diff --git a/include/drm/drm_pagemap.h b/include/drm/drm_pagemap.h new file mode 100644 index 0000000000000000000000000000000000000000..202c157ff4d77c5cb4e7fb636f133e088a5dd168 --- /dev/null +++ b/include/drm/drm_pagemap.h @@ -0,0 +1,107 @@ +/* SPDX-License-Identifier: MIT */ +#ifndef _DRM_PAGEMAP_H_ +#define _DRM_PAGEMAP_H_ + +#include <linux/dma-direction.h> +#include <linux/hmm.h> +#include <linux/types.h> + +struct drm_pagemap; +struct device; + +/** + * enum drm_interconnect_protocol - Used to identify an interconnect protocol. + * + * @DRM_INTERCONNECT_SYSTEM: DMA map is system pages + * @DRM_INTERCONNECT_DRIVER: DMA map is driver defined + */ +enum drm_interconnect_protocol { + DRM_INTERCONNECT_SYSTEM, + DRM_INTERCONNECT_DRIVER, + /* A driver can add private values beyond DRM_INTERCONNECT_DRIVER */ +}; + +/** + * struct drm_pagemap_device_addr - Device address representation. + * @addr: The dma address or driver-defined address for driver private interconnects. + * @proto: The interconnect protocol. + * @order: The page order of the device mapping. (Size is PAGE_SIZE << order). + * @dir: The DMA direction. + * + * Note: There is room for improvement here. We should be able to pack into + * 64 bits. + */ +struct drm_pagemap_device_addr { + dma_addr_t addr; + u64 proto : 54; + u64 order : 8; + u64 dir : 2; +}; + +/** + * drm_pagemap_device_addr_encode() - Encode a dma address with metadata + * @addr: The dma address or driver-defined address for driver private interconnects. + * @proto: The interconnect protocol. + * @order: The page order of the dma mapping. (Size is PAGE_SIZE << order). + * @dir: The DMA direction. + * + * Return: A struct drm_pagemap_device_addr encoding the above information. + */ +static inline struct drm_pagemap_device_addr +drm_pagemap_device_addr_encode(dma_addr_t addr, + enum drm_interconnect_protocol proto, + unsigned int order, + enum dma_data_direction dir) +{ + return (struct drm_pagemap_device_addr) { + .addr = addr, + .proto = proto, + .order = order, + .dir = dir, + }; +} + +/** + * struct drm_pagemap_ops: Ops for a drm-pagemap. + */ +struct drm_pagemap_ops { + /** + * @device_map: Map for device access or provide a virtual address suitable for + * + * @dpagemap: The struct drm_pagemap for the page. + * @dev: The device mapper. + * @page: The page to map. + * @order: The page order of the device mapping. (Size is PAGE_SIZE << order). + * @dir: The transfer direction. + */ + struct drm_pagemap_device_addr (*device_map)(struct drm_pagemap *dpagemap, + struct device *dev, + struct page *page, + unsigned int order, + enum dma_data_direction dir); + + /** + * @device_unmap: Unmap a device address previously obtained using @device_map. + * + * @dpagemap: The struct drm_pagemap for the mapping. + * @dev: The device unmapper. + * @addr: The device address obtained when mapping. + */ + void (*device_unmap)(struct drm_pagemap *dpagemap, + struct device *dev, + struct drm_pagemap_device_addr addr); + +}; + +/** + * struct drm_pagemap: Additional information for a struct dev_pagemap + * used for device p2p handshaking. + * @ops: The struct drm_pagemap_ops. + * @dev: The struct drevice owning the device-private memory. + */ +struct drm_pagemap { + const struct drm_pagemap_ops *ops; + struct device *dev; +}; + +#endif