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iommu/dma: Refactor the page array remapping allocator

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Move the call to dma_common_pages_remap into __iommu_dma_alloc and
rename it to iommu_dma_alloc_remap.  This creates a self-contained
helper for remapped pages allocation and mapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Christoph Hellwig 2019-05-20 09:29:34 +02:00 committed by Joerg Roedel
parent 4c360acee9
commit 21b95aaf5f
1 changed files with 27 additions and 29 deletions
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56
drivers/iommu/dma-iommu.c
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@ -564,9 +564,9 @@ static struct page **__iommu_dma_get_pages(void *cpu_addr)
}
/**
* iommu_dma_free - Free a buffer allocated by __iommu_dma_alloc()
* iommu_dma_free - Free a buffer allocated by iommu_dma_alloc_remap()
* @dev: Device which owns this buffer
* @pages: Array of buffer pages as returned by __iommu_dma_alloc()
* @pages: Array of buffer pages as returned by __iommu_dma_alloc_remap()
* @size: Size of buffer in bytes
* @handle: DMA address of buffer
*
@ -582,33 +582,35 @@ static void __iommu_dma_free(struct device *dev, struct page **pages,
}
/**
* __iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space
* iommu_dma_alloc_remap - Allocate and map a buffer contiguous in IOVA space
* @dev: Device to allocate memory for. Must be a real device
* attached to an iommu_dma_domain
* @size: Size of buffer in bytes
* @dma_handle: Out argument for allocated DMA handle
* @gfp: Allocation flags
* @attrs: DMA attributes for this allocation
* @prot: IOMMU mapping flags
* @handle: Out argument for allocated DMA handle
*
* If @size is less than PAGE_SIZE, then a full CPU page will be allocated,
* but an IOMMU which supports smaller pages might not map the whole thing.
*
* Return: Array of struct page pointers describing the buffer,
* or NULL on failure.
* Return: Mapped virtual address, or NULL on failure.
*/
static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
gfp_t gfp, unsigned long attrs, int prot, dma_addr_t *handle)
static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
struct iommu_domain *domain = iommu_get_dma_domain(dev);
struct iommu_dma_cookie *cookie = domain->iova_cookie;
struct iova_domain *iovad = &cookie->iovad;
bool coherent = dev_is_dma_coherent(dev);
int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
struct page **pages;
struct sg_table sgt;
dma_addr_t iova;
unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
void *vaddr;
*handle = DMA_MAPPING_ERROR;
*dma_handle = DMA_MAPPING_ERROR;
min_size = alloc_sizes & -alloc_sizes;
if (min_size < PAGE_SIZE) {
@ -634,7 +636,7 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
goto out_free_iova;
if (!(prot & IOMMU_CACHE)) {
if (!(ioprot & IOMMU_CACHE)) {
struct scatterlist *sg;
int i;
@ -642,14 +644,21 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
arch_dma_prep_coherent(sg_page(sg), sg->length);
}
if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot)
if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, ioprot)
< size)
goto out_free_sg;
*handle = iova;
sg_free_table(&sgt);
return pages;
vaddr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
__builtin_return_address(0));
if (!vaddr)
goto out_unmap;
*dma_handle = iova;
sg_free_table(&sgt);
return vaddr;
out_unmap:
__iommu_dma_unmap(dev, iova, size);
out_free_sg:
sg_free_table(&sgt);
out_free_iova:
@ -1008,18 +1017,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
size >> PAGE_SHIFT);
}
} else {
pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
struct page **pages;
pages = __iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
handle);
if (!pages)
return NULL;
addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
__builtin_return_address(0));
if (!addr)
__iommu_dma_free(dev, pages, iosize, handle);
addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);
}
return addr;
}
@ -1033,7 +1031,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
/*
* @cpu_addr will be one of 4 things depending on how it was allocated:
* - A remapped array of pages for contiguous allocations.
* - A remapped array of pages from __iommu_dma_alloc(), for all
* - A remapped array of pages from iommu_dma_alloc_remap(), for all
* non-atomic allocations.
* - A non-cacheable alias from the atomic pool, for atomic
* allocations by non-coherent devices.