1 /* $NetBSD: xen_drm_front_kms.c,v 1.2 2021/12/18 23:45:45 riastradh Exp $ */ 2 3 // SPDX-License-Identifier: GPL-2.0 OR MIT 4 5 /* 6 * Xen para-virtual DRM device 7 * 8 * Copyright (C) 2016-2018 EPAM Systems Inc. 9 * 10 * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko (at) epam.com> 11 */ 12 13 #include <sys/cdefs.h> 14 __KERNEL_RCSID(0, "$NetBSD: xen_drm_front_kms.c,v 1.2 2021/12/18 23:45:45 riastradh Exp $"); 15 16 #include <drm/drm_atomic.h> 17 #include <drm/drm_atomic_helper.h> 18 #include <drm/drm_drv.h> 19 #include <drm/drm_fourcc.h> 20 #include <drm/drm_gem.h> 21 #include <drm/drm_gem_framebuffer_helper.h> 22 #include <drm/drm_probe_helper.h> 23 #include <drm/drm_vblank.h> 24 25 #include "xen_drm_front.h" 26 #include "xen_drm_front_conn.h" 27 #include "xen_drm_front_kms.h" 28 29 /* 30 * Timeout in ms to wait for frame done event from the backend: 31 * must be a bit more than IO time-out 32 */ 33 #define FRAME_DONE_TO_MS (XEN_DRM_FRONT_WAIT_BACK_MS + 100) 34 35 static struct xen_drm_front_drm_pipeline * 36 to_xen_drm_pipeline(struct drm_simple_display_pipe *pipe) 37 { 38 return container_of(pipe, struct xen_drm_front_drm_pipeline, pipe); 39 } 40 41 static void fb_destroy(struct drm_framebuffer *fb) 42 { 43 struct xen_drm_front_drm_info *drm_info = fb->dev->dev_private; 44 int idx; 45 46 if (drm_dev_enter(fb->dev, &idx)) { 47 xen_drm_front_fb_detach(drm_info->front_info, 48 xen_drm_front_fb_to_cookie(fb)); 49 drm_dev_exit(idx); 50 } 51 drm_gem_fb_destroy(fb); 52 } 53 54 static const struct drm_framebuffer_funcs fb_funcs = { 55 .destroy = fb_destroy, 56 }; 57 58 static struct drm_framebuffer * 59 fb_create(struct drm_device *dev, struct drm_file *filp, 60 const struct drm_mode_fb_cmd2 *mode_cmd) 61 { 62 struct xen_drm_front_drm_info *drm_info = dev->dev_private; 63 struct drm_framebuffer *fb; 64 struct drm_gem_object *gem_obj; 65 int ret; 66 67 fb = drm_gem_fb_create_with_funcs(dev, filp, mode_cmd, &fb_funcs); 68 if (IS_ERR_OR_NULL(fb)) 69 return fb; 70 71 gem_obj = fb->obj[0]; 72 73 ret = xen_drm_front_fb_attach(drm_info->front_info, 74 xen_drm_front_dbuf_to_cookie(gem_obj), 75 xen_drm_front_fb_to_cookie(fb), 76 fb->width, fb->height, 77 fb->format->format); 78 if (ret < 0) { 79 DRM_ERROR("Back failed to attach FB %p: %d\n", fb, ret); 80 goto fail; 81 } 82 83 return fb; 84 85 fail: 86 drm_gem_fb_destroy(fb); 87 return ERR_PTR(ret); 88 } 89 90 static const struct drm_mode_config_funcs mode_config_funcs = { 91 .fb_create = fb_create, 92 .atomic_check = drm_atomic_helper_check, 93 .atomic_commit = drm_atomic_helper_commit, 94 }; 95 96 static void send_pending_event(struct xen_drm_front_drm_pipeline *pipeline) 97 { 98 struct drm_crtc *crtc = &pipeline->pipe.crtc; 99 struct drm_device *dev = crtc->dev; 100 unsigned long flags; 101 102 spin_lock_irqsave(&dev->event_lock, flags); 103 if (pipeline->pending_event) 104 drm_crtc_send_vblank_event(crtc, pipeline->pending_event); 105 pipeline->pending_event = NULL; 106 spin_unlock_irqrestore(&dev->event_lock, flags); 107 } 108 109 static void display_enable(struct drm_simple_display_pipe *pipe, 110 struct drm_crtc_state *crtc_state, 111 struct drm_plane_state *plane_state) 112 { 113 struct xen_drm_front_drm_pipeline *pipeline = 114 to_xen_drm_pipeline(pipe); 115 struct drm_crtc *crtc = &pipe->crtc; 116 struct drm_framebuffer *fb = plane_state->fb; 117 int ret, idx; 118 119 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 120 return; 121 122 ret = xen_drm_front_mode_set(pipeline, crtc->x, crtc->y, 123 fb->width, fb->height, 124 fb->format->cpp[0] * 8, 125 xen_drm_front_fb_to_cookie(fb)); 126 127 if (ret) { 128 DRM_ERROR("Failed to enable display: %d\n", ret); 129 pipeline->conn_connected = false; 130 } 131 132 drm_dev_exit(idx); 133 } 134 135 static void display_disable(struct drm_simple_display_pipe *pipe) 136 { 137 struct xen_drm_front_drm_pipeline *pipeline = 138 to_xen_drm_pipeline(pipe); 139 int ret = 0, idx; 140 141 if (drm_dev_enter(pipe->crtc.dev, &idx)) { 142 ret = xen_drm_front_mode_set(pipeline, 0, 0, 0, 0, 0, 143 xen_drm_front_fb_to_cookie(NULL)); 144 drm_dev_exit(idx); 145 } 146 if (ret) 147 DRM_ERROR("Failed to disable display: %d\n", ret); 148 149 /* Make sure we can restart with enabled connector next time */ 150 pipeline->conn_connected = true; 151 152 /* release stalled event if any */ 153 send_pending_event(pipeline); 154 } 155 156 void xen_drm_front_kms_on_frame_done(struct xen_drm_front_drm_pipeline *pipeline, 157 u64 fb_cookie) 158 { 159 /* 160 * This runs in interrupt context, e.g. under 161 * drm_info->front_info->io_lock, so we cannot call _sync version 162 * to cancel the work 163 */ 164 cancel_delayed_work(&pipeline->pflip_to_worker); 165 166 send_pending_event(pipeline); 167 } 168 169 static void pflip_to_worker(struct work_struct *work) 170 { 171 struct delayed_work *delayed_work = to_delayed_work(work); 172 struct xen_drm_front_drm_pipeline *pipeline = 173 container_of(delayed_work, 174 struct xen_drm_front_drm_pipeline, 175 pflip_to_worker); 176 177 DRM_ERROR("Frame done timed-out, releasing"); 178 send_pending_event(pipeline); 179 } 180 181 static bool display_send_page_flip(struct drm_simple_display_pipe *pipe, 182 struct drm_plane_state *old_plane_state) 183 { 184 struct drm_plane_state *plane_state = 185 drm_atomic_get_new_plane_state(old_plane_state->state, 186 &pipe->plane); 187 188 /* 189 * If old_plane_state->fb is NULL and plane_state->fb is not, 190 * then this is an atomic commit which will enable display. 191 * If old_plane_state->fb is not NULL and plane_state->fb is, 192 * then this is an atomic commit which will disable display. 193 * Ignore these and do not send page flip as this framebuffer will be 194 * sent to the backend as a part of display_set_config call. 195 */ 196 if (old_plane_state->fb && plane_state->fb) { 197 struct xen_drm_front_drm_pipeline *pipeline = 198 to_xen_drm_pipeline(pipe); 199 struct xen_drm_front_drm_info *drm_info = pipeline->drm_info; 200 int ret; 201 202 schedule_delayed_work(&pipeline->pflip_to_worker, 203 msecs_to_jiffies(FRAME_DONE_TO_MS)); 204 205 ret = xen_drm_front_page_flip(drm_info->front_info, 206 pipeline->index, 207 xen_drm_front_fb_to_cookie(plane_state->fb)); 208 if (ret) { 209 DRM_ERROR("Failed to send page flip request to backend: %d\n", ret); 210 211 pipeline->conn_connected = false; 212 /* 213 * Report the flip not handled, so pending event is 214 * sent, unblocking user-space. 215 */ 216 return false; 217 } 218 /* 219 * Signal that page flip was handled, pending event will be sent 220 * on frame done event from the backend. 221 */ 222 return true; 223 } 224 225 return false; 226 } 227 228 static void display_update(struct drm_simple_display_pipe *pipe, 229 struct drm_plane_state *old_plane_state) 230 { 231 struct xen_drm_front_drm_pipeline *pipeline = 232 to_xen_drm_pipeline(pipe); 233 struct drm_crtc *crtc = &pipe->crtc; 234 struct drm_pending_vblank_event *event; 235 int idx; 236 237 event = crtc->state->event; 238 if (event) { 239 struct drm_device *dev = crtc->dev; 240 unsigned long flags; 241 242 WARN_ON(pipeline->pending_event); 243 244 spin_lock_irqsave(&dev->event_lock, flags); 245 crtc->state->event = NULL; 246 247 pipeline->pending_event = event; 248 spin_unlock_irqrestore(&dev->event_lock, flags); 249 } 250 251 if (!drm_dev_enter(pipe->crtc.dev, &idx)) { 252 send_pending_event(pipeline); 253 return; 254 } 255 256 /* 257 * Send page flip request to the backend *after* we have event cached 258 * above, so on page flip done event from the backend we can 259 * deliver it and there is no race condition between this code and 260 * event from the backend. 261 * If this is not a page flip, e.g. no flip done event from the backend 262 * is expected, then send now. 263 */ 264 if (!display_send_page_flip(pipe, old_plane_state)) 265 send_pending_event(pipeline); 266 267 drm_dev_exit(idx); 268 } 269 270 static enum drm_mode_status 271 display_mode_valid(struct drm_simple_display_pipe *pipe, 272 const struct drm_display_mode *mode) 273 { 274 struct xen_drm_front_drm_pipeline *pipeline = 275 container_of(pipe, struct xen_drm_front_drm_pipeline, 276 pipe); 277 278 if (mode->hdisplay != pipeline->width) 279 return MODE_ERROR; 280 281 if (mode->vdisplay != pipeline->height) 282 return MODE_ERROR; 283 284 return MODE_OK; 285 } 286 287 static const struct drm_simple_display_pipe_funcs display_funcs = { 288 .mode_valid = display_mode_valid, 289 .enable = display_enable, 290 .disable = display_disable, 291 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, 292 .update = display_update, 293 }; 294 295 static int display_pipe_init(struct xen_drm_front_drm_info *drm_info, 296 int index, struct xen_drm_front_cfg_connector *cfg, 297 struct xen_drm_front_drm_pipeline *pipeline) 298 { 299 struct drm_device *dev = drm_info->drm_dev; 300 const u32 *formats; 301 int format_count; 302 int ret; 303 304 pipeline->drm_info = drm_info; 305 pipeline->index = index; 306 pipeline->height = cfg->height; 307 pipeline->width = cfg->width; 308 309 INIT_DELAYED_WORK(&pipeline->pflip_to_worker, pflip_to_worker); 310 311 ret = xen_drm_front_conn_init(drm_info, &pipeline->conn); 312 if (ret) 313 return ret; 314 315 formats = xen_drm_front_conn_get_formats(&format_count); 316 317 return drm_simple_display_pipe_init(dev, &pipeline->pipe, 318 &display_funcs, formats, 319 format_count, NULL, 320 &pipeline->conn); 321 } 322 323 int xen_drm_front_kms_init(struct xen_drm_front_drm_info *drm_info) 324 { 325 struct drm_device *dev = drm_info->drm_dev; 326 int i, ret; 327 328 drm_mode_config_init(dev); 329 330 dev->mode_config.min_width = 0; 331 dev->mode_config.min_height = 0; 332 dev->mode_config.max_width = 4095; 333 dev->mode_config.max_height = 2047; 334 dev->mode_config.funcs = &mode_config_funcs; 335 336 for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) { 337 struct xen_drm_front_cfg_connector *cfg = 338 &drm_info->front_info->cfg.connectors[i]; 339 struct xen_drm_front_drm_pipeline *pipeline = 340 &drm_info->pipeline[i]; 341 342 ret = display_pipe_init(drm_info, i, cfg, pipeline); 343 if (ret) { 344 drm_mode_config_cleanup(dev); 345 return ret; 346 } 347 } 348 349 drm_mode_config_reset(dev); 350 drm_kms_helper_poll_init(dev); 351 return 0; 352 } 353 354 void xen_drm_front_kms_fini(struct xen_drm_front_drm_info *drm_info) 355 { 356 int i; 357 358 for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) { 359 struct xen_drm_front_drm_pipeline *pipeline = 360 &drm_info->pipeline[i]; 361 362 cancel_delayed_work_sync(&pipeline->pflip_to_worker); 363 364 send_pending_event(pipeline); 365 } 366 } 367
Indexes created Mon Sep 22 10:09:38 GMT 2025