| Message ID | 20211019191351.10242-2-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: syscfg: dynamic load | expand |
Good morning Mike, On Tue, Oct 19, 2021 at 08:13:47PM +0100, Mike Leach wrote: > 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> I couldn't remember the patchset so I started reviewing it again from scratch. I didn't find any flaws in the code. On the flip side I think there is two things happening here: 1) the addition of the owner concept and 2) the enhancement of the API to add/remove configurations/features. Please consider splitting in two different patches. More comments tomorrow... Thanks, Mathieu > --- > .../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); > -- > 2.17.1 >
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);