diff options
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-config.h | 2 | ||||
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-syscfg.c | 191 | ||||
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-syscfg.h | 13 |
3 files changed, 165 insertions, 41 deletions
diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h index 2e1670523461..6ba013975741 100644 --- a/drivers/hwtracing/coresight/coresight-config.h +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -134,6 +134,7 @@ struct cscfg_feature_desc { * @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. + * @available: config can be activated - multi-stage load sets true on completion. */ struct cscfg_config_desc { const char *name; @@ -148,6 +149,7 @@ struct cscfg_config_desc { atomic_t active_cnt; void *load_owner; struct config_group *fs_group; + bool available; }; /** diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index 17e728ab5c99..11138a9762b0 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -447,6 +447,8 @@ static void cscfg_unload_owned_cfgs_feats(void *load_owner) struct cscfg_feature_desc *feat_desc, *feat_tmp; struct cscfg_registered_csdev *csdev_item; + lockdep_assert_held(&cscfg_mutex); + /* remove from each csdev instance feature and config lists */ list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) { /* @@ -460,7 +462,6 @@ static void cscfg_unload_owned_cfgs_feats(void *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); } @@ -469,12 +470,90 @@ static void cscfg_unload_owned_cfgs_feats(void *load_owner) /* 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); } } } +/* + * load the features and configs to the lists - called with list mutex held + */ +static int cscfg_load_owned_cfgs_feats(struct cscfg_config_desc **config_descs, + struct cscfg_feature_desc **feat_descs, + struct cscfg_load_owner_info *owner_info) +{ + int i, err; + + lockdep_assert_held(&cscfg_mutex); + + /* load features first */ + if (feat_descs) { + for (i = 0; feat_descs[i]; i++) { + err = cscfg_load_feat(feat_descs[i]); + if (err) { + pr_err("coresight-syscfg: Failed to load feature %s\n", + feat_descs[i]->name); + return err; + } + feat_descs[i]->load_owner = owner_info; + } + } + + /* next any configurations to check feature dependencies */ + if (config_descs) { + for (i = 0; config_descs[i]; i++) { + err = cscfg_load_config(config_descs[i]); + if (err) { + pr_err("coresight-syscfg: Failed to load configuration %s\n", + config_descs[i]->name); + return err; + } + config_descs[i]->load_owner = owner_info; + config_descs[i]->available = false; + } + } + return 0; +} + +/* set configurations as available to activate at the end of the load process */ +static void cscfg_set_configs_available(struct cscfg_config_desc **config_descs) +{ + int i; + + lockdep_assert_held(&cscfg_mutex); + + if (config_descs) { + for (i = 0; config_descs[i]; i++) + config_descs[i]->available = true; + } +} + +/* + * Create and register each of the configurations and features with configfs. + * Called without mutex being held. + */ +static int cscfg_fs_register_cfgs_feats(struct cscfg_config_desc **config_descs, + struct cscfg_feature_desc **feat_descs) +{ + int i, err; + + if (feat_descs) { + for (i = 0; feat_descs[i]; i++) { + err = cscfg_configfs_add_feature(feat_descs[i]); + if (err) + return err; + } + } + if (config_descs) { + for (i = 0; config_descs[i]; i++) { + err = cscfg_configfs_add_config(config_descs[i]); + if (err) + return err; + } + } + return 0; +} + /** * cscfg_load_config_sets - API function to load feature and config sets. * @@ -497,57 +576,63 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs, struct cscfg_feature_desc **feat_descs, struct cscfg_load_owner_info *owner_info) { - int err = 0, i = 0; + int err = 0; mutex_lock(&cscfg_mutex); - - /* load features first */ - if (feat_descs) { - while (feat_descs[i]) { - err = cscfg_load_feat(feat_descs[i]); - if (!err) - err = cscfg_configfs_add_feature(feat_descs[i]); - 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++; - } + if (cscfg_mgr->load_state != CSCFG_NONE) { + mutex_unlock(&cscfg_mutex); + return -EBUSY; } + cscfg_mgr->load_state = CSCFG_LOAD; - /* next any configurations to check feature dependencies */ - i = 0; - if (config_descs) { - while (config_descs[i]) { - err = cscfg_load_config(config_descs[i]); - if (!err) - err = cscfg_configfs_add_config(config_descs[i]); - 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++; - } - } + /* first load and add to the lists */ + err = cscfg_load_owned_cfgs_feats(config_descs, feat_descs, owner_info); + if (err) + goto err_clean_load; /* 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); - } + if (err) + goto err_clean_owner_list; } + /* + * make visible to configfs - configfs manipulation must occur outside + * the list mutex lock to avoid circular lockdep issues with configfs + * built in mutexes and semaphores. This is safe as it is not possible + * to start a new load/unload operation till the current one is done. + */ + mutex_unlock(&cscfg_mutex); + + /* create the configfs elements */ + err = cscfg_fs_register_cfgs_feats(config_descs, feat_descs); + mutex_lock(&cscfg_mutex); + + if (err) + goto err_clean_cfs; + + /* mark any new configs as available for activation */ + cscfg_set_configs_available(config_descs); + goto exit_unlock; + +err_clean_cfs: + /* cleanup after error registering with configfs */ + cscfg_fs_unregister_cfgs_feats(owner_info); + + if (!list_is_singular(&cscfg_mgr->load_order_list)) + cscfg_owner_put(list_prev_entry(owner_info, item)); + +err_clean_owner_list: + list_del(&owner_info->item); + +err_clean_load: + cscfg_unload_owned_cfgs_feats(owner_info); + exit_unlock: + cscfg_mgr->load_state = CSCFG_NONE; mutex_unlock(&cscfg_mutex); return err; } @@ -564,6 +649,9 @@ EXPORT_SYMBOL_GPL(cscfg_load_config_sets); * 1) no configurations are active. * 2) the set being unloaded was the last to be loaded to maintain dependencies. * + * Once the unload operation commences, we disallow any configuration being + * made active until it is complete. + * * @owner_info: Information on owner for set being unloaded. */ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info) @@ -572,6 +660,13 @@ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info) struct cscfg_load_owner_info *load_list_item = NULL; mutex_lock(&cscfg_mutex); + if (cscfg_mgr->load_state != CSCFG_NONE) { + mutex_unlock(&cscfg_mutex); + return -EBUSY; + } + + /* unload op in progress also prevents activation of any config */ + cscfg_mgr->load_state = CSCFG_UNLOAD; /* cannot unload if anything is active */ if (atomic_read(&cscfg_mgr->sys_active_cnt)) { @@ -592,7 +687,12 @@ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info) goto exit_unlock; } - /* unload all belonging to load_owner */ + /* remove from configfs - again outside the scope of the list mutex */ + mutex_unlock(&cscfg_mutex); + cscfg_fs_unregister_cfgs_feats(owner_info); + mutex_lock(&cscfg_mutex); + + /* unload everything from lists belonging to load_owner */ cscfg_unload_owned_cfgs_feats(owner_info); /* remove from load order list */ @@ -603,6 +703,7 @@ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info) list_del(&owner_info->item); exit_unlock: + cscfg_mgr->load_state = CSCFG_NONE; mutex_unlock(&cscfg_mutex); return err; } @@ -780,8 +881,15 @@ static int _cscfg_activate_config(unsigned long cfg_hash) struct cscfg_config_desc *config_desc; int err = -EINVAL; + if (cscfg_mgr->load_state == CSCFG_UNLOAD) + return -EBUSY; + list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) { if ((unsigned long)config_desc->event_ea->var == cfg_hash) { + /* if we happen upon a partly loaded config, can't use it */ + if (config_desc->available == false) + return -EBUSY; + /* must ensure that config cannot be unloaded in use */ err = cscfg_owner_get(config_desc->load_owner); if (err) @@ -1071,6 +1179,7 @@ static int cscfg_create_device(void) INIT_LIST_HEAD(&cscfg_mgr->config_desc_list); INIT_LIST_HEAD(&cscfg_mgr->load_order_list); atomic_set(&cscfg_mgr->sys_active_cnt, 0); + cscfg_mgr->load_state = CSCFG_NONE; /* setup the device */ dev = cscfg_device(); diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h index 9106ffab4833..66e2db890d82 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.h +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -12,6 +12,17 @@ #include "coresight-config.h" +/* + * Load operation types. + * When loading or unloading, another load operation cannot be run. + * When unloading configurations cannot be activated. + */ +enum cscfg_load_ops { + CSCFG_NONE, + CSCFG_LOAD, + CSCFG_UNLOAD +}; + /** * System configuration manager device. * @@ -30,6 +41,7 @@ * @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. + * @load_state: A multi-stage load/unload operation is in progress. */ struct cscfg_manager { struct device dev; @@ -41,6 +53,7 @@ struct cscfg_manager { struct configfs_subsystem cfgfs_subsys; u32 sysfs_active_config; int sysfs_active_preset; + enum cscfg_load_ops load_state; }; /* get reference to dev in cscfg_manager */ |