[mirror_ubuntu-bionic-kernel.git] / drivers / base / dma-coherent.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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;
	bool		use_dev_dma_pfn_offset;
};

static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init;

static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev)
{
	if (dev && dev->dma_mem)
		return dev->dma_mem;
	return NULL;
}

static inline dma_addr_t dma_get_device_base(struct device *dev,
					     struct dma_coherent_mem * mem)
{
	if (mem->use_dev_dma_pfn_offset)
		return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT;
	else
		return mem->device_base;
}

static int 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);
	int ret;

	if (!size) {
		ret = -EINVAL;
		goto out;
	}

	mem_base = memremap(phys_addr, size, MEMREMAP_WC);
	if (!mem_base) {
		ret = -EINVAL;
		goto out;
	}
	dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
	if (!dma_mem) {
		ret = -ENOMEM;
		goto out;
	}
	dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
	if (!dma_mem->bitmap) {
		ret = -ENOMEM;
		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 0;

out:
	kfree(dma_mem);
	if (mem_base)
		memunmap(mem_base);
	return ret;
}

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

	memunmap(mem->virt_base);
	kfree(mem->bitmap);
	kfree(mem);
}

static int dma_assign_coherent_memory(struct device *dev,
				      struct dma_coherent_mem *mem)
{
	if (!dev)
		return -ENODEV;

	if (dev->dma_mem)
		return -EBUSY;

	dev->dma_mem = mem;
	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;
	int ret;

	ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, &mem);
	if (ret)
		return ret;

	ret = dma_assign_coherent_memory(dev, mem);
	if (ret)
		dma_release_coherent_memory(mem);
	return ret;
}
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 = PFN_DOWN(device_addr - dma_get_device_base(dev, mem));
	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);

static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem,
		ssize_t size, dma_addr_t *dma_handle)
{
	int order = get_order(size);
	unsigned long flags;
	int pageno;
	void *ret;

	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 coherent area.
	 */
	*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
	ret = mem->virt_base + (pageno << PAGE_SHIFT);
	spin_unlock_irqrestore(&mem->spinlock, flags);
	memset(ret, 0, size);
	return ret;
err:
	spin_unlock_irqrestore(&mem->spinlock, flags);
	return NULL;
}

/**
 * dma_alloc_from_dev_coherent() - allocate memory from device coherent pool
 * @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_dev_coherent(struct device *dev, ssize_t size,
		dma_addr_t *dma_handle, void **ret)
{
	struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);

	if (!mem)
		return 0;

	*ret = __dma_alloc_from_coherent(mem, size, dma_handle);
	if (*ret)
		return 1;

	/*
	 * 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_dev_coherent);

void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle)
{
	if (!dma_coherent_default_memory)
		return NULL;

	return __dma_alloc_from_coherent(dma_coherent_default_memory, size,
			dma_handle);
}

static int __dma_release_from_coherent(struct dma_coherent_mem *mem,
				       int order, void *vaddr)
{
	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;
}

/**
 * dma_release_from_dev_coherent() - free memory to 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 the caller should
 * proceed with releasing memory from generic pools.
 */
int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr)
{
	struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);

	return __dma_release_from_coherent(mem, order, vaddr);
}
EXPORT_SYMBOL(dma_release_from_dev_coherent);

int dma_release_from_global_coherent(int order, void *vaddr)
{
	if (!dma_coherent_default_memory)
		return 0;

	return __dma_release_from_coherent(dma_coherent_default_memory, order,
			vaddr);
}

static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem,
		struct vm_area_struct *vma, void *vaddr, size_t size, int *ret)
{
	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_pages(vma);
		int count = PAGE_ALIGN(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;
}

/**
 * dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool
 * @dev:	device from which the memory was allocated
 * @vma:	vm_area for the userspace memory
 * @vaddr:	cpu address returned by dma_alloc_from_dev_coherent
 * @size:	size of the memory buffer allocated
 * @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_dev_coherent(struct device *dev, struct vm_area_struct *vma,
			   void *vaddr, size_t size, int *ret)
{
	struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);

	return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret);
}
EXPORT_SYMBOL(dma_mmap_from_dev_coherent);

int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr,
				   size_t size, int *ret)
{
	if (!dma_coherent_default_memory)
		return 0;

	return __dma_mmap_from_coherent(dma_coherent_default_memory, vma,
					vaddr, size, ret);
}

/*
 * 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 struct reserved_mem *dma_reserved_default_memory __initdata;

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

	if (!mem) {
		ret = dma_init_coherent_memory(rmem->base, rmem->base,
					       rmem->size,
					       DMA_MEMORY_EXCLUSIVE, &mem);
		if (ret) {
			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 ret;
		}
	}
	mem->use_dev_dma_pfn_offset = true;
	rmem->priv = mem;
	dma_assign_coherent_memory(dev, mem);
	return 0;
}

static void rmem_dma_device_release(struct reserved_mem *rmem,
				    struct device *dev)
{
	if (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;
	}

	if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) {
		WARN(dma_reserved_default_memory,
		     "Reserved memory: region for default DMA coherent area is redefined\n");
		dma_reserved_default_memory = rmem;
	}
#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;
}

static int __init dma_init_reserved_memory(void)
{
	const struct reserved_mem_ops *ops;
	int ret;

	if (!dma_reserved_default_memory)
		return -ENOMEM;

	ops = dma_reserved_default_memory->ops;

	/*
	 * We rely on rmem_dma_device_init() does not propagate error of
	 * dma_assign_coherent_memory() for "NULL" device.
	 */
	ret = ops->device_init(dma_reserved_default_memory, NULL);

	if (!ret) {
		dma_coherent_default_memory = dma_reserved_default_memory->priv;
		pr_info("DMA: default coherent area is set\n");
	}

	return ret;
}

core_initcall(dma_init_reserved_memory);

RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
#endif
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
ee7e5516 DES	2	/*
	3	* Coherent per-device memory handling.
	4	* Borrowed from i386
	5	*/
6b03ae0d	6	#include <linux/io.h>
5a0e3ad6	7	#include <linux/slab.h>
ee7e5516	8	#include <linux/kernel.h>
08a999ce	9	#include <linux/module.h>
ee7e5516 DES	10	#include <linux/dma-mapping.h>
	11
	12	struct dma_coherent_mem {
	13	void *virt_base;
ed1d218c	14	dma_addr_t device_base;
88a984ba	15	unsigned long pfn_base;
ee7e5516 DES	16	int size;
	17	int flags;
	18	unsigned long *bitmap;
7bfa5ab6	19	spinlock_t spinlock;
c41f9ea9	20	bool use_dev_dma_pfn_offset;
ee7e5516 DES	21	};
ee7e5516 DES	22
93228b44 VM	23	static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init;
	24
	25	static inline struct dma_coherent_mem dev_get_coherent_memory(struct device dev)
	26	{
	27	if (dev && dev->dma_mem)
	28	return dev->dma_mem;
43fc509c	29	return NULL;
93228b44 VM	30	}
93228b44 VM	31
c41f9ea9 VM	32	static inline dma_addr_t dma_get_device_base(struct device *dev,
	33	struct dma_coherent_mem * mem)
	34	{
	35	if (mem->use_dev_dma_pfn_offset)
	36	return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT;
	37	else
	38	return mem->device_base;
	39	}
	40
d35b0996	41	static int dma_init_coherent_memory(
9e5b3d6f MN	42	phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags,
9e5b3d6f MN	43	struct dma_coherent_mem **mem)
ee7e5516	44	{
7bfa5ab6	45	struct dma_coherent_mem *dma_mem = NULL;
ee7e5516 DES	46	void __iomem *mem_base = NULL;
	47	int pages = size >> PAGE_SHIFT;
	48	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
d35b0996	49	int ret;
ee7e5516	50
d35b0996 AB	51	if (!size) {
d35b0996 AB	52	ret = -EINVAL;
ee7e5516	53	goto out;
d35b0996	54	}
ee7e5516	55
2436bdcd	56	mem_base = memremap(phys_addr, size, MEMREMAP_WC);
d35b0996 AB	57	if (!mem_base) {
d35b0996 AB	58	ret = -EINVAL;
ee7e5516	59	goto out;
d35b0996	60	}
7bfa5ab6	61	dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
d35b0996 AB	62	if (!dma_mem) {
d35b0996 AB	63	ret = -ENOMEM;
ee7e5516	64	goto out;
d35b0996	65	}
7bfa5ab6	66	dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
d35b0996 AB	67	if (!dma_mem->bitmap) {
d35b0996 AB	68	ret = -ENOMEM;
7bfa5ab6	69	goto out;
d35b0996	70	}
7bfa5ab6 MS	71
	72	dma_mem->virt_base = mem_base;
	73	dma_mem->device_base = device_addr;
	74	dma_mem->pfn_base = PFN_DOWN(phys_addr);
	75	dma_mem->size = pages;
	76	dma_mem->flags = flags;
	77	spin_lock_init(&dma_mem->spinlock);
ee7e5516	78
7bfa5ab6	79	*mem = dma_mem;
d35b0996	80	return 0;
ee7e5516	81
7bfa5ab6 MS	82	out:
7bfa5ab6 MS	83	kfree(dma_mem);
2436bdcd CH	84	if (mem_base)
2436bdcd CH	85	memunmap(mem_base);
d35b0996	86	return ret;
ee7e5516	87	}
7bfa5ab6 MS	88
	89	static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
	90	{
	91	if (!mem)
	92	return;
6b03ae0d	93
2436bdcd	94	memunmap(mem->virt_base);
7bfa5ab6 MS	95	kfree(mem->bitmap);
	96	kfree(mem);
	97	}
	98
	99	static int dma_assign_coherent_memory(struct device *dev,
	100	struct dma_coherent_mem *mem)
	101	{
93228b44 VM	102	if (!dev)
	103	return -ENODEV;
	104
7bfa5ab6 MS	105	if (dev->dma_mem)
	106	return -EBUSY;
	107
	108	dev->dma_mem = mem;
7bfa5ab6 MS	109	return 0;
	110	}
	111
	112	int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
	113	dma_addr_t device_addr, size_t size, int flags)
	114	{
	115	struct dma_coherent_mem *mem;
2436bdcd	116	int ret;
7bfa5ab6	117
2436bdcd CH	118	ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, &mem);
	119	if (ret)
	120	return ret;
7bfa5ab6	121
2436bdcd CH	122	ret = dma_assign_coherent_memory(dev, mem);
	123	if (ret)
	124	dma_release_coherent_memory(mem);
	125	return ret;
7bfa5ab6	126	}
ee7e5516 DES	127	EXPORT_SYMBOL(dma_declare_coherent_memory);
	128
	129	void dma_release_declared_memory(struct device *dev)
	130	{
	131	struct dma_coherent_mem *mem = dev->dma_mem;
	132
	133	if (!mem)
	134	return;
7bfa5ab6	135	dma_release_coherent_memory(mem);
ee7e5516	136	dev->dma_mem = NULL;
ee7e5516 DES	137	}
	138	EXPORT_SYMBOL(dma_release_declared_memory);
	139
	140	void dma_mark_declared_memory_occupied(struct device dev,
	141	dma_addr_t device_addr, size_t size)
	142	{
	143	struct dma_coherent_mem *mem = dev->dma_mem;
7bfa5ab6	144	unsigned long flags;
ee7e5516	145	int pos, err;
ee7e5516	146
d2dc1f4a	147	size += device_addr & ~PAGE_MASK;
ee7e5516 DES	148
	149	if (!mem)
	150	return ERR_PTR(-EINVAL);
	151
7bfa5ab6	152	spin_lock_irqsave(&mem->spinlock, flags);
c41f9ea9	153	pos = PFN_DOWN(device_addr - dma_get_device_base(dev, mem));
d2dc1f4a	154	err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
7bfa5ab6 MS	155	spin_unlock_irqrestore(&mem->spinlock, flags);
7bfa5ab6 MS	156
ee7e5516 DES	157	if (err != 0)
	158	return ERR_PTR(err);
	159	return mem->virt_base + (pos << PAGE_SHIFT);
	160	}
	161	EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
	162
43fc509c VM	163	static void __dma_alloc_from_coherent(struct dma_coherent_mem mem,
43fc509c VM	164	ssize_t size, dma_addr_t *dma_handle)
ee7e5516	165	{
ee7e5516	166	int order = get_order(size);
7bfa5ab6	167	unsigned long flags;
eccd83e1	168	int pageno;
43fc509c	169	void *ret;
ee7e5516	170
7bfa5ab6	171	spin_lock_irqsave(&mem->spinlock, flags);
0609697e	172
cdf57cab	173	if (unlikely(size > (mem->size << PAGE_SHIFT)))
0609697e	174	goto err;
eccd83e1 AM	175
eccd83e1 AM	176	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
0609697e PM	177	if (unlikely(pageno < 0))
	178	goto err;
	179
	180	/*
43fc509c	181	* Memory was found in the coherent area.
0609697e	182	*/
43fc509c VM	183	*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
43fc509c VM	184	ret = mem->virt_base + (pageno << PAGE_SHIFT);
dd01c75f	185	spin_unlock_irqrestore(&mem->spinlock, flags);
2436bdcd	186	memset(ret, 0, size);
43fc509c	187	return ret;
0609697e	188	err:
7bfa5ab6	189	spin_unlock_irqrestore(&mem->spinlock, flags);
43fc509c VM	190	return NULL;
	191	}
	192
	193	/**
	194	* dma_alloc_from_dev_coherent() - allocate memory from device coherent pool
	195	* @dev: device from which we allocate memory
	196	* @size: size of requested memory area
	197	* @dma_handle: This will be filled with the correct dma handle
	198	* @ret: This pointer will be filled with the virtual address
	199	* to allocated area.
	200	*
	201	* This function should be only called from per-arch dma_alloc_coherent()
	202	* to support allocation from per-device coherent memory pools.
	203	*
	204	* Returns 0 if dma_alloc_coherent should continue with allocating from
	205	* generic memory areas, or !0 if dma_alloc_coherent should return @ret.
	206	*/
	207	int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
	208	dma_addr_t dma_handle, void *ret)
	209	{
	210	struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
	211
	212	if (!mem)
	213	return 0;
	214
	215	*ret = __dma_alloc_from_coherent(mem, size, dma_handle);
	216	if (*ret)
	217	return 1;
	218
0609697e PM	219	/*
	220	* In the case where the allocation can not be satisfied from the
	221	* per-device area, try to fall back to generic memory if the
	222	* constraints allow it.
	223	*/
	224	return mem->flags & DMA_MEMORY_EXCLUSIVE;
ee7e5516	225	}
43fc509c	226	EXPORT_SYMBOL(dma_alloc_from_dev_coherent);
ee7e5516	227
43fc509c	228	void dma_alloc_from_global_coherent(ssize_t size, dma_addr_t dma_handle)
ee7e5516	229	{
43fc509c VM	230	if (!dma_coherent_default_memory)
	231	return NULL;
	232
	233	return __dma_alloc_from_coherent(dma_coherent_default_memory, size,
	234	dma_handle);
	235	}
ee7e5516	236
43fc509c VM	237	static int __dma_release_from_coherent(struct dma_coherent_mem *mem,
	238	int order, void *vaddr)
	239	{
ee7e5516 DES	240	if (mem && vaddr >= mem->virt_base && vaddr <
	241	(mem->virt_base + (mem->size << PAGE_SHIFT))) {
	242	int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
7bfa5ab6	243	unsigned long flags;
ee7e5516	244
7bfa5ab6	245	spin_lock_irqsave(&mem->spinlock, flags);
ee7e5516	246	bitmap_release_region(mem->bitmap, page, order);
7bfa5ab6	247	spin_unlock_irqrestore(&mem->spinlock, flags);
ee7e5516 DES	248	return 1;
	249	}
	250	return 0;
	251	}
bca0fa5f MS	252
bca0fa5f MS	253	/**
43fc509c	254	* dma_release_from_dev_coherent() - free memory to device coherent memory pool
bca0fa5f	255	* @dev: device from which the memory was allocated
43fc509c VM	256	* @order: the order of pages allocated
43fc509c VM	257	* @vaddr: virtual address of allocated pages
bca0fa5f MS	258	*
bca0fa5f MS	259	* This checks whether the memory was allocated from the per-device
43fc509c	260	* coherent memory pool and if so, releases that memory.
bca0fa5f	261	*
43fc509c VM	262	* Returns 1 if we correctly released the memory, or 0 if the caller should
43fc509c VM	263	* proceed with releasing memory from generic pools.
bca0fa5f	264	*/
43fc509c	265	int dma_release_from_dev_coherent(struct device dev, int order, void vaddr)
bca0fa5f	266	{
93228b44	267	struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
bca0fa5f	268
43fc509c VM	269	return __dma_release_from_coherent(mem, order, vaddr);
	270	}
	271	EXPORT_SYMBOL(dma_release_from_dev_coherent);
	272
	273	int dma_release_from_global_coherent(int order, void *vaddr)
	274	{
	275	if (!dma_coherent_default_memory)
	276	return 0;
	277
	278	return __dma_release_from_coherent(dma_coherent_default_memory, order,
	279	vaddr);
	280	}
	281
	282	static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem,
	283	struct vm_area_struct vma, void vaddr, size_t size, int *ret)
	284	{
bca0fa5f MS	285	if (mem && vaddr >= mem->virt_base && vaddr + size <=
	286	(mem->virt_base + (mem->size << PAGE_SHIFT))) {
	287	unsigned long off = vma->vm_pgoff;
	288	int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;
e688f144	289	int user_count = vma_pages(vma);
9ca5d4fd	290	int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
bca0fa5f MS	291
	292	*ret = -ENXIO;
	293	if (off < count && user_count <= count - off) {
88a984ba	294	unsigned long pfn = mem->pfn_base + start + off;
bca0fa5f MS	295	*ret = remap_pfn_range(vma, vma->vm_start, pfn,
	296	user_count << PAGE_SHIFT,
	297	vma->vm_page_prot);
	298	}
	299	return 1;
	300	}
	301	return 0;
	302	}
43fc509c VM	303
	304	/**
	305	* dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool
	306	* @dev: device from which the memory was allocated
	307	* @vma: vm_area for the userspace memory
	308	* @vaddr: cpu address returned by dma_alloc_from_dev_coherent
	309	* @size: size of the memory buffer allocated
	310	* @ret: result from remap_pfn_range()
	311	*
	312	* This checks whether the memory was allocated from the per-device
	313	* coherent memory pool and if so, maps that memory to the provided vma.
	314	*
	315	* Returns 1 if we correctly mapped the memory, or 0 if the caller should
	316	* proceed with mapping memory from generic pools.
	317	*/
	318	int dma_mmap_from_dev_coherent(struct device dev, struct vm_area_struct vma,
	319	void vaddr, size_t size, int ret)
	320	{
	321	struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
	322
	323	return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret);
	324	}
	325	EXPORT_SYMBOL(dma_mmap_from_dev_coherent);
	326
	327	int dma_mmap_from_global_coherent(struct vm_area_struct vma, void vaddr,
	328	size_t size, int *ret)
	329	{
	330	if (!dma_coherent_default_memory)
	331	return 0;
	332
	333	return __dma_mmap_from_coherent(dma_coherent_default_memory, vma,
	334	vaddr, size, ret);
	335	}
7bfa5ab6 MS	336
	337	/*
	338	* Support for reserved memory regions defined in device tree
	339	*/
	340	#ifdef CONFIG_OF_RESERVED_MEM
	341	#include <linux/of.h>
	342	#include <linux/of_fdt.h>
	343	#include <linux/of_reserved_mem.h>
	344
93228b44 VM	345	static struct reserved_mem *dma_reserved_default_memory __initdata;
93228b44 VM	346
7bfa5ab6 MS	347	static int rmem_dma_device_init(struct reserved_mem rmem, struct device dev)
	348	{
	349	struct dma_coherent_mem *mem = rmem->priv;
d35b0996 AB	350	int ret;
d35b0996 AB	351
6d573398 AB	352	if (!mem) {
	353	ret = dma_init_coherent_memory(rmem->base, rmem->base,
	354	rmem->size,
	355	DMA_MEMORY_EXCLUSIVE, &mem);
	356	if (ret) {
	357	pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
	358	&rmem->base, (unsigned long)rmem->size / SZ_1M);
	359	return ret;
	360	}
7bfa5ab6	361	}
c41f9ea9	362	mem->use_dev_dma_pfn_offset = true;
7bfa5ab6 MS	363	rmem->priv = mem;
	364	dma_assign_coherent_memory(dev, mem);
	365	return 0;
	366	}
	367
	368	static void rmem_dma_device_release(struct reserved_mem *rmem,
	369	struct device *dev)
	370	{
93228b44 VM	371	if (dev)
93228b44 VM	372	dev->dma_mem = NULL;
7bfa5ab6 MS	373	}
	374
	375	static const struct reserved_mem_ops rmem_dma_ops = {
	376	.device_init = rmem_dma_device_init,
	377	.device_release = rmem_dma_device_release,
	378	};
	379
	380	static int __init rmem_dma_setup(struct reserved_mem *rmem)
	381	{
	382	unsigned long node = rmem->fdt_node;
	383
	384	if (of_get_flat_dt_prop(node, "reusable", NULL))
	385	return -EINVAL;
	386
	387	#ifdef CONFIG_ARM
	388	if (!of_get_flat_dt_prop(node, "no-map", NULL)) {
	389	pr_err("Reserved memory: regions without no-map are not yet supported\n");
	390	return -EINVAL;
	391	}
93228b44 VM	392
	393	if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) {
	394	WARN(dma_reserved_default_memory,
	395	"Reserved memory: region for default DMA coherent area is redefined\n");
	396	dma_reserved_default_memory = rmem;
	397	}
7bfa5ab6 MS	398	#endif
	399
	400	rmem->ops = &rmem_dma_ops;
	401	pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n",
	402	&rmem->base, (unsigned long)rmem->size / SZ_1M);
	403	return 0;
	404	}
93228b44 VM	405
	406	static int __init dma_init_reserved_memory(void)
	407	{
	408	const struct reserved_mem_ops *ops;
	409	int ret;
	410
	411	if (!dma_reserved_default_memory)
	412	return -ENOMEM;
	413
	414	ops = dma_reserved_default_memory->ops;
	415
	416	/*
	417	* We rely on rmem_dma_device_init() does not propagate error of
	418	* dma_assign_coherent_memory() for "NULL" device.
	419	*/
	420	ret = ops->device_init(dma_reserved_default_memory, NULL);
	421
	422	if (!ret) {
	423	dma_coherent_default_memory = dma_reserved_default_memory->priv;
	424	pr_info("DMA: default coherent area is set\n");
	425	}
	426
	427	return ret;
	428	}
	429
	430	core_initcall(dma_init_reserved_memory);
	431
7bfa5ab6 MS	432	RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
7bfa5ab6 MS	433	#endif