[PATCH v6 2/6] coresight: configfs: Update memory allocation / free for configfs elements

11 May 2023

Previously, the objects backing the configfs directories and files were
created using devm managed memory on the coresight device.
Now we are adding configfs load/unload, configurations can be loaded
many times over the lifetime of the device, so it is more appropriate to
use normally allocated and freed memory.
Signed-off-by: Mike Leach mike.leach@linaro.org
---
 .../coresight/coresight-syscfg-configfs.c     | 119 +++++++++++++-----
 1 file changed, 88 insertions(+), 31 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c
index 433ede94dd63..6e8c8db52d39 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg-configfs.c
+++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c
@@ -14,7 +14,7 @@ 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);
+	ci_type = kzalloc(sizeof(*ci_type), GFP_KERNEL);
    if (ci_type)
    	ci_type->ct_owner = THIS_MODULE;
@@ -175,6 +175,19 @@ static struct config_item_type cscfg_config_preset_type = {
    .ct_attrs = cscfg_config_preset_attrs,
 };
+
+/* walk list of presets and free the previously allocated memory */
+static void cscfg_destroy_preset_groups(struct config_group *cfg_view_group)
+{
+	struct cscfg_fs_preset *cfg_fs_preset;
+	struct config_group *p_group;
+
+	list_for_each_entry(p_group, &cfg_view_group->default_groups, default_groups) {
+		cfg_fs_preset = container_of(p_group, struct cscfg_fs_preset, group);
+		kfree(cfg_fs_preset);
+	}
+}
+
 static int cscfg_add_preset_groups(struct cscfg_fs_config *cfg_view)
 {
    int preset_num;
@@ -186,11 +199,12 @@ static int cscfg_add_preset_groups(struct cscfg_fs_config *cfg_view)
    	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);
+		cfg_fs_preset = kzalloc(sizeof(struct cscfg_fs_preset), GFP_KERNEL);
-		if (!cfg_fs_preset)
+		if (!cfg_fs_preset) {
+			cscfg_destroy_preset_groups(&cfg_view->group);
    		return -ENOMEM;
+		}
snprintf(name, CONFIGFS_ITEM_NAME_LEN, "preset%d", preset_num);
    	cfg_fs_preset->preset_num = preset_num;
@@ -204,14 +218,10 @@ static int cscfg_add_preset_groups(struct cscfg_fs_config *cfg_view)
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();
+	struct cscfg_fs_config *cfg_view = NULL;
    int err;
-	if (!dev)
-		return ERR_PTR(-EINVAL);
-
-	cfg_view = devm_kzalloc(dev, sizeof(struct cscfg_fs_config), GFP_KERNEL);
+	cfg_view = kzalloc(sizeof(struct cscfg_fs_config), GFP_KERNEL);
    if (!cfg_view)
    	return ERR_PTR(-ENOMEM);
@@ -220,12 +230,21 @@ static struct config_group *cscfg_create_config_group(struct cscfg_config_desc *
/* add in a preset<n> dir for each preset */
    err = cscfg_add_preset_groups(cfg_view);
-	if (err)
+	if (err) {
+		kfree(cfg_view);
    	return ERR_PTR(err);
-
+	}
    return &cfg_view->group;
 }
+static void cscfg_destroy_config_group(struct config_group *group)
+{
+	struct cscfg_fs_config *cfg_view = container_of(group, struct cscfg_fs_config, group);
+
+	cscfg_destroy_preset_groups(&cfg_view->group);
+	kfree(cfg_view);
+}
+
 /* attributes for features view */
static ssize_t cscfg_feat_description_show(struct config_item *item, char *page)
@@ -314,6 +333,17 @@ static struct config_item_type cscfg_param_view_type = {
    .ct_attrs = cscfg_param_view_attrs,
 };
+/* walk the list of default groups - which were set as param items and remove */
+static void cscfg_destroy_params_group_items(struct config_group *params_group)
+{
+	struct cscfg_fs_param *param_item;
+	struct config_group *p_group;
+
+	list_for_each_entry(p_group, &params_group->default_groups, default_groups) {
+		param_item = container_of(p_group, struct cscfg_fs_param, group);
+		kfree(param_item);
+	}
+}
 /*
  * 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
@@ -322,15 +352,16 @@ static struct config_item_type cscfg_param_view_type = {
 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)
+		param_item = kzalloc(sizeof(struct cscfg_fs_param), GFP_KERNEL);
+		if (!param_item) {
+			cscfg_destroy_params_group_items(params_group);
    		return -ENOMEM;
+		}
    	param_item->feat_desc = feat_desc;
    	param_item->param_idx = i;
    	config_group_init_type_name(&param_item->group,
@@ -343,27 +374,22 @@ static int cscfg_create_params_group_items(struct cscfg_feature_desc *feat_desc,
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 cscfg_fs_feature *feat_view = NULL;
+	struct config_item_type *params_group_type = NULL;
    struct config_group *params_group = NULL;
-	struct device *dev = cscfg_device();
-	int item_err;
-
-	if (!dev)
-		return ERR_PTR(-EINVAL);
+	int err = -ENOMEM;
-	feat_view = devm_kzalloc(dev, sizeof(struct cscfg_fs_feature), GFP_KERNEL);
+	feat_view = kzalloc(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);
+		params_group = kzalloc(sizeof(struct config_group), GFP_KERNEL);
    	if (!params_group)
-			return ERR_PTR(-ENOMEM);
-
+			goto exit_err_free_mem;
    	params_group_type = cscfg_create_ci_type();
    	if (!params_group_type)
-			return ERR_PTR(-ENOMEM);
+			goto exit_err_free_mem;
    }
feat_view->feat_desc = feat_desc;
@@ -373,11 +399,36 @@ static struct config_group *cscfg_create_feature_group(struct cscfg_feature_desc
    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);
+		err = cscfg_create_params_group_items(feat_desc, params_group);
+		if (err)
+			goto exit_err_free_mem;
    }
    return &feat_view->group;
+
+exit_err_free_mem:
+	kfree(feat_view);
+	kfree(params_group_type);
+	kfree(params_group);
+	return ERR_PTR(err);
+}
+
+static void cscfg_destroy_feature_group(struct config_group *feat_group)
+{
+	struct cscfg_fs_feature *feat_view;
+	struct config_group *params_group = NULL;
+
+	feat_view = container_of(feat_group, struct cscfg_fs_feature, group);
+
+	/* params group is the first item on the default group list */
+	if (!list_empty(&feat_group->default_groups)) {
+		params_group = list_first_entry(&feat_group->default_groups,
+						struct config_group, default_groups);
+		cscfg_destroy_params_group_items(params_group);
+		/* free the item type, then the group */
+		kfree(params_group->cg_item.ci_type);
+		kfree(params_group);
+	}
+	kfree(feat_view);
 }
static struct config_item_type cscfg_configs_type = {
@@ -403,6 +454,8 @@ int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc)
    err =  configfs_register_group(&cscfg_configs_grp, new_group);
    if (!err)
    	config_desc->fs_group = new_group;
+	else
+		cscfg_destroy_config_group(new_group);
    return err;
 }
@@ -410,6 +463,7 @@ void cscfg_configfs_del_config(struct cscfg_config_desc *config_desc)
 {
    if (config_desc->fs_group) {
    	configfs_unregister_group(config_desc->fs_group);
+		cscfg_destroy_config_group(config_desc->fs_group);
    	config_desc->fs_group = NULL;
    }
 }
@@ -434,9 +488,11 @@ int cscfg_configfs_add_feature(struct cscfg_feature_desc *feat_desc)
    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);
+	err = configfs_register_group(&cscfg_features_grp, new_group);
    if (!err)
    	feat_desc->fs_group = new_group;
+	else
+		cscfg_destroy_feature_group(new_group);
    return err;
 }
@@ -444,6 +500,7 @@ void cscfg_configfs_del_feature(struct cscfg_feature_desc *feat_desc)
 {
    if (feat_desc->fs_group) {
    	configfs_unregister_group(feat_desc->fs_group);
+		cscfg_destroy_feature_group(feat_desc->fs_group);
    	feat_desc->fs_group = NULL;
    }
 }
-- 
2.17.1


    

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[PATCH v6 2/6] coresight: configfs: Update memory allocation / free for configfs elements