From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= Subject: [PATCHv7 3/6] dma-mapping: add dma_{map,unmap}_resource Date: Wed, 1 Jun 2016 17:22:26 +0200 Message-ID: <1464794549-6601-4-git-send-email-niklas.soderlund+renesas@ragnatech.se> References: <1464794549-6601-1-git-send-email-niklas.soderlund+renesas@ragnatech.se> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1464794549-6601-1-git-send-email-niklas.soderlund+renesas@ragnatech.se> Sender: linux-renesas-soc-owner@vger.kernel.org To: hch@infradead.org, linux-renesas-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org, iommu@lists.linux-foundation.org Cc: dan.j.williams@intel.com, vinod.koul@intel.com, robin.murphy@arm.com, laurent.pinchart@ideasonboard.com, linus.walleij@linaro.org, arnd@arndb.de, =?UTF-8?q?Niklas=20S=C3=B6derlund?= List-Id: iommu@lists.linux-foundation.org Map/Unmap a device MMIO resource from a physical address. If no dma_map= _ops method is available the operation is a no-op. Signed-off-by: Niklas S=C3=B6derlund --- Documentation/DMA-API.txt | 22 +++++++++++++++++----- include/linux/dma-mapping.h | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+), 5 deletions(-) diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 45ef3f2..c7e5f99 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -277,14 +277,26 @@ and parameters are provided to do partial = page mapping, it is recommended that you never use these unless you really know what the cache width is. =20 +dma_addr_t +dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t siz= e, + enum dma_data_direction dir, struct dma_attrs *attrs) + +void +dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, + enum dma_data_direction dir, struct dma_attrs *attrs) + +API for mapping and unmapping for MMIO resources. All the notes and +warnings for the other mapping APIs apply here. The API should only be +used to map device MMIO resources, mapping of RAM is not permitted. + int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) =20 -In some circumstances dma_map_single() and dma_map_page() will fail to= create -a mapping. A driver can check for these errors by testing the returned -DMA address with dma_mapping_error(). A non-zero return value means th= e mapping -could not be created and the driver should take appropriate action (e.= g. -reduce current DMA mapping usage or delay and try again later). +In some circumstances dma_map_single(), dma_map_page() and dma_map_res= ource() +will fail to create a mapping. A driver can check for these errors by = testing +the returned DMA address with dma_mapping_error(). A non-zero return v= alue +means the mapping could not be created and the driver should take appr= opriate +action (e.g. reduce current DMA mapping usage or delay and try again l= ater). =20 int dma_map_sg(struct device *dev, struct scatterlist *sg, diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index a11ff9d..4c381ba 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -218,6 +218,42 @@ static inline void dma_unmap_page(struct device *d= ev, dma_addr_t addr, debug_dma_unmap_page(dev, addr, size, dir, false); } =20 +static inline dma_addr_t dma_map_resource(struct device *dev, + phys_addr_t phys_addr, + size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct dma_map_ops *ops =3D get_dma_ops(dev); + unsigned long pfn =3D __phys_to_pfn(phys_addr); + dma_addr_t addr; + + BUG_ON(!valid_dma_direction(dir)); + + /* Don't allow RAM to be mapped */ + BUG_ON(pfn_valid(pfn)); + + addr =3D phys_addr; + if (ops->map_resource) + addr =3D ops->map_resource(dev, phys_addr, size, dir, attrs); + + debug_dma_map_resource(dev, phys_addr, size, dir, addr); + + return addr; +} + +static inline void dma_unmap_resource(struct device *dev, dma_addr_t a= ddr, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct dma_map_ops *ops =3D get_dma_ops(dev); + + BUG_ON(!valid_dma_direction(dir)); + if (ops->unmap_resource) + ops->unmap_resource(dev, addr, size, dir, attrs); + debug_dma_unmap_resource(dev, addr, size, dir); +} + static inline void dma_sync_single_for_cpu(struct device *dev, dma_add= r_t addr, size_t size, enum dma_data_direction dir) --=20 2.8.2