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Commit 232a71e1 authored by Prakash Gupta's avatar Prakash Gupta Committed by Gerrit - the friendly Code Review server
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arm64: dma-mapping: alloc page order based on domain pgsize 



Restrict higher-order allocation to pgsize preferce per domain and avoid
wasting any time or effort on other sizes which offer no benefit.

Change-Id: Ic0a7843917e7c6e2959e7b566c20fec6a96670f3
Signed-off-by: default avatarPrakash Gupta <guptap@codeaurora.org>
parent 38177a28

arch/arm64/mm/dma-mapping.c

+13 −2
Original line number Diff line number Diff line
@@ -1256,6 +1256,9 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, 
	size_t array_size = count * sizeof(struct page *);

	int i = 0;

	bool is_coherent = is_dma_coherent(dev, attrs);

	struct dma_iommu_mapping *mapping = dev->archdata.mapping;

	unsigned int alloc_sizes = mapping->domain->pgsize_bitmap;

	unsigned long order_mask;



	if (array_size <= PAGE_SIZE)

		pages = kzalloc(array_size, gfp);
@@ -1284,14 +1287,22 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, 
	 * IOMMU can map any pages, so himem can also be used here

	 */

	gfp |= __GFP_NOWARN | __GFP_HIGHMEM;

	order_mask = alloc_sizes >> PAGE_SHIFT;

	order_mask &= (2U << MAX_ORDER) - 1;

	if (!order_mask)

		goto error;



	while (count) {

		int j, order = __fls(count);

		int j, order;



		order_mask &= (2U << __fls(count)) - 1;

		order = __fls(order_mask);



		pages[i] = alloc_pages(order ? (gfp | __GFP_NORETRY) &

					~__GFP_RECLAIM : gfp, order);

		while (!pages[i] && order) {

			order--;

			order_mask &= ~(1U << order);

			order = __fls(order_mask);

			pages[i] = alloc_pages(order ? (gfp | __GFP_NORETRY) &

					~__GFP_RECLAIM : gfp, order);

		}