summaryrefslogtreecommitdiff
path: root/drivers/base/devres.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/base/devres.c
Initial import
Diffstat (limited to 'drivers/base/devres.c')
-rw-r--r--drivers/base/devres.c986
1 files changed, 986 insertions, 0 deletions
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
new file mode 100644
index 000000000..c8a53d1e0
--- /dev/null
+++ b/drivers/base/devres.c
@@ -0,0 +1,986 @@
+/*
+ * drivers/base/devres.c - device resource management
+ *
+ * Copyright (c) 2006 SUSE Linux Products GmbH
+ * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "base.h"
+
+struct devres_node {
+ struct list_head entry;
+ dr_release_t release;
+#ifdef CONFIG_DEBUG_DEVRES
+ const char *name;
+ size_t size;
+#endif
+};
+
+struct devres {
+ struct devres_node node;
+ /* -- 3 pointers */
+ unsigned long long data[]; /* guarantee ull alignment */
+};
+
+struct devres_group {
+ struct devres_node node[2];
+ void *id;
+ int color;
+ /* -- 8 pointers */
+};
+
+#ifdef CONFIG_DEBUG_DEVRES
+static int log_devres = 0;
+module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
+
+static void set_node_dbginfo(struct devres_node *node, const char *name,
+ size_t size)
+{
+ node->name = name;
+ node->size = size;
+}
+
+static void devres_log(struct device *dev, struct devres_node *node,
+ const char *op)
+{
+ if (unlikely(log_devres))
+ dev_err(dev, "DEVRES %3s %p %s (%lu bytes)\n",
+ op, node, node->name, (unsigned long)node->size);
+}
+#else /* CONFIG_DEBUG_DEVRES */
+#define set_node_dbginfo(node, n, s) do {} while (0)
+#define devres_log(dev, node, op) do {} while (0)
+#endif /* CONFIG_DEBUG_DEVRES */
+
+/*
+ * Release functions for devres group. These callbacks are used only
+ * for identification.
+ */
+static void group_open_release(struct device *dev, void *res)
+{
+ /* noop */
+}
+
+static void group_close_release(struct device *dev, void *res)
+{
+ /* noop */
+}
+
+static struct devres_group * node_to_group(struct devres_node *node)
+{
+ if (node->release == &group_open_release)
+ return container_of(node, struct devres_group, node[0]);
+ if (node->release == &group_close_release)
+ return container_of(node, struct devres_group, node[1]);
+ return NULL;
+}
+
+static __always_inline struct devres * alloc_dr(dr_release_t release,
+ size_t size, gfp_t gfp)
+{
+ size_t tot_size = sizeof(struct devres) + size;
+ struct devres *dr;
+
+ dr = kmalloc_track_caller(tot_size, gfp);
+ if (unlikely(!dr))
+ return NULL;
+
+ memset(dr, 0, offsetof(struct devres, data));
+
+ INIT_LIST_HEAD(&dr->node.entry);
+ dr->node.release = release;
+ return dr;
+}
+
+static void add_dr(struct device *dev, struct devres_node *node)
+{
+ devres_log(dev, node, "ADD");
+ BUG_ON(!list_empty(&node->entry));
+ list_add_tail(&node->entry, &dev->devres_head);
+}
+
+#ifdef CONFIG_DEBUG_DEVRES
+void * __devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
+ const char *name)
+{
+ struct devres *dr;
+
+ dr = alloc_dr(release, size, gfp | __GFP_ZERO);
+ if (unlikely(!dr))
+ return NULL;
+ set_node_dbginfo(&dr->node, name, size);
+ return dr->data;
+}
+EXPORT_SYMBOL_GPL(__devres_alloc);
+#else
+/**
+ * devres_alloc - Allocate device resource data
+ * @release: Release function devres will be associated with
+ * @size: Allocation size
+ * @gfp: Allocation flags
+ *
+ * Allocate devres of @size bytes. The allocated area is zeroed, then
+ * associated with @release. The returned pointer can be passed to
+ * other devres_*() functions.
+ *
+ * RETURNS:
+ * Pointer to allocated devres on success, NULL on failure.
+ */
+void * devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
+{
+ struct devres *dr;
+
+ dr = alloc_dr(release, size, gfp | __GFP_ZERO);
+ if (unlikely(!dr))
+ return NULL;
+ return dr->data;
+}
+EXPORT_SYMBOL_GPL(devres_alloc);
+#endif
+
+/**
+ * devres_for_each_res - Resource iterator
+ * @dev: Device to iterate resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ * @fn: Function to be called for each matched resource.
+ * @data: Data for @fn, the 3rd parameter of @fn
+ *
+ * Call @fn for each devres of @dev which is associated with @release
+ * and for which @match returns 1.
+ *
+ * RETURNS:
+ * void
+ */
+void devres_for_each_res(struct device *dev, dr_release_t release,
+ dr_match_t match, void *match_data,
+ void (*fn)(struct device *, void *, void *),
+ void *data)
+{
+ struct devres_node *node;
+ struct devres_node *tmp;
+ unsigned long flags;
+
+ if (!fn)
+ return;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+ list_for_each_entry_safe_reverse(node, tmp,
+ &dev->devres_head, entry) {
+ struct devres *dr = container_of(node, struct devres, node);
+
+ if (node->release != release)
+ continue;
+ if (match && !match(dev, dr->data, match_data))
+ continue;
+ fn(dev, dr->data, data);
+ }
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+}
+EXPORT_SYMBOL_GPL(devres_for_each_res);
+
+/**
+ * devres_free - Free device resource data
+ * @res: Pointer to devres data to free
+ *
+ * Free devres created with devres_alloc().
+ */
+void devres_free(void *res)
+{
+ if (res) {
+ struct devres *dr = container_of(res, struct devres, data);
+
+ BUG_ON(!list_empty(&dr->node.entry));
+ kfree(dr);
+ }
+}
+EXPORT_SYMBOL_GPL(devres_free);
+
+/**
+ * devres_add - Register device resource
+ * @dev: Device to add resource to
+ * @res: Resource to register
+ *
+ * Register devres @res to @dev. @res should have been allocated
+ * using devres_alloc(). On driver detach, the associated release
+ * function will be invoked and devres will be freed automatically.
+ */
+void devres_add(struct device *dev, void *res)
+{
+ struct devres *dr = container_of(res, struct devres, data);
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+ add_dr(dev, &dr->node);
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+}
+EXPORT_SYMBOL_GPL(devres_add);
+
+static struct devres *find_dr(struct device *dev, dr_release_t release,
+ dr_match_t match, void *match_data)
+{
+ struct devres_node *node;
+
+ list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+ struct devres *dr = container_of(node, struct devres, node);
+
+ if (node->release != release)
+ continue;
+ if (match && !match(dev, dr->data, match_data))
+ continue;
+ return dr;
+ }
+
+ return NULL;
+}
+
+/**
+ * devres_find - Find device resource
+ * @dev: Device to lookup resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev which is associated with @release
+ * and for which @match returns 1. If @match is NULL, it's considered
+ * to match all.
+ *
+ * RETURNS:
+ * Pointer to found devres, NULL if not found.
+ */
+void * devres_find(struct device *dev, dr_release_t release,
+ dr_match_t match, void *match_data)
+{
+ struct devres *dr;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+ dr = find_dr(dev, release, match, match_data);
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+ if (dr)
+ return dr->data;
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(devres_find);
+
+/**
+ * devres_get - Find devres, if non-existent, add one atomically
+ * @dev: Device to lookup or add devres for
+ * @new_res: Pointer to new initialized devres to add if not found
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev which has the same release function
+ * as @new_res and for which @match return 1. If found, @new_res is
+ * freed; otherwise, @new_res is added atomically.
+ *
+ * RETURNS:
+ * Pointer to found or added devres.
+ */
+void * devres_get(struct device *dev, void *new_res,
+ dr_match_t match, void *match_data)
+{
+ struct devres *new_dr = container_of(new_res, struct devres, data);
+ struct devres *dr;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+ dr = find_dr(dev, new_dr->node.release, match, match_data);
+ if (!dr) {
+ add_dr(dev, &new_dr->node);
+ dr = new_dr;
+ new_dr = NULL;
+ }
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+ devres_free(new_dr);
+
+ return dr->data;
+}
+EXPORT_SYMBOL_GPL(devres_get);
+
+/**
+ * devres_remove - Find a device resource and remove it
+ * @dev: Device to find resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev associated with @release and for
+ * which @match returns 1. If @match is NULL, it's considered to
+ * match all. If found, the resource is removed atomically and
+ * returned.
+ *
+ * RETURNS:
+ * Pointer to removed devres on success, NULL if not found.
+ */
+void * devres_remove(struct device *dev, dr_release_t release,
+ dr_match_t match, void *match_data)
+{
+ struct devres *dr;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+ dr = find_dr(dev, release, match, match_data);
+ if (dr) {
+ list_del_init(&dr->node.entry);
+ devres_log(dev, &dr->node, "REM");
+ }
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+ if (dr)
+ return dr->data;
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(devres_remove);
+
+/**
+ * devres_destroy - Find a device resource and destroy it
+ * @dev: Device to find resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev associated with @release and for
+ * which @match returns 1. If @match is NULL, it's considered to
+ * match all. If found, the resource is removed atomically and freed.
+ *
+ * Note that the release function for the resource will not be called,
+ * only the devres-allocated data will be freed. The caller becomes
+ * responsible for freeing any other data.
+ *
+ * RETURNS:
+ * 0 if devres is found and freed, -ENOENT if not found.
+ */
+int devres_destroy(struct device *dev, dr_release_t release,
+ dr_match_t match, void *match_data)
+{
+ void *res;
+
+ res = devres_remove(dev, release, match, match_data);
+ if (unlikely(!res))
+ return -ENOENT;
+
+ devres_free(res);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devres_destroy);
+
+
+/**
+ * devres_release - Find a device resource and destroy it, calling release
+ * @dev: Device to find resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev associated with @release and for
+ * which @match returns 1. If @match is NULL, it's considered to
+ * match all. If found, the resource is removed atomically, the
+ * release function called and the resource freed.
+ *
+ * RETURNS:
+ * 0 if devres is found and freed, -ENOENT if not found.
+ */
+int devres_release(struct device *dev, dr_release_t release,
+ dr_match_t match, void *match_data)
+{
+ void *res;
+
+ res = devres_remove(dev, release, match, match_data);
+ if (unlikely(!res))
+ return -ENOENT;
+
+ (*release)(dev, res);
+ devres_free(res);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devres_release);
+
+static int remove_nodes(struct device *dev,
+ struct list_head *first, struct list_head *end,
+ struct list_head *todo)
+{
+ int cnt = 0, nr_groups = 0;
+ struct list_head *cur;
+
+ /* First pass - move normal devres entries to @todo and clear
+ * devres_group colors.
+ */
+ cur = first;
+ while (cur != end) {
+ struct devres_node *node;
+ struct devres_group *grp;
+
+ node = list_entry(cur, struct devres_node, entry);
+ cur = cur->next;
+
+ grp = node_to_group(node);
+ if (grp) {
+ /* clear color of group markers in the first pass */
+ grp->color = 0;
+ nr_groups++;
+ } else {
+ /* regular devres entry */
+ if (&node->entry == first)
+ first = first->next;
+ list_move_tail(&node->entry, todo);
+ cnt++;
+ }
+ }
+
+ if (!nr_groups)
+ return cnt;
+
+ /* Second pass - Scan groups and color them. A group gets
+ * color value of two iff the group is wholly contained in
+ * [cur, end). That is, for a closed group, both opening and
+ * closing markers should be in the range, while just the
+ * opening marker is enough for an open group.
+ */
+ cur = first;
+ while (cur != end) {
+ struct devres_node *node;
+ struct devres_group *grp;
+
+ node = list_entry(cur, struct devres_node, entry);
+ cur = cur->next;
+
+ grp = node_to_group(node);
+ BUG_ON(!grp || list_empty(&grp->node[0].entry));
+
+ grp->color++;
+ if (list_empty(&grp->node[1].entry))
+ grp->color++;
+
+ BUG_ON(grp->color <= 0 || grp->color > 2);
+ if (grp->color == 2) {
+ /* No need to update cur or end. The removed
+ * nodes are always before both.
+ */
+ list_move_tail(&grp->node[0].entry, todo);
+ list_del_init(&grp->node[1].entry);
+ }
+ }
+
+ return cnt;
+}
+
+static int release_nodes(struct device *dev, struct list_head *first,
+ struct list_head *end, unsigned long flags)
+ __releases(&dev->devres_lock)
+{
+ LIST_HEAD(todo);
+ int cnt;
+ struct devres *dr, *tmp;
+
+ cnt = remove_nodes(dev, first, end, &todo);
+
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+ /* Release. Note that both devres and devres_group are
+ * handled as devres in the following loop. This is safe.
+ */
+ list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
+ devres_log(dev, &dr->node, "REL");
+ dr->node.release(dev, dr->data);
+ kfree(dr);
+ }
+
+ return cnt;
+}
+
+/**
+ * devres_release_all - Release all managed resources
+ * @dev: Device to release resources for
+ *
+ * Release all resources associated with @dev. This function is
+ * called on driver detach.
+ */
+int devres_release_all(struct device *dev)
+{
+ unsigned long flags;
+
+ /* Looks like an uninitialized device structure */
+ if (WARN_ON(dev->devres_head.next == NULL))
+ return -ENODEV;
+ spin_lock_irqsave(&dev->devres_lock, flags);
+ return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
+ flags);
+}
+
+/**
+ * devres_open_group - Open a new devres group
+ * @dev: Device to open devres group for
+ * @id: Separator ID
+ * @gfp: Allocation flags
+ *
+ * Open a new devres group for @dev with @id. For @id, using a
+ * pointer to an object which won't be used for another group is
+ * recommended. If @id is NULL, address-wise unique ID is created.
+ *
+ * RETURNS:
+ * ID of the new group, NULL on failure.
+ */
+void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
+{
+ struct devres_group *grp;
+ unsigned long flags;
+
+ grp = kmalloc(sizeof(*grp), gfp);
+ if (unlikely(!grp))
+ return NULL;
+
+ grp->node[0].release = &group_open_release;
+ grp->node[1].release = &group_close_release;
+ INIT_LIST_HEAD(&grp->node[0].entry);
+ INIT_LIST_HEAD(&grp->node[1].entry);
+ set_node_dbginfo(&grp->node[0], "grp<", 0);
+ set_node_dbginfo(&grp->node[1], "grp>", 0);
+ grp->id = grp;
+ if (id)
+ grp->id = id;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+ add_dr(dev, &grp->node[0]);
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+ return grp->id;
+}
+EXPORT_SYMBOL_GPL(devres_open_group);
+
+/* Find devres group with ID @id. If @id is NULL, look for the latest. */
+static struct devres_group * find_group(struct device *dev, void *id)
+{
+ struct devres_node *node;
+
+ list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+ struct devres_group *grp;
+
+ if (node->release != &group_open_release)
+ continue;
+
+ grp = container_of(node, struct devres_group, node[0]);
+
+ if (id) {
+ if (grp->id == id)
+ return grp;
+ } else if (list_empty(&grp->node[1].entry))
+ return grp;
+ }
+
+ return NULL;
+}
+
+/**
+ * devres_close_group - Close a devres group
+ * @dev: Device to close devres group for
+ * @id: ID of target group, can be NULL
+ *
+ * Close the group identified by @id. If @id is NULL, the latest open
+ * group is selected.
+ */
+void devres_close_group(struct device *dev, void *id)
+{
+ struct devres_group *grp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+
+ grp = find_group(dev, id);
+ if (grp)
+ add_dr(dev, &grp->node[1]);
+ else
+ WARN_ON(1);
+
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+}
+EXPORT_SYMBOL_GPL(devres_close_group);
+
+/**
+ * devres_remove_group - Remove a devres group
+ * @dev: Device to remove group for
+ * @id: ID of target group, can be NULL
+ *
+ * Remove the group identified by @id. If @id is NULL, the latest
+ * open group is selected. Note that removing a group doesn't affect
+ * any other resources.
+ */
+void devres_remove_group(struct device *dev, void *id)
+{
+ struct devres_group *grp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+
+ grp = find_group(dev, id);
+ if (grp) {
+ list_del_init(&grp->node[0].entry);
+ list_del_init(&grp->node[1].entry);
+ devres_log(dev, &grp->node[0], "REM");
+ } else
+ WARN_ON(1);
+
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+ kfree(grp);
+}
+EXPORT_SYMBOL_GPL(devres_remove_group);
+
+/**
+ * devres_release_group - Release resources in a devres group
+ * @dev: Device to release group for
+ * @id: ID of target group, can be NULL
+ *
+ * Release all resources in the group identified by @id. If @id is
+ * NULL, the latest open group is selected. The selected group and
+ * groups properly nested inside the selected group are removed.
+ *
+ * RETURNS:
+ * The number of released non-group resources.
+ */
+int devres_release_group(struct device *dev, void *id)
+{
+ struct devres_group *grp;
+ unsigned long flags;
+ int cnt = 0;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+
+ grp = find_group(dev, id);
+ if (grp) {
+ struct list_head *first = &grp->node[0].entry;
+ struct list_head *end = &dev->devres_head;
+
+ if (!list_empty(&grp->node[1].entry))
+ end = grp->node[1].entry.next;
+
+ cnt = release_nodes(dev, first, end, flags);
+ } else {
+ WARN_ON(1);
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+ }
+
+ return cnt;
+}
+EXPORT_SYMBOL_GPL(devres_release_group);
+
+/*
+ * Custom devres actions allow inserting a simple function call
+ * into the teadown sequence.
+ */
+
+struct action_devres {
+ void *data;
+ void (*action)(void *);
+};
+
+static int devm_action_match(struct device *dev, void *res, void *p)
+{
+ struct action_devres *devres = res;
+ struct action_devres *target = p;
+
+ return devres->action == target->action &&
+ devres->data == target->data;
+}
+
+static void devm_action_release(struct device *dev, void *res)
+{
+ struct action_devres *devres = res;
+
+ devres->action(devres->data);
+}
+
+/**
+ * devm_add_action() - add a custom action to list of managed resources
+ * @dev: Device that owns the action
+ * @action: Function that should be called
+ * @data: Pointer to data passed to @action implementation
+ *
+ * This adds a custom action to the list of managed resources so that
+ * it gets executed as part of standard resource unwinding.
+ */
+int devm_add_action(struct device *dev, void (*action)(void *), void *data)
+{
+ struct action_devres *devres;
+
+ devres = devres_alloc(devm_action_release,
+ sizeof(struct action_devres), GFP_KERNEL);
+ if (!devres)
+ return -ENOMEM;
+
+ devres->data = data;
+ devres->action = action;
+
+ devres_add(dev, devres);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_add_action);
+
+/**
+ * devm_remove_action() - removes previously added custom action
+ * @dev: Device that owns the action
+ * @action: Function implementing the action
+ * @data: Pointer to data passed to @action implementation
+ *
+ * Removes instance of @action previously added by devm_add_action().
+ * Both action and data should match one of the existing entries.
+ */
+void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
+{
+ struct action_devres devres = {
+ .data = data,
+ .action = action,
+ };
+
+ WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
+ &devres));
+
+}
+EXPORT_SYMBOL_GPL(devm_remove_action);
+
+/*
+ * Managed kmalloc/kfree
+ */
+static void devm_kmalloc_release(struct device *dev, void *res)
+{
+ /* noop */
+}
+
+static int devm_kmalloc_match(struct device *dev, void *res, void *data)
+{
+ return res == data;
+}
+
+/**
+ * devm_kmalloc - Resource-managed kmalloc
+ * @dev: Device to allocate memory for
+ * @size: Allocation size
+ * @gfp: Allocation gfp flags
+ *
+ * Managed kmalloc. Memory allocated with this function is
+ * automatically freed on driver detach. Like all other devres
+ * resources, guaranteed alignment is unsigned long long.
+ *
+ * RETURNS:
+ * Pointer to allocated memory on success, NULL on failure.
+ */
+void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
+{
+ struct devres *dr;
+
+ /* use raw alloc_dr for kmalloc caller tracing */
+ dr = alloc_dr(devm_kmalloc_release, size, gfp);
+ if (unlikely(!dr))
+ return NULL;
+
+ /*
+ * This is named devm_kzalloc_release for historical reasons
+ * The initial implementation did not support kmalloc, only kzalloc
+ */
+ set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
+ devres_add(dev, dr->data);
+ return dr->data;
+}
+EXPORT_SYMBOL_GPL(devm_kmalloc);
+
+/**
+ * devm_kstrdup - Allocate resource managed space and
+ * copy an existing string into that.
+ * @dev: Device to allocate memory for
+ * @s: the string to duplicate
+ * @gfp: the GFP mask used in the devm_kmalloc() call when
+ * allocating memory
+ * RETURNS:
+ * Pointer to allocated string on success, NULL on failure.
+ */
+char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
+{
+ size_t size;
+ char *buf;
+
+ if (!s)
+ return NULL;
+
+ size = strlen(s) + 1;
+ buf = devm_kmalloc(dev, size, gfp);
+ if (buf)
+ memcpy(buf, s, size);
+ return buf;
+}
+EXPORT_SYMBOL_GPL(devm_kstrdup);
+
+/**
+ * devm_kvasprintf - Allocate resource managed space and format a string
+ * into that.
+ * @dev: Device to allocate memory for
+ * @gfp: the GFP mask used in the devm_kmalloc() call when
+ * allocating memory
+ * @fmt: The printf()-style format string
+ * @ap: Arguments for the format string
+ * RETURNS:
+ * Pointer to allocated string on success, NULL on failure.
+ */
+char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
+ va_list ap)
+{
+ unsigned int len;
+ char *p;
+ va_list aq;
+
+ va_copy(aq, ap);
+ len = vsnprintf(NULL, 0, fmt, aq);
+ va_end(aq);
+
+ p = devm_kmalloc(dev, len+1, gfp);
+ if (!p)
+ return NULL;
+
+ vsnprintf(p, len+1, fmt, ap);
+
+ return p;
+}
+EXPORT_SYMBOL(devm_kvasprintf);
+
+/**
+ * devm_kasprintf - Allocate resource managed space and format a string
+ * into that.
+ * @dev: Device to allocate memory for
+ * @gfp: the GFP mask used in the devm_kmalloc() call when
+ * allocating memory
+ * @fmt: The printf()-style format string
+ * @...: Arguments for the format string
+ * RETURNS:
+ * Pointer to allocated string on success, NULL on failure.
+ */
+char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
+{
+ va_list ap;
+ char *p;
+
+ va_start(ap, fmt);
+ p = devm_kvasprintf(dev, gfp, fmt, ap);
+ va_end(ap);
+
+ return p;
+}
+EXPORT_SYMBOL_GPL(devm_kasprintf);
+
+/**
+ * devm_kfree - Resource-managed kfree
+ * @dev: Device this memory belongs to
+ * @p: Memory to free
+ *
+ * Free memory allocated with devm_kmalloc().
+ */
+void devm_kfree(struct device *dev, void *p)
+{
+ int rc;
+
+ rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
+ WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_kfree);
+
+/**
+ * devm_kmemdup - Resource-managed kmemdup
+ * @dev: Device this memory belongs to
+ * @src: Memory region to duplicate
+ * @len: Memory region length
+ * @gfp: GFP mask to use
+ *
+ * Duplicate region of a memory using resource managed kmalloc
+ */
+void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
+{
+ void *p;
+
+ p = devm_kmalloc(dev, len, gfp);
+ if (p)
+ memcpy(p, src, len);
+
+ return p;
+}
+EXPORT_SYMBOL_GPL(devm_kmemdup);
+
+struct pages_devres {
+ unsigned long addr;
+ unsigned int order;
+};
+
+static int devm_pages_match(struct device *dev, void *res, void *p)
+{
+ struct pages_devres *devres = res;
+ struct pages_devres *target = p;
+
+ return devres->addr == target->addr;
+}
+
+static void devm_pages_release(struct device *dev, void *res)
+{
+ struct pages_devres *devres = res;
+
+ free_pages(devres->addr, devres->order);
+}
+
+/**
+ * devm_get_free_pages - Resource-managed __get_free_pages
+ * @dev: Device to allocate memory for
+ * @gfp_mask: Allocation gfp flags
+ * @order: Allocation size is (1 << order) pages
+ *
+ * Managed get_free_pages. Memory allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * RETURNS:
+ * Address of allocated memory on success, 0 on failure.
+ */
+
+unsigned long devm_get_free_pages(struct device *dev,
+ gfp_t gfp_mask, unsigned int order)
+{
+ struct pages_devres *devres;
+ unsigned long addr;
+
+ addr = __get_free_pages(gfp_mask, order);
+
+ if (unlikely(!addr))
+ return 0;
+
+ devres = devres_alloc(devm_pages_release,
+ sizeof(struct pages_devres), GFP_KERNEL);
+ if (unlikely(!devres)) {
+ free_pages(addr, order);
+ return 0;
+ }
+
+ devres->addr = addr;
+ devres->order = order;
+
+ devres_add(dev, devres);
+ return addr;
+}
+EXPORT_SYMBOL_GPL(devm_get_free_pages);
+
+/**
+ * devm_free_pages - Resource-managed free_pages
+ * @dev: Device this memory belongs to
+ * @addr: Memory to free
+ *
+ * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
+ * there is no need to supply the @order.
+ */
+void devm_free_pages(struct device *dev, unsigned long addr)
+{
+ struct pages_devres devres = { .addr = addr };
+
+ WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
+ &devres));
+}
+EXPORT_SYMBOL_GPL(devm_free_pages);