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

On Tue, Nov 30, 2021 at 10:00:56PM +0000, Mike Leach wrote:

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@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);

I am still very ambivalent about this status thing... Especially since it only reports on the last item that was loaded/unloaded.

+} +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