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92f1b85187
Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
652 lines
16 KiB
C
652 lines
16 KiB
C
/*
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* drivers/base/devres.c - device resource management
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*
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* Copyright (c) 2006 SUSE Linux Products GmbH
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* Copyright (c) 2006 Tejun Heo <teheo@suse.de>
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include "base.h"
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struct devres_node {
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struct list_head entry;
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dr_release_t release;
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#ifdef CONFIG_DEBUG_DEVRES
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const char *name;
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size_t size;
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#endif
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};
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struct devres {
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struct devres_node node;
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/* -- 3 pointers */
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unsigned long long data[]; /* guarantee ull alignment */
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};
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struct devres_group {
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struct devres_node node[2];
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void *id;
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int color;
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/* -- 8 pointers */
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};
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#ifdef CONFIG_DEBUG_DEVRES
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static int log_devres = 0;
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module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
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static void set_node_dbginfo(struct devres_node *node, const char *name,
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size_t size)
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{
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node->name = name;
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node->size = size;
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}
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static void devres_log(struct device *dev, struct devres_node *node,
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const char *op)
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{
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if (unlikely(log_devres))
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dev_printk(KERN_ERR, dev, "DEVRES %3s %p %s (%lu bytes)\n",
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op, node, node->name, (unsigned long)node->size);
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}
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#else /* CONFIG_DEBUG_DEVRES */
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#define set_node_dbginfo(node, n, s) do {} while (0)
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#define devres_log(dev, node, op) do {} while (0)
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#endif /* CONFIG_DEBUG_DEVRES */
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/*
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* Release functions for devres group. These callbacks are used only
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* for identification.
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*/
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static void group_open_release(struct device *dev, void *res)
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{
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/* noop */
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}
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static void group_close_release(struct device *dev, void *res)
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{
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/* noop */
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}
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static struct devres_group * node_to_group(struct devres_node *node)
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{
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if (node->release == &group_open_release)
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return container_of(node, struct devres_group, node[0]);
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if (node->release == &group_close_release)
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return container_of(node, struct devres_group, node[1]);
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return NULL;
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}
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static __always_inline struct devres * alloc_dr(dr_release_t release,
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size_t size, gfp_t gfp)
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{
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size_t tot_size = sizeof(struct devres) + size;
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struct devres *dr;
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dr = kmalloc_track_caller(tot_size, gfp);
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if (unlikely(!dr))
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return NULL;
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memset(dr, 0, tot_size);
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INIT_LIST_HEAD(&dr->node.entry);
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dr->node.release = release;
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return dr;
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}
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static void add_dr(struct device *dev, struct devres_node *node)
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{
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devres_log(dev, node, "ADD");
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BUG_ON(!list_empty(&node->entry));
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list_add_tail(&node->entry, &dev->devres_head);
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}
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#ifdef CONFIG_DEBUG_DEVRES
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void * __devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
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const char *name)
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{
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struct devres *dr;
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dr = alloc_dr(release, size, gfp);
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if (unlikely(!dr))
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return NULL;
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set_node_dbginfo(&dr->node, name, size);
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return dr->data;
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}
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EXPORT_SYMBOL_GPL(__devres_alloc);
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#else
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/**
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* devres_alloc - Allocate device resource data
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* @release: Release function devres will be associated with
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* @size: Allocation size
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* @gfp: Allocation flags
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*
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* Allocate devres of @size bytes. The allocated area is zeroed, then
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* associated with @release. The returned pointer can be passed to
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* other devres_*() functions.
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*
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* RETURNS:
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* Pointer to allocated devres on success, NULL on failure.
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*/
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void * devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
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{
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struct devres *dr;
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dr = alloc_dr(release, size, gfp);
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if (unlikely(!dr))
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return NULL;
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return dr->data;
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}
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EXPORT_SYMBOL_GPL(devres_alloc);
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#endif
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/**
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* devres_free - Free device resource data
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* @res: Pointer to devres data to free
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*
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* Free devres created with devres_alloc().
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*/
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void devres_free(void *res)
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{
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if (res) {
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struct devres *dr = container_of(res, struct devres, data);
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BUG_ON(!list_empty(&dr->node.entry));
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kfree(dr);
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}
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}
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EXPORT_SYMBOL_GPL(devres_free);
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/**
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* devres_add - Register device resource
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* @dev: Device to add resource to
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* @res: Resource to register
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*
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* Register devres @res to @dev. @res should have been allocated
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* using devres_alloc(). On driver detach, the associated release
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* function will be invoked and devres will be freed automatically.
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*/
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void devres_add(struct device *dev, void *res)
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{
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struct devres *dr = container_of(res, struct devres, data);
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unsigned long flags;
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spin_lock_irqsave(&dev->devres_lock, flags);
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add_dr(dev, &dr->node);
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spin_unlock_irqrestore(&dev->devres_lock, flags);
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}
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EXPORT_SYMBOL_GPL(devres_add);
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static struct devres *find_dr(struct device *dev, dr_release_t release,
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dr_match_t match, void *match_data)
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{
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struct devres_node *node;
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list_for_each_entry_reverse(node, &dev->devres_head, entry) {
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struct devres *dr = container_of(node, struct devres, node);
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if (node->release != release)
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continue;
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if (match && !match(dev, dr->data, match_data))
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continue;
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return dr;
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}
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return NULL;
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}
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/**
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* devres_find - Find device resource
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* @dev: Device to lookup resource from
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* @release: Look for resources associated with this release function
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* @match: Match function (optional)
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* @match_data: Data for the match function
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*
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* Find the latest devres of @dev which is associated with @release
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* and for which @match returns 1. If @match is NULL, it's considered
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* to match all.
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*
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* RETURNS:
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* Pointer to found devres, NULL if not found.
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*/
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void * devres_find(struct device *dev, dr_release_t release,
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dr_match_t match, void *match_data)
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{
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struct devres *dr;
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unsigned long flags;
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spin_lock_irqsave(&dev->devres_lock, flags);
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dr = find_dr(dev, release, match, match_data);
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spin_unlock_irqrestore(&dev->devres_lock, flags);
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if (dr)
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return dr->data;
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return NULL;
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}
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EXPORT_SYMBOL_GPL(devres_find);
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/**
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* devres_get - Find devres, if non-existent, add one atomically
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* @dev: Device to lookup or add devres for
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* @new_res: Pointer to new initialized devres to add if not found
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* @match: Match function (optional)
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* @match_data: Data for the match function
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*
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* Find the latest devres of @dev which has the same release function
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* as @new_res and for which @match return 1. If found, @new_res is
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* freed; otherwise, @new_res is added atomically.
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*
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* RETURNS:
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* Pointer to found or added devres.
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*/
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void * devres_get(struct device *dev, void *new_res,
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dr_match_t match, void *match_data)
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{
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struct devres *new_dr = container_of(new_res, struct devres, data);
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struct devres *dr;
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unsigned long flags;
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spin_lock_irqsave(&dev->devres_lock, flags);
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dr = find_dr(dev, new_dr->node.release, match, match_data);
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if (!dr) {
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add_dr(dev, &new_dr->node);
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dr = new_dr;
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new_dr = NULL;
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}
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spin_unlock_irqrestore(&dev->devres_lock, flags);
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devres_free(new_dr);
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return dr->data;
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}
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EXPORT_SYMBOL_GPL(devres_get);
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/**
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* devres_remove - Find a device resource and remove it
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* @dev: Device to find resource from
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* @release: Look for resources associated with this release function
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* @match: Match function (optional)
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* @match_data: Data for the match function
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*
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* Find the latest devres of @dev associated with @release and for
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* which @match returns 1. If @match is NULL, it's considered to
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* match all. If found, the resource is removed atomically and
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* returned.
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*
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* RETURNS:
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* Pointer to removed devres on success, NULL if not found.
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*/
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void * devres_remove(struct device *dev, dr_release_t release,
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dr_match_t match, void *match_data)
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{
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struct devres *dr;
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unsigned long flags;
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spin_lock_irqsave(&dev->devres_lock, flags);
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dr = find_dr(dev, release, match, match_data);
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if (dr) {
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list_del_init(&dr->node.entry);
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devres_log(dev, &dr->node, "REM");
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}
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spin_unlock_irqrestore(&dev->devres_lock, flags);
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if (dr)
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return dr->data;
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return NULL;
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}
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EXPORT_SYMBOL_GPL(devres_remove);
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/**
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* devres_destroy - Find a device resource and destroy it
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* @dev: Device to find resource from
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* @release: Look for resources associated with this release function
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* @match: Match function (optional)
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* @match_data: Data for the match function
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*
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* Find the latest devres of @dev associated with @release and for
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* which @match returns 1. If @match is NULL, it's considered to
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* match all. If found, the resource is removed atomically and freed.
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*
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* RETURNS:
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* 0 if devres is found and freed, -ENOENT if not found.
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*/
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int devres_destroy(struct device *dev, dr_release_t release,
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dr_match_t match, void *match_data)
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{
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void *res;
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res = devres_remove(dev, release, match, match_data);
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if (unlikely(!res))
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return -ENOENT;
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devres_free(res);
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return 0;
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}
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EXPORT_SYMBOL_GPL(devres_destroy);
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static int remove_nodes(struct device *dev,
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struct list_head *first, struct list_head *end,
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struct list_head *todo)
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{
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int cnt = 0, nr_groups = 0;
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struct list_head *cur;
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/* First pass - move normal devres entries to @todo and clear
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* devres_group colors.
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*/
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cur = first;
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while (cur != end) {
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struct devres_node *node;
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struct devres_group *grp;
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node = list_entry(cur, struct devres_node, entry);
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cur = cur->next;
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grp = node_to_group(node);
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if (grp) {
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/* clear color of group markers in the first pass */
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grp->color = 0;
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nr_groups++;
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} else {
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/* regular devres entry */
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if (&node->entry == first)
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first = first->next;
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list_move_tail(&node->entry, todo);
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cnt++;
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}
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}
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if (!nr_groups)
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return cnt;
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/* Second pass - Scan groups and color them. A group gets
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* color value of two iff the group is wholly contained in
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* [cur, end). That is, for a closed group, both opening and
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* closing markers should be in the range, while just the
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* opening marker is enough for an open group.
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*/
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cur = first;
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while (cur != end) {
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struct devres_node *node;
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struct devres_group *grp;
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node = list_entry(cur, struct devres_node, entry);
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cur = cur->next;
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grp = node_to_group(node);
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BUG_ON(!grp || list_empty(&grp->node[0].entry));
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grp->color++;
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if (list_empty(&grp->node[1].entry))
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grp->color++;
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BUG_ON(grp->color <= 0 || grp->color > 2);
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if (grp->color == 2) {
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/* No need to update cur or end. The removed
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* nodes are always before both.
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*/
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list_move_tail(&grp->node[0].entry, todo);
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list_del_init(&grp->node[1].entry);
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}
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}
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return cnt;
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}
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static int release_nodes(struct device *dev, struct list_head *first,
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struct list_head *end, unsigned long flags)
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__releases(&dev->devres_lock)
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{
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LIST_HEAD(todo);
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int cnt;
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struct devres *dr, *tmp;
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cnt = remove_nodes(dev, first, end, &todo);
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spin_unlock_irqrestore(&dev->devres_lock, flags);
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/* Release. Note that both devres and devres_group are
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* handled as devres in the following loop. This is safe.
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*/
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list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
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devres_log(dev, &dr->node, "REL");
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dr->node.release(dev, dr->data);
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kfree(dr);
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}
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return cnt;
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}
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/**
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* devres_release_all - Release all managed resources
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* @dev: Device to release resources for
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*
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* Release all resources associated with @dev. This function is
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* called on driver detach.
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*/
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int devres_release_all(struct device *dev)
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{
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unsigned long flags;
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/* Looks like an uninitialized device structure */
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if (WARN_ON(dev->devres_head.next == NULL))
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return -ENODEV;
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spin_lock_irqsave(&dev->devres_lock, flags);
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return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
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flags);
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}
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/**
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* devres_open_group - Open a new devres group
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* @dev: Device to open devres group for
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* @id: Separator ID
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* @gfp: Allocation flags
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*
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* Open a new devres group for @dev with @id. For @id, using a
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* pointer to an object which won't be used for another group is
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* recommended. If @id is NULL, address-wise unique ID is created.
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*
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* RETURNS:
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* ID of the new group, NULL on failure.
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*/
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void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
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{
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struct devres_group *grp;
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unsigned long flags;
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grp = kmalloc(sizeof(*grp), gfp);
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if (unlikely(!grp))
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return NULL;
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grp->node[0].release = &group_open_release;
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grp->node[1].release = &group_close_release;
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INIT_LIST_HEAD(&grp->node[0].entry);
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INIT_LIST_HEAD(&grp->node[1].entry);
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set_node_dbginfo(&grp->node[0], "grp<", 0);
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set_node_dbginfo(&grp->node[1], "grp>", 0);
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grp->id = grp;
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if (id)
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grp->id = id;
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spin_lock_irqsave(&dev->devres_lock, flags);
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add_dr(dev, &grp->node[0]);
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spin_unlock_irqrestore(&dev->devres_lock, flags);
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return grp->id;
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}
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EXPORT_SYMBOL_GPL(devres_open_group);
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/* Find devres group with ID @id. If @id is NULL, look for the latest. */
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static struct devres_group * find_group(struct device *dev, void *id)
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{
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struct devres_node *node;
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list_for_each_entry_reverse(node, &dev->devres_head, entry) {
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struct devres_group *grp;
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if (node->release != &group_open_release)
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continue;
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grp = container_of(node, struct devres_group, node[0]);
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if (id) {
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if (grp->id == id)
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return grp;
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} else if (list_empty(&grp->node[1].entry))
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return grp;
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}
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return NULL;
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}
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/**
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* devres_close_group - Close a devres group
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* @dev: Device to close devres group for
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* @id: ID of target group, can be NULL
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*
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* Close the group identified by @id. If @id is NULL, the latest open
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* group is selected.
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*/
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void devres_close_group(struct device *dev, void *id)
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{
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struct devres_group *grp;
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unsigned long flags;
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spin_lock_irqsave(&dev->devres_lock, flags);
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grp = find_group(dev, id);
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if (grp)
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add_dr(dev, &grp->node[1]);
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else
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WARN_ON(1);
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spin_unlock_irqrestore(&dev->devres_lock, flags);
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}
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EXPORT_SYMBOL_GPL(devres_close_group);
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/**
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* devres_remove_group - Remove a devres group
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* @dev: Device to remove group for
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* @id: ID of target group, can be NULL
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*
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|
* 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);
|
|
|
|
/*
|
|
* Managed kzalloc/kfree
|
|
*/
|
|
static void devm_kzalloc_release(struct device *dev, void *res)
|
|
{
|
|
/* noop */
|
|
}
|
|
|
|
static int devm_kzalloc_match(struct device *dev, void *res, void *data)
|
|
{
|
|
return res == data;
|
|
}
|
|
|
|
/**
|
|
* devm_kzalloc - Resource-managed kzalloc
|
|
* @dev: Device to allocate memory for
|
|
* @size: Allocation size
|
|
* @gfp: Allocation gfp flags
|
|
*
|
|
* Managed kzalloc. 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_kzalloc(struct device *dev, size_t size, gfp_t gfp)
|
|
{
|
|
struct devres *dr;
|
|
|
|
/* use raw alloc_dr for kmalloc caller tracing */
|
|
dr = alloc_dr(devm_kzalloc_release, size, gfp);
|
|
if (unlikely(!dr))
|
|
return NULL;
|
|
|
|
set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
|
|
devres_add(dev, dr->data);
|
|
return dr->data;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_kzalloc);
|
|
|
|
/**
|
|
* devm_kfree - Resource-managed kfree
|
|
* @dev: Device this memory belongs to
|
|
* @p: Memory to free
|
|
*
|
|
* Free memory allocated with devm_kzalloc().
|
|
*/
|
|
void devm_kfree(struct device *dev, void *p)
|
|
{
|
|
int rc;
|
|
|
|
rc = devres_destroy(dev, devm_kzalloc_release, devm_kzalloc_match, p);
|
|
WARN_ON(rc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_kfree);
|