[mirror_ubuntu-jammy-kernel.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>

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

#if defined(CONFIG_HAVE_MEMBLOCK)
#include <linux/memblock.h>
int __init __weak 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;
	/*
	 * We use __memblock_alloc_base() because memblock_alloc_base()
	 * panic()s on allocation failure.
	 */
	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
	base = __memblock_alloc_base(size, align, end);
	if (!base)
		return -ENOMEM;

	/*
	 * Check if the allocated region fits in to start..end window
	 */
	if (base < start) {
		memblock_free(base, size);
		return -ENOMEM;
	}

	*res_base = base;
	if (nomap)
		return memblock_remove(base, size);
	return 0;
}
#else
int __init __weak 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)
{
	pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
		  size, nomap ? " (nomap)" : "");
	return -ENOSYS;
}
#endif

/**
 * 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;

	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;

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

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;

		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)
			__reserved_mem_init_node(rmem);
	}
}

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;

	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);
		/* ensure that dma_ops is set for virtual devices
		 * using reserved memory
		 */
		of_dma_configure(dev, np, true);

		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>
3f0c8206	23
22f8cc6e	24	#define MAX_RESERVED_REGIONS 32
3f0c8206 MS	25	static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
	26	static int reserved_mem_count;
	27
	28	#if defined(CONFIG_HAVE_MEMBLOCK)
	29	#include <linux/memblock.h>
	30	int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
	31	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
	32	phys_addr_t *res_base)
	33	{
e53b50c0	34	phys_addr_t base;
3f0c8206 MS	35	/*
	36	* We use __memblock_alloc_base() because memblock_alloc_base()
	37	* panic()s on allocation failure.
	38	*/
e53b50c0 VM	39	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
e53b50c0 VM	40	base = __memblock_alloc_base(size, align, end);
3f0c8206 MS	41	if (!base)
	42	return -ENOMEM;
	43
	44	/*
	45	* Check if the allocated region fits in to start..end window
	46	*/
	47	if (base < start) {
	48	memblock_free(base, size);
	49	return -ENOMEM;
	50	}
	51
	52	*res_base = base;
	53	if (nomap)
	54	return memblock_remove(base, size);
	55	return 0;
	56	}
	57	#else
	58	int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
	59	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
	60	phys_addr_t *res_base)
	61	{
	62	pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
	63	size, nomap ? " (nomap)" : "");
	64	return -ENOSYS;
	65	}
	66	#endif
	67
	68	/**
	69	* res_mem_save_node() - save fdt node for second pass initialization
	70	*/
	71	void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
	72	phys_addr_t base, phys_addr_t size)
	73	{
	74	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
	75
	76	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
606ad42a	77	pr_err("not enough space all defined regions.\n");
3f0c8206 MS	78	return;
	79	}
	80
	81	rmem->fdt_node = node;
	82	rmem->name = uname;
	83	rmem->base = base;
	84	rmem->size = size;
	85
	86	reserved_mem_count++;
	87	return;
	88	}
	89
	90	/**
	91	* res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
	92	* and 'alloc-ranges' properties
	93	*/
	94	static int __init __reserved_mem_alloc_size(unsigned long node,
	95	const char uname, phys_addr_t res_base, phys_addr_t *res_size)
	96	{
	97	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
	98	phys_addr_t start = 0, end = 0;
	99	phys_addr_t base = 0, align = 0, size;
9d0c4dfe RH	100	int len;
9d0c4dfe RH	101	const __be32 *prop;
3f0c8206 MS	102	int nomap;
	103	int ret;
	104
	105	prop = of_get_flat_dt_prop(node, "size", &len);
	106	if (!prop)
	107	return -EINVAL;
	108
	109	if (len != dt_root_size_cells * sizeof(__be32)) {
606ad42a	110	pr_err("invalid size property in '%s' node.\n", uname);
3f0c8206 MS	111	return -EINVAL;
	112	}
	113	size = dt_mem_next_cell(dt_root_size_cells, &prop);
	114
	115	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
	116
	117	prop = of_get_flat_dt_prop(node, "alignment", &len);
	118	if (prop) {
	119	if (len != dt_root_addr_cells * sizeof(__be32)) {
606ad42a	120	pr_err("invalid alignment property in '%s' node.\n",
3f0c8206 MS	121	uname);
	122	return -EINVAL;
	123	}
	124	align = dt_mem_next_cell(dt_root_addr_cells, &prop);
	125	}
	126
1cc8e345	127	/* Need adjust the alignment to satisfy the CMA requirement */
7d482813 J	128	if (IS_ENABLED(CONFIG_CMA)
	129	&& of_flat_dt_is_compatible(node, "shared-dma-pool")
	130	&& of_get_flat_dt_prop(node, "reusable", NULL)
aaaab56d SR	131	&& !of_get_flat_dt_prop(node, "no-map", NULL)) {
	132	unsigned long order =
	133	max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
	134
	135	align = max(align, (phys_addr_t)PAGE_SIZE << order);
	136	}
1cc8e345	137
3f0c8206 MS	138	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
	139	if (prop) {
	140
	141	if (len % t_len != 0) {
606ad42a	142	pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
3f0c8206 MS	143	uname);
	144	return -EINVAL;
	145	}
	146
	147	base = 0;
	148
	149	while (len > 0) {
	150	start = dt_mem_next_cell(dt_root_addr_cells, &prop);
	151	end = start + dt_mem_next_cell(dt_root_size_cells,
	152	&prop);
	153
	154	ret = early_init_dt_alloc_reserved_memory_arch(size,
	155	align, start, end, nomap, &base);
	156	if (ret == 0) {
606ad42a	157	pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
3f0c8206 MS	158	uname, &base,
	159	(unsigned long)size / SZ_1M);
	160	break;
	161	}
	162	len -= t_len;
	163	}
	164
	165	} else {
	166	ret = early_init_dt_alloc_reserved_memory_arch(size, align,
	167	0, 0, nomap, &base);
	168	if (ret == 0)
606ad42a	169	pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
3f0c8206 MS	170	uname, &base, (unsigned long)size / SZ_1M);
	171	}
	172
	173	if (base == 0) {
606ad42a	174	pr_info("failed to allocate memory for node '%s'\n", uname);
3f0c8206 MS	175	return -ENOMEM;
	176	}
	177
	178	*res_base = base;
	179	*res_size = size;
	180
	181	return 0;
	182	}
	183
f618c470 MS	184	static const struct of_device_id __rmem_of_table_sentinel
	185	__used __section(__reservedmem_of_table_end);
	186
	187	/**
	188	* res_mem_init_node() - call region specific reserved memory init code
	189	*/
	190	static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
	191	{
	192	extern const struct of_device_id __reservedmem_of_table[];
	193	const struct of_device_id *i;
	194
	195	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
df3ed932	196	reservedmem_of_init_fn initfn = i->data;
f618c470 MS	197	const char *compat = i->compatible;
	198
	199	if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
	200	continue;
	201
9dd31075	202	if (initfn(rmem) == 0) {
606ad42a	203	pr_info("initialized node %s, compatible id %s\n",
f618c470 MS	204	rmem->name, compat);
	205	return 0;
	206	}
	207	}
	208	return -ENOENT;
	209	}
	210
ae1add24 MH	211	static int __init __rmem_cmp(const void a, const void b)
	212	{
	213	const struct reserved_mem ra = a, rb = b;
	214
9eb8cd2b ME	215	if (ra->base < rb->base)
	216	return -1;
	217
	218	if (ra->base > rb->base)
	219	return 1;
	220
	221	return 0;
ae1add24 MH	222	}
	223
	224	static void __init __rmem_check_for_overlap(void)
	225	{
	226	int i;
	227
	228	if (reserved_mem_count < 2)
	229	return;
	230
	231	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
	232	__rmem_cmp, NULL);
	233	for (i = 0; i < reserved_mem_count - 1; i++) {
	234	struct reserved_mem this, next;
	235
	236	this = &reserved_mem[i];
	237	next = &reserved_mem[i + 1];
	238	if (!(this->base && next->base))
	239	continue;
	240	if (this->base + this->size > next->base) {
	241	phys_addr_t this_end, next_end;
	242
	243	this_end = this->base + this->size;
	244	next_end = next->base + next->size;
606ad42a	245	pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
85a1c77f ME	246	this->name, &this->base, &this_end,
85a1c77f ME	247	next->name, &next->base, &next_end);
ae1add24 MH	248	}
	249	}
	250	}
	251
3f0c8206 MS	252	/**
	253	* fdt_init_reserved_mem - allocate and init all saved reserved memory regions
	254	*/
	255	void __init fdt_init_reserved_mem(void)
	256	{
	257	int i;
ae1add24 MH	258
	259	/* check for overlapping reserved regions */
	260	__rmem_check_for_overlap();
	261
3f0c8206 MS	262	for (i = 0; i < reserved_mem_count; i++) {
	263	struct reserved_mem *rmem = &reserved_mem[i];
	264	unsigned long node = rmem->fdt_node;
9dcfee01 MS	265	int len;
9dcfee01 MS	266	const __be32 *prop;
3f0c8206 MS	267	int err = 0;
3f0c8206 MS	268
9dcfee01 MS	269	prop = of_get_flat_dt_prop(node, "phandle", &len);
	270	if (!prop)
	271	prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
	272	if (prop)
	273	rmem->phandle = of_read_number(prop, len/4);
	274
3f0c8206 MS	275	if (rmem->size == 0)
	276	err = __reserved_mem_alloc_size(node, rmem->name,
	277	&rmem->base, &rmem->size);
f618c470 MS	278	if (err == 0)
f618c470 MS	279	__reserved_mem_init_node(rmem);
3f0c8206 MS	280	}
3f0c8206 MS	281	}
9dcfee01 MS	282
	283	static inline struct reserved_mem __find_rmem(struct device_node node)
	284	{
	285	unsigned int i;
	286
	287	if (!node->phandle)
	288	return NULL;
	289
	290	for (i = 0; i < reserved_mem_count; i++)
	291	if (reserved_mem[i].phandle == node->phandle)
	292	return &reserved_mem[i];
	293	return NULL;
	294	}
	295
59ce4039 MS	296	struct rmem_assigned_device {
	297	struct device *dev;
	298	struct reserved_mem *rmem;
	299	struct list_head list;
	300	};
	301
	302	static LIST_HEAD(of_rmem_assigned_device_list);
	303	static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
	304
9dcfee01	305	/**
59ce4039 MS	306	* of_reserved_mem_device_init_by_idx() - assign reserved memory region to
	307	* given device
	308	* @dev: Pointer to the device to configure
	309	* @np: Pointer to the device_node with 'reserved-memory' property
	310	* @idx: Index of selected region
9dcfee01	311	*
59ce4039 MS	312	* This function assigns respective DMA-mapping operations based on reserved
	313	* memory region specified by 'memory-region' property in @np node to the @dev
	314	* device. When driver needs to use more than one reserved memory region, it
	315	* should allocate child devices and initialize regions by name for each of
	316	* child device.
	317	*
	318	* Returns error code or zero on success.
9dcfee01	319	*/
59ce4039 MS	320	int of_reserved_mem_device_init_by_idx(struct device *dev,
59ce4039 MS	321	struct device_node *np, int idx)
9dcfee01	322	{
59ce4039 MS	323	struct rmem_assigned_device *rd;
59ce4039 MS	324	struct device_node *target;
9dcfee01	325	struct reserved_mem *rmem;
47f29df7	326	int ret;
9dcfee01	327
59ce4039 MS	328	if (!np \|\| !dev)
	329	return -EINVAL;
	330
	331	target = of_parse_phandle(np, "memory-region", idx);
	332	if (!target)
9f5a802b	333	return -ENODEV;
9dcfee01	334
59ce4039 MS	335	rmem = __find_rmem(target);
59ce4039 MS	336	of_node_put(target);
9dcfee01 MS	337
9dcfee01 MS	338	if (!rmem \|\| !rmem->ops \|\| !rmem->ops->device_init)
47f29df7 MS	339	return -EINVAL;
47f29df7 MS	340
59ce4039 MS	341	rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
	342	if (!rd)
	343	return -ENOMEM;
	344
47f29df7	345	ret = rmem->ops->device_init(rmem, dev);
59ce4039 MS	346	if (ret == 0) {
	347	rd->dev = dev;
	348	rd->rmem = rmem;
	349
	350	mutex_lock(&of_rmem_assigned_device_mutex);
	351	list_add(&rd->list, &of_rmem_assigned_device_list);
	352	mutex_unlock(&of_rmem_assigned_device_mutex);
a3b398e6 SM	353	/* ensure that dma_ops is set for virtual devices
	354	* using reserved memory
	355	*/
3d6ce86e	356	of_dma_configure(dev, np, true);
59ce4039	357
47f29df7	358	dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
59ce4039 MS	359	} else {
	360	kfree(rd);
	361	}
9dcfee01	362
47f29df7	363	return ret;
9dcfee01	364	}
59ce4039	365	EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
9dcfee01 MS	366
	367	/**
	368	* of_reserved_mem_device_release() - release reserved memory device structures
59ce4039	369	* @dev: Pointer to the device to deconfigure
9dcfee01 MS	370	*
	371	* This function releases structures allocated for memory region handling for
	372	* the given device.
	373	*/
	374	void of_reserved_mem_device_release(struct device *dev)
	375	{
59ce4039 MS	376	struct rmem_assigned_device *rd;
	377	struct reserved_mem *rmem = NULL;
	378
	379	mutex_lock(&of_rmem_assigned_device_mutex);
	380	list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
	381	if (rd->dev == dev) {
	382	rmem = rd->rmem;
	383	list_del(&rd->list);
	384	kfree(rd);
	385	break;
	386	}
	387	}
	388	mutex_unlock(&of_rmem_assigned_device_mutex);
9dcfee01 MS	389
	390	if (!rmem \|\| !rmem->ops \|\| !rmem->ops->device_release)
	391	return;
	392
	393	rmem->ops->device_release(rmem, dev);
	394	}
615fde79	395	EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
eb297bc7 BA	396
	397	/**
	398	* of_reserved_mem_lookup() - acquire reserved_mem from a device node
	399	* @np: node pointer of the desired reserved-memory region
	400	*
	401	* This function allows drivers to acquire a reference to the reserved_mem
	402	* struct based on a device node handle.
	403	*
	404	* Returns a reserved_mem reference, or NULL on error.
	405	*/
	406	struct reserved_mem of_reserved_mem_lookup(struct device_node np)
	407	{
	408	const char *name;
	409	int i;
	410
	411	if (!np->full_name)
	412	return NULL;
	413
	414	name = kbasename(np->full_name);
	415	for (i = 0; i < reserved_mem_count; i++)
	416	if (!strcmp(reserved_mem[i].name, name))
	417	return &reserved_mem[i];
	418
	419	return NULL;
	420	}
	421	EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);