[PATCH 5.15.y 06/10] dma-direct: factor the swiotlb code out of __dma_direct_alloc_pages

[Sasha Levin <sashal@kernel.org>]

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit aea7e2a86a94b2583e1e812c596140034398a169 ]

Add a new helper to deal with the swiotlb case.  This keeps the code
nicely boundled and removes the not required call to
dma_direct_optimal_gfp_mask for the swiotlb case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Stable-dep-of: 94a04ad732c9 ("dma-direct: return struct page from dma_direct_alloc_from_pool()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/dma/direct.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 8ed15fd0abf83..0f9b9a52b274c 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -102,6 +102,18 @@ static void __dma_direct_free_pages(struct device *dev, struct page *page,
 	dma_free_contiguous(dev, page, size);
 }
 
+static struct page *dma_direct_alloc_swiotlb(struct device *dev, size_t size)
+{
+	struct page *page = swiotlb_alloc(dev, size);
+
+	if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
+		swiotlb_free(dev, page, size);
+		return NULL;
+	}
+
+	return page;
+}
+
 static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
 		gfp_t gfp, bool allow_highmem)
 {
@@ -111,17 +123,11 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
 
 	WARN_ON_ONCE(!PAGE_ALIGNED(size));
 
+	if (is_swiotlb_for_alloc(dev))
+		return dma_direct_alloc_swiotlb(dev, size);
+
 	gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
 					   &phys_limit);
-	if (is_swiotlb_for_alloc(dev)) {
-		page = swiotlb_alloc(dev, size);
-		if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
-			__dma_direct_free_pages(dev, page, size);
-			return NULL;
-		}
-		return page;
-	}
-
 	page = dma_alloc_contiguous(dev, size, gfp);
 	if (page) {
 		if (!dma_coherent_ok(dev, page_to_phys(page), size) ||
-- 
2.53.0