path: root/drivers/base/devres.c

// 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(!