You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
154 lines
4.0 KiB
154 lines
4.0 KiB
/*
|
|
* 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);
|
|
|
|
/**
|
|
* 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 = 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);
|
|
} else if (mem->flags & DMA_MEMORY_EXCLUSIVE)
|
|
*ret = NULL;
|
|
}
|
|
return (mem != NULL);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
|
|
bitmap_release_region(mem->bitmap, page, order);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|