[PATCH 18/25] iommu/dma: Cleanup variable naming in iommu_dma_alloc

Christoph Hellwig
2019-04-30T10:55:34Z

From: Robin Murphy <robin.murphy@arm.com>

Most importantly clear up the size / iosize confusion. Also rename addr
to cpu_addr to match the surrounding code and make the intention a little
more clear.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/iommu/dma-iommu.c | 45 +++++++++++++++++++--------------------
1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 9ba35b98506c..2b4f6dd93116 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -958,64 +958,63 @@ 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);
- size_t iosize = size;
+ size_t alloc_size = PAGE_ALIGN(size);
struct page *page = NULL;
- void *addr;
+ void *cpu_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);
+ return iommu_dma_alloc_remap(dev, size, handle, gfp, attrs);

if (!gfpflags_allow_blocking(gfp) && !coherent) {
- addr = dma_alloc_from_pool(size, &page, gfp);
- if (!addr)
+ cpu_addr = dma_alloc_from_pool(alloc_size, &page, gfp);
+ if (!cpu_addr)
return NULL;

- *handle = __iommu_dma_map(dev, page_to_phys(page), iosize,
+ *handle = __iommu_dma_map(dev, page_to_phys(page), size,
ioprot);
if (*handle == DMA_MAPPING_ERROR) {
- dma_free_from_pool(addr, size);
+ dma_free_from_pool(cpu_addr, alloc_size);
return NULL;
}
- return addr;
+ return cpu_addr;
}

if (gfpflags_allow_blocking(gfp))
- page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
- get_order(size),
+ page = dma_alloc_from_contiguous(dev, alloc_size >> PAGE_SHIFT,
+ get_order(alloc_size),
gfp & __GFP_NOWARN);
if (!page)
- page = alloc_pages(gfp, get_order(size));
+ page = alloc_pages(gfp, get_order(alloc_size));
if (!page)
return NULL;

- *handle = __iommu_dma_map(dev, page_to_phys(page), iosize, ioprot);
+ *handle = __iommu_dma_map(dev, page_to_phys(page), size, ioprot);
if (*handle == DMA_MAPPING_ERROR)
goto out_free_pages;

if (!coherent || PageHighMem(page)) {
pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);

- addr = dma_common_contiguous_remap(page, size, VM_USERMAP, prot,
- __builtin_return_address(0));
- if (!addr)
+ cpu_addr = dma_common_contiguous_remap(page, alloc_size,
+ VM_USERMAP, prot, __builtin_return_address(0));
+ if (!cpu_addr)
goto out_unmap;

if (!coherent)
- arch_dma_prep_coherent(page, iosize);
+ arch_dma_prep_coherent(page, size);
} else {
- addr = page_address(page);
+ cpu_addr = page_address(page);
}
- memset(addr, 0, size);
- return addr;
+ memset(cpu_addr, 0, alloc_size);
+ return cpu_addr;
out_unmap:
- __iommu_dma_unmap(dev, *handle, iosize);
+ __iommu_dma_unmap(dev, *handle, size);
out_free_pages:
- if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
- __free_pages(page, get_order(size));
+ if (!dma_release_from_contiguous(dev, page, alloc_size >> PAGE_SHIFT))
+ __free_pages(page, get_order(alloc_size));
return NULL;