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iommu/dma: Refactor iommu_dma_alloc

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Shuffle around the self-contained atomic and non-contiguous cases to
return early and get out of the way of the CMA case that we're about to
work on next.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[hch: slight changes to the code flow]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Robin Murphy 2019-05-20 09:29:37 +02:00 committed by Joerg Roedel
parent bcf4b9c4c2
commit 072bebc069
1 changed files with 30 additions and 30 deletions
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60
drivers/iommu/dma-iommu.c
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@ -973,14 +973,19 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
{
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);
size_t iosize = size;
struct page *page;
void *addr;
size = PAGE_ALIGN(size);
gfp |= __GFP_ZERO;
if (gfpflags_allow_blocking(gfp) &&
!(attrs & DMA_ATTR_FORCE_CONTIGUOUS))
return iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);
if (!gfpflags_allow_blocking(gfp)) {
struct page *page;
/*
* In atomic context we can't remap anything, so we'll only
* get the virtually contiguous buffer we need by way of a
@ -1002,39 +1007,34 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
__free_pages(page, get_order(size));
else
dma_free_from_pool(addr, size);
addr = NULL;
}
} else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
struct page *page;
page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
get_order(size), gfp & __GFP_NOWARN);
if (!page)
return NULL;
*handle = __iommu_dma_map(dev, page_to_phys(page), iosize, ioprot);
if (*handle == DMA_MAPPING_ERROR) {
dma_release_from_contiguous(dev, page,
size >> PAGE_SHIFT);
return NULL;
}
addr = dma_common_contiguous_remap(page, size, VM_USERMAP,
prot,
__builtin_return_address(0));
if (addr) {
if (!coherent)
arch_dma_prep_coherent(page, iosize);
memset(addr, 0, size);
} else {
__iommu_dma_unmap(dev, *handle, iosize);
dma_release_from_contiguous(dev, page,
size >> PAGE_SHIFT);
}
} else {
addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);
return addr;
}
page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
get_order(size), gfp & __GFP_NOWARN);
if (!page)
return NULL;
*handle = __iommu_dma_map(dev, page_to_phys(page), iosize, ioprot);
if (*handle == DMA_MAPPING_ERROR)
goto out_free_pages;
addr = dma_common_contiguous_remap(page, size, VM_USERMAP, prot,
__builtin_return_address(0));
if (!addr)
goto out_unmap;
if (!coherent)
arch_dma_prep_coherent(page, iosize);
memset(addr, 0, size);
return addr;
out_unmap:
__iommu_dma_unmap(dev, *handle, iosize);
out_free_pages:
dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
return NULL;
}
static int __iommu_dma_mmap_pfn(struct vm_area_struct *vma,