From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753859Ab1KDVgI (ORCPT ); Fri, 4 Nov 2011 17:36:08 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:38109 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752954Ab1KDVgG (ORCPT ); Fri, 4 Nov 2011 17:36:06 -0400 From: Stephen Warren To: Russell King Cc: Jon Medhurst , Nicolas Pitre , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sumit Bhattacharya , Stephen Warren Subject: [PATCH] arm: dma: Drop GFP_COMP for DMA memory allocations Date: Fri, 4 Nov 2011 15:35:39 -0600 Message-Id: <1320442539-7753-1-git-send-email-swarren@nvidia.com> X-Mailer: git-send-email 1.7.0.4 X-NVConfidentiality: public Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sumit Bhattacharya dma_alloc_coherent wants to split pages after allocation in order to reduce the memory footprint. This does not work well with GFP_COMP pages, so drop this flag before allocation. This patch is ported from arch/avr32 (commit 3611553ef985ef7c5863c8a94641738addd04cff). Signed-off-by: Sumit Bhattacharya Tested-by: Varun Colbert [swarren: s/HUGETLB_PAGE/HUGETLBFS/ in comment, minor comment cleanup] Signed-off-by: Stephen Warren --- arch/arm/mm/dma-mapping.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index e4e7f6c..68d64b4 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -332,6 +332,15 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, struct page *page; void *addr; + /* + * Following is a work-around (a.k.a. hack) to prevent pages + * with __GFP_COMP being passed to split_page() which cannot + * handle them. The real problem is that this flag probably + * should be 0 on ARM as it is not supported on this + * platform; see CONFIG_HUGETLBFS. + */ + gfp &= ~(__GFP_COMP); + *handle = ~0; size = PAGE_ALIGN(size); -- 1.7.0.4