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alistair23-linux/arch/arm/include/asm/device.h

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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Arch specific extensions to struct device
*/
#ifndef ASMARM_DEVICE_H
#define ASMARM_DEVICE_H
struct dev_archdata {
#ifdef CONFIG_DMABOUNCE
struct dmabounce_device_info *dmabounce;
#endif
#ifdef CONFIG_IOMMU_API
void *iommu; /* private IOMMU data */
#endif
ARM: dma-mapping: add support for IOMMU mapper This patch add a complete implementation of DMA-mapping API for devices which have IOMMU support. This implementation tries to optimize dma address space usage by remapping all possible physical memory chunks into a single dma address space chunk. DMA address space is managed on top of the bitmap stored in the dma_iommu_mapping structure stored in device->archdata. Platform setup code has to initialize parameters of the dma address space (base address, size, allocation precision order) with arm_iommu_create_mapping() function. To reduce the size of the bitmap, all allocations are aligned to the specified order of base 4 KiB pages. dma_alloc_* functions allocate physical memory in chunks, each with alloc_pages() function to avoid failing if the physical memory gets fragmented. In worst case the allocated buffer is composed of 4 KiB page chunks. dma_map_sg() function minimizes the total number of dma address space chunks by merging of physical memory chunks into one larger dma address space chunk. If requested chunk (scatter list entry) boundaries match physical page boundaries, most calls to dma_map_sg() requests will result in creating only one chunk in dma address space. dma_map_page() simply creates a mapping for the given page(s) in the dma address space. All dma functions also perform required cache operation like their counterparts from the arm linear physical memory mapping version. This patch contains code and fixes kindly provided by: - Krishna Reddy <vdumpa@nvidia.com>, - Andrzej Pietrasiewicz <andrzej.p@samsung.com>, - Hiroshi DOYU <hdoyu@nvidia.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Tested-By: Subash Patel <subash.ramaswamy@linaro.org>
2012-05-16 07:48:21 -06:00
#ifdef CONFIG_ARM_DMA_USE_IOMMU
struct dma_iommu_mapping *mapping;
#endif
#ifdef CONFIG_XEN
const struct dma_map_ops *dev_dma_ops;
ARM: dma-mapping: add support for IOMMU mapper This patch add a complete implementation of DMA-mapping API for devices which have IOMMU support. This implementation tries to optimize dma address space usage by remapping all possible physical memory chunks into a single dma address space chunk. DMA address space is managed on top of the bitmap stored in the dma_iommu_mapping structure stored in device->archdata. Platform setup code has to initialize parameters of the dma address space (base address, size, allocation precision order) with arm_iommu_create_mapping() function. To reduce the size of the bitmap, all allocations are aligned to the specified order of base 4 KiB pages. dma_alloc_* functions allocate physical memory in chunks, each with alloc_pages() function to avoid failing if the physical memory gets fragmented. In worst case the allocated buffer is composed of 4 KiB page chunks. dma_map_sg() function minimizes the total number of dma address space chunks by merging of physical memory chunks into one larger dma address space chunk. If requested chunk (scatter list entry) boundaries match physical page boundaries, most calls to dma_map_sg() requests will result in creating only one chunk in dma address space. dma_map_page() simply creates a mapping for the given page(s) in the dma address space. All dma functions also perform required cache operation like their counterparts from the arm linear physical memory mapping version. This patch contains code and fixes kindly provided by: - Krishna Reddy <vdumpa@nvidia.com>, - Andrzej Pietrasiewicz <andrzej.p@samsung.com>, - Hiroshi DOYU <hdoyu@nvidia.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Tested-By: Subash Patel <subash.ramaswamy@linaro.org>
2012-05-16 07:48:21 -06:00
#endif
ARM: dma-mapping: Don't tear down third-party mappings arch_setup_dma_ops() is used in device probe code paths to create an IOMMU mapping and attach it to the device. The function assumes that the device is attached to a device-specific IOMMU instance (or at least a device-specific TLB in a shared IOMMU instance) and thus creates a separate mapping for every device. On several systems (Renesas R-Car Gen2 being one of them), that assumption is not true, and IOMMU mappings must be shared between multiple devices. In those cases the IOMMU driver knows better than the generic ARM dma-mapping layer and attaches mapping to devices manually with arm_iommu_attach_device(), which sets the DMA ops for the device. The arch_setup_dma_ops() function takes this into account and bails out immediately if the device already has DMA ops assigned. However, the corresponding arch_teardown_dma_ops() function, called from driver unbind code paths (including probe deferral), will tear the mapping down regardless of who created it. When the device is reprobed arch_setup_dma_ops() will be called again but won't perform any operation as the DMA ops will still be set. We need to reset the DMA ops in arch_teardown_dma_ops() to fix this. However, we can't do so unconditionally, as then a new mapping would be created by arch_setup_dma_ops() when the device is reprobed, regardless of whether the device needs to share a mapping or not. We must thus keep track of whether arch_setup_dma_ops() created the mapping, and only in that case tear it down in arch_teardown_dma_ops(). Keep track of that information in the dev_archdata structure. As the structure is embedded in all instances of struct device let's not grow it, but turn the existing dma_coherent bool field into a bitfield that can be used for other purposes. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-05-27 07:47:43 -06:00
unsigned int dma_coherent:1;
unsigned int dma_ops_setup:1;
};
struct omap_device;
struct pdev_archdata {
#ifdef CONFIG_ARCH_OMAP
struct omap_device *od;
#endif
};
#ifdef CONFIG_ARM_DMA_USE_IOMMU
#define to_dma_iommu_mapping(dev) ((dev)->archdata.mapping)
#else
#define to_dma_iommu_mapping(dev) NULL
#endif
#endif