linux/drivers/base/devres.c

988 lines
24 KiB
C
Raw Normal View History

/*
* 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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 09:04:11 +01:00
#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, int nid)
{
size_t tot_size = sizeof(struct devres) + size;
struct devres *dr;
dr = kmalloc_node_track_caller(tot_size, gfp, nid);
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_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
const char *name)
{
struct devres *dr;
dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
if (unlikely(!dr))
return NULL;
set_node_dbginfo(&dr->node, name, size);
return dr->data;
}
EXPORT_SYMBOL_GPL(__devres_alloc_node);
#else
/**
* devres_alloc - Allocate device resource data
* @release: Release function devres will be associated with
* @size: Allocation size
* @gfp: Allocation flags
* @nid: NUMA node
*
* 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_node(dr_release_t release, size_t size, gfp_t gfp, int nid)
{
struct devres *dr;
dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
if (unlikely(!dr))
return NULL;
return dr->data;
}
EXPORT_SYMBOL_GPL(devres_alloc_node);
#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_res = NULL;
}
spin_unlock_irqrestore(&dev->devres_lock, flags);
devres_free(new_res);
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, dev_to_node(dev));
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);