Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752239AbdGDN4E (ORCPT ); Tue, 4 Jul 2017 09:56:04 -0400 Received: from mail-pf0-f173.google.com ([209.85.192.173]:36595 "EHLO mail-pf0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750872AbdGDN4D (ORCPT ); Tue, 4 Jul 2017 09:56:03 -0400 From: Tomasz Figa To: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, Joerg Roedel , Robin Murphy , Tomasz Figa Subject: [PATCH v2 1/2] iommu/dma: Respect __GFP_DMA and __GFP_DMA32 in incoming GFP flags Date: Tue, 4 Jul 2017 22:55:55 +0900 Message-Id: <20170704135556.21704-1-tfiga@chromium.org> X-Mailer: git-send-email 2.13.2.725.g09c95d1e9-goog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1365 Lines: 40 Current implementation of __iommu_dma_alloc_pages() keeps adding __GFP_HIGHMEM to GFP flags regardless of whether other zone flags are already included in the incoming flags. If __GFP_DMA or __GFP_DMA32 is set at the same time as __GFP_HIGHMEM, the allocation fails due to invalid zone flag combination. Fix this by checking for __GFP_DMA and __GFP_DMA32 in incoming GFP flags and adding __GFP_HIGHMEM only if they are not present. Signed-off-by: Tomasz Figa --- drivers/iommu/dma-iommu.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) Changes from v1: - Update the comment as per Robin's suggestion. diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 9d1cebe7f6cb..bf23989b5158 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -445,8 +445,14 @@ static struct page **__iommu_dma_alloc_pages(unsigned int count, if (!pages) return NULL; - /* IOMMU can map any pages, so himem can also be used here */ - gfp |= __GFP_NOWARN | __GFP_HIGHMEM; + /* + * Unless we have some addressing limitation implied by GFP_DMA flags, + * assume the IOMMU can map all of RAM and we can allocate anywhere. + */ + if (!(gfp & (__GFP_DMA | __GFP_DMA32))) + gfp |= __GFP_HIGHMEM; + + gfp |= __GFP_NOWARN; while (count) { struct page *page = NULL; -- 2.13.2.725.g09c95d1e9-goog