1 files changed, 396 insertions, 0 deletions
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@linaro.org>
+ */
+
+#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(&param_item->group,
+					    feat_desc->params_desc[i].name,
+					    &cscfg_param_view_type);
+		configfs_add_default_group(&param_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);
+}