[PATCH 1/9] thunderbolt: Add tb_property_merge_dir()

Mika Westerberg
2026-04-28T07:22:14Z

This allows merging one XDomain property directory into another. We are
going to use this in the subsequent patch.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/thunderbolt/property.c | 154 ++++++++++++++++++++++++---------
include/linux/thunderbolt.h | 3 +
2 files changed, 114 insertions(+), 43 deletions(-)

diff --git a/drivers/thunderbolt/property.c b/drivers/thunderbolt/property.c
index 50cbfc92fe65..6b9666b61181 100644
--- a/drivers/thunderbolt/property.c
+++ b/drivers/thunderbolt/property.c
@@ -38,6 +38,7 @@ struct tb_property_dir_entry {
static struct tb_property_dir *__tb_property_parse_dir(const u32 *block,
size_t block_len, unsigned int dir_offset, size_t dir_len,
bool is_root);
+static struct tb_property *tb_property_copy(const struct tb_property *property);

static inline void parse_dwdata(void *dst, const void *src, size_t dwords)
{
@@ -507,17 +508,9 @@ ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
return ret < 0 ? ret : 0;
}

-/**
- * tb_property_copy_dir() - Take a deep copy of directory
- * @dir: Directory to copy
- *
- * The resulting directory needs to be released by calling tb_property_free_dir().
- *
- * Return: Pointer to &struct tb_property_dir, %NULL in case of failure.
- */
-struct tb_property_dir *tb_property_copy_dir(const struct tb_property_dir *dir)
+static struct tb_property_dir *copy_dir(const struct tb_property_dir *dir)
{
- struct tb_property *property, *p = NULL;
+ struct tb_property *property, *p;
struct tb_property_dir *d;

if (!dir)
@@ -528,56 +521,131 @@ struct tb_property_dir *tb_property_copy_dir(const struct tb_property_dir *dir)
return NULL;

list_for_each_entry(property, &dir->properties, list) {
- struct tb_property *p;
-
- p = tb_property_alloc(property->key, property->type);
+ p = tb_property_copy(property);
if (!p)
goto err_free;
+ list_add_tail(&p->list, &d->properties);
+ }

- p->length = property->length;
+ return d;

- switch (property->type) {
- case TB_PROPERTY_TYPE_DIRECTORY:
- p->value.dir = tb_property_copy_dir(property->value.dir);
- if (!p->value.dir)
- goto err_free;
- break;
+err_free:
+ tb_property_free_dir(d);
+ return NULL;
+}

- case TB_PROPERTY_TYPE_DATA:
- p->value.data = kmemdup(property->value.data,
- property->length * 4,
- GFP_KERNEL);
- if (!p->value.data)
- goto err_free;
- break;
+static struct tb_property *tb_property_copy(const struct tb_property *property)
+{
+ struct tb_property *p;

- case TB_PROPERTY_TYPE_TEXT:
- p->value.text = kzalloc(p->length * 4, GFP_KERNEL);
- if (!p->value.text)
- goto err_free;
- strcpy(p->value.text, property->value.text);
- break;
+ p = tb_property_alloc(property->key, property->type);
+ if (!p)
+ return NULL;

- case TB_PROPERTY_TYPE_VALUE:
- p->value.immediate = property->value.immediate;
- break;
+ p->length = property->length;
+ switch (property->type) {
+ case TB_PROPERTY_TYPE_DIRECTORY:
+ p->value.dir = copy_dir(property->value.dir);
+ if (!p->value.dir)
+ goto err_free;
+ break;

- default:
- break;
- }
+ case TB_PROPERTY_TYPE_DATA:
+ p->value.data = kmemdup(property->value.data,
+ property->length * 4,
+ GFP_KERNEL);
+ if (!p->value.data)
+ goto err_free;
+ break;

- list_add_tail(&p->list, &d->properties);
+ case TB_PROPERTY_TYPE_TEXT:
+ p->value.text = kzalloc(p->length * 4, GFP_KERNEL);
+ if (!p->value.text)
+ goto err_free;
+ strcpy(p->value.text, property->value.text);
+ break;
+
+ case TB_PROPERTY_TYPE_VALUE:
+ p->value.immediate = property->value.immediate;
+ break;
+
+ default:
+ break;
}

- return d;
+ return p;

err_free:
kfree(p);
- tb_property_free_dir(d);
-
return NULL;
}

+/**
+ * tb_property_copy_dir() - Take a deep copy of directory
+ * @dir: Directory to copy
+ *
+ * The resulting directory needs to be released by calling tb_property_free_dir().
+ *
+ * Return: Pointer to &struct tb_property_dir, %NULL in case of failure.
+ */
+struct tb_property_dir *tb_property_copy_dir(const struct tb_property_dir *dir)
+{
+ return copy_dir(dir);
+}
+EXPORT_SYMBOL_GPL(tb_property_copy_dir);
+
+/**
+ * tb_property_merge_dir() - Merges directory into parent
+ * @parent: Directory to merge @dir
+ * @dir: Directory that is merged
+ * @replace: Replace existing entries
+ *
+ * This will merge @dir into @parent. Both must have same UUID. The
+ * properties in @dir will overwrite overlapping properties in @parent
+ * if @replace is %true. Contents of @dir is copied (so if it is not
+ * needed afterwards it needs to relesed by calling tb_property_free_dir()).
+ */
+int tb_property_merge_dir(struct tb_property_dir *parent,
+ const struct tb_property_dir *dir,
+ bool replace)
+{
+ const struct tb_property *property;
+
+ if (WARN_ON(parent == dir))
+ return -EINVAL;
+
+ if (!uuid_equal(parent->uuid, dir->uuid))
+ return -EINVAL;
+
+ list_for_each_entry(property, &dir->properties, list) {
+ struct tb_property *p, *tmp;
+
+ tmp = tb_property_copy(property);
+ if (!tmp)
+ return -ENOMEM;
+
+ p = tb_property_find(parent, property->key, property->type);
+ if (p) {
+ if (replace) {
+ /*
+ * Found existing property in parent so
+ * replace with the new one.
+ */
+ list_replace(&p->list, &tmp->list);
+ tb_property_free(p);
+ } else {
+ tb_property_free(tmp);
+ continue;
+ }
+ } else {
+ list_add_tail(&tmp->list, &parent->properties);
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tb_property_merge_dir);
+
/**
* tb_property_add_immediate() - Add immediate property to directory
* @parent: Directory to add the property
diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h
index bbdbbc84c999..e98d569779f9 100644
--- a/include/linux/thunderbolt.h
+++ b/include/linux/thunderbolt.h
@@ -153,6 +153,9 @@ struct tb_property_dir *tb_property_parse_dir(const u32 *block,
ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
size_t block_len);
struct tb_property_dir *tb_property_copy_dir(const struct tb_property_dir *dir);
+int tb_property_merge_dir(struct tb_property_dir *parent,
+ const struct tb_property_dir *dir,
+ bool replace);
struct tb_property_dir *tb_property_create_dir(const uuid_t *uuid);
void tb_property_free_dir(struct tb_property_dir *dir);
int tb_property_add_immediate(struct tb_property_dir *parent, const char *key,
--
2.50.1