On Fri, Apr 09, 2021 at 11:37:21AM +0100, Mike Leach wrote: > Adds configfs subsystem and attributes to the configuration manager > to enable the listing of loaded configurations and features. > > The default values of feature parameters can be accessed and altered > from these attributes to affect all installed devices using the feature. > > Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx> > --- > drivers/hwtracing/coresight/Makefile | 3 +- > .../coresight/coresight-syscfg-configfs.c | 396 ++++++++++++++++++ > .../coresight/coresight-syscfg-configfs.h | 45 ++ > .../hwtracing/coresight/coresight-syscfg.c | 76 ++++ > .../hwtracing/coresight/coresight-syscfg.h | 7 + > 5 files changed, 526 insertions(+), 1 deletion(-) > create mode 100644 drivers/hwtracing/coresight/coresight-syscfg-configfs.c > create mode 100644 drivers/hwtracing/coresight/coresight-syscfg-configfs.h > Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> > diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile > index ad44f0fe3069..b6c4a48140ec 100644 > --- a/drivers/hwtracing/coresight/Makefile > +++ b/drivers/hwtracing/coresight/Makefile > @@ -5,7 +5,8 @@ > obj-$(CONFIG_CORESIGHT) += coresight.o > coresight-y := coresight-core.o coresight-etm-perf.o coresight-platform.o \ > coresight-sysfs.o coresight-syscfg.o coresight-config.o \ > - coresight-cfg-preload.o coresight-cfg-afdo.o > + coresight-cfg-preload.o coresight-cfg-afdo.o \ > + coresight-syscfg-configfs.o > obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o > coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \ > coresight-tmc-etr.o > diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c > new file mode 100644 > index 000000000000..c547816b9000 > --- /dev/null > +++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c > @@ -0,0 +1,396 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2020 Linaro Limited, All rights reserved. > + * Author: Mike Leach <mike.leach@xxxxxxxxxx> > + */ > + > +#include <linux/configfs.h> > + > +#include "coresight-syscfg-configfs.h" > + > +/* create a default ci_type. */ > +static inline struct config_item_type *cscfg_create_ci_type(void) > +{ > + struct config_item_type *ci_type; > + > + ci_type = devm_kzalloc(cscfg_device(), sizeof(*ci_type), GFP_KERNEL); > + if (ci_type) > + ci_type->ct_owner = THIS_MODULE; > + > + return ci_type; > +} > + > +/* configurations sub-group */ > + > +/* attributes for the config view group */ > +static ssize_t cscfg_cfg_description_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, "%s", fs_config->config_desc->description); > +} > +CONFIGFS_ATTR_RO(cscfg_cfg_, description); > + > +static ssize_t cscfg_cfg_feature_refs_show(struct config_item *item, char *page) > +{ > + struct cscfg_fs_config *fs_config = container_of(to_config_group(item), > + struct cscfg_fs_config, group); > + const struct cscfg_config_desc *config_desc = fs_config->config_desc; > + ssize_t ch_used = 0; > + int i; > + > + for (i = 0; i < config_desc->nr_feat_refs; i++) > + ch_used += scnprintf(page + ch_used, PAGE_SIZE - ch_used, > + "%s\n", config_desc->feat_ref_names[i]); > + return ch_used; > +} > +CONFIGFS_ATTR_RO(cscfg_cfg_, feature_refs); > + > +/* list preset values in order of features and params */ > +static ssize_t cscfg_cfg_values_show(struct config_item *item, char *page) > +{ > + const struct cscfg_feature_desc *feat_desc; > + const struct cscfg_config_desc *config_desc; > + struct cscfg_fs_preset *fs_preset; > + int i, j, val_idx, preset_idx; > + ssize_t used = 0; > + > + fs_preset = container_of(to_config_group(item), struct cscfg_fs_preset, group); > + config_desc = fs_preset->config_desc; > + > + if (!config_desc->nr_presets) > + return 0; > + > + preset_idx = fs_preset->preset_num - 1; > + > + /* start index on the correct array line */ > + val_idx = config_desc->nr_total_params * preset_idx; > + > + /* > + * A set of presets is the sum of all params in used features, > + * in order of declaration of features and params in the features > + */ > + for (i = 0; i < config_desc->nr_feat_refs; i++) { > + feat_desc = cscfg_get_named_feat_desc(config_desc->feat_ref_names[i]); > + for (j = 0; j < feat_desc->nr_params; j++) { > + used += scnprintf(page + used, PAGE_SIZE - used, > + "%s.%s = 0x%llx ", > + feat_desc->name, > + feat_desc->params_desc[j].name, > + config_desc->presets[val_idx++]); > + } > + } > + used += scnprintf(page + used, PAGE_SIZE - used, "\n"); > + > + return used; > +} > +CONFIGFS_ATTR_RO(cscfg_cfg_, values); > + > +static struct configfs_attribute *cscfg_config_view_attrs[] = { > + &cscfg_cfg_attr_description, > + &cscfg_cfg_attr_feature_refs, > + NULL, > +}; > + > +static struct config_item_type cscfg_config_view_type = { > + .ct_owner = THIS_MODULE, > + .ct_attrs = cscfg_config_view_attrs, > +}; > + > +static struct configfs_attribute *cscfg_config_preset_attrs[] = { > + &cscfg_cfg_attr_values, > + NULL, > +}; > + > +static struct config_item_type cscfg_config_preset_type = { > + .ct_owner = THIS_MODULE, > + .ct_attrs = cscfg_config_preset_attrs, > +}; > + > +static int cscfg_add_preset_groups(struct cscfg_fs_config *cfg_view) > +{ > + int preset_num; > + struct cscfg_fs_preset *cfg_fs_preset; > + struct cscfg_config_desc *config_desc = cfg_view->config_desc; > + char name[CONFIGFS_ITEM_NAME_LEN]; > + > + if (!config_desc->nr_presets) > + return 0; > + > + for (preset_num = 1; preset_num <= config_desc->nr_presets; preset_num++) { > + cfg_fs_preset = devm_kzalloc(cscfg_device(), > + sizeof(struct cscfg_fs_preset), GFP_KERNEL); > + > + if (!cfg_fs_preset) > + return -ENOMEM; > + > + snprintf(name, CONFIGFS_ITEM_NAME_LEN, "preset%d", preset_num); > + cfg_fs_preset->preset_num = preset_num; > + cfg_fs_preset->config_desc = cfg_view->config_desc; > + config_group_init_type_name(&cfg_fs_preset->group, name, > + &cscfg_config_preset_type); > + configfs_add_default_group(&cfg_fs_preset->group, &cfg_view->group); > + } > + return 0; > +} > + > +static struct config_group *cscfg_create_config_group(struct cscfg_config_desc *config_desc) > +{ > + struct cscfg_fs_config *cfg_view; > + struct device *dev = cscfg_device(); > + int err; > + > + if (!dev) > + return ERR_PTR(-EINVAL); > + > + cfg_view = devm_kzalloc(dev, sizeof(struct cscfg_fs_config), GFP_KERNEL); > + if (!cfg_view) > + return ERR_PTR(-ENOMEM); > + > + cfg_view->config_desc = config_desc; > + config_group_init_type_name(&cfg_view->group, config_desc->name, &cscfg_config_view_type); > + > + /* add in a preset<n> dir for each preset */ > + err = cscfg_add_preset_groups(cfg_view); > + if (err) > + return ERR_PTR(err); > + > + return &cfg_view->group; > +} > + > +/* attributes for features view */ > + > +static ssize_t cscfg_feat_description_show(struct config_item *item, char *page) > +{ > + struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item), > + struct cscfg_fs_feature, group); > + > + return scnprintf(page, PAGE_SIZE, "%s", fs_feat->feat_desc->description); > +} > +CONFIGFS_ATTR_RO(cscfg_feat_, description); > + > +static ssize_t cscfg_feat_matches_show(struct config_item *item, char *page) > +{ > + struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item), > + struct cscfg_fs_feature, group); > + u32 match_flags = fs_feat->feat_desc->match_flags; > + int used = 0; > + > + if (match_flags & CS_CFG_MATCH_CLASS_SRC_ALL) > + used = scnprintf(page, PAGE_SIZE, "SRC_ALL "); > + > + if (match_flags & CS_CFG_MATCH_CLASS_SRC_ETM4) > + used += scnprintf(page + used, PAGE_SIZE - used, "SRC_ETMV4 "); > + > + used += scnprintf(page + used, PAGE_SIZE - used, "\n"); > + return used; > +} > +CONFIGFS_ATTR_RO(cscfg_feat_, matches); > + > +static ssize_t cscfg_feat_nr_params_show(struct config_item *item, char *page) > +{ > + struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item), > + struct cscfg_fs_feature, group); > + > + return scnprintf(page, PAGE_SIZE, "%d\n", fs_feat->feat_desc->nr_params); > +} > +CONFIGFS_ATTR_RO(cscfg_feat_, nr_params); > + > +/* base feature desc attrib structures */ > +static struct configfs_attribute *cscfg_feature_view_attrs[] = { > + &cscfg_feat_attr_description, > + &cscfg_feat_attr_matches, > + &cscfg_feat_attr_nr_params, > + NULL, > +}; > + > +static struct config_item_type cscfg_feature_view_type = { > + .ct_owner = THIS_MODULE, > + .ct_attrs = cscfg_feature_view_attrs, > +}; > + > +static ssize_t cscfg_param_value_show(struct config_item *item, char *page) > +{ > + struct cscfg_fs_param *param_item = container_of(to_config_group(item), > + struct cscfg_fs_param, group); > + u64 value = param_item->feat_desc->params_desc[param_item->param_idx].value; > + > + return scnprintf(page, PAGE_SIZE, "0x%llx\n", value); > +} > + > +static ssize_t cscfg_param_value_store(struct config_item *item, > + const char *page, size_t size) > +{ > + struct cscfg_fs_param *param_item = container_of(to_config_group(item), > + struct cscfg_fs_param, group); > + struct cscfg_feature_desc *feat_desc = param_item->feat_desc; > + int param_idx = param_item->param_idx; > + u64 value; > + int err; > + > + err = kstrtoull(page, 0, &value); > + if (!err) > + err = cscfg_update_feat_param_val(feat_desc, param_idx, value); > + > + return err ? err : size; > +} > +CONFIGFS_ATTR(cscfg_param_, value); > + > +static struct configfs_attribute *cscfg_param_view_attrs[] = { > + &cscfg_param_attr_value, > + NULL, > +}; > + > +static struct config_item_type cscfg_param_view_type = { > + .ct_owner = THIS_MODULE, > + .ct_attrs = cscfg_param_view_attrs, > +}; > + > +/* > + * configfs has far less functionality provided to add attributes dynamically than sysfs, > + * and the show and store fns pass the enclosing config_item so the actual attribute cannot > + * be determined. Therefore we add each item as a group directory, with a value attribute. > + */ > +static int cscfg_create_params_group_items(struct cscfg_feature_desc *feat_desc, > + struct config_group *params_group) > +{ > + struct device *dev = cscfg_device(); > + struct cscfg_fs_param *param_item; > + int i; > + > + /* parameter items - as groups with default_value attribute */ > + for (i = 0; i < feat_desc->nr_params; i++) { > + param_item = devm_kzalloc(dev, sizeof(struct cscfg_fs_param), GFP_KERNEL); > + if (!param_item) > + return -ENOMEM; > + param_item->feat_desc = feat_desc; > + param_item->param_idx = i; > + config_group_init_type_name(¶m_item->group, > + feat_desc->params_desc[i].name, > + &cscfg_param_view_type); > + configfs_add_default_group(¶m_item->group, params_group); > + } > + return 0; > +} > + > +static struct config_group *cscfg_create_feature_group(struct cscfg_feature_desc *feat_desc) > +{ > + struct cscfg_fs_feature *feat_view; > + struct config_item_type *params_group_type; > + struct config_group *params_group = NULL; > + struct device *dev = cscfg_device(); > + int item_err; > + > + if (!dev) > + return ERR_PTR(-EINVAL); > + > + feat_view = devm_kzalloc(dev, sizeof(struct cscfg_fs_feature), GFP_KERNEL); > + if (!feat_view) > + return ERR_PTR(-ENOMEM); > + > + if (feat_desc->nr_params) { > + params_group = devm_kzalloc(dev, sizeof(struct config_group), GFP_KERNEL); > + if (!params_group) > + return ERR_PTR(-ENOMEM); > + > + params_group_type = cscfg_create_ci_type(); > + if (!params_group_type) > + return ERR_PTR(-ENOMEM); > + } > + > + feat_view->feat_desc = feat_desc; > + config_group_init_type_name(&feat_view->group, > + feat_desc->name, > + &cscfg_feature_view_type); > + if (params_group) { > + config_group_init_type_name(params_group, "params", params_group_type); > + configfs_add_default_group(params_group, &feat_view->group); > + item_err = cscfg_create_params_group_items(feat_desc, params_group); > + if (item_err) > + return ERR_PTR(item_err); > + } > + return &feat_view->group; > +} > + > +static struct config_item_type cscfg_configs_type = { > + .ct_owner = THIS_MODULE, > +}; > + > +static struct config_group cscfg_configs_grp = { > + .cg_item = { > + .ci_namebuf = "configurations", > + .ci_type = &cscfg_configs_type, > + }, > +}; > + > +/* add configuration to configurations group */ > +int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc) > +{ > + struct config_group *new_group; > + int err; > + > + new_group = cscfg_create_config_group(config_desc); > + if (IS_ERR(new_group)) > + return PTR_ERR(new_group); > + err = configfs_register_group(&cscfg_configs_grp, new_group); > + return err; > +} > + > +static struct config_item_type cscfg_features_type = { > + .ct_owner = THIS_MODULE, > +}; > + > +static struct config_group cscfg_features_grp = { > + .cg_item = { > + .ci_namebuf = "features", > + .ci_type = &cscfg_features_type, > + }, > +}; > + > +/* add feature to features group */ > +int cscfg_configfs_add_feature(struct cscfg_feature_desc *feat_desc) > +{ > + struct config_group *new_group; > + int err; > + > + new_group = cscfg_create_feature_group(feat_desc); > + if (IS_ERR(new_group)) > + return PTR_ERR(new_group); > + err = configfs_register_group(&cscfg_features_grp, new_group); > + return err; > +} > + > +int cscfg_configfs_init(struct cscfg_manager *cscfg_mgr) > +{ > + struct configfs_subsystem *subsys; > + struct config_item_type *ci_type; > + > + if (!cscfg_mgr) > + return -EINVAL; > + > + ci_type = cscfg_create_ci_type(); > + if (!ci_type) > + return -ENOMEM; > + > + subsys = &cscfg_mgr->cfgfs_subsys; > + config_item_set_name(&subsys->su_group.cg_item, CSCFG_FS_SUBSYS_NAME); > + subsys->su_group.cg_item.ci_type = ci_type; > + > + config_group_init(&subsys->su_group); > + mutex_init(&subsys->su_mutex); > + > + /* Add default groups to subsystem */ > + config_group_init(&cscfg_configs_grp); > + configfs_add_default_group(&cscfg_configs_grp, &subsys->su_group); > + > + config_group_init(&cscfg_features_grp); > + configfs_add_default_group(&cscfg_features_grp, &subsys->su_group); > + > + return configfs_register_subsystem(subsys); > +} > + > +void cscfg_configfs_release(struct cscfg_manager *cscfg_mgr) > +{ > + configfs_unregister_subsystem(&cscfg_mgr->cfgfs_subsys); > +} > diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.h b/drivers/hwtracing/coresight/coresight-syscfg-configfs.h > new file mode 100644 > index 000000000000..7d6ffe35ca4c > --- /dev/null > +++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.h > @@ -0,0 +1,45 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Coresight system configuration driver - support for configfs. > + */ > + > +#ifndef CORESIGHT_SYSCFG_CONFIGFS_H > +#define CORESIGHT_SYSCFG_CONFIGFS_H > + > +#include <linux/configfs.h> > +#include "coresight-syscfg.h" > + > +#define CSCFG_FS_SUBSYS_NAME "cs-syscfg" > + > +/* container for configuration view */ > +struct cscfg_fs_config { > + struct cscfg_config_desc *config_desc; > + struct config_group group; > +}; > + > +/* container for feature view */ > +struct cscfg_fs_feature { > + struct cscfg_feature_desc *feat_desc; > + struct config_group group; > +}; > + > +/* container for parameter view */ > +struct cscfg_fs_param { > + int param_idx; > + struct cscfg_feature_desc *feat_desc; > + struct config_group group; > +}; > + > +/* container for preset view */ > +struct cscfg_fs_preset { > + int preset_num; > + struct cscfg_config_desc *config_desc; > + struct config_group group; > +}; > + > +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); > + > +#endif /* CORESIGHT_SYSCFG_CONFIGFS_H */ > diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c > index 41f742190639..180202402eb5 100644 > --- a/drivers/hwtracing/coresight/coresight-syscfg.c > +++ b/drivers/hwtracing/coresight/coresight-syscfg.c > @@ -9,6 +9,7 @@ > #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 > @@ -287,6 +288,72 @@ static int cscfg_load_config(struct cscfg_config_desc *config_desc) > 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; > +} > + > /** > * cscfg_load_config_sets - API function to load feature and config sets. > * > @@ -308,6 +375,8 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs, > 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); > @@ -322,6 +391,8 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs, > 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); > @@ -691,6 +762,7 @@ static void cscfg_clear_device(void) > list_for_each_entry(cfg_desc, &cscfg_mgr->config_desc_list, item) { > etm_perf_del_symlink_cscfg(cfg_desc); > } > + cscfg_configfs_release(cscfg_mgr); > device_unregister(cscfg_device()); > mutex_unlock(&cscfg_mutex); > } > @@ -704,6 +776,10 @@ int __init cscfg_init(void) > if (err) > return err; > > + err = cscfg_configfs_init(cscfg_mgr); > + if (err) > + goto exit_err; > + > INIT_LIST_HEAD(&cscfg_mgr->csdev_desc_list); > INIT_LIST_HEAD(&cscfg_mgr->feat_desc_list); > INIT_LIST_HEAD(&cscfg_mgr->config_desc_list); > diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h > index 7bb8c8e497ba..8d018efd6ead 100644 > --- a/drivers/hwtracing/coresight/coresight-syscfg.h > +++ b/drivers/hwtracing/coresight/coresight-syscfg.h > @@ -6,6 +6,7 @@ > #ifndef CORESIGHT_SYSCFG_H > #define CORESIGHT_SYSCFG_H > > +#include <linux/configfs.h> > #include <linux/coresight.h> > #include <linux/device.h> > > @@ -25,6 +26,7 @@ > * @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. > * @sys_active_cnt: Total number of active config descriptor references. > + * @cfgfs_subsys: configfs subsystem used to manage configurations. > */ > struct cscfg_manager { > struct device dev; > @@ -32,6 +34,7 @@ struct cscfg_manager { > struct list_head feat_desc_list; > struct list_head config_desc_list; > atomic_t sys_active_cnt; > + struct configfs_subsystem cfgfs_subsys; > }; > > /* get reference to dev in cscfg_manager */ > @@ -57,6 +60,10 @@ struct cscfg_registered_csdev { > int __init cscfg_init(void); > void cscfg_exit(void); > int cscfg_preload(void); > +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); > + > > /* syscfg manager external API */ > int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, > -- > 2.17.1 >