[PATCH v2 1/4] device property: export code duplicating array of property entries

Dmitry Torokhov
2017-02-01T02:11:34Z

When augmenting ACPI-enumerated devices with additional property data based
on DMI info, a module has often several potential property sets, with only
one being active on a given box. In order to save memory it should be
possible to mark everything and __initdata or __initconst, execute DMI
match early, and duplicate relevant properties. Then kernel will discard
the rest of them.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/base/property.c | 137 +++++++++++++++++++++++++++++------------------
include/linux/property.h | 5 ++
2 files changed, 90 insertions(+), 52 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 43a36d68c3fd..934845fc72e5 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -682,41 +682,8 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
}
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)
+static int property_entry_copy(struct property_entry *dst,
+ const struct property_entry *src)
{
const char **d, **s;
size_t i, nval;
@@ -765,6 +732,84 @@ static int pset_copy_entry(struct property_entry *dst,
}

/**
+ * property_entries_dup - duplicate array of properties
+ * @properties: array of properties to copy
+ *
+ * This function creates a deep copy of the given NULL-terminated array
+ * of property entries.
+ */
+struct property_entry *
+property_entries_dup(const struct property_entry *properties)
+{
+ struct property_entry *p;
+ int i, n = 0;
+
+ while (properties[n].name)
+ n++;
+
+ p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < n; i++) {
+ int ret = property_entry_copy(&p[i], &properties[i]);
+ if (ret) {
+ kfree(p);
+ return ERR_PTR(ret);
+ }
+ }
+
+ return p;
+}
+EXPORT_SYMBOL_GPL(property_entries_dup);
+
+/**
+ * property_entries_free - free previously allocated array of properties
+ * @properties: array of properties to destroy
+ *
+ * This function frees given NULL-terminated array of property entries,
+ * along with their data.
+ */
+void property_entries_free(const struct property_entry *properties)
+{
+ const struct property_entry *p;
+ size_t i, nval;
+
+ for (p = properties; p->name; p++) {
+ if (p->is_array) {
+ if (p->is_string && p->pointer.str) {
+ nval = p->length / sizeof(const char *);
+ for (i = 0; i < nval; i++)
+ kfree(p->pointer.str[i]);
+ }
+ kfree(p->pointer.raw_data);
+ } else if (p->is_string) {
+ kfree(p->value.str);
+ }
+ kfree(p->name);
+ }
+
+ kfree(properties);
+}
+EXPORT_SYMBOL_GPL(property_entries_free);
+
+/**
+ * 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)
+{
+ if (!pset)
+ return;
+
+ property_entries_free(pset->properties);
+ kfree(pset);
+}
+
+/**
* pset_copy_set - copies property set
* @pset: Property set to copy
*
@@ -776,32 +821,20 @@ static int pset_copy_entry(struct property_entry *dst,
*/
static struct property_set *pset_copy_set(const struct property_set *pset)
{
- const struct property_entry *entry;
+ struct property_entry *properties;
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) {
+ properties = property_entries_dup(pset->properties);
+ if (IS_ERR(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 ERR_CAST(properties);
}

+ p->properties = properties;
return p;
}

diff --git a/include/linux/property.h b/include/linux/property.h
index 856e50b2140c..48f154ae7e99 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -241,6 +241,11 @@ struct property_entry {
.name = _name_, \
}

+struct property_entry *
+property_entries_dup(const struct property_entry *properties);
+
+void property_entries_free(const struct property_entry *properties);
+
int device_add_properties(struct device *dev,
struct property_entry *properties);
void device_remove_properties(struct device *dev);
--
2.11.0.483.g087da7b7c-goog