From mboxrd@z Thu Jan 1 00:00:00 1970 From: m.szyprowski@samsung.com (Marek Szyprowski) Date: Tue, 16 Sep 2014 13:54:28 +0200 Subject: [PATCH v2 01/18] arm: dma-mapping: arm_iommu_attach_device: automatically set max_seg_size In-Reply-To: <1410868485-4143-1-git-send-email-m.szyprowski@samsung.com> References: <1410868485-4143-1-git-send-email-m.szyprowski@samsung.com> Message-ID: <1410868485-4143-2-git-send-email-m.szyprowski@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org If device has no max_seg_size set, we assume that there is no limit and force it to DMA_BIT_MASK(32) to always use contiguous mappings in DMA address space. Signed-off-by: Marek Szyprowski --- arch/arm/mm/dma-mapping.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index bcd5f836f27e..84705e24571b 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2050,6 +2050,22 @@ int arm_iommu_attach_device(struct device *dev, { int err; + /* + * if device has no max_seg_size set, we assume that there is no limit + * and force it to DMA_BIT_MASK(32) to always use contiguous mappings + * in DMA address space + */ + if (!dev->dma_parms) { + dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL); + if (!dev->dma_parms) + return -ENOMEM; + } + if (!dev->dma_parms->max_segment_size) { + err = dma_set_max_seg_size(dev, DMA_BIT_MASK(32)); + if (err) + return err; + } + err = iommu_attach_device(mapping->domain, dev); if (err) return err; -- 1.9.2