linux-kernel - [PATCH 16/23] iommu/dma: Cleanup variable naming in iommu_dma

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Message-Id: <20190523070028.7435-17-hch@lst.de>
Date:   Thu, 23 May 2019 09:00:21 +0200
From:   Christoph Hellwig <hch@....de>
To:     Robin Murphy <robin.murphy@....com>
Cc:     Tom Murphy <tmurphy@...sta.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        linux-kernel@...r.kernel.org, iommu@...ts.linux-foundation.org,
        linux-arm-kernel@...ts.infradead.org
Subject: [PATCH 16/23] iommu/dma: Cleanup variable naming in iommu_dma_alloc

From: Robin Murphy <robin.murphy@....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@....com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@....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 33d1ce8cc640..9ac76d286df1 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -977,64 +977,63 @@ 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;
 }
 
-- 
2.20.1