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

[Mika Westerberg <mika.westerberg@linux.intel.com>]

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