tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
9struct drm_pagemap;
10struct device;
11
12/**
13 * enum drm_interconnect_protocol - Used to identify an interconnect protocol.
14 *
15 * @DRM_INTERCONNECT_SYSTEM: DMA map is system pages
16 * @DRM_INTERCONNECT_DRIVER: DMA map is driver defined
17 */
18enum drm_interconnect_protocol {
19 DRM_INTERCONNECT_SYSTEM,
20 DRM_INTERCONNECT_DRIVER,
21 /* A driver can add private values beyond DRM_INTERCONNECT_DRIVER */
22};
23
24/**
25 * struct drm_pagemap_device_addr - Device address representation.
26 * @addr: The dma address or driver-defined address for driver private interconnects.
27 * @proto: The interconnect protocol.
28 * @order: The page order of the device mapping. (Size is PAGE_SIZE << order).
29 * @dir: The DMA direction.
30 *
31 * Note: There is room for improvement here. We should be able to pack into
32 * 64 bits.
33 */
34struct drm_pagemap_device_addr {
35 dma_addr_t addr;
36 u64 proto : 54;
37 u64 order : 8;
38 u64 dir : 2;
39};
40
41/**
42 * drm_pagemap_device_addr_encode() - Encode a dma address with metadata
43 * @addr: The dma address or driver-defined address for driver private interconnects.
44 * @proto: The interconnect protocol.
45 * @order: The page order of the dma mapping. (Size is PAGE_SIZE << order).
46 * @dir: The DMA direction.
47 *
48 * Return: A struct drm_pagemap_device_addr encoding the above information.
49 */
50static inline struct drm_pagemap_device_addr
51drm_pagemap_device_addr_encode(dma_addr_t addr,
52 enum drm_interconnect_protocol proto,
53 unsigned int order,
54 enum dma_data_direction dir)
55{
56 return (struct drm_pagemap_device_addr) {
57 .addr = addr,
58 .proto = proto,
59 .order = order,
60 .dir = dir,
61 };
62}
63
64/**
65 * struct drm_pagemap_ops: Ops for a drm-pagemap.
66 */
67struct drm_pagemap_ops {
68 /**
69 * @device_map: Map for device access or provide a virtual address suitable for
70 *
71 * @dpagemap: The struct drm_pagemap for the page.
72 * @dev: The device mapper.
73 * @page: The page to map.
74 * @order: The page order of the device mapping. (Size is PAGE_SIZE << order).
75 * @dir: The transfer direction.
76 */
77 struct drm_pagemap_device_addr (*device_map)(struct drm_pagemap *dpagemap,
78 struct device *dev,
79 struct page *page,
80 unsigned int order,
81 enum dma_data_direction dir);
82
83 /**
84 * @device_unmap: Unmap a device address previously obtained using @device_map.
85 *
86 * @dpagemap: The struct drm_pagemap for the mapping.
87 * @dev: The device unmapper.
88 * @addr: The device address obtained when mapping.
89 */
90 void (*device_unmap)(struct drm_pagemap *dpagemap,
91 struct device *dev,
92 struct drm_pagemap_device_addr addr);
93
94};
95
96/**
97 * struct drm_pagemap: Additional information for a struct dev_pagemap
98 * used for device p2p handshaking.
99 * @ops: The struct drm_pagemap_ops.
100 * @dev: The struct drevice owning the device-private memory.
101 */
102struct drm_pagemap {
103 const struct drm_pagemap_ops *ops;
104 struct device *dev;
105};
106
107#endif