device property: Take a copy of the property set

It is convenient if the property set associated with the device secondary
firmware node is a copy of the original. This allows passing property set
from a stack for example for devices created dynamically. This also ties
the property set lifetime to the associated device.

Because of that we provide new function device_remove_property_set() that
is used to disassociate and release memory allocated for the property set.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/property.c b/drivers/base/property.c
index ebcbe34..0b22c8a 100644 (file)
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -19,24 +19,6 @@
 #include <linux/etherdevice.h>
 #include <linux/phy.h>
 
-/**
- * device_add_property_set - Add a collection of properties to a device object.
- * @dev: Device to add properties to.
- * @pset: Collection of properties to add.
- *
- * Associate a collection of device properties represented by @pset with @dev
- * as its secondary firmware node.
- */
-void device_add_property_set(struct device *dev, struct property_set *pset)
-{
-       if (!pset)
-               return;
-
-       pset->fwnode.type = FWNODE_PDATA;
-       set_secondary_fwnode(dev, &pset->fwnode);
-}
-EXPORT_SYMBOL_GPL(device_add_property_set);
-
 static inline bool is_pset_node(struct fwnode_handle *fwnode)
 {
        return fwnode && fwnode->type == FWNODE_PDATA;
@@ -692,6 +674,179 @@ out:
 }
 EXPORT_SYMBOL_GPL(fwnode_property_match_string);
 
+/**
+ * pset_free_set - releases memory allocated for copied property set
+ * @pset: Property set to release
+ *
+ * Function takes previously copied property set and releases all the
+ * memory allocated to it.
+ */
+static void pset_free_set(struct property_set *pset)
+{
+       const struct property_entry *prop;
+       size_t i, nval;
+
+       if (!pset)
+               return;
+
+       for (prop = pset->properties; prop->name; prop++) {
+               if (prop->is_array) {
+                       if (prop->is_string && prop->pointer.str) {
+                               nval = prop->length / sizeof(const char *);
+                               for (i = 0; i < nval; i++)
+                                       kfree(prop->pointer.str[i]);
+                       }
+                       kfree(prop->pointer.raw_data);
+               } else if (prop->is_string) {
+                       kfree(prop->value.str);
+               }
+               kfree(prop->name);
+       }
+
+       kfree(pset->properties);
+       kfree(pset);
+}
+
+static int pset_copy_entry(struct property_entry *dst,
+                          const struct property_entry *src)
+{
+       const char **d, **s;
+       size_t i, nval;
+
+       dst->name = kstrdup(src->name, GFP_KERNEL);
+       if (!dst->name)
+               return -ENOMEM;
+
+       if (src->is_array) {
+               if (src->is_string) {
+                       nval = src->length / sizeof(const char *);
+                       dst->pointer.str = kcalloc(nval, sizeof(const char *),
+                                                  GFP_KERNEL);
+                       if (!dst->pointer.str)
+                               return -ENOMEM;
+
+                       d = dst->pointer.str;
+                       s = src->pointer.str;
+                       for (i = 0; i < nval; i++) {
+                               d[i] = kstrdup(s[i], GFP_KERNEL);
+                               if (!d[i] && s[i])
+                                       return -ENOMEM;
+                       }
+               } else {
+                       dst->pointer.raw_data = kmemdup(src->pointer.raw_data,
+                                                       src->length, GFP_KERNEL);
+                       if (!dst->pointer.raw_data)
+                               return -ENOMEM;
+               }
+       } else if (src->is_string) {
+               dst->value.str = kstrdup(src->value.str, GFP_KERNEL);
+               if (!dst->value.str && src->value.str)
+                       return -ENOMEM;
+       } else {
+               dst->value.raw_data = src->value.raw_data;
+       }
+
+       dst->length = src->length;
+       dst->is_array = src->is_array;
+       dst->is_string = src->is_string;
+
+       return 0;
+}
+
+/**
+ * pset_copy_set - copies property set
+ * @pset: Property set to copy
+ *
+ * This function takes a deep copy of the given property set and returns
+ * pointer to the copy. Call device_free_property_set() to free resources
+ * allocated in this function.
+ *
+ * Return: Pointer to the new property set or error pointer.
+ */
+static struct property_set *pset_copy_set(const struct property_set *pset)
+{
+       const struct property_entry *entry;
+       struct property_set *p;
+       size_t i, n = 0;
+
+       p = kzalloc(sizeof(*p), GFP_KERNEL);
+       if (!p)
+               return ERR_PTR(-ENOMEM);
+
+       while (pset->properties[n].name)
+               n++;
+
+       p->properties = kcalloc(n + 1, sizeof(*entry), GFP_KERNEL);
+       if (!p->properties) {
+               kfree(p);
+               return ERR_PTR(-ENOMEM);
+       }
+
+       for (i = 0; i < n; i++) {
+               int ret = pset_copy_entry(&p->properties[i],
+                                         &pset->properties[i]);
+               if (ret) {
+                       pset_free_set(p);
+                       return ERR_PTR(ret);
+               }
+       }
+
+       return p;
+}
+
+/**
+ * device_remove_property_set - Remove properties from a device object.
+ * @dev: Device whose properties to remove.
+ *
+ * The function removes properties previously associated to the device
+ * secondary firmware node with device_add_property_set(). Memory allocated
+ * to the properties will also be released.
+ */
+void device_remove_property_set(struct device *dev)
+{
+       struct fwnode_handle *fwnode;
+
+       fwnode = dev_fwnode(dev);
+       if (!fwnode)
+               return;
+       /*
+        * Pick either primary or secondary node depending which one holds
+        * the pset. If there is no real firmware node (ACPI/DT) primary
+        * will hold the pset.
+        */
+       if (!is_pset_node(fwnode))
+               fwnode = fwnode->secondary;
+       if (!IS_ERR(fwnode) && is_pset_node(fwnode))
+               pset_free_set(to_pset_node(fwnode));
+       set_secondary_fwnode(dev, NULL);
+}
+EXPORT_SYMBOL_GPL(device_remove_property_set);
+
+/**
+ * device_add_property_set - Add a collection of properties to a device object.
+ * @dev: Device to add properties to.
+ * @pset: Collection of properties to add.
+ *
+ * Associate a collection of device properties represented by @pset with @dev
+ * as its secondary firmware node. The function takes a copy of @pset.
+ */
+int device_add_property_set(struct device *dev, const struct property_set *pset)
+{
+       struct property_set *p;
+
+       if (!pset)
+               return -EINVAL;
+
+       p = pset_copy_set(pset);
+       if (IS_ERR(p))
+               return PTR_ERR(p);
+
+       p->fwnode.type = FWNODE_PDATA;
+       set_secondary_fwnode(dev, &p->fwnode);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(device_add_property_set);
+
 /**
  * device_get_next_child_node - Return the next child node handle for a device
  * @dev: Device to find the next child node for.

diff --git a/include/linux/property.h b/include/linux/property.h
index d1cf208..3a8c7d7 100644 (file)
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -240,7 +240,8 @@ struct property_set {
        struct property_entry *properties;
 };
 
-void device_add_property_set(struct device *dev, struct property_set *pset);
+int device_add_property_set(struct device *dev, const struct property_set *pset);
+void device_remove_property_set(struct device *dev);
 
 bool device_dma_supported(struct device *dev);