[PATCH v2 2/6] coresight: configfs: Add in binary attributes to load files

Mike Leach mike.leach at linaro.org
Tue Nov 30 14:00:56 PST 2021


Add in functionality and binary attribute to load configurations
as binary data.

Reads the incoming attribute, which must be formatted correctly
as defined in the file reader code - and will create a configuration
and/or features and load them into the system.

These will then appear in configfs ready for use.

Unload functionality is also provided.

Signed-off-by: Mike Leach <mike.leach at linaro.org>
---
 .../coresight/coresight-config-file.h         |   7 +
 .../coresight/coresight-syscfg-configfs.c     | 148 +++++++++++++++++-
 .../coresight/coresight-syscfg-configfs.h     |   8 +
 .../hwtracing/coresight/coresight-syscfg.c    |  36 +++++
 .../hwtracing/coresight/coresight-syscfg.h    |   1 +
 5 files changed, 193 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-config-file.h b/drivers/hwtracing/coresight/coresight-config-file.h
index 6c8c5af0a614..03899f7d94c9 100644
--- a/drivers/hwtracing/coresight/coresight-config-file.h
+++ b/drivers/hwtracing/coresight/coresight-config-file.h
@@ -115,4 +115,11 @@ struct cscfg_file_elem_str {
 	char *str;
 };
 
+/* kernel configfs needs to read the incoming file buffers to load. */
+int cscfg_file_read_buffer(const u8 *buffer, const int buflen,
+			   struct cscfg_fs_load_descs *desc_arrays);
+/* to unload we just need the first name - config or first feature */
+int cscfg_file_read_buffer_first_name(const u8 *buffer, const int buflen,
+				      const char **name);
+
 #endif /* _CORESIGHT_CORESIGHT_CONFIG_FILE_H */
diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c
index 433ede94dd63..50abdb5aa6b6 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c
+++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c
@@ -7,6 +7,7 @@
 #include <linux/configfs.h>
 
 #include "coresight-config.h"
+#include "coresight-config-file.h"
 #include "coresight-syscfg-configfs.h"
 
 /* create a default ci_type. */
@@ -380,14 +381,147 @@ static struct config_group *cscfg_create_feature_group(struct cscfg_feature_desc
 	return &feat_view->group;
 }
 
+/* Attributes in configfs that allow load and unload of configuration binary files */
+
+/* load "buffer" as a configuration binary file */
+static ssize_t cscfg_cfg_load_write(struct config_item *item, const void *buffer, size_t size)
+{
+	struct cscfg_fs_configs_grp *configs_grp;
+	struct cscfg_fs_load_descs *load_descs = 0;
+	struct cscfg_load_owner_info *owner_info = 0;
+	int err = 0;
+	const char *name;
+
+	configs_grp = container_of(to_config_group(item), struct cscfg_fs_configs_grp, group);
+	if (size > CSCFG_FILE_MAXSIZE) {
+		scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+			  "Load error: Input file too large.\n");
+		return -EINVAL;
+	}
+
+	load_descs = kzalloc(sizeof(struct cscfg_fs_load_descs), GFP_KERNEL);
+	owner_info = kzalloc(sizeof(struct cscfg_load_owner_info), GFP_KERNEL);
+	if (!load_descs || !owner_info) {
+		err = -ENOMEM;
+		goto exit_memfree;
+	}
+
+	load_descs->owner_info = owner_info;
+	owner_info->owner_handle = load_descs;
+	owner_info->type = CSCFG_OWNER_CONFIGFS;
+
+	err = cscfg_file_read_buffer(buffer, size, load_descs);
+	if (err) {
+		scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+			  "Load error: Failed to read input file.\n");
+		goto exit_memfree;
+	}
+
+	err = cscfg_load_config_sets(load_descs->config_descs, load_descs->feat_descs, owner_info);
+	if (err) {
+		scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+			  "Load error: Failed to load configuaration file.\n");
+		goto exit_memfree;
+	}
+
+	/* name of config if there is one, otherwise first feature */
+	if (load_descs->config_descs[0])
+		name = load_descs->config_descs[0]->name;
+	else
+		name = load_descs->feat_descs[0]->name;
+	scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+		  "OK: configuration file loaded (%s).\n", name);
+
+	return size;
+
+exit_memfree:
+	kfree(load_descs);
+	kfree(owner_info);
+	return err;
+}
+CONFIGFS_BIN_ATTR_WO(cscfg_cfg_, load, NULL, CSCFG_FILE_MAXSIZE);
+
+/* read "buffer" and unload configuration */
+static ssize_t cscfg_cfg_unload_write(struct config_item *item, const void *buffer, size_t size)
+{
+	struct cscfg_fs_configs_grp *configs_grp;
+	struct cscfg_fs_load_descs *load_descs;
+	const char *name;
+	int err;
+
+	configs_grp = container_of(to_config_group(item), struct cscfg_fs_configs_grp, group);
+	if (size > CSCFG_FILE_MAXSIZE) {
+		scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+			  "Unload error: Input file too large\n");
+		return -EINVAL;
+	}
+
+	err = cscfg_file_read_buffer_first_name(buffer, size, &name);
+	if (err) {
+		scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+			  "Unload error: Failed to read input file\n");
+		return err;
+	}
+
+	load_descs = cscfg_find_fs_owned_cfg_by_name(name);
+	if (!load_descs) {
+		scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+			  "Unload error: Failed to find configuration %s from input file\n",
+			  name);
+		return err;
+	}
+	err = cscfg_unload_config_sets(load_descs->owner_info);
+	if (err) {
+		scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+			  "Unload error: Cannot unload configuration %s\n",
+			  name);
+		return err;
+	}
+
+	scnprintf(configs_grp->status, CSCFG_FS_STATUS_STRLEN,
+		  "OK: configuration file unloaded (%s).\n", name);
+
+	kfree((struct cscfg_load_owner_info *)load_descs->owner_info);
+	kfree(load_descs);
+	return size;
+}
+CONFIGFS_BIN_ATTR_WO(cscfg_cfg_, unload, NULL, CSCFG_FILE_MAXSIZE);
+
+/* show the status of the last load / unload operation */
+static ssize_t cscfg_cfg_last_load_status_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_configs_grp *configs_grp;
+
+	configs_grp = container_of(to_config_group(item), struct cscfg_fs_configs_grp, group);
+
+	return scnprintf(page, PAGE_SIZE, "%s\n", configs_grp->status);
+}
+CONFIGFS_ATTR_RO(cscfg_cfg_, last_load_status);
+
+static struct configfs_attribute *cscfg_config_configs_attrs[] = {
+	&cscfg_cfg_attr_last_load_status,
+	NULL,
+};
+
+static struct configfs_bin_attribute *cscfg_config_configfs_bin_attrs[] = {
+	&cscfg_cfg_attr_load,
+	&cscfg_cfg_attr_unload,
+	NULL,
+};
+
 static struct config_item_type cscfg_configs_type = {
 	.ct_owner = THIS_MODULE,
+	.ct_bin_attrs = cscfg_config_configfs_bin_attrs,
+	.ct_attrs = cscfg_config_configs_attrs,
 };
 
-static struct config_group cscfg_configs_grp = {
-	.cg_item = {
-		.ci_namebuf = "configurations",
-		.ci_type = &cscfg_configs_type,
+/* group for configurations dir, with load, unload and status attribs */
+static struct cscfg_fs_configs_grp cscfg_configs_grp = {
+	.group = {
+		.cg_item = {
+			.ci_namebuf = "configurations",
+			.ci_type = &cscfg_configs_type,
+		},
 	},
 };
 
@@ -400,7 +534,7 @@ int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc)
 	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);
+	err =  configfs_register_group(&cscfg_configs_grp.group, new_group);
 	if (!err)
 		config_desc->fs_group = new_group;
 	return err;
@@ -468,8 +602,8 @@ int cscfg_configfs_init(struct cscfg_manager *cscfg_mgr)
 	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_configs_grp.group);
+	configfs_add_default_group(&cscfg_configs_grp.group, &subsys->su_group);
 
 	config_group_init(&cscfg_features_grp);
 	configfs_add_default_group(&cscfg_features_grp, &subsys->su_group);
diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.h b/drivers/hwtracing/coresight/coresight-syscfg-configfs.h
index 373d84d43268..8d6900e8c1ea 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg-configfs.h
+++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.h
@@ -11,6 +11,14 @@
 
 #define CSCFG_FS_SUBSYS_NAME "cs-syscfg"
 
+#define CSCFG_FS_STATUS_STRLEN 256
+
+/* container for configs group */
+struct cscfg_fs_configs_grp {
+	struct config_group group;
+	char status[CSCFG_FS_STATUS_STRLEN];
+};
+
 /* container for configuration view */
 struct cscfg_fs_config {
 	struct cscfg_config_desc *config_desc;
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c
index 098fc34c4829..b5804cc2af9c 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg.c
+++ b/drivers/hwtracing/coresight/coresight-syscfg.c
@@ -587,6 +587,42 @@ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info)
 }
 EXPORT_SYMBOL_GPL(cscfg_unload_config_sets);
 
+/* find a configuration owned by configfs by name of config / first feature */
+struct cscfg_fs_load_descs *cscfg_find_fs_owned_cfg_by_name(const char *name)
+{
+	struct cscfg_load_owner_info *owner_info;
+	struct cscfg_fs_load_descs *fs_load_cfg = NULL;
+	struct cscfg_config_desc *config_desc;
+	struct cscfg_feature_desc *feat_desc;
+
+	mutex_lock(&cscfg_mutex);
+
+	/* search the load_owner list for CONFIGFS loaded types */
+	list_for_each_entry(owner_info, &cscfg_mgr->load_order_list, item) {
+		/* if this is a config fs owned item, then try to match */
+		if (owner_info->type == CSCFG_OWNER_CONFIGFS) {
+			fs_load_cfg = owner_info->owner_handle;
+			/* first try to match the name against the config if it exists */
+			if (fs_load_cfg->config_descs[0]) {
+				config_desc = fs_load_cfg->config_descs[0];
+				if (!strcmp(config_desc->name, name))
+					goto exit_unlock;
+			/* no config - match against first feature name */
+			} else {
+				feat_desc = fs_load_cfg->feat_descs[0];
+				if (!strcmp(feat_desc->name, name))
+					goto exit_unlock;
+			}
+			/* no match - move on */
+			fs_load_cfg = NULL;
+		}
+	}
+
+exit_unlock:
+	mutex_unlock(&cscfg_mutex);
+	return fs_load_cfg;
+}
+
 /* Handle coresight device registration and add configs and features to devices */
 
 /* iterate through config lists and load matching configs to device */
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h
index 6a6e33585be9..6bc29abe0650 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg.h
+++ b/drivers/hwtracing/coresight/coresight-syscfg.h
@@ -95,6 +95,7 @@ int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc,
 				int param_idx, u64 value);
 int cscfg_config_sysfs_activate(struct cscfg_config_desc *cfg_desc, bool activate);
 void cscfg_config_sysfs_set_preset(int preset);
+struct cscfg_fs_load_descs *cscfg_find_fs_owned_cfg_by_name(const char *name);
 
 /* syscfg manager external API */
 int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs,
-- 
2.17.1




More information about the linux-arm-kernel mailing list