From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hqemgate14.nvidia.com ([216.228.121.143]:7931 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751785AbbIORMB (ORCPT ); Tue, 15 Sep 2015 13:12:01 -0400 From: Will Davis To: Bjorn Helgaas CC: Alex Williamson , Joerg Roedel , , , Konrad Wilk , Mark Hounschell , "David S. Miller" , Jonathan Corbet , Terence Ripperda , John Hubbard , Jerome Glisse , Will Davis Subject: [PATCH 17/22] iommu/vt-d: implement (un)map_peer_resource Date: Tue, 15 Sep 2015 12:11:02 -0500 Message-ID: <1442337067-22964-18-git-send-email-wdavis@nvidia.com> In-Reply-To: <1442337067-22964-1-git-send-email-wdavis@nvidia.com> References: <1442337067-22964-1-git-send-email-wdavis@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-pci-owner@vger.kernel.org List-ID: Implement 'map_peer_resource' for the Intel IOMMU driver. Simply translate the resource to a physical address and route it to the same handlers used by the 'map_page' API. This allows a device to map another's resource, to enable peer-to-peer transactions. Add behind CONFIG_HAS_DMA_P2P guards, since the dma_map_ops members are behind them as well. Signed-off-by: Will Davis Reviewed-by: Terence Ripperda Reviewed-by: John Hubbard --- drivers/iommu/intel-iommu.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index a98a7b2..0d3746f 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3544,6 +3544,40 @@ static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr, intel_unmap(dev, dev_addr); } +#ifdef CONFIG_HAS_DMA_P2P +static dma_peer_addr_t intel_map_peer_resource(struct device *dev, + struct device *peer, + struct resource *res, + unsigned long offset, + size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct pci_dev *pdev; + struct pci_dev *ppeer; + + if (!dev_is_pci(dev) || !dev_is_pci(peer)) + return 0; + + pdev = to_pci_dev(dev); + ppeer = to_pci_dev(peer); + + if (!pci_peer_traffic_supported(pdev, ppeer)) + return 0; + + return __intel_map_single(dev, res->start + offset, size, + dir, *dev->dma_mask); +} + +static void intel_unmap_peer_resource(struct device *dev, + dma_peer_addr_t dev_addr, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + intel_unmap(dev, dev_addr); +} +#endif + static void *intel_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flags, struct dma_attrs *attrs) @@ -3700,6 +3734,10 @@ struct dma_map_ops intel_dma_ops = { .unmap_sg = intel_unmap_sg, .map_page = intel_map_page, .unmap_page = intel_unmap_page, +#ifdef CONFIG_HAS_DMA_P2P + .map_peer_resource = intel_map_peer_resource, + .unmap_peer_resource = intel_unmap_peer_resource, +#endif .mapping_error = intel_mapping_error, }; -- 2.5.1