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/*
* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
*
* Provide default implementations of the DMA mapping callbacks for
* busses using the iommu infrastructure
*/
#include <asm/iommu.h>
/*
* Generic iommu implementation
*/
/* Allocates a contiguous real buffer and creates mappings over it.
* Returns the virtual address of the buffer and sets dma_handle
* to the dma address (mapping) of the first page.
*/
static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
return iommu_alloc_coherent(dev, dev->archdata.dma_data, size,
dma_handle, device_to_mask(dev), flag,
dev_to_node(dev));
}
static void dma_iommu_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
iommu_free_coherent(dev->archdata.dma_data, size, vaddr, dma_handle);
}
/* Creates TCEs for a user provided buffer. The user buffer must be
* contiguous real kernel storage (not vmalloc). The address passed here
* comprises a page address and offset into that page. The dma_addr_t
* returned will point to the same byte within the page as was passed in.
*/
static dma_addr_t dma_iommu_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
return iommu_map_page(dev, dev->archdata.dma_data, page, offset, size,
device_to_mask(dev), direction, attrs);
}
static void dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
iommu_unmap_page(dev->archdata.dma_data, dma_handle, size, direction,
attrs);
}
static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
return iommu_map_sg(dev, dev->archdata.dma_data, sglist, nelems,
device_to_mask(dev), direction, attrs);
}
static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
iommu_unmap_sg(dev->archdata.dma_data, sglist, nelems, direction,
attrs);
}
/* We support DMA to/from any memory page via the iommu */
static int dma_iommu_dma_supported(struct device *dev, u64 mask)
{
struct iommu_table *tbl = dev->archdata.dma_data;
if (!tbl || tbl->it_offset > mask) {
printk(KERN_INFO
"Warning: IOMMU offset too big for device mask\n");
if (tbl)
printk(KERN_INFO
"mask: 0x%08lx, table offset: 0x%08lx\n",
mask, tbl->it_offset);
else
printk(KERN_INFO "mask: 0x%08lx, table unavailable\n",
mask);
return 0;
} else
return 1;
}
struct dma_mapping_ops dma_iommu_ops = {
.alloc_coherent = dma_iommu_alloc_coherent,
.free_coherent = dma_iommu_free_coherent,
.map_sg = dma_iommu_map_sg,
.unmap_sg = dma_iommu_unmap_sg,
.dma_supported = dma_iommu_dma_supported,
.map_page = dma_iommu_map_page,
.unmap_page = dma_iommu_unmap_page,
};
EXPORT_SYMBOL(dma_iommu_ops);
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