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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/hwtracing/coresight/coresight-syscfg.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-syscfg.c')
-rw-r--r-- | drivers/hwtracing/coresight/coresight-syscfg.c | 1298 |
1 files changed, 1298 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c new file mode 100644 index 0000000000..11138a9762 --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -0,0 +1,1298 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020 Linaro Limited, All rights reserved. + * Author: Mike Leach <mike.leach@linaro.org> + */ + +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include "coresight-config.h" +#include "coresight-etm-perf.h" +#include "coresight-syscfg.h" +#include "coresight-syscfg-configfs.h" + +/* + * cscfg_ API manages configurations and features for the entire coresight + * infrastructure. + * + * It allows the loading of configurations and features, and loads these into + * coresight devices as appropriate. + */ + +/* protect the cscsg_data and device */ +static DEFINE_MUTEX(cscfg_mutex); + +/* only one of these */ +static struct cscfg_manager *cscfg_mgr; + +/* load features and configuations into the lists */ + +/* get name feature instance from a coresight device list of features */ +static struct cscfg_feature_csdev * +cscfg_get_feat_csdev(struct coresight_device *csdev, const char *name) +{ + struct cscfg_feature_csdev *feat_csdev = NULL; + + list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node) { + if (strcmp(feat_csdev->feat_desc->name, name) == 0) + return feat_csdev; + } + return NULL; +} + +/* allocate the device config instance - with max number of used features */ +static struct cscfg_config_csdev * +cscfg_alloc_csdev_cfg(struct coresight_device *csdev, int nr_feats) +{ + struct cscfg_config_csdev *config_csdev = NULL; + struct device *dev = csdev->dev.parent; + + /* this is being allocated using the devm for the coresight device */ + config_csdev = devm_kzalloc(dev, + offsetof(struct cscfg_config_csdev, feats_csdev[nr_feats]), + GFP_KERNEL); + if (!config_csdev) + return NULL; + + config_csdev->csdev = csdev; + return config_csdev; +} + +/* Load a config into a device if there are any feature matches between config and device */ +static int cscfg_add_csdev_cfg(struct coresight_device *csdev, + struct cscfg_config_desc *config_desc) +{ + struct cscfg_config_csdev *config_csdev = NULL; + struct cscfg_feature_csdev *feat_csdev; + unsigned long flags; + int i; + + /* look at each required feature and see if it matches any feature on the device */ + for (i = 0; i < config_desc->nr_feat_refs; i++) { + /* look for a matching name */ + feat_csdev = cscfg_get_feat_csdev(csdev, config_desc->feat_ref_names[i]); + if (feat_csdev) { + /* + * At least one feature on this device matches the config + * add a config instance to the device and a reference to the feature. + */ + if (!config_csdev) { + config_csdev = cscfg_alloc_csdev_cfg(csdev, + config_desc->nr_feat_refs); + if (!config_csdev) + return -ENOMEM; + config_csdev->config_desc = config_desc; + } + config_csdev->feats_csdev[config_csdev->nr_feat++] = feat_csdev; + } + } + /* if matched features, add config to device.*/ + if (config_csdev) { + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + list_add(&config_csdev->node, &csdev->config_csdev_list); + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + } + + return 0; +} + +/* + * Add the config to the set of registered devices - call with mutex locked. + * Iterates through devices - any device that matches one or more of the + * configuration features will load it, the others will ignore it. + */ +static int cscfg_add_cfg_to_csdevs(struct cscfg_config_desc *config_desc) +{ + struct cscfg_registered_csdev *csdev_item; + int err; + + list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) { + err = cscfg_add_csdev_cfg(csdev_item->csdev, config_desc); + if (err) + return err; + } + return 0; +} + +/* + * Allocate a feature object for load into a csdev. + * memory allocated using the csdev->dev object using devm managed allocator. + */ +static struct cscfg_feature_csdev * +cscfg_alloc_csdev_feat(struct coresight_device *csdev, struct cscfg_feature_desc *feat_desc) +{ + struct cscfg_feature_csdev *feat_csdev = NULL; + struct device *dev = csdev->dev.parent; + int i; + + feat_csdev = devm_kzalloc(dev, sizeof(struct cscfg_feature_csdev), GFP_KERNEL); + if (!feat_csdev) + return NULL; + + /* parameters are optional - could be 0 */ + feat_csdev->nr_params = feat_desc->nr_params; + + /* + * if we need parameters, zero alloc the space here, the load routine in + * the csdev device driver will fill out some information according to + * feature descriptor. + */ + if (feat_csdev->nr_params) { + feat_csdev->params_csdev = devm_kcalloc(dev, feat_csdev->nr_params, + sizeof(struct cscfg_parameter_csdev), + GFP_KERNEL); + if (!feat_csdev->params_csdev) + return NULL; + + /* + * fill in the feature reference in the param - other fields + * handled by loader in csdev. + */ + for (i = 0; i < feat_csdev->nr_params; i++) + feat_csdev->params_csdev[i].feat_csdev = feat_csdev; + } + + /* + * Always have registers to program - again the load routine in csdev device + * will fill out according to feature descriptor and device requirements. + */ + feat_csdev->nr_regs = feat_desc->nr_regs; + feat_csdev->regs_csdev = devm_kcalloc(dev, feat_csdev->nr_regs, + sizeof(struct cscfg_regval_csdev), + GFP_KERNEL); + if (!feat_csdev->regs_csdev) + return NULL; + + /* load the feature default values */ + feat_csdev->feat_desc = feat_desc; + feat_csdev->csdev = csdev; + + return feat_csdev; +} + +/* load one feature into one coresight device */ +static int cscfg_load_feat_csdev(struct coresight_device *csdev, + struct cscfg_feature_desc *feat_desc, + struct cscfg_csdev_feat_ops *ops) +{ + struct cscfg_feature_csdev *feat_csdev; + unsigned long flags; + int err; + + if (!ops->load_feat) + return -EINVAL; + + feat_csdev = cscfg_alloc_csdev_feat(csdev, feat_desc); + if (!feat_csdev) + return -ENOMEM; + + /* load the feature into the device */ + err = ops->load_feat(csdev, feat_csdev); + if (err) + return err; + + /* add to internal csdev feature list & initialise using reset call */ + cscfg_reset_feat(feat_csdev); + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + list_add(&feat_csdev->node, &csdev->feature_csdev_list); + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + + return 0; +} + +/* + * Add feature to any matching devices - call with mutex locked. + * Iterates through devices - any device that matches the feature will be + * called to load it. + */ +static int cscfg_add_feat_to_csdevs(struct cscfg_feature_desc *feat_desc) +{ + struct cscfg_registered_csdev *csdev_item; + int err; + + list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) { + if (csdev_item->match_flags & feat_desc->match_flags) { + err = cscfg_load_feat_csdev(csdev_item->csdev, feat_desc, &csdev_item->ops); + if (err) + return err; + } + } + return 0; +} + +/* check feature list for a named feature - call with mutex locked. */ +static bool cscfg_match_list_feat(const char *name) +{ + struct cscfg_feature_desc *feat_desc; + + list_for_each_entry(feat_desc, &cscfg_mgr->feat_desc_list, item) { + if (strcmp(feat_desc->name, name) == 0) + return true; + } + return false; +} + +/* check all feat needed for cfg are in the list - call with mutex locked. */ +static int cscfg_check_feat_for_cfg(struct cscfg_config_desc *config_desc) +{ + int i; + + for (i = 0; i < config_desc->nr_feat_refs; i++) + if (!cscfg_match_list_feat(config_desc->feat_ref_names[i])) + return -EINVAL; + return 0; +} + +/* + * load feature - add to feature list. + */ +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); + if (err) + return err; + + list_add(&feat_desc->item, &cscfg_mgr->feat_desc_list); + return 0; +} + +/* + * load config into the system - validate used features exist then add to + * config list. + */ +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); + if (err) + return err; + + /* add config to any matching registered device */ + err = cscfg_add_cfg_to_csdevs(config_desc); + if (err) + return err; + + /* add config to perf fs to allow selection */ + err = etm_perf_add_symlink_cscfg(cscfg_device(), config_desc); + if (err) + return err; + + list_add(&config_desc->item, &cscfg_mgr->config_desc_list); + atomic_set(&config_desc->active_cnt, 0); + return 0; +} + +/* get a feature descriptor by name */ +const struct cscfg_feature_desc *cscfg_get_named_feat_desc(const char *name) +{ + const struct cscfg_feature_desc *feat_desc = NULL, *feat_desc_item; + + mutex_lock(&cscfg_mutex); + + list_for_each_entry(feat_desc_item, &cscfg_mgr->feat_desc_list, item) { + if (strcmp(feat_desc_item->name, name) == 0) { + feat_desc = feat_desc_item; + break; + } + } + + mutex_unlock(&cscfg_mutex); + return feat_desc; +} + +/* called with cscfg_mutex held */ +static struct cscfg_feature_csdev * +cscfg_csdev_get_feat_from_desc(struct coresight_device *csdev, + struct cscfg_feature_desc *feat_desc) +{ + struct cscfg_feature_csdev *feat_csdev; + + list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node) { + if (feat_csdev->feat_desc == feat_desc) + return feat_csdev; + } + return NULL; +} + +int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc, + int param_idx, u64 value) +{ + int err = 0; + struct cscfg_feature_csdev *feat_csdev; + struct cscfg_registered_csdev *csdev_item; + + mutex_lock(&cscfg_mutex); + + /* check if any config active & return busy */ + if (atomic_read(&cscfg_mgr->sys_active_cnt)) { + err = -EBUSY; + goto unlock_exit; + } + + /* set the value */ + if ((param_idx < 0) || (param_idx >= feat_desc->nr_params)) { + err = -EINVAL; + goto unlock_exit; + } + feat_desc->params_desc[param_idx].value = value; + + /* update loaded instances.*/ + list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) { + feat_csdev = cscfg_csdev_get_feat_from_desc(csdev_item->csdev, feat_desc); + if (feat_csdev) + feat_csdev->params_csdev[param_idx].current_value = value; + } + +unlock_exit: + mutex_unlock(&cscfg_mutex); + 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; + + 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); + } +} + +/* + * Unregister all configuration and features from configfs owned by load_owner. + * Although this is called without the list mutex being held, it is in the + * context of an unload operation which are strictly serialised, + * so the lists cannot change during this call. + */ +static void cscfg_fs_unregister_cfgs_feats(void *load_owner) +{ + struct cscfg_config_desc *config_desc; + struct cscfg_feature_desc *feat_desc; + + list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) { + if (config_desc->load_owner == load_owner) + cscfg_configfs_del_config(config_desc); + } + list_for_each_entry(feat_desc, &cscfg_mgr->feat_desc_list, item) { + if (feat_desc->load_owner == load_owner) + cscfg_configfs_del_feature(feat_desc); + } +} + +/* + * 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; + + 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) { + /* + * 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) { + 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) { + 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. + * + * Take a 0 terminated array of feature descriptors and/or configuration + * 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_load_owner_info *owner_info) +{ + int err = 0; + + mutex_lock(&cscfg_mutex); + if (cscfg_mgr->load_state != CSCFG_NONE) { + mutex_unlock(&cscfg_mutex); + return -EBUSY; + } + cscfg_mgr->load_state = CSCFG_LOAD; + + /* 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) + 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; +} +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. + * + * 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) +{ + int err = 0; + 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)) { + 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; + } + + /* 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 */ + 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: + cscfg_mgr->load_state = CSCFG_NONE; + 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 */ +static int cscfg_add_cfgs_csdev(struct coresight_device *csdev) +{ + struct cscfg_config_desc *config_desc; + int err = 0; + + list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) { + err = cscfg_add_csdev_cfg(csdev, config_desc); + if (err) + break; + } + return err; +} + +/* iterate through feature lists and load matching features to device */ +static int cscfg_add_feats_csdev(struct coresight_device *csdev, + u32 match_flags, + struct cscfg_csdev_feat_ops *ops) +{ + struct cscfg_feature_desc *feat_desc; + int err = 0; + + if (!ops->load_feat) + return -EINVAL; + + list_for_each_entry(feat_desc, &cscfg_mgr->feat_desc_list, item) { + if (feat_desc->match_flags & match_flags) { + err = cscfg_load_feat_csdev(csdev, feat_desc, ops); + if (err) + break; + } + } + return err; +} + +/* Add coresight device to list and copy its matching info */ +static int cscfg_list_add_csdev(struct coresight_device *csdev, + u32 match_flags, + struct cscfg_csdev_feat_ops *ops) +{ + struct cscfg_registered_csdev *csdev_item; + + /* allocate the list entry structure */ + csdev_item = kzalloc(sizeof(struct cscfg_registered_csdev), GFP_KERNEL); + if (!csdev_item) + return -ENOMEM; + + csdev_item->csdev = csdev; + csdev_item->match_flags = match_flags; + csdev_item->ops.load_feat = ops->load_feat; + list_add(&csdev_item->item, &cscfg_mgr->csdev_desc_list); + + INIT_LIST_HEAD(&csdev->feature_csdev_list); + INIT_LIST_HEAD(&csdev->config_csdev_list); + spin_lock_init(&csdev->cscfg_csdev_lock); + + return 0; +} + +/* remove a coresight device from the list and free data */ +static void cscfg_list_remove_csdev(struct coresight_device *csdev) +{ + struct cscfg_registered_csdev *csdev_item, *tmp; + + list_for_each_entry_safe(csdev_item, tmp, &cscfg_mgr->csdev_desc_list, item) { + if (csdev_item->csdev == csdev) { + list_del(&csdev_item->item); + kfree(csdev_item); + break; + } + } +} + +/** + * cscfg_register_csdev - register a coresight device with the syscfg manager. + * + * Registers the coresight device with the system. @match_flags used to check + * if the device is a match for registered features. Any currently registered + * configurations and features that match the device will be loaded onto it. + * + * @csdev: The coresight device to register. + * @match_flags: Matching information to load features. + * @ops: Standard operations supported by the device. + */ +int cscfg_register_csdev(struct coresight_device *csdev, + u32 match_flags, + struct cscfg_csdev_feat_ops *ops) +{ + int ret = 0; + + mutex_lock(&cscfg_mutex); + + /* add device to list of registered devices */ + ret = cscfg_list_add_csdev(csdev, match_flags, ops); + if (ret) + goto reg_csdev_unlock; + + /* now load any registered features and configs matching the device. */ + ret = cscfg_add_feats_csdev(csdev, match_flags, ops); + if (ret) { + cscfg_list_remove_csdev(csdev); + goto reg_csdev_unlock; + } + + ret = cscfg_add_cfgs_csdev(csdev); + if (ret) { + cscfg_list_remove_csdev(csdev); + goto reg_csdev_unlock; + } + + pr_info("CSCFG registered %s", dev_name(&csdev->dev)); + +reg_csdev_unlock: + mutex_unlock(&cscfg_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(cscfg_register_csdev); + +/** + * cscfg_unregister_csdev - remove coresight device from syscfg manager. + * + * @csdev: Device to remove. + */ +void cscfg_unregister_csdev(struct coresight_device *csdev) +{ + mutex_lock(&cscfg_mutex); + cscfg_list_remove_csdev(csdev); + mutex_unlock(&cscfg_mutex); +} +EXPORT_SYMBOL_GPL(cscfg_unregister_csdev); + +/** + * cscfg_csdev_reset_feats - reset features for a CoreSight device. + * + * Resets all parameters and register values for any features loaded + * into @csdev to their default values. + * + * @csdev: The CoreSight device. + */ +void cscfg_csdev_reset_feats(struct coresight_device *csdev) +{ + struct cscfg_feature_csdev *feat_csdev; + unsigned long flags; + + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + if (list_empty(&csdev->feature_csdev_list)) + goto unlock_exit; + + list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node) + cscfg_reset_feat(feat_csdev); + +unlock_exit: + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); +} +EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats); + +/* + * 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. + */ +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) + break; + /* + * increment the global active count - control changes to + * active configurations + */ + atomic_inc(&cscfg_mgr->sys_active_cnt); + + /* + * mark the descriptor as active so enable config on a + * device instance will use it + */ + atomic_inc(&config_desc->active_cnt); + + err = 0; + dev_dbg(cscfg_device(), "Activate config %s.\n", config_desc->name); + 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; +} +EXPORT_SYMBOL_GPL(cscfg_activate_config); + +/** + * cscfg_deactivate_config - Mark a config descriptor as inactive. + * + * Decrement the configuration and global active counts. + * + * @cfg_hash: Hash value of the selected configuration name. + */ +void cscfg_deactivate_config(unsigned long cfg_hash) +{ + mutex_lock(&cscfg_mutex); + _cscfg_deactivate_config(cfg_hash); + mutex_unlock(&cscfg_mutex); +} +EXPORT_SYMBOL_GPL(cscfg_deactivate_config); + +/** + * cscfg_csdev_enable_active_config - Enable matching active configuration for device. + * + * Enables the configuration selected by @cfg_hash if the configuration is supported + * on the device and has been activated. + * + * If active and supported the CoreSight device @csdev will be programmed with the + * configuration, using @preset parameters. + * + * Should be called before driver hardware enable for the requested device, prior to + * programming and enabling the physical hardware. + * + * @csdev: CoreSight device to program. + * @cfg_hash: Selector for the configuration. + * @preset: Preset parameter values to use, 0 for current / default values. + */ +int cscfg_csdev_enable_active_config(struct coresight_device *csdev, + unsigned long cfg_hash, int preset) +{ + struct cscfg_config_csdev *config_csdev_active = NULL, *config_csdev_item; + const struct cscfg_config_desc *config_desc; + unsigned long flags; + int err = 0; + + /* quickly check global count */ + if (!atomic_read(&cscfg_mgr->sys_active_cnt)) + return 0; + + /* + * Look for matching configuration - set the active configuration + * context if found. + */ + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + list_for_each_entry(config_csdev_item, &csdev->config_csdev_list, node) { + config_desc = config_csdev_item->config_desc; + if ((atomic_read(&config_desc->active_cnt)) && + ((unsigned long)config_desc->event_ea->var == cfg_hash)) { + config_csdev_active = config_csdev_item; + csdev->active_cscfg_ctxt = (void *)config_csdev_active; + break; + } + } + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + + /* + * If found, attempt to enable + */ + if (config_csdev_active) { + /* + * Call the generic routine that will program up the internal + * driver structures prior to programming up the hardware. + * This routine takes the driver spinlock saved in the configs. + */ + err = cscfg_csdev_enable_config(config_csdev_active, preset); + if (!err) { + /* + * Successful programming. Check the active_cscfg_ctxt + * pointer to ensure no pre-emption disabled it via + * cscfg_csdev_disable_active_config() before + * we could start. + * + * Set enabled if OK, err if not. + */ + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + if (csdev->active_cscfg_ctxt) + config_csdev_active->enabled = true; + else + err = -EBUSY; + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + } + } + return err; +} +EXPORT_SYMBOL_GPL(cscfg_csdev_enable_active_config); + +/** + * cscfg_csdev_disable_active_config - disable an active config on the device. + * + * Disables the active configuration on the CoreSight device @csdev. + * Disable will save the values of any registers marked in the configurations + * as save on disable. + * + * Should be called after driver hardware disable for the requested device, + * after disabling the physical hardware and reading back registers. + * + * @csdev: The CoreSight device. + */ +void cscfg_csdev_disable_active_config(struct coresight_device *csdev) +{ + struct cscfg_config_csdev *config_csdev; + unsigned long flags; + + /* + * Check if we have an active config, and that it was successfully enabled. + * If it was not enabled, we have no work to do, otherwise mark as disabled. + * Clear the active config pointer. + */ + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + config_csdev = (struct cscfg_config_csdev *)csdev->active_cscfg_ctxt; + if (config_csdev) { + if (!config_csdev->enabled) + config_csdev = NULL; + else + config_csdev->enabled = false; + } + csdev->active_cscfg_ctxt = NULL; + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + + /* true if there was an enabled active config */ + if (config_csdev) + cscfg_csdev_disable_config(config_csdev); +} +EXPORT_SYMBOL_GPL(cscfg_csdev_disable_active_config); + +/* Initialise system configuration management device. */ + +struct device *cscfg_device(void) +{ + return cscfg_mgr ? &cscfg_mgr->dev : NULL; +} + +/* Must have a release function or the kernel will complain on module unload */ +static void cscfg_dev_release(struct device *dev) +{ + mutex_lock(&cscfg_mutex); + kfree(cscfg_mgr); + cscfg_mgr = NULL; + mutex_unlock(&cscfg_mutex); +} + +/* a device is needed to "own" some kernel elements such as sysfs entries. */ +static int cscfg_create_device(void) +{ + struct device *dev; + int err = -ENOMEM; + + mutex_lock(&cscfg_mutex); + if (cscfg_mgr) { + err = -EINVAL; + goto create_dev_exit_unlock; + } + + cscfg_mgr = kzalloc(sizeof(struct cscfg_manager), GFP_KERNEL); + if (!cscfg_mgr) + goto create_dev_exit_unlock; + + /* initialise the cscfg_mgr structure */ + 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); + cscfg_mgr->load_state = CSCFG_NONE; + + /* setup the device */ + dev = cscfg_device(); + dev->release = cscfg_dev_release; + dev->init_name = "cs_system_cfg"; + + err = device_register(dev); + if (err) + put_device(dev); + +create_dev_exit_unlock: + mutex_unlock(&cscfg_mutex); + return err; +} + +/* + * Loading and unloading is generally on user discretion. + * If exiting due to coresight module unload, we need to unload any configurations that remain, + * before we unregister the configfs intrastructure. + * + * Do this by walking the load_owner list and taking appropriate action, depending on the load + * owner type. + */ +static void cscfg_unload_cfgs_on_exit(void) +{ + struct cscfg_load_owner_info *owner_info = NULL; + + /* + * grab the mutex - even though we are exiting, some configfs files + * may still be live till we dump them, so ensure list data is + * protected from a race condition. + */ + mutex_lock(&cscfg_mutex); + while (!list_empty(&cscfg_mgr->load_order_list)) { + + /* remove in reverse order of loading */ + owner_info = list_last_entry(&cscfg_mgr->load_order_list, + struct cscfg_load_owner_info, item); + + /* action according to type */ + switch (owner_info->type) { + case CSCFG_OWNER_PRELOAD: + /* + * preloaded descriptors are statically allocated in + * this module - just need to unload dynamic items from + * csdev lists, and remove from configfs directories. + */ + pr_info("cscfg: unloading preloaded configurations\n"); + break; + + case CSCFG_OWNER_MODULE: + /* + * this is an error - the loadable module must have been unloaded prior + * to the coresight module unload. Therefore that module has not + * correctly unloaded configs in its own exit code. + * Nothing to do other than emit an error string as the static descriptor + * references we need to unload will have disappeared with the module. + */ + pr_err("cscfg: ERROR: prior module failed to unload configuration\n"); + goto list_remove; + } + + /* remove from configfs - outside the scope of the list mutex */ + mutex_unlock(&cscfg_mutex); + cscfg_fs_unregister_cfgs_feats(owner_info); + mutex_lock(&cscfg_mutex); + + /* Next unload from csdev lists. */ + cscfg_unload_owned_cfgs_feats(owner_info); + +list_remove: + /* remove from load order list */ + list_del(&owner_info->item); + } + mutex_unlock(&cscfg_mutex); +} + +static void cscfg_clear_device(void) +{ + cscfg_unload_cfgs_on_exit(); + cscfg_configfs_release(cscfg_mgr); + device_unregister(cscfg_device()); +} + +/* Initialise system config management API device */ +int __init cscfg_init(void) +{ + int err = 0; + + /* create the device and init cscfg_mgr */ + err = cscfg_create_device(); + if (err) + return err; + + /* initialise configfs subsystem */ + err = cscfg_configfs_init(cscfg_mgr); + if (err) + goto exit_err; + + /* preload built-in configurations */ + err = cscfg_preload(THIS_MODULE); + if (err) + goto exit_err; + + dev_info(cscfg_device(), "CoreSight Configuration manager initialised"); + return 0; + +exit_err: + cscfg_clear_device(); + return err; +} + +void cscfg_exit(void) +{ + cscfg_clear_device(); +} |