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

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

struct dma_coherent_mem {
	void		*virt_base;
	u32		device_base;
	int		size;
	int		flags;
	unsigned long	*bitmap;
};

int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
				dma_addr_t device_addr, size_t size, int flags)
{
	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 (dev->dma_mem)
		goto out;

	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */

	mem_base = ioremap(bus_addr, size);
	if (!mem_base)
		goto out;

	dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
	if (!dev->dma_mem)
		goto out;
	dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
	if (!dev->dma_mem->bitmap)
		goto free1_out;

	dev->dma_mem->virt_base = mem_base;
	dev->dma_mem->device_base = device_addr;
	dev->dma_mem->size = pages;
	dev->dma_mem->flags = flags;

	if (flags & DMA_MEMORY_MAP)
		return DMA_MEMORY_MAP;

	return DMA_MEMORY_IO;

 free1_out:
	kfree(dev->dma_mem);
 out:
	if (mem_base)
		iounmap(mem_base);
	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;
	dev->dma_mem = NULL;
	iounmap(mem->virt_base);
	kfree(mem->bitmap);
	kfree(mem);
}
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;
	int pos, err;
	int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1);

	pages >>= PAGE_SHIFT;

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

	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
	err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
	if (err != 0)
		return ERR_PTR(err);
	return mem->virt_base + (pos << PAGE_SHIFT);
}
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);

int dma_alloc_from_coherent(struct device *dev, ssize_t size,
				       dma_addr_t *dma_handle, void **ret)
{
	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
	int order = get_order(size);

	if (mem) {
		int page = bitmap_find_free_region(mem->bitmap, mem->size,
						     order);
		if (page >= 0) {
			*dma_handle = mem->device_base + (page << PAGE_SHIFT);
			*ret = mem->virt_base + (page << PAGE_SHIFT);
			memset(*ret, 0, size);
		}
		if (mem->flags & DMA_MEMORY_EXCLUSIVE)
			*ret = NULL;
	}
	return (mem != NULL);
}

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;

		bitmap_release_region(mem->bitmap, page, order);
		return 1;
	}
	return 0;
}
Commit	Line	Data
ee7e5516 DES	1	/*
	2	* Coherent per-device memory handling.
	3	* Borrowed from i386
	4	*/
	5	#include <linux/kernel.h>
	6	#include <linux/dma-mapping.h>
	7
	8	struct dma_coherent_mem {
	9	void *virt_base;
	10	u32 device_base;
	11	int size;
	12	int flags;
	13	unsigned long *bitmap;
	14	};
	15
	16	int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
	17	dma_addr_t device_addr, size_t size, int flags)
	18	{
	19	void __iomem *mem_base = NULL;
	20	int pages = size >> PAGE_SHIFT;
	21	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
	22
	23	if ((flags & (DMA_MEMORY_MAP \| DMA_MEMORY_IO)) == 0)
	24	goto out;
	25	if (!size)
	26	goto out;
	27	if (dev->dma_mem)
	28	goto out;
	29
	30	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
	31
	32	mem_base = ioremap(bus_addr, size);
	33	if (!mem_base)
	34	goto out;
	35
	36	dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
	37	if (!dev->dma_mem)
	38	goto out;
	39	dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
	40	if (!dev->dma_mem->bitmap)
	41	goto free1_out;
	42
	43	dev->dma_mem->virt_base = mem_base;
	44	dev->dma_mem->device_base = device_addr;
	45	dev->dma_mem->size = pages;
	46	dev->dma_mem->flags = flags;
	47
	48	if (flags & DMA_MEMORY_MAP)
	49	return DMA_MEMORY_MAP;
	50
	51	return DMA_MEMORY_IO;
	52
	53	free1_out:
	54	kfree(dev->dma_mem);
	55	out:
	56	if (mem_base)
	57	iounmap(mem_base);
	58	return 0;
	59	}
	60	EXPORT_SYMBOL(dma_declare_coherent_memory);
	61
	62	void dma_release_declared_memory(struct device *dev)
	63	{
	64	struct dma_coherent_mem *mem = dev->dma_mem;
65
66	if (!mem)
67	return;
68	dev->dma_mem = NULL;
69	iounmap(mem->virt_base);
70	kfree(mem->bitmap);
71	kfree(mem);
72	}
73	EXPORT_SYMBOL(dma_release_declared_memory);
74
75	void dma_mark_declared_memory_occupied(struct device dev,
76	dma_addr_t device_addr, size_t size)
77	{
78	struct dma_coherent_mem *mem = dev->dma_mem;
79	int pos, err;
80	int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1);
81
82	pages >>= PAGE_SHIFT;
83
84	if (!mem)
85	return ERR_PTR(-EINVAL);
86
87	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
88	err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
89	if (err != 0)
90	return ERR_PTR(err);
91	return mem->virt_base + (pos << PAGE_SHIFT);
92	}
93	EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
94
95	int dma_alloc_from_coherent(struct device *dev, ssize_t size,
96	dma_addr_t dma_handle, void *ret)
97	{
98	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
99	int order = get_order(size);
100
101	if (mem) {
102	int page = bitmap_find_free_region(mem->bitmap, mem->size,
103	order);
104	if (page >= 0) {
105	*dma_handle = mem->device_base + (page << PAGE_SHIFT);
106	*ret = mem->virt_base + (page << PAGE_SHIFT);
107	memset(*ret, 0, size);
108	}
109	if (mem->flags & DMA_MEMORY_EXCLUSIVE)
110	*ret = NULL;
111	}
112	return (mem != NULL);
113	}
114
115	int dma_release_from_coherent(struct device dev, int order, void vaddr)
116	{
117	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
118
119	if (mem && vaddr >= mem->virt_base && vaddr <
120	(mem->virt_base + (mem->size << PAGE_SHIFT))) {
121	int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
122
123	bitmap_release_region(mem->bitmap, page, order);
124	return 1;
125	}
126	return 0;
127	}