1 | /* SPDX-License-Identifier: GPL-2.0 OR MIT */ |
2 | |
3 | /* |
4 | * Xen para-virtual DRM device |
5 | * |
6 | * Copyright (C) 2016-2018 EPAM Systems Inc. |
7 | * |
8 | * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
9 | */ |
10 | |
11 | #ifndef __XEN_DRM_FRONT_H_ |
12 | #define __XEN_DRM_FRONT_H_ |
13 | |
14 | #include <linux/scatterlist.h> |
15 | |
16 | #include <drm/drm_connector.h> |
17 | #include <drm/drm_simple_kms_helper.h> |
18 | |
19 | #include "xen_drm_front_cfg.h" |
20 | |
21 | struct drm_device; |
22 | struct drm_framebuffer; |
23 | struct drm_gem_object; |
24 | struct drm_pending_vblank_event; |
25 | |
26 | /** |
27 | * DOC: Driver modes of operation in terms of display buffers used |
28 | * |
29 | * Depending on the requirements for the para-virtualized environment, namely |
30 | * requirements dictated by the accompanying DRM/(v)GPU drivers running in both |
31 | * host and guest environments, display buffers can be allocated by either |
32 | * frontend driver or backend. |
33 | */ |
34 | |
35 | /** |
36 | * DOC: Buffers allocated by the frontend driver |
37 | * |
38 | * In this mode of operation driver allocates buffers from system memory. |
39 | * |
40 | * Note! If used with accompanying DRM/(v)GPU drivers this mode of operation |
41 | * may require IOMMU support on the platform, so accompanying DRM/vGPU |
42 | * hardware can still reach display buffer memory while importing PRIME |
43 | * buffers from the frontend driver. |
44 | */ |
45 | |
46 | /** |
47 | * DOC: Buffers allocated by the backend |
48 | * |
49 | * This mode of operation is run-time configured via guest domain configuration |
50 | * through XenStore entries. |
51 | * |
52 | * For systems which do not provide IOMMU support, but having specific |
53 | * requirements for display buffers it is possible to allocate such buffers |
54 | * at backend side and share those with the frontend. |
55 | * For example, if host domain is 1:1 mapped and has DRM/GPU hardware expecting |
56 | * physically contiguous memory, this allows implementing zero-copying |
57 | * use-cases. |
58 | * |
59 | * Note, while using this scenario the following should be considered: |
60 | * |
61 | * #. If guest domain dies then pages/grants received from the backend |
62 | * cannot be claimed back |
63 | * |
64 | * #. Misbehaving guest may send too many requests to the |
65 | * backend exhausting its grant references and memory |
66 | * (consider this from security POV) |
67 | */ |
68 | |
69 | /** |
70 | * DOC: Driver limitations |
71 | * |
72 | * #. Only primary plane without additional properties is supported. |
73 | * |
74 | * #. Only one video mode per connector supported which is configured |
75 | * via XenStore. |
76 | * |
77 | * #. All CRTCs operate at fixed frequency of 60Hz. |
78 | */ |
79 | |
80 | /* timeout in ms to wait for backend to respond */ |
81 | #define XEN_DRM_FRONT_WAIT_BACK_MS 3000 |
82 | |
83 | struct xen_drm_front_info { |
84 | struct xenbus_device *xb_dev; |
85 | struct xen_drm_front_drm_info *drm_info; |
86 | |
87 | /* to protect data between backend IO code and interrupt handler */ |
88 | spinlock_t io_lock; |
89 | |
90 | int num_evt_pairs; |
91 | struct xen_drm_front_evtchnl_pair *evt_pairs; |
92 | struct xen_drm_front_cfg cfg; |
93 | |
94 | /* display buffers */ |
95 | struct list_head dbuf_list; |
96 | }; |
97 | |
98 | struct xen_drm_front_drm_pipeline { |
99 | struct xen_drm_front_drm_info *drm_info; |
100 | |
101 | int index; |
102 | |
103 | struct drm_simple_display_pipe pipe; |
104 | |
105 | struct drm_connector conn; |
106 | /* These are only for connector mode checking */ |
107 | int width, height; |
108 | |
109 | struct drm_pending_vblank_event *pending_event; |
110 | |
111 | struct delayed_work pflip_to_worker; |
112 | |
113 | bool conn_connected; |
114 | }; |
115 | |
116 | struct xen_drm_front_drm_info { |
117 | struct xen_drm_front_info *front_info; |
118 | struct drm_device *drm_dev; |
119 | |
120 | struct xen_drm_front_drm_pipeline pipeline[XEN_DRM_FRONT_MAX_CRTCS]; |
121 | }; |
122 | |
123 | static inline u64 xen_drm_front_fb_to_cookie(struct drm_framebuffer *fb) |
124 | { |
125 | return (uintptr_t)fb; |
126 | } |
127 | |
128 | static inline u64 xen_drm_front_dbuf_to_cookie(struct drm_gem_object *gem_obj) |
129 | { |
130 | return (uintptr_t)gem_obj; |
131 | } |
132 | |
133 | int xen_drm_front_mode_set(struct xen_drm_front_drm_pipeline *pipeline, |
134 | u32 x, u32 y, u32 width, u32 height, |
135 | u32 bpp, u64 fb_cookie); |
136 | |
137 | int xen_drm_front_dbuf_create(struct xen_drm_front_info *front_info, |
138 | u64 dbuf_cookie, u32 width, u32 height, |
139 | u32 bpp, u64 size, u32 offset, struct page **pages); |
140 | |
141 | int xen_drm_front_fb_attach(struct xen_drm_front_info *front_info, |
142 | u64 dbuf_cookie, u64 fb_cookie, u32 width, |
143 | u32 height, u32 pixel_format); |
144 | |
145 | int xen_drm_front_fb_detach(struct xen_drm_front_info *front_info, |
146 | u64 fb_cookie); |
147 | |
148 | int xen_drm_front_page_flip(struct xen_drm_front_info *front_info, |
149 | int conn_idx, u64 fb_cookie); |
150 | |
151 | void xen_drm_front_on_frame_done(struct xen_drm_front_info *front_info, |
152 | int conn_idx, u64 fb_cookie); |
153 | |
154 | void xen_drm_front_gem_object_free(struct drm_gem_object *obj); |
155 | |
156 | #endif /* __XEN_DRM_FRONT_H_ */ |
157 | |