1 /* SPDX-License-Identifier: MIT */ 2 #ifndef _DRM_PAGEMAP_H_ 3 #define _DRM_PAGEMAP_H_ 4 5 #include <linux/dma-direction.h> 6 #include <linux/hmm.h> 7 #include <linux/types.h> 8 9 struct drm_pagemap; 10 struct drm_pagemap_zdd; 11 struct device; 12 13 /** 14 * enum drm_interconnect_protocol - Used to identify an interconnect protocol. 15 * 16 * @DRM_INTERCONNECT_SYSTEM: DMA map is system pages 17 * @DRM_INTERCONNECT_DRIVER: DMA map is driver defined 18 */ 19 enum drm_interconnect_protocol { 20 DRM_INTERCONNECT_SYSTEM, 21 DRM_INTERCONNECT_DRIVER, 22 /* A driver can add private values beyond DRM_INTERCONNECT_DRIVER */ 23 }; 24 25 /** 26 * struct drm_pagemap_device_addr - Device address representation. 27 * @addr: The dma address or driver-defined address for driver private interconnects. 28 * @proto: The interconnect protocol. 29 * @order: The page order of the device mapping. (Size is PAGE_SIZE << order). 30 * @dir: The DMA direction. 31 * 32 * Note: There is room for improvement here. We should be able to pack into 33 * 64 bits. 34 */ 35 struct drm_pagemap_device_addr { 36 dma_addr_t addr; 37 u64 proto : 54; 38 u64 order : 8; 39 u64 dir : 2; 40 }; 41 42 /** 43 * drm_pagemap_device_addr_encode() - Encode a dma address with metadata 44 * @addr: The dma address or driver-defined address for driver private interconnects. 45 * @proto: The interconnect protocol. 46 * @order: The page order of the dma mapping. (Size is PAGE_SIZE << order). 47 * @dir: The DMA direction. 48 * 49 * Return: A struct drm_pagemap_device_addr encoding the above information. 50 */ 51 static inline struct drm_pagemap_device_addr 52 drm_pagemap_device_addr_encode(dma_addr_t addr, 53 enum drm_interconnect_protocol proto, 54 unsigned int order, 55 enum dma_data_direction dir) 56 { 57 return (struct drm_pagemap_device_addr) { 58 .addr = addr, 59 .proto = proto, 60 .order = order, 61 .dir = dir, 62 }; 63 } 64 65 /** 66 * struct drm_pagemap_ops: Ops for a drm-pagemap. 67 */ 68 struct drm_pagemap_ops { 69 /** 70 * @device_map: Map for device access or provide a virtual address suitable for 71 * 72 * @dpagemap: The struct drm_pagemap for the page. 73 * @dev: The device mapper. 74 * @page: The page to map. 75 * @order: The page order of the device mapping. (Size is PAGE_SIZE << order). 76 * @dir: The transfer direction. 77 */ 78 struct drm_pagemap_device_addr (*device_map)(struct drm_pagemap *dpagemap, 79 struct device *dev, 80 struct page *page, 81 unsigned int order, 82 enum dma_data_direction dir); 83 84 /** 85 * @device_unmap: Unmap a device address previously obtained using @device_map. 86 * 87 * @dpagemap: The struct drm_pagemap for the mapping. 88 * @dev: The device unmapper. 89 * @addr: The device address obtained when mapping. 90 */ 91 void (*device_unmap)(struct drm_pagemap *dpagemap, 92 struct device *dev, 93 struct drm_pagemap_device_addr addr); 94 95 }; 96 97 /** 98 * struct drm_pagemap: Additional information for a struct dev_pagemap 99 * used for device p2p handshaking. 100 * @ops: The struct drm_pagemap_ops. 101 * @dev: The struct drevice owning the device-private memory. 102 */ 103 struct drm_pagemap { 104 const struct drm_pagemap_ops *ops; 105 struct device *dev; 106 }; 107 108 struct drm_pagemap_devmem; 109 110 /** 111 * struct drm_pagemap_devmem_ops - Operations structure for GPU SVM device memory 112 * 113 * This structure defines the operations for GPU Shared Virtual Memory (SVM) 114 * device memory. These operations are provided by the GPU driver to manage device memory 115 * allocations and perform operations such as migration between device memory and system 116 * RAM. 117 */ 118 struct drm_pagemap_devmem_ops { 119 /** 120 * @devmem_release: Release device memory allocation (optional) 121 * @devmem_allocation: device memory allocation 122 * 123 * Release device memory allocation and drop a reference to device 124 * memory allocation. 125 */ 126 void (*devmem_release)(struct drm_pagemap_devmem *devmem_allocation); 127 128 /** 129 * @populate_devmem_pfn: Populate device memory PFN (required for migration) 130 * @devmem_allocation: device memory allocation 131 * @npages: Number of pages to populate 132 * @pfn: Array of page frame numbers to populate 133 * 134 * Populate device memory page frame numbers (PFN). 135 * 136 * Return: 0 on success, a negative error code on failure. 137 */ 138 int (*populate_devmem_pfn)(struct drm_pagemap_devmem *devmem_allocation, 139 unsigned long npages, unsigned long *pfn); 140 141 /** 142 * @copy_to_devmem: Copy to device memory (required for migration) 143 * @pages: Pointer to array of device memory pages (destination) 144 * @dma_addr: Pointer to array of DMA addresses (source) 145 * @npages: Number of pages to copy 146 * 147 * Copy pages to device memory. 148 * 149 * Return: 0 on success, a negative error code on failure. 150 */ 151 int (*copy_to_devmem)(struct page **pages, 152 dma_addr_t *dma_addr, 153 unsigned long npages); 154 155 /** 156 * @copy_to_ram: Copy to system RAM (required for migration) 157 * @pages: Pointer to array of device memory pages (source) 158 * @dma_addr: Pointer to array of DMA addresses (destination) 159 * @npages: Number of pages to copy 160 * 161 * Copy pages to system RAM. 162 * 163 * Return: 0 on success, a negative error code on failure. 164 */ 165 int (*copy_to_ram)(struct page **pages, 166 dma_addr_t *dma_addr, 167 unsigned long npages); 168 }; 169 170 /** 171 * struct drm_pagemap_devmem - Structure representing a GPU SVM device memory allocation 172 * 173 * @dev: Pointer to the device structure which device memory allocation belongs to 174 * @mm: Pointer to the mm_struct for the address space 175 * @detached: device memory allocations is detached from device pages 176 * @ops: Pointer to the operations structure for GPU SVM device memory 177 * @dpagemap: The struct drm_pagemap of the pages this allocation belongs to. 178 * @size: Size of device memory allocation 179 * @timeslice_expiration: Timeslice expiration in jiffies 180 */ 181 struct drm_pagemap_devmem { 182 struct device *dev; 183 struct mm_struct *mm; 184 struct completion detached; 185 const struct drm_pagemap_devmem_ops *ops; 186 struct drm_pagemap *dpagemap; 187 size_t size; 188 u64 timeslice_expiration; 189 }; 190 191 int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation, 192 struct mm_struct *mm, 193 unsigned long start, unsigned long end, 194 unsigned long timeslice_ms, 195 void *pgmap_owner); 196 197 int drm_pagemap_evict_to_ram(struct drm_pagemap_devmem *devmem_allocation); 198 199 const struct dev_pagemap_ops *drm_pagemap_pagemap_ops_get(void); 200 201 struct drm_pagemap *drm_pagemap_page_to_dpagemap(struct page *page); 202 203 void drm_pagemap_devmem_init(struct drm_pagemap_devmem *devmem_allocation, 204 struct device *dev, struct mm_struct *mm, 205 const struct drm_pagemap_devmem_ops *ops, 206 struct drm_pagemap *dpagemap, size_t size); 207 208 #endif 209