[deliverable/linux.git] / drivers / base / dma-coherent.c

/*
 * Coherent per-device memory handling.
 * Borrowed from i386
 */
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>

struct dma_coherent_mem {
	void		*virt_base;
	dma_addr_t	device_base;
	unsigned long	pfn_base;
	int		size;
	int		flags;
	unsigned long	*bitmap;
	spinlock_t	spinlock;
};

static bool dma_init_coherent_memory(
	phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags,
	struct dma_coherent_mem **mem)
{
	struct dma_coherent_mem *dma_mem = NULL;
	void __iomem *mem_base = NULL;
	int pages = size >> PAGE_SHIFT;
	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);

	if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
		goto out;
	if (!size)
		goto out;

	if (flags & DMA_MEMORY_MAP)
		mem_base = memremap(phys_addr, size, MEMREMAP_WC);
	else
		mem_base = ioremap(phys_addr, size);
	if (!mem_base)
		goto out;

	dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
	if (!dma_mem)
		goto out;
	dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
	if (!dma_mem->bitmap)
		goto out;

	dma_mem->virt_base = mem_base;
	dma_mem->device_base = device_addr;
	dma_mem->pfn_base = PFN_DOWN(phys_addr);
	dma_mem->size = pages;
	dma_mem->flags = flags;
	spin_lock_init(&dma_mem->spinlock);

	*mem = dma_mem;
	return true;

out:
	kfree(dma_mem);
	if (mem_base) {
		if (flags & DMA_MEMORY_MAP)
			memunmap(mem_base);
		else
			iounmap(mem_base);
	}
	return false;
}

static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
{
	if (!mem)
		return;

	if (mem->flags & DMA_MEMORY_MAP)
		memunmap(mem->virt_base);
	else
		iounmap(mem->virt_base);
	kfree(mem->bitmap);
	kfree(mem);
}

static int dma_assign_coherent_memory(struct device *dev,
				      struct dma_coherent_mem *mem)
{
	if (dev->dma_mem)
		return -EBUSY;

	dev->dma_mem = mem;
	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */

	return 0;
}

int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
				dma_addr_t device_addr, size_t size, int flags)
{
	struct dma_coherent_mem *mem;

	if (!dma_init_coherent_memory(phys_addr, device_addr, size, flags,
				      &mem))
		return 0;

	if (dma_assign_coherent_memory(dev, mem) == 0)
		return flags & DMA_MEMORY_MAP ? DMA_MEMORY_MAP : DMA_MEMORY_IO;

	dma_release_coherent_memory(mem);
	return 0;
}
EXPORT_SYMBOL(dma_declare_coherent_memory);

void dma_release_declared_memory(struct device *dev)
{
	struct dma_coherent_mem *mem = dev->dma_mem;

	if (!mem)
		return;
	dma_release_coherent_memory(mem);
	dev->dma_mem = NULL;
}
EXPORT_SYMBOL(dma_release_declared_memory);

void *dma_mark_declared_memory_occupied(struct device *dev,
					dma_addr_t device_addr, size_t size)
{
	struct dma_coherent_mem *mem = dev->dma_mem;
	unsigned long flags;
	int pos, err;

	size += device_addr & ~PAGE_MASK;

	if (!mem)
		return ERR_PTR(-EINVAL);

	spin_lock_irqsave(&mem->spinlock, flags);
	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
	err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
	spin_unlock_irqrestore(&mem->spinlock, flags);

	if (err != 0)
		return ERR_PTR(err);
	return mem->virt_base + (pos << PAGE_SHIFT);
}
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);

/**
 * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area
 *
 * @dev:	device from which we allocate memory
 * @size:	size of requested memory area
 * @dma_handle:	This will be filled with the correct dma handle
 * @ret:	This pointer will be filled with the virtual address
 *		to allocated area.
 *
 * This function should be only called from per-arch dma_alloc_coherent()
 * to support allocation from per-device coherent memory pools.
 *
 * Returns 0 if dma_alloc_coherent should continue with allocating from
 * generic memory areas, or !0 if dma_alloc_coherent should return @ret.
 */
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
				       dma_addr_t *dma_handle, void **ret)
{
	struct dma_coherent_mem *mem;
	int order = get_order(size);
	unsigned long flags;
	int pageno;

	if (!dev)
		return 0;
	mem = dev->dma_mem;
	if (!mem)
		return 0;

	*ret = NULL;
	spin_lock_irqsave(&mem->spinlock, flags);

	if (unlikely(size > (mem->size << PAGE_SHIFT)))
		goto err;

	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
	if (unlikely(pageno < 0))
		goto err;

	/*
	 * Memory was found in the per-device area.
	 */
	*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
	*ret = mem->virt_base + (pageno << PAGE_SHIFT);
	memset(*ret, 0, size);
	spin_unlock_irqrestore(&mem->spinlock, flags);

	return 1;

err:
	spin_unlock_irqrestore(&mem->spinlock, flags);
	/*
	 * In the case where the allocation can not be satisfied from the
	 * per-device area, try to fall back to generic memory if the
	 * constraints allow it.
	 */
	return mem->flags & DMA_MEMORY_EXCLUSIVE;
}
EXPORT_SYMBOL(dma_alloc_from_coherent);

/**
 * dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool
 * @dev:	device from which the memory was allocated
 * @order:	the order of pages allocated
 * @vaddr:	virtual address of allocated pages
 *
 * This checks whether the memory was allocated from the per-device
 * coherent memory pool and if so, releases that memory.
 *
 * Returns 1 if we correctly released the memory, or 0 if
 * dma_release_coherent() should proceed with releasing memory from
 * generic pools.
 */
int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
{
	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;

	if (mem && vaddr >= mem->virt_base && vaddr <
		   (mem->virt_base + (mem->size << PAGE_SHIFT))) {
		int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
		unsigned long flags;

		spin_lock_irqsave(&mem->spinlock, flags);
		bitmap_release_region(mem->bitmap, page, order);
		spin_unlock_irqrestore(&mem->spinlock, flags);
		return 1;
	}
	return 0;
}
EXPORT_SYMBOL(dma_release_from_coherent);

/**
 * dma_mmap_from_coherent() - try to mmap the memory allocated from
 * per-device coherent memory pool to userspace
 * @dev:	device from which the memory was allocated
 * @vma:	vm_area for the userspace memory
 * @vaddr:	cpu address returned by dma_alloc_from_coherent
 * @size:	size of the memory buffer allocated by dma_alloc_from_coherent
 * @ret:	result from remap_pfn_range()
 *
 * This checks whether the memory was allocated from the per-device
 * coherent memory pool and if so, maps that memory to the provided vma.
 *
 * Returns 1 if we correctly mapped the memory, or 0 if the caller should
 * proceed with mapping memory from generic pools.
 */
int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
			   void *vaddr, size_t size, int *ret)
{
	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;

	if (mem && vaddr >= mem->virt_base && vaddr + size <=
		   (mem->virt_base + (mem->size << PAGE_SHIFT))) {
		unsigned long off = vma->vm_pgoff;
		int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;
		int user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
		int count = size >> PAGE_SHIFT;

		*ret = -ENXIO;
		if (off < count && user_count <= count - off) {
			unsigned long pfn = mem->pfn_base + start + off;
			*ret = remap_pfn_range(vma, vma->vm_start, pfn,
					       user_count << PAGE_SHIFT,
					       vma->vm_page_prot);
		}
		return 1;
	}
	return 0;
}
EXPORT_SYMBOL(dma_mmap_from_coherent);

/*
 * Support for reserved memory regions defined in device tree
 */
#ifdef CONFIG_OF_RESERVED_MEM
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>

static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
{
	struct dma_coherent_mem *mem = rmem->priv;

	if (!mem &&
	    !dma_init_coherent_memory(rmem->base, rmem->base, rmem->size,
				      DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE,
				      &mem)) {
		pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
			&rmem->base, (unsigned long)rmem->size / SZ_1M);
		return -ENODEV;
	}
	rmem->priv = mem;
	dma_assign_coherent_memory(dev, mem);
	return 0;
}

static void rmem_dma_device_release(struct reserved_mem *rmem,
				    struct device *dev)
{
	dev->dma_mem = NULL;
}

static const struct reserved_mem_ops rmem_dma_ops = {
	.device_init	= rmem_dma_device_init,
	.device_release	= rmem_dma_device_release,
};

static int __init rmem_dma_setup(struct reserved_mem *rmem)
{
	unsigned long node = rmem->fdt_node;

	if (of_get_flat_dt_prop(node, "reusable", NULL))
		return -EINVAL;

#ifdef CONFIG_ARM
	if (!of_get_flat_dt_prop(node, "no-map", NULL)) {
		pr_err("Reserved memory: regions without no-map are not yet supported\n");
		return -EINVAL;
	}
#endif

	rmem->ops = &rmem_dma_ops;
	pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n",
		&rmem->base, (unsigned long)rmem->size / SZ_1M);
	return 0;
}
RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
#endif
Commit	Line	Data
ee7e5516 DB	1	/*
	2	* Coherent per-device memory handling.
	3	* Borrowed from i386
	4	*/
6b03ae0d	5	#include <linux/io.h>
5a0e3ad6	6	#include <linux/slab.h>
ee7e5516	7	#include <linux/kernel.h>
08a999ce	8	#include <linux/module.h>
ee7e5516 DB	9	#include <linux/dma-mapping.h>
	10
	11	struct dma_coherent_mem {
	12	void *virt_base;
ed1d218c	13	dma_addr_t device_base;
88a984ba	14	unsigned long pfn_base;
ee7e5516 DB	15	int size;
	16	int flags;
	17	unsigned long *bitmap;
7bfa5ab6	18	spinlock_t spinlock;
ee7e5516 DB	19	};
ee7e5516 DB	20
9e5b3d6f MN	21	static bool dma_init_coherent_memory(
	22	phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags,
	23	struct dma_coherent_mem **mem)
ee7e5516	24	{
7bfa5ab6	25	struct dma_coherent_mem *dma_mem = NULL;
ee7e5516 DB	26	void __iomem *mem_base = NULL;
	27	int pages = size >> PAGE_SHIFT;
	28	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
	29
	30	if ((flags & (DMA_MEMORY_MAP \| DMA_MEMORY_IO)) == 0)
	31	goto out;
	32	if (!size)
	33	goto out;
ee7e5516	34
6b03ae0d BS	35	if (flags & DMA_MEMORY_MAP)
	36	mem_base = memremap(phys_addr, size, MEMREMAP_WC);
	37	else
	38	mem_base = ioremap(phys_addr, size);
ee7e5516 DB	39	if (!mem_base)
	40	goto out;
	41
7bfa5ab6 MS	42	dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
7bfa5ab6 MS	43	if (!dma_mem)
ee7e5516	44	goto out;
7bfa5ab6 MS	45	dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
	46	if (!dma_mem->bitmap)
	47	goto out;
	48
	49	dma_mem->virt_base = mem_base;
	50	dma_mem->device_base = device_addr;
	51	dma_mem->pfn_base = PFN_DOWN(phys_addr);
	52	dma_mem->size = pages;
	53	dma_mem->flags = flags;
	54	spin_lock_init(&dma_mem->spinlock);
ee7e5516	55
7bfa5ab6	56	*mem = dma_mem;
9e5b3d6f	57	return true;
ee7e5516	58
7bfa5ab6 MS	59	out:
7bfa5ab6 MS	60	kfree(dma_mem);
6b03ae0d BS	61	if (mem_base) {
	62	if (flags & DMA_MEMORY_MAP)
	63	memunmap(mem_base);
	64	else
	65	iounmap(mem_base);
	66	}
9e5b3d6f	67	return false;
ee7e5516	68	}
7bfa5ab6 MS	69
	70	static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
	71	{
	72	if (!mem)
	73	return;
6b03ae0d BS	74
	75	if (mem->flags & DMA_MEMORY_MAP)
	76	memunmap(mem->virt_base);
	77	else
	78	iounmap(mem->virt_base);
7bfa5ab6 MS	79	kfree(mem->bitmap);
	80	kfree(mem);
	81	}
	82
	83	static int dma_assign_coherent_memory(struct device *dev,
	84	struct dma_coherent_mem *mem)
	85	{
	86	if (dev->dma_mem)
	87	return -EBUSY;
	88
	89	dev->dma_mem = mem;
	90	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
	91
	92	return 0;
	93	}
	94
	95	int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
	96	dma_addr_t device_addr, size_t size, int flags)
	97	{
	98	struct dma_coherent_mem *mem;
7bfa5ab6	99
9e5b3d6f MN	100	if (!dma_init_coherent_memory(phys_addr, device_addr, size, flags,
9e5b3d6f MN	101	&mem))
7bfa5ab6 MS	102	return 0;
	103
	104	if (dma_assign_coherent_memory(dev, mem) == 0)
9e5b3d6f	105	return flags & DMA_MEMORY_MAP ? DMA_MEMORY_MAP : DMA_MEMORY_IO;
7bfa5ab6 MS	106
	107	dma_release_coherent_memory(mem);
	108	return 0;
	109	}
ee7e5516 DB	110	EXPORT_SYMBOL(dma_declare_coherent_memory);
	111
	112	void dma_release_declared_memory(struct device *dev)
	113	{
	114	struct dma_coherent_mem *mem = dev->dma_mem;
	115
	116	if (!mem)
	117	return;
7bfa5ab6	118	dma_release_coherent_memory(mem);
ee7e5516	119	dev->dma_mem = NULL;
ee7e5516 DB	120	}
	121	EXPORT_SYMBOL(dma_release_declared_memory);
	122
	123	void dma_mark_declared_memory_occupied(struct device dev,
	124	dma_addr_t device_addr, size_t size)
	125	{
	126	struct dma_coherent_mem *mem = dev->dma_mem;
7bfa5ab6	127	unsigned long flags;
ee7e5516	128	int pos, err;
ee7e5516	129
d2dc1f4a	130	size += device_addr & ~PAGE_MASK;
ee7e5516 DB	131
	132	if (!mem)
	133	return ERR_PTR(-EINVAL);
	134
7bfa5ab6	135	spin_lock_irqsave(&mem->spinlock, flags);
ee7e5516	136	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
d2dc1f4a	137	err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
7bfa5ab6 MS	138	spin_unlock_irqrestore(&mem->spinlock, flags);
7bfa5ab6 MS	139
ee7e5516 DB	140	if (err != 0)
	141	return ERR_PTR(err);
	142	return mem->virt_base + (pos << PAGE_SHIFT);
	143	}
	144	EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
	145
b6d4f7e3	146	/**
cb3952bf	147	* dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area
b6d4f7e3 DB	148	*
	149	* @dev: device from which we allocate memory
	150	* @size: size of requested memory area
	151	* @dma_handle: This will be filled with the correct dma handle
	152	* @ret: This pointer will be filled with the virtual address
0609697e	153	* to allocated area.
b6d4f7e3	154	*
cb3952bf	155	* This function should be only called from per-arch dma_alloc_coherent()
b6d4f7e3 DB	156	* to support allocation from per-device coherent memory pools.
	157	*
	158	* Returns 0 if dma_alloc_coherent should continue with allocating from
cb3952bf	159	* generic memory areas, or !0 if dma_alloc_coherent should return @ret.
b6d4f7e3	160	*/
ee7e5516 DB	161	int dma_alloc_from_coherent(struct device *dev, ssize_t size,
	162	dma_addr_t dma_handle, void *ret)
	163	{
eccd83e1	164	struct dma_coherent_mem *mem;
ee7e5516	165	int order = get_order(size);
7bfa5ab6	166	unsigned long flags;
eccd83e1	167	int pageno;
ee7e5516	168
eccd83e1 AM	169	if (!dev)
	170	return 0;
	171	mem = dev->dma_mem;
	172	if (!mem)
	173	return 0;
0609697e PM	174
0609697e PM	175	*ret = NULL;
7bfa5ab6	176	spin_lock_irqsave(&mem->spinlock, flags);
0609697e	177
cdf57cab	178	if (unlikely(size > (mem->size << PAGE_SHIFT)))
0609697e	179	goto err;
eccd83e1 AM	180
eccd83e1 AM	181	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
0609697e PM	182	if (unlikely(pageno < 0))
	183	goto err;
	184
	185	/*
	186	* Memory was found in the per-device area.
	187	*/
	188	*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
	189	*ret = mem->virt_base + (pageno << PAGE_SHIFT);
	190	memset(*ret, 0, size);
7bfa5ab6	191	spin_unlock_irqrestore(&mem->spinlock, flags);
0609697e	192
eccd83e1	193	return 1;
0609697e PM	194
0609697e PM	195	err:
7bfa5ab6	196	spin_unlock_irqrestore(&mem->spinlock, flags);
0609697e PM	197	/*
	198	* In the case where the allocation can not be satisfied from the
	199	* per-device area, try to fall back to generic memory if the
	200	* constraints allow it.
	201	*/
	202	return mem->flags & DMA_MEMORY_EXCLUSIVE;
ee7e5516	203	}
a38409fb	204	EXPORT_SYMBOL(dma_alloc_from_coherent);
ee7e5516	205
b6d4f7e3	206	/**
cb3952bf	207	* dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool
b6d4f7e3 DB	208	* @dev: device from which the memory was allocated
	209	* @order: the order of pages allocated
	210	* @vaddr: virtual address of allocated pages
	211	*
	212	* This checks whether the memory was allocated from the per-device
	213	* coherent memory pool and if so, releases that memory.
	214	*
	215	* Returns 1 if we correctly released the memory, or 0 if
cb3952bf	216	* dma_release_coherent() should proceed with releasing memory from
b6d4f7e3 DB	217	* generic pools.
b6d4f7e3 DB	218	*/
ee7e5516 DB	219	int dma_release_from_coherent(struct device dev, int order, void vaddr)
	220	{
	221	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
	222
	223	if (mem && vaddr >= mem->virt_base && vaddr <
	224	(mem->virt_base + (mem->size << PAGE_SHIFT))) {
	225	int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
7bfa5ab6	226	unsigned long flags;
ee7e5516	227
7bfa5ab6	228	spin_lock_irqsave(&mem->spinlock, flags);
ee7e5516	229	bitmap_release_region(mem->bitmap, page, order);
7bfa5ab6	230	spin_unlock_irqrestore(&mem->spinlock, flags);
ee7e5516 DB	231	return 1;
	232	}
	233	return 0;
	234	}
a38409fb	235	EXPORT_SYMBOL(dma_release_from_coherent);
bca0fa5f MS	236
	237	/**
	238	* dma_mmap_from_coherent() - try to mmap the memory allocated from
	239	* per-device coherent memory pool to userspace
	240	* @dev: device from which the memory was allocated
	241	* @vma: vm_area for the userspace memory
	242	* @vaddr: cpu address returned by dma_alloc_from_coherent
	243	* @size: size of the memory buffer allocated by dma_alloc_from_coherent
6e7b4a59	244	* @ret: result from remap_pfn_range()
bca0fa5f MS	245	*
	246	* This checks whether the memory was allocated from the per-device
	247	* coherent memory pool and if so, maps that memory to the provided vma.
	248	*
ba4d93bc LP	249	* Returns 1 if we correctly mapped the memory, or 0 if the caller should
ba4d93bc LP	250	* proceed with mapping memory from generic pools.
bca0fa5f MS	251	*/
	252	int dma_mmap_from_coherent(struct device dev, struct vm_area_struct vma,
	253	void vaddr, size_t size, int ret)
	254	{
	255	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
	256
	257	if (mem && vaddr >= mem->virt_base && vaddr + size <=
	258	(mem->virt_base + (mem->size << PAGE_SHIFT))) {
	259	unsigned long off = vma->vm_pgoff;
	260	int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;
	261	int user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
	262	int count = size >> PAGE_SHIFT;
	263
	264	*ret = -ENXIO;
	265	if (off < count && user_count <= count - off) {
88a984ba	266	unsigned long pfn = mem->pfn_base + start + off;
bca0fa5f MS	267	*ret = remap_pfn_range(vma, vma->vm_start, pfn,
	268	user_count << PAGE_SHIFT,
	269	vma->vm_page_prot);
	270	}
	271	return 1;
	272	}
	273	return 0;
	274	}
	275	EXPORT_SYMBOL(dma_mmap_from_coherent);
7bfa5ab6 MS	276
	277	/*
	278	* Support for reserved memory regions defined in device tree
	279	*/
	280	#ifdef CONFIG_OF_RESERVED_MEM
	281	#include <linux/of.h>
	282	#include <linux/of_fdt.h>
	283	#include <linux/of_reserved_mem.h>
	284
	285	static int rmem_dma_device_init(struct reserved_mem rmem, struct device dev)
	286	{
	287	struct dma_coherent_mem *mem = rmem->priv;
	288
	289	if (!mem &&
9e5b3d6f MN	290	!dma_init_coherent_memory(rmem->base, rmem->base, rmem->size,
	291	DMA_MEMORY_MAP \| DMA_MEMORY_EXCLUSIVE,
	292	&mem)) {
7bfa5ab6 MS	293	pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
	294	&rmem->base, (unsigned long)rmem->size / SZ_1M);
	295	return -ENODEV;
	296	}
	297	rmem->priv = mem;
	298	dma_assign_coherent_memory(dev, mem);
	299	return 0;
	300	}
	301
	302	static void rmem_dma_device_release(struct reserved_mem *rmem,
	303	struct device *dev)
	304	{
	305	dev->dma_mem = NULL;
	306	}
	307
	308	static const struct reserved_mem_ops rmem_dma_ops = {
	309	.device_init = rmem_dma_device_init,
	310	.device_release = rmem_dma_device_release,
	311	};
	312
	313	static int __init rmem_dma_setup(struct reserved_mem *rmem)
	314	{
	315	unsigned long node = rmem->fdt_node;
	316
	317	if (of_get_flat_dt_prop(node, "reusable", NULL))
	318	return -EINVAL;
	319
	320	#ifdef CONFIG_ARM
	321	if (!of_get_flat_dt_prop(node, "no-map", NULL)) {
	322	pr_err("Reserved memory: regions without no-map are not yet supported\n");
	323	return -EINVAL;
	324	}
	325	#endif
	326
	327	rmem->ops = &rmem_dma_ops;
	328	pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n",
	329	&rmem->base, (unsigned long)rmem->size / SZ_1M);
	330	return 0;
	331	}
	332	RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
	333	#endif