linux/linux-5.18.11/drivers/base/devres.c

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2024-03-22 18:12:32 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* drivers/base/devres.c - device resource management
*
* Copyright (c) 2006 SUSE Linux Products GmbH
* Copyright (c) 2006 Tejun Heo <teheo@suse.de>
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/percpu.h>
#include <asm/sections.h>
#include "base.h"
#include "trace.h"
struct devres_node {
struct list_head entry;
dr_release_t release;
const char *name;
size_t size;
};
struct devres {
struct devres_node node;
/*
* Some archs want to perform DMA into kmalloc caches
* and need a guaranteed alignment larger than
* the alignment of a 64-bit integer.
* Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same
* buffer alignment as if it was allocated by plain kmalloc().
*/
u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
};
struct devres_group {
struct devres_node node[2];
void *id;
int color;
/* -- 8 pointers */
};
static void set_node_dbginfo(struct devres_node *node, const char *name,
size_t size)
{
node->name = name;
node->size = size;
}
#ifdef CONFIG_DEBUG_DEVRES
static int log_devres = 0;
module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
static void devres_dbg(struct device *dev, struct devres_node *node,
const char *op)
{
if (unlikely(log_devres))
dev_err(dev, "DEVRES %3s %p %s (%zu bytes)\n",
op, node, node->name, node->size);
}
#else /* CONFIG_DEBUG_DEVRES */
#define devres_dbg(dev, node, op) do {} while (0)
#endif /* CONFIG_DEBUG_DEVRES */
static void devres_log(struct device *dev, struct devres_node *node,
const char *op)
{
trace_devres_log(dev, op, node, node->name, node->size);
devres_dbg(dev, node, op);
}
/*
* 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 bool check_dr_size(size_t size, size_t *tot_size)
{
/* We must catch any near-SIZE_MAX cases that could overflow. */
if (unlikely(check_add_overflow(sizeof(struct devres),
size, tot_size)))
return false;
return true;
}
static __always_inline struct devres * alloc_dr(dr_release_t release,
size_t size, gfp_t gfp, int nid)
{
size_t tot_size;
struct devres *dr;
if (!check_dr_size(size, &tot_size))
return NULL;
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);
}
static void replace_dr(struct device *dev,
struct devres_node *old, struct devres_node *new)
{
devres_log(dev, old, "REPLACE");
BUG_ON(!list_empty(&new->entry));
list_replace(&old->entry, &new->entry);
}
/**
* __devres_alloc_node - Allocate device resource data
* @release: Release function devres will be associated with
* @size: Allocation size
* @gfp: Allocation flags
* @nid: NUMA node
* @name: Name of the resource
*
* 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,
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);
/**
* 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)
{
struct devres_node *node, *n;
int cnt = 0, nr_groups = 0;
/* First pass - move normal devres entries to @todo and clear
* devres_group colors.
*/
node = list_entry(first, struct devres_node, entry);
list_for_each_entry_safe_from(node, n, end, entry) {
struct devres_group *grp;
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
* [current node, 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.
*/
node = list_entry(first, struct devres_node, entry);
list_for_each_entry_safe_from(node, n, end, entry) {
struct devres_group *grp;
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 current node 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 void release_nodes(struct device *dev, struct list_head *todo)
{
struct devres *dr, *tmp;
/* 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);
}
}
/**
* 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;
LIST_HEAD(todo);
int cnt;
/* Looks like an uninitialized device structure */
if (WARN_ON(dev->devres_head.next == NULL))
return -ENODEV;
/* Nothing to release if list is empty */
if (list_empty(&dev->devres_head))
return 0;
spin_lock_irqsave(&dev->devres_lock, flags);
cnt = remove_nodes(dev, dev->devres_head.next, &dev->devres_head, &todo);
spin_unlock_irqrestore(&dev->devres_lock, flags);
release_nodes(dev, &todo);
return cnt;
}
/**
* 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;
LIST_HEAD(todo);
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 = remove_nodes(dev, first, end, &todo);
spin_unlock_irqrestore(&dev->devres_lock, flags);
release_nodes(dev, &todo);
} 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 teardown 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);
/**
* devm_release_action() - release previously added custom action
* @dev: Device that owns the action
* @action: Function implementing the action
* @data: Pointer to data passed to @action implementation
*
* Releases and removes instance of @action previously added by
* devm_add_action(). Both action and data should match one of the
* existing entries.
*/
void devm_release_action(struct device *dev, void (*action)(void *), void *data)
{
struct action_devres devres = {
.data = data,
.action = action,
};
WARN_ON(devres_release(dev, devm_action_release, devm_action_match,
&devres));
}
EXPORT_SYMBOL_GPL(devm_release_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;
if (unlikely(!size))
return ZERO_SIZE_PTR;
/* 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_krealloc - Resource-managed krealloc()
* @dev: Device to re-allocate memory for
* @ptr: Pointer to the memory chunk to re-allocate
* @new_size: New allocation size
* @gfp: Allocation gfp flags
*
* Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc().
* Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR,
* it's the equivalent of devm_kmalloc(). If new_size is zero, it frees the
* previously allocated memory and returns ZERO_SIZE_PTR. This function doesn't
* change the order in which the release callback for the re-alloc'ed devres
* will be called (except when falling back to devm_kmalloc() or when freeing
* resources when new_size is zero). The contents of the memory are preserved
* up to the lesser of new and old sizes.
*/
void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
{
size_t total_new_size, total_old_size;
struct devres *old_dr, *new_dr;
unsigned long flags;
if (unlikely(!new_size)) {
devm_kfree(dev, ptr);
return ZERO_SIZE_PTR;
}
if (unlikely(ZERO_OR_NULL_PTR(ptr)))
return devm_kmalloc(dev, new_size, gfp);
if (WARN_ON(is_kernel_rodata((unsigned long)ptr)))
/*
* We cannot reliably realloc a const string returned by
* devm_kstrdup_const().
*/
return NULL;
if (!check_dr_size(new_size, &total_new_size))
return NULL;
total_old_size = ksize(container_of(ptr, struct devres, data));
if (total_old_size == 0) {
WARN(1, "Pointer doesn't point to dynamically allocated memory.");
return NULL;
}
/*
* If new size is smaller or equal to the actual number of bytes
* allocated previously - just return the same pointer.
*/
if (total_new_size <= total_old_size)
return ptr;
/*
* Otherwise: allocate new, larger chunk. We need to allocate before
* taking the lock as most probably the caller uses GFP_KERNEL.
*/
new_dr = alloc_dr(devm_kmalloc_release,
total_new_size, gfp, dev_to_node(dev));
if (!new_dr)
return NULL;
/*
* The spinlock protects the linked list against concurrent
* modifications but not the resource itself.
*/
spin_lock_irqsave(&dev->devres_lock, flags);
old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
if (!old_dr) {
spin_unlock_irqrestore(&dev->devres_lock, flags);
kfree(new_dr);
WARN(1, "Memory chunk not managed or managed by a different device.");
return NULL;
}
replace_dr(dev, &old_dr->node, &new_dr->node);
spin_unlock_irqrestore(&dev->devres_lock, flags);
/*
* We can copy the memory contents after releasing the lock as we're
* no longer modifying the list links.
*/
memcpy(new_dr->data, old_dr->data,
total_old_size - offsetof(struct devres, data));
/*
* Same for releasing the old devres - it's now been removed from the
* list. This is also the reason why we must not use devm_kfree() - the
* links are no longer valid.
*/
kfree(old_dr);
return new_dr->data;
}
EXPORT_SYMBOL_GPL(devm_krealloc);
/**
* 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_kstrdup_const - resource managed conditional string duplication
* @dev: device for which to duplicate the string
* @s: the string to duplicate
* @gfp: the GFP mask used in the kmalloc() call when allocating memory
*
* Strings allocated by devm_kstrdup_const will be automatically freed when
* the associated device is detached.
*
* RETURNS:
* Source string if it is in .rodata section otherwise it falls back to
* devm_kstrdup.
*/
const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
{
if (is_kernel_rodata((unsigned long)s))
return s;
return devm_kstrdup(dev, s, gfp);
}
EXPORT_SYMBOL_GPL(devm_kstrdup_const);
/**
* 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, const void *p)
{
int rc;
/*
* Special cases: pointer to a string in .rodata returned by
* devm_kstrdup_const() or NULL/ZERO ptr.
*/
if (unlikely(is_kernel_rodata((unsigned long)p) || ZERO_OR_NULL_PTR(p)))
return;
rc = devres_destroy(dev, devm_kmalloc_release,
devm_kmalloc_match, (void *)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);
static void devm_percpu_release(struct device *dev, void *pdata)
{
void __percpu *p;
p = *(void __percpu **)pdata;
free_percpu(p);
}
static int devm_percpu_match(struct device *dev, void *data, void *p)
{
struct devres *devr = container_of(data, struct devres, data);
return *(void **)devr->data == p;
}
/**
* __devm_alloc_percpu - Resource-managed alloc_percpu
* @dev: Device to allocate per-cpu memory for
* @size: Size of per-cpu memory to allocate
* @align: Alignment of per-cpu memory to allocate
*
* Managed alloc_percpu. Per-cpu memory allocated with this function is
* automatically freed on driver detach.
*
* RETURNS:
* Pointer to allocated memory on success, NULL on failure.
*/
void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
size_t align)
{
void *p;
void __percpu *pcpu;
pcpu = __alloc_percpu(size, align);
if (!pcpu)
return NULL;
p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
if (!p) {
free_percpu(pcpu);
return NULL;
}
*(void __percpu **)p = pcpu;
devres_add(dev, p);
return pcpu;
}
EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
/**
* devm_free_percpu - Resource-managed free_percpu
* @dev: Device this memory belongs to
* @pdata: Per-cpu memory to free
*
* Free memory allocated with devm_alloc_percpu().
*/
void devm_free_percpu(struct device *dev, void __percpu *pdata)
{
WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
(__force void *)pdata));
}
EXPORT_SYMBOL_GPL(devm_free_percpu);