfs_subsystem cfgfs_subsys; }; @@ -56,10 +58,32 @@ struct cscfg_registered_csdev { struct list_head item; };

+/* owner types for loading and unloading of config and feature sets */ +enum cscfg_load_owner_type { + CSCFG_OWNER_PRELOAD, +}; + +/** + * Load item - item to add to the load order list allowing dynamic load and + * unload of configurations and features. Caller loading a config + * set provides a context handle for unload. API ensures that + * items unloaded strictly in reverse order from load to ensure + * dependencies are respected. + * + * @item: list entry for load order list. + * @type: type of owner - allows interpretation of owner_handle. + * @owner_handle: load context - handle for owner of loaded configs. + */ +struct cscfg_load_owner_info { + struct list_head item; + int type; + void *owner_handle; +}; + /* internal core operations for cscfg */ int __init cscfg_init(void); void cscfg_exit(void); -int cscfg_preload(void); +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); @@ -67,7 +91,9 @@ int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc,

/* syscfg manager external API */ int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, - struct cscfg_feature_desc **feat_descs); + struct cscfg_feature_desc **feat_descs, + struct cscfg_load_owner_info *owner_info); +int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info); int cscfg_register_csdev(struct coresight_device *csdev, u32 match_flags, struct cscfg_csdev_feat_ops *ops); void cscfg_unregister_csdev(struct coresight_device *csdev);

CoreSight configurations and features can be added as kernel loadable modules. This patch updates the load owner API to ensure that the module cannot be unloaded either: 1) if the config it supplies is in use 2) if the module is not the last in the load order list.

Signed-off-by: Mike Leach mike.leach@linaro.org Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org --- .../hwtracing/coresight/coresight-syscfg.c | 39 ++++++++++++++++++- .../hwtracing/coresight/coresight-syscfg.h | 1 + 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index 9bb0b0913a9a..4b91d8d9bc37 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -367,6 +367,26 @@ int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc, return err; }

+/* + * Conditionally up reference count on owner to prevent unload. + * + * module loaded configs need to be locked in to prevent premature unload. + */ +static int cscfg_owner_get(struct cscfg_load_owner_info *owner_info) +{ + if ((owner_info->type == CSCFG_OWNER_MODULE) && + (!try_module_get(owner_info->owner_handle))) + return -EINVAL; + return 0; +} + +/* conditionally lower ref count on an owner */ +static void cscfg_owner_put(struct cscfg_load_owner_info *owner_info) +{ + if (owner_info->type == CSCFG_OWNER_MODULE) + module_put(owner_info->owner_handle); +} + static void cscfg_remove_owned_csdev_configs(struct coresight_device *csdev, void *load_owner) { struct cscfg_config_csdev *config_csdev, *tmp; @@ -496,6 +516,14 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs,

/* add the load owner to the load order list */ list_add_tail(&owner_info->item, &cscfg_mgr->load_order_list); + if (!list_is_singular(&cscfg_mgr->load_order_list)) { + /* lock previous item in load order list */ + err = cscfg_owner_get(list_prev_entry(owner_info, item)); + if (err) { + cscfg_unload_owned_cfgs_feats(owner_info); + list_del(&owner_info->item); + } + }

exit_unlock: mutex_unlock(&cscfg_mutex); @@ -546,7 +574,11 @@ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info) cscfg_unload_owned_cfgs_feats(owner_info);

/* remove from load order list */ - list_del(&load_list_item->item); + if (!list_is_singular(&cscfg_mgr->load_order_list)) { + /* unlock previous item in load order list */ + cscfg_owner_put(list_prev_entry(owner_info, item)); + } + list_del(&owner_info->item);

exit_unlock: mutex_unlock(&cscfg_mutex); @@ -738,6 +770,10 @@ int cscfg_activate_config(unsigned long cfg_hash)

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 */ + err = cscfg_owner_get(config_desc->load_owner); + if (err) + break; /* * increment the global active count - control changes to * active configurations @@ -778,6 +814,7 @@ void cscfg_deactivate_config(unsigned long cfg_hash) 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; } diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h index e2b2bdab31aa..1da37874f70f 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.h +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -61,6 +61,7 @@ struct cscfg_registered_csdev { /* owner types for loading and unloading of config and feature sets */ enum cscfg_load_owner_type { CSCFG_OWNER_PRELOAD, + CSCFG_OWNER_MODULE, };

/**

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: Mike Leach mike.leach@linaro.org --- .../coresight/coresight-etm4x-core.c | 11 +- .../coresight/coresight-syscfg-configfs.c | 67 ++++++++++ .../coresight/coresight-syscfg-configfs.h | 2 + .../hwtracing/coresight/coresight-syscfg.c | 126 ++++++++++++++---- .../hwtracing/coresight/coresight-syscfg.h | 8 +- 5 files changed, 186 insertions(+), 28 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 86a313857b58..bf18128cf5de 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -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);

diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c index 345a62f1b728..c388a77a2683 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c +++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c @@ -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_activate_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_activate_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_, activate); + +static ssize_t cscfg_cfg_active_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_active_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_, active_preset); + static struct configfs_attribute *cscfg_config_view_attrs[] = { &cscfg_cfg_attr_description, &cscfg_cfg_attr_feature_refs, + &cscfg_cfg_attr_activate, + &cscfg_cfg_attr_active_preset, NULL, };

diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.h b/drivers/hwtracing/coresight/coresight-syscfg-configfs.h index ea1e54d29f7f..373d84d43268 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg-configfs.h +++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.h @@ -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 */ diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index 4b91d8d9bc37..759c32889efd 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -744,30 +744,20 @@ 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 */ @@ -791,6 +781,101 @@ 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; @@ -806,19 +891,8 @@ 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); diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h index 1da37874f70f..9106ffab4833 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.h +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -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 */

Update the CoreSight System Configuration document to cover the use of loadable modules to add configurations and features to the system.

Signed-off-by: Mike Leach mike.leach@linaro.org --- .../trace/coresight/coresight-config.rst | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)

diff --git a/Documentation/trace/coresight/coresight-config.rst b/Documentation/trace/coresight/coresight-config.rst index a4e3ef295240..911db4da7f99 100644 --- a/Documentation/trace/coresight/coresight-config.rst +++ b/Documentation/trace/coresight/coresight-config.rst @@ -242,3 +242,22 @@ A preset to override the current parameter values can also be selected::

When configurations are selected in this way, then the trace sink used is automatically selected. + +Creating and Loading Custom Configurations +========================================== + +Custom configurations and / or features can be dynamically loaded into the +system by using a loadable module. + +An example of a custom configuration is found in ./samples/coresight. + +This creates a new configuration that uses the existing built in +strobing feature, but provides a different set of presets. + +When the module is loaded, then the configuration appears in the configfs +file system and is selectable in the same way as the built in configuration +described above. + +Configurations can use previously loaded features. The system will ensure +that it is not possible to unload a feature that is currently in use, by +enforcing the unload order as the strict reverse of the load order.