[linux-2.6-block.git] / drivers / of / of_reserved_mem.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Device tree based initialization code for reserved memory.
 *
 * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
 * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 * Author: Marek Szyprowski <m.szyprowski@samsung.com>
 * Author: Josh Cartwright <joshc@codeaurora.org>
 */

#define pr_fmt(fmt)	"OF: reserved mem: " fmt

#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#include <linux/mm.h>
#include <linux/sizes.h>
#include <linux/of_reserved_mem.h>
#include <linux/sort.h>
#include <linux/slab.h>
#include <linux/memblock.h>

#define MAX_RESERVED_REGIONS	32
static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
static int reserved_mem_count;

static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
	phys_addr_t *res_base)
{
	phys_addr_t base;

	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
	align = !align ? SMP_CACHE_BYTES : align;
	base = memblock_find_in_range(start, end, size, align);
	if (!base)
		return -ENOMEM;

	*res_base = base;
	if (nomap)
		return memblock_remove(base, size);

	return memblock_reserve(base, size);
}

/**
 * res_mem_save_node() - save fdt node for second pass initialization
 */
void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
				      phys_addr_t base, phys_addr_t size)
{
	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];

	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
		pr_err("not enough space all defined regions.\n");
		return;
	}

	rmem->fdt_node = node;
	rmem->name = uname;
	rmem->base = base;
	rmem->size = size;

	reserved_mem_count++;
	return;
}

/**
 * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
 *			  and 'alloc-ranges' properties
 */
static int __init __reserved_mem_alloc_size(unsigned long node,
	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
{
	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
	phys_addr_t start = 0, end = 0;
	phys_addr_t base = 0, align = 0, size;
	int len;
	const __be32 *prop;
	int nomap;
	int ret;

	prop = of_get_flat_dt_prop(node, "size", &len);
	if (!prop)
		return -EINVAL;

	if (len != dt_root_size_cells * sizeof(__be32)) {
		pr_err("invalid size property in '%s' node.\n", uname);
		return -EINVAL;
	}
	size = dt_mem_next_cell(dt_root_size_cells, &prop);

	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;

	prop = of_get_flat_dt_prop(node, "alignment", &len);
	if (prop) {
		if (len != dt_root_addr_cells * sizeof(__be32)) {
			pr_err("invalid alignment property in '%s' node.\n",
				uname);
			return -EINVAL;
		}
		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
	}

	/* Need adjust the alignment to satisfy the CMA requirement */
	if (IS_ENABLED(CONFIG_CMA)
	    && of_flat_dt_is_compatible(node, "shared-dma-pool")
	    && of_get_flat_dt_prop(node, "reusable", NULL)
	    && !of_get_flat_dt_prop(node, "no-map", NULL)) {
		unsigned long order =
			max_t(unsigned long, MAX_ORDER - 1, pageblock_order);

		align = max(align, (phys_addr_t)PAGE_SIZE << order);
	}

	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
	if (prop) {

		if (len % t_len != 0) {
			pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
			       uname);
			return -EINVAL;
		}

		base = 0;

		while (len > 0) {
			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
			end = start + dt_mem_next_cell(dt_root_size_cells,
						       &prop);

			ret = early_init_dt_alloc_reserved_memory_arch(size,
					align, start, end, nomap, &base);
			if (ret == 0) {
				pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
					uname, &base,
					(unsigned long)size / SZ_1M);
				break;
			}
			len -= t_len;
		}

	} else {
		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
							0, 0, nomap, &base);
		if (ret == 0)
			pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
				uname, &base, (unsigned long)size / SZ_1M);
	}

	if (base == 0) {
		pr_info("failed to allocate memory for node '%s'\n", uname);
		return -ENOMEM;
	}

	*res_base = base;
	*res_size = size;

	return 0;
}

static const struct of_device_id __rmem_of_table_sentinel
	__used __section(__reservedmem_of_table_end);

/**
 * res_mem_init_node() - call region specific reserved memory init code
 */
static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
{
	extern const struct of_device_id __reservedmem_of_table[];
	const struct of_device_id *i;
	int ret = -ENOENT;

	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
		reservedmem_of_init_fn initfn = i->data;
		const char *compat = i->compatible;

		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
			continue;

		ret = initfn(rmem);
		if (ret == 0) {
			pr_info("initialized node %s, compatible id %s\n",
				rmem->name, compat);
			break;
		}
	}
	return ret;
}

static int __init __rmem_cmp(const void *a, const void *b)
{
	const struct reserved_mem *ra = a, *rb = b;

	if (ra->base < rb->base)
		return -1;

	if (ra->base > rb->base)
		return 1;

	return 0;
}

static void __init __rmem_check_for_overlap(void)
{
	int i;

	if (reserved_mem_count < 2)
		return;

	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
	     __rmem_cmp, NULL);
	for (i = 0; i < reserved_mem_count - 1; i++) {
		struct reserved_mem *this, *next;

		this = &reserved_mem[i];
		next = &reserved_mem[i + 1];
		if (!(this->base && next->base))
			continue;
		if (this->base + this->size > next->base) {
			phys_addr_t this_end, next_end;

			this_end = this->base + this->size;
			next_end = next->base + next->size;
			pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
			       this->name, &this->base, &this_end,
			       next->name, &next->base, &next_end);
		}
	}
}

/**
 * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
 */
void __init fdt_init_reserved_mem(void)
{
	int i;

	/* check for overlapping reserved regions */
	__rmem_check_for_overlap();

	for (i = 0; i < reserved_mem_count; i++) {
		struct reserved_mem *rmem = &reserved_mem[i];
		unsigned long node = rmem->fdt_node;
		int len;
		const __be32 *prop;
		int err = 0;
		int nomap;

		nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
		prop = of_get_flat_dt_prop(node, "phandle", &len);
		if (!prop)
			prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
		if (prop)
			rmem->phandle = of_read_number(prop, len/4);

		if (rmem->size == 0)
			err = __reserved_mem_alloc_size(node, rmem->name,
						 &rmem->base, &rmem->size);
		if (err == 0) {
			err = __reserved_mem_init_node(rmem);
			if (err != 0 && err != -ENOENT) {
				pr_info("node %s compatible matching fail\n",
					rmem->name);
				memblock_free(rmem->base, rmem->size);
				if (nomap)
					memblock_add(rmem->base, rmem->size);
			}
		}
	}
}

static inline struct reserved_mem *__find_rmem(struct device_node *node)
{
	unsigned int i;

	if (!node->phandle)
		return NULL;

	for (i = 0; i < reserved_mem_count; i++)
		if (reserved_mem[i].phandle == node->phandle)
			return &reserved_mem[i];
	return NULL;
}

struct rmem_assigned_device {
	struct device *dev;
	struct reserved_mem *rmem;
	struct list_head list;
};

static LIST_HEAD(of_rmem_assigned_device_list);
static DEFINE_MUTEX(of_rmem_assigned_device_mutex);

/**
 * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
 *					  given device
 * @dev:	Pointer to the device to configure
 * @np:		Pointer to the device_node with 'reserved-memory' property
 * @idx:	Index of selected region
 *
 * This function assigns respective DMA-mapping operations based on reserved
 * memory region specified by 'memory-region' property in @np node to the @dev
 * device. When driver needs to use more than one reserved memory region, it
 * should allocate child devices and initialize regions by name for each of
 * child device.
 *
 * Returns error code or zero on success.
 */
int of_reserved_mem_device_init_by_idx(struct device *dev,
				       struct device_node *np, int idx)
{
	struct rmem_assigned_device *rd;
	struct device_node *target;
	struct reserved_mem *rmem;
	int ret;

	if (!np || !dev)
		return -EINVAL;

	target = of_parse_phandle(np, "memory-region", idx);
	if (!target)
		return -ENODEV;

	if (!of_device_is_available(target))
		return 0;

	rmem = __find_rmem(target);
	of_node_put(target);

	if (!rmem || !rmem->ops || !rmem->ops->device_init)
		return -EINVAL;

	rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
	if (!rd)
		return -ENOMEM;

	ret = rmem->ops->device_init(rmem, dev);
	if (ret == 0) {
		rd->dev = dev;
		rd->rmem = rmem;

		mutex_lock(&of_rmem_assigned_device_mutex);
		list_add(&rd->list, &of_rmem_assigned_device_list);
		mutex_unlock(&of_rmem_assigned_device_mutex);

		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
	} else {
		kfree(rd);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);

/**
 * of_reserved_mem_device_release() - release reserved memory device structures
 * @dev:	Pointer to the device to deconfigure
 *
 * This function releases structures allocated for memory region handling for
 * the given device.
 */
void of_reserved_mem_device_release(struct device *dev)
{
	struct rmem_assigned_device *rd;
	struct reserved_mem *rmem = NULL;

	mutex_lock(&of_rmem_assigned_device_mutex);
	list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
		if (rd->dev == dev) {
			rmem = rd->rmem;
			list_del(&rd->list);
			kfree(rd);
			break;
		}
	}
	mutex_unlock(&of_rmem_assigned_device_mutex);

	if (!rmem || !rmem->ops || !rmem->ops->device_release)
		return;

	rmem->ops->device_release(rmem, dev);
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);

/**
 * of_reserved_mem_lookup() - acquire reserved_mem from a device node
 * @np:		node pointer of the desired reserved-memory region
 *
 * This function allows drivers to acquire a reference to the reserved_mem
 * struct based on a device node handle.
 *
 * Returns a reserved_mem reference, or NULL on error.
 */
struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
{
	const char *name;
	int i;

	if (!np->full_name)
		return NULL;

	name = kbasename(np->full_name);
	for (i = 0; i < reserved_mem_count; i++)
		if (!strcmp(reserved_mem[i].name, name))
			return &reserved_mem[i];

	return NULL;
}
EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
Commit	Line	Data
af6074fc	1	// SPDX-License-Identifier: GPL-2.0+
3f0c8206 MS	2	/*
	3	* Device tree based initialization code for reserved memory.
	4	*
ae1add24	5	* Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
3f0c8206 MS	6	* Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
	7	* http://www.samsung.com
	8	* Author: Marek Szyprowski <m.szyprowski@samsung.com>
	9	* Author: Josh Cartwright <joshc@codeaurora.org>
3f0c8206 MS	10	*/
3f0c8206 MS	11
606ad42a RH	12	#define pr_fmt(fmt) "OF: reserved mem: " fmt
606ad42a RH	13
3f0c8206 MS	14	#include <linux/err.h>
	15	#include <linux/of.h>
	16	#include <linux/of_fdt.h>
	17	#include <linux/of_platform.h>
	18	#include <linux/mm.h>
	19	#include <linux/sizes.h>
	20	#include <linux/of_reserved_mem.h>
ae1add24	21	#include <linux/sort.h>
59ce4039	22	#include <linux/slab.h>
aca52c39	23	#include <linux/memblock.h>
3f0c8206	24
22f8cc6e	25	#define MAX_RESERVED_REGIONS 32
3f0c8206 MS	26	static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
	27	static int reserved_mem_count;
	28
221e1e0b	29	static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
3f0c8206 MS	30	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
	31	phys_addr_t *res_base)
	32	{
e53b50c0	33	phys_addr_t base;
42b46aef	34
e53b50c0	35	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
7e1c4e27	36	align = !align ? SMP_CACHE_BYTES : align;
5c01a25a	37	base = memblock_find_in_range(start, end, size, align);
3f0c8206 MS	38	if (!base)
	39	return -ENOMEM;
	40
3f0c8206 MS	41	*res_base = base;
	42	if (nomap)
	43	return memblock_remove(base, size);
5c01a25a MR	44
5c01a25a MR	45	return memblock_reserve(base, size);
3f0c8206	46	}
3f0c8206 MS	47
	48	/**
	49	* res_mem_save_node() - save fdt node for second pass initialization
	50	*/
	51	void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
	52	phys_addr_t base, phys_addr_t size)
	53	{
	54	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
	55
	56	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
606ad42a	57	pr_err("not enough space all defined regions.\n");
3f0c8206 MS	58	return;
	59	}
	60
	61	rmem->fdt_node = node;
	62	rmem->name = uname;
	63	rmem->base = base;
	64	rmem->size = size;
	65
	66	reserved_mem_count++;
	67	return;
	68	}
	69
	70	/**
	71	* res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
	72	* and 'alloc-ranges' properties
	73	*/
	74	static int __init __reserved_mem_alloc_size(unsigned long node,
	75	const char uname, phys_addr_t res_base, phys_addr_t *res_size)
	76	{
	77	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
	78	phys_addr_t start = 0, end = 0;
	79	phys_addr_t base = 0, align = 0, size;
9d0c4dfe RH	80	int len;
9d0c4dfe RH	81	const __be32 *prop;
3f0c8206 MS	82	int nomap;
	83	int ret;
	84
	85	prop = of_get_flat_dt_prop(node, "size", &len);
	86	if (!prop)
	87	return -EINVAL;
	88
	89	if (len != dt_root_size_cells * sizeof(__be32)) {
606ad42a	90	pr_err("invalid size property in '%s' node.\n", uname);
3f0c8206 MS	91	return -EINVAL;
	92	}
	93	size = dt_mem_next_cell(dt_root_size_cells, &prop);
	94
	95	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
	96
	97	prop = of_get_flat_dt_prop(node, "alignment", &len);
	98	if (prop) {
	99	if (len != dt_root_addr_cells * sizeof(__be32)) {
606ad42a	100	pr_err("invalid alignment property in '%s' node.\n",
3f0c8206 MS	101	uname);
	102	return -EINVAL;
	103	}
	104	align = dt_mem_next_cell(dt_root_addr_cells, &prop);
	105	}
	106
1cc8e345	107	/* Need adjust the alignment to satisfy the CMA requirement */
7d482813 J	108	if (IS_ENABLED(CONFIG_CMA)
	109	&& of_flat_dt_is_compatible(node, "shared-dma-pool")
	110	&& of_get_flat_dt_prop(node, "reusable", NULL)
aaaab56d SR	111	&& !of_get_flat_dt_prop(node, "no-map", NULL)) {
	112	unsigned long order =
	113	max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
	114
	115	align = max(align, (phys_addr_t)PAGE_SIZE << order);
	116	}
1cc8e345	117
3f0c8206 MS	118	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
	119	if (prop) {
	120
	121	if (len % t_len != 0) {
606ad42a	122	pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
3f0c8206 MS	123	uname);
	124	return -EINVAL;
	125	}
	126
	127	base = 0;
	128
	129	while (len > 0) {
	130	start = dt_mem_next_cell(dt_root_addr_cells, &prop);
	131	end = start + dt_mem_next_cell(dt_root_size_cells,
	132	&prop);
	133
	134	ret = early_init_dt_alloc_reserved_memory_arch(size,
	135	align, start, end, nomap, &base);
	136	if (ret == 0) {
606ad42a	137	pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
3f0c8206 MS	138	uname, &base,
	139	(unsigned long)size / SZ_1M);
	140	break;
	141	}
	142	len -= t_len;
	143	}
	144
	145	} else {
	146	ret = early_init_dt_alloc_reserved_memory_arch(size, align,
	147	0, 0, nomap, &base);
	148	if (ret == 0)
606ad42a	149	pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
3f0c8206 MS	150	uname, &base, (unsigned long)size / SZ_1M);
	151	}
	152
	153	if (base == 0) {
606ad42a	154	pr_info("failed to allocate memory for node '%s'\n", uname);
3f0c8206 MS	155	return -ENOMEM;
	156	}
	157
	158	*res_base = base;
	159	*res_size = size;
	160
	161	return 0;
	162	}
	163
f618c470 MS	164	static const struct of_device_id __rmem_of_table_sentinel
	165	__used __section(__reservedmem_of_table_end);
	166
	167	/**
	168	* res_mem_init_node() - call region specific reserved memory init code
	169	*/
	170	static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
	171	{
	172	extern const struct of_device_id __reservedmem_of_table[];
	173	const struct of_device_id *i;
d0b8ed47	174	int ret = -ENOENT;
f618c470 MS	175
f618c470 MS	176	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
df3ed932	177	reservedmem_of_init_fn initfn = i->data;
f618c470 MS	178	const char *compat = i->compatible;
	179
	180	if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
	181	continue;
	182
d0b8ed47 K	183	ret = initfn(rmem);
d0b8ed47 K	184	if (ret == 0) {
606ad42a	185	pr_info("initialized node %s, compatible id %s\n",
f618c470	186	rmem->name, compat);
d0b8ed47	187	break;
f618c470 MS	188	}
f618c470 MS	189	}
d0b8ed47	190	return ret;
f618c470 MS	191	}
f618c470 MS	192
ae1add24 MH	193	static int __init __rmem_cmp(const void a, const void b)
	194	{
	195	const struct reserved_mem ra = a, rb = b;
	196
9eb8cd2b ME	197	if (ra->base < rb->base)
	198	return -1;
	199
	200	if (ra->base > rb->base)
	201	return 1;
	202
	203	return 0;
ae1add24 MH	204	}
	205
	206	static void __init __rmem_check_for_overlap(void)
	207	{
	208	int i;
	209
	210	if (reserved_mem_count < 2)
	211	return;
	212
	213	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
	214	__rmem_cmp, NULL);
	215	for (i = 0; i < reserved_mem_count - 1; i++) {
	216	struct reserved_mem this, next;
	217
	218	this = &reserved_mem[i];
	219	next = &reserved_mem[i + 1];
	220	if (!(this->base && next->base))
	221	continue;
	222	if (this->base + this->size > next->base) {
	223	phys_addr_t this_end, next_end;
	224
	225	this_end = this->base + this->size;
	226	next_end = next->base + next->size;
606ad42a	227	pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
85a1c77f ME	228	this->name, &this->base, &this_end,
85a1c77f ME	229	next->name, &next->base, &next_end);
ae1add24 MH	230	}
	231	}
	232	}
	233
3f0c8206 MS	234	/**
	235	* fdt_init_reserved_mem - allocate and init all saved reserved memory regions
	236	*/
	237	void __init fdt_init_reserved_mem(void)
	238	{
	239	int i;
ae1add24 MH	240
	241	/* check for overlapping reserved regions */
	242	__rmem_check_for_overlap();
	243
3f0c8206 MS	244	for (i = 0; i < reserved_mem_count; i++) {
	245	struct reserved_mem *rmem = &reserved_mem[i];
	246	unsigned long node = rmem->fdt_node;
9dcfee01 MS	247	int len;
9dcfee01 MS	248	const __be32 *prop;
3f0c8206	249	int err = 0;
d0b8ed47	250	int nomap;
3f0c8206	251
d0b8ed47	252	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
9dcfee01 MS	253	prop = of_get_flat_dt_prop(node, "phandle", &len);
	254	if (!prop)
	255	prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
	256	if (prop)
	257	rmem->phandle = of_read_number(prop, len/4);
	258
3f0c8206 MS	259	if (rmem->size == 0)
	260	err = __reserved_mem_alloc_size(node, rmem->name,
	261	&rmem->base, &rmem->size);
d0b8ed47 K	262	if (err == 0) {
	263	err = __reserved_mem_init_node(rmem);
	264	if (err != 0 && err != -ENOENT) {
	265	pr_info("node %s compatible matching fail\n",
	266	rmem->name);
	267	memblock_free(rmem->base, rmem->size);
	268	if (nomap)
	269	memblock_add(rmem->base, rmem->size);
	270	}
	271	}
3f0c8206 MS	272	}
3f0c8206 MS	273	}
9dcfee01 MS	274
	275	static inline struct reserved_mem __find_rmem(struct device_node node)
	276	{
	277	unsigned int i;
	278
	279	if (!node->phandle)
	280	return NULL;
	281
	282	for (i = 0; i < reserved_mem_count; i++)
	283	if (reserved_mem[i].phandle == node->phandle)
	284	return &reserved_mem[i];
	285	return NULL;
	286	}
	287
59ce4039 MS	288	struct rmem_assigned_device {
	289	struct device *dev;
	290	struct reserved_mem *rmem;
	291	struct list_head list;
	292	};
	293
	294	static LIST_HEAD(of_rmem_assigned_device_list);
	295	static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
	296
9dcfee01	297	/**
59ce4039 MS	298	* of_reserved_mem_device_init_by_idx() - assign reserved memory region to
	299	* given device
	300	* @dev: Pointer to the device to configure
	301	* @np: Pointer to the device_node with 'reserved-memory' property
	302	* @idx: Index of selected region
9dcfee01	303	*
59ce4039 MS	304	* This function assigns respective DMA-mapping operations based on reserved
	305	* memory region specified by 'memory-region' property in @np node to the @dev
	306	* device. When driver needs to use more than one reserved memory region, it
	307	* should allocate child devices and initialize regions by name for each of
	308	* child device.
	309	*
	310	* Returns error code or zero on success.
9dcfee01	311	*/
59ce4039 MS	312	int of_reserved_mem_device_init_by_idx(struct device *dev,
59ce4039 MS	313	struct device_node *np, int idx)
9dcfee01	314	{
59ce4039 MS	315	struct rmem_assigned_device *rd;
59ce4039 MS	316	struct device_node *target;
9dcfee01	317	struct reserved_mem *rmem;
47f29df7	318	int ret;
9dcfee01	319
59ce4039 MS	320	if (!np \|\| !dev)
	321	return -EINVAL;
	322
	323	target = of_parse_phandle(np, "memory-region", idx);
	324	if (!target)
9f5a802b	325	return -ENODEV;
9dcfee01	326
d698a388 KR	327	if (!of_device_is_available(target))
	328	return 0;
	329
59ce4039 MS	330	rmem = __find_rmem(target);
59ce4039 MS	331	of_node_put(target);
9dcfee01 MS	332
9dcfee01 MS	333	if (!rmem \|\| !rmem->ops \|\| !rmem->ops->device_init)
47f29df7 MS	334	return -EINVAL;
47f29df7 MS	335
59ce4039 MS	336	rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
	337	if (!rd)
	338	return -ENOMEM;
	339
47f29df7	340	ret = rmem->ops->device_init(rmem, dev);
59ce4039 MS	341	if (ret == 0) {
	342	rd->dev = dev;
	343	rd->rmem = rmem;
	344
	345	mutex_lock(&of_rmem_assigned_device_mutex);
	346	list_add(&rd->list, &of_rmem_assigned_device_list);
	347	mutex_unlock(&of_rmem_assigned_device_mutex);
	348
47f29df7	349	dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
59ce4039 MS	350	} else {
	351	kfree(rd);
	352	}
9dcfee01	353
47f29df7	354	return ret;
9dcfee01	355	}
59ce4039	356	EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
9dcfee01 MS	357
	358	/**
	359	* of_reserved_mem_device_release() - release reserved memory device structures
59ce4039	360	* @dev: Pointer to the device to deconfigure
9dcfee01 MS	361	*
	362	* This function releases structures allocated for memory region handling for
	363	* the given device.
	364	*/
	365	void of_reserved_mem_device_release(struct device *dev)
	366	{
59ce4039 MS	367	struct rmem_assigned_device *rd;
	368	struct reserved_mem *rmem = NULL;
	369
	370	mutex_lock(&of_rmem_assigned_device_mutex);
	371	list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
	372	if (rd->dev == dev) {
	373	rmem = rd->rmem;
	374	list_del(&rd->list);
	375	kfree(rd);
	376	break;
	377	}
	378	}
	379	mutex_unlock(&of_rmem_assigned_device_mutex);
9dcfee01 MS	380
	381	if (!rmem \|\| !rmem->ops \|\| !rmem->ops->device_release)
	382	return;
	383
	384	rmem->ops->device_release(rmem, dev);
	385	}
615fde79	386	EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
eb297bc7 BA	387
	388	/**
	389	* of_reserved_mem_lookup() - acquire reserved_mem from a device node
	390	* @np: node pointer of the desired reserved-memory region
	391	*
	392	* This function allows drivers to acquire a reference to the reserved_mem
	393	* struct based on a device node handle.
	394	*
	395	* Returns a reserved_mem reference, or NULL on error.
	396	*/
	397	struct reserved_mem of_reserved_mem_lookup(struct device_node np)
	398	{
	399	const char *name;
	400	int i;
	401
	402	if (!np->full_name)
	403	return NULL;
	404
	405	name = kbasename(np->full_name);
	406	for (i = 0; i < reserved_mem_count; i++)
	407	if (!strcmp(reserved_mem[i].name, name))
	408	return &reserved_mem[i];
	409
	410	return NULL;
	411	}
	412	EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);