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