diff options
Diffstat (limited to 'drivers/base/devres.c')
| -rw-r--r-- | drivers/base/devres.c | 986 |
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); |