1 /*
2  * Copyright (C) 2015 Red Hat, Inc.
3  * All Rights Reserved.
4  *
5  * Authors:
6  *    Dave Airlie <airlied@redhat.com>
7  *    Gerd Hoffmann <kraxel@redhat.com>
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a
10  * copy of this software and associated documentation files (the "Software"),
11  * to deal in the Software without restriction, including without limitation
12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13  * and/or sell copies of the Software, and to permit persons to whom the
14  * Software is furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice (including the next
17  * paragraph) shall be included in all copies or substantial portions of the
18  * Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
23  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
24  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
25  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26  * OTHER DEALINGS IN THE SOFTWARE.
27  */
28 
29 #include <drm/drmP.h>
30 #include "virtgpu_drv.h"
31 #include <linux/virtio.h>
32 #include <linux/virtio_config.h>
33 #include <linux/virtio_ring.h>
34 
35 #define MAX_INLINE_CMD_SIZE   96
36 #define MAX_INLINE_RESP_SIZE  24
37 #define VBUFFER_SIZE          (sizeof(struct virtio_gpu_vbuffer) \
38 			       + MAX_INLINE_CMD_SIZE		 \
39 			       + MAX_INLINE_RESP_SIZE)
40 
41 void virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev,
42 				uint32_t *resid)
43 {
44 	int handle;
45 
46 	idr_preload(GFP_KERNEL);
47 	spin_lock(&vgdev->resource_idr_lock);
48 	handle = idr_alloc(&vgdev->resource_idr, NULL, 1, 0, GFP_NOWAIT);
49 	spin_unlock(&vgdev->resource_idr_lock);
50 	idr_preload_end();
51 	*resid = handle;
52 }
53 
54 void virtio_gpu_resource_id_put(struct virtio_gpu_device *vgdev, uint32_t id)
55 {
56 	spin_lock(&vgdev->resource_idr_lock);
57 	idr_remove(&vgdev->resource_idr, id);
58 	spin_unlock(&vgdev->resource_idr_lock);
59 }
60 
61 void virtio_gpu_ctrl_ack(struct virtqueue *vq)
62 {
63 	struct drm_device *dev = vq->vdev->priv;
64 	struct virtio_gpu_device *vgdev = dev->dev_private;
65 	schedule_work(&vgdev->ctrlq.dequeue_work);
66 }
67 
68 void virtio_gpu_cursor_ack(struct virtqueue *vq)
69 {
70 	struct drm_device *dev = vq->vdev->priv;
71 	struct virtio_gpu_device *vgdev = dev->dev_private;
72 	schedule_work(&vgdev->cursorq.dequeue_work);
73 }
74 
75 int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev)
76 {
77 	struct virtio_gpu_vbuffer *vbuf;
78 	int i, size, count = 0;
79 	void *ptr;
80 
81 	INIT_LIST_HEAD(&vgdev->free_vbufs);
82 	count += virtqueue_get_vring_size(vgdev->ctrlq.vq);
83 	count += virtqueue_get_vring_size(vgdev->cursorq.vq);
84 	size = count * VBUFFER_SIZE;
85 	DRM_INFO("virtio vbuffers: %d bufs, %zdB each, %dkB total.\n",
86 		 count, VBUFFER_SIZE, size / 1024);
87 
88 	vgdev->vbufs = kzalloc(size, GFP_KERNEL);
89 	if (!vgdev->vbufs)
90 		return -ENOMEM;
91 
92 	for (i = 0, ptr = vgdev->vbufs;
93 	     i < count;
94 	     i++, ptr += VBUFFER_SIZE) {
95 		vbuf = ptr;
96 		list_add(&vbuf->list, &vgdev->free_vbufs);
97 	}
98 	return 0;
99 }
100 
101 void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
102 {
103 	struct virtio_gpu_vbuffer *vbuf;
104 	int i, count = 0;
105 
106 	count += virtqueue_get_vring_size(vgdev->ctrlq.vq);
107 	count += virtqueue_get_vring_size(vgdev->cursorq.vq);
108 
109 	for (i = 0; i < count; i++) {
110 		if (WARN_ON(list_empty(&vgdev->free_vbufs)))
111 			return;
112 		vbuf = list_first_entry(&vgdev->free_vbufs,
113 					struct virtio_gpu_vbuffer, list);
114 		list_del(&vbuf->list);
115 	}
116 	kfree(vgdev->vbufs);
117 }
118 
119 static struct virtio_gpu_vbuffer*
120 virtio_gpu_get_vbuf(struct virtio_gpu_device *vgdev,
121 		    int size, int resp_size, void *resp_buf,
122 		    virtio_gpu_resp_cb resp_cb)
123 {
124 	struct virtio_gpu_vbuffer *vbuf;
125 
126 	BUG_ON(list_empty(&vgdev->free_vbufs));
127 	vbuf = list_first_entry(&vgdev->free_vbufs,
128 				struct virtio_gpu_vbuffer, list);
129 	list_del(&vbuf->list);
130 	memset(vbuf, 0, VBUFFER_SIZE);
131 
132 	BUG_ON(size > MAX_INLINE_CMD_SIZE);
133 	vbuf->buf = (void *)vbuf + sizeof(*vbuf);
134 	vbuf->size = size;
135 
136 	vbuf->resp_cb = resp_cb;
137 	vbuf->resp_size = resp_size;
138 	if (resp_size <= MAX_INLINE_RESP_SIZE)
139 		vbuf->resp_buf = (void *)vbuf->buf + size;
140 	else
141 		vbuf->resp_buf = resp_buf;
142 	BUG_ON(!vbuf->resp_buf);
143 	return vbuf;
144 }
145 
146 static void *virtio_gpu_alloc_cmd(struct virtio_gpu_device *vgdev,
147 				  struct virtio_gpu_vbuffer **vbuffer_p,
148 				  int size)
149 {
150 	struct virtio_gpu_vbuffer *vbuf;
151 
152 	vbuf = virtio_gpu_get_vbuf(vgdev, size,
153 				   sizeof(struct virtio_gpu_ctrl_hdr),
154 				   NULL, NULL);
155 	if (IS_ERR(vbuf)) {
156 		*vbuffer_p = NULL;
157 		return ERR_CAST(vbuf);
158 	}
159 	*vbuffer_p = vbuf;
160 	return vbuf->buf;
161 }
162 
163 static struct virtio_gpu_update_cursor*
164 virtio_gpu_alloc_cursor(struct virtio_gpu_device *vgdev,
165 			struct virtio_gpu_vbuffer **vbuffer_p)
166 {
167 	struct virtio_gpu_vbuffer *vbuf;
168 
169 	vbuf = virtio_gpu_get_vbuf
170 		(vgdev, sizeof(struct virtio_gpu_update_cursor),
171 		 0, NULL, NULL);
172 	if (IS_ERR(vbuf)) {
173 		*vbuffer_p = NULL;
174 		return ERR_CAST(vbuf);
175 	}
176 	*vbuffer_p = vbuf;
177 	return (struct virtio_gpu_update_cursor *)vbuf->buf;
178 }
179 
180 static void *virtio_gpu_alloc_cmd_resp(struct virtio_gpu_device *vgdev,
181 				       virtio_gpu_resp_cb cb,
182 				       struct virtio_gpu_vbuffer **vbuffer_p,
183 				       int cmd_size, int resp_size,
184 				       void *resp_buf)
185 {
186 	struct virtio_gpu_vbuffer *vbuf;
187 
188 	vbuf = virtio_gpu_get_vbuf(vgdev, cmd_size,
189 				   resp_size, resp_buf, cb);
190 	if (IS_ERR(vbuf)) {
191 		*vbuffer_p = NULL;
192 		return ERR_CAST(vbuf);
193 	}
194 	*vbuffer_p = vbuf;
195 	return (struct virtio_gpu_command *)vbuf->buf;
196 }
197 
198 static void free_vbuf(struct virtio_gpu_device *vgdev,
199 		      struct virtio_gpu_vbuffer *vbuf)
200 {
201 	if (vbuf->resp_size > MAX_INLINE_RESP_SIZE)
202 		kfree(vbuf->resp_buf);
203 	kfree(vbuf->data_buf);
204 	list_add(&vbuf->list, &vgdev->free_vbufs);
205 }
206 
207 static void reclaim_vbufs(struct virtqueue *vq, struct list_head *reclaim_list)
208 {
209 	struct virtio_gpu_vbuffer *vbuf;
210 	unsigned int len;
211 	int freed = 0;
212 
213 	while ((vbuf = virtqueue_get_buf(vq, &len))) {
214 		list_add_tail(&vbuf->list, reclaim_list);
215 		freed++;
216 	}
217 	if (freed == 0)
218 		DRM_DEBUG("Huh? zero vbufs reclaimed");
219 }
220 
221 void virtio_gpu_dequeue_ctrl_func(struct work_struct *work)
222 {
223 	struct virtio_gpu_device *vgdev =
224 		container_of(work, struct virtio_gpu_device,
225 			     ctrlq.dequeue_work);
226 	struct list_head reclaim_list;
227 	struct virtio_gpu_vbuffer *entry, *tmp;
228 	struct virtio_gpu_ctrl_hdr *resp;
229 	u64 fence_id = 0;
230 
231 	INIT_LIST_HEAD(&reclaim_list);
232 	spin_lock(&vgdev->ctrlq.qlock);
233 	do {
234 		virtqueue_disable_cb(vgdev->ctrlq.vq);
235 		reclaim_vbufs(vgdev->ctrlq.vq, &reclaim_list);
236 
237 	} while (!virtqueue_enable_cb(vgdev->ctrlq.vq));
238 	spin_unlock(&vgdev->ctrlq.qlock);
239 
240 	list_for_each_entry_safe(entry, tmp, &reclaim_list, list) {
241 		resp = (struct virtio_gpu_ctrl_hdr *)entry->resp_buf;
242 		if (resp->type != cpu_to_le32(VIRTIO_GPU_RESP_OK_NODATA))
243 			DRM_DEBUG("response 0x%x\n", le32_to_cpu(resp->type));
244 		if (resp->flags & cpu_to_le32(VIRTIO_GPU_FLAG_FENCE)) {
245 			u64 f = le64_to_cpu(resp->fence_id);
246 
247 			if (fence_id > f) {
248 				DRM_ERROR("%s: Oops: fence %llx -> %llx\n",
249 					  __func__, fence_id, f);
250 			} else {
251 				fence_id = f;
252 			}
253 		}
254 		if (entry->resp_cb)
255 			entry->resp_cb(vgdev, entry);
256 
257 		list_del(&entry->list);
258 		free_vbuf(vgdev, entry);
259 	}
260 	wake_up(&vgdev->ctrlq.ack_queue);
261 
262 	if (fence_id)
263 		virtio_gpu_fence_event_process(vgdev, fence_id);
264 }
265 
266 void virtio_gpu_dequeue_cursor_func(struct work_struct *work)
267 {
268 	struct virtio_gpu_device *vgdev =
269 		container_of(work, struct virtio_gpu_device,
270 			     cursorq.dequeue_work);
271 	struct list_head reclaim_list;
272 	struct virtio_gpu_vbuffer *entry, *tmp;
273 
274 	INIT_LIST_HEAD(&reclaim_list);
275 	spin_lock(&vgdev->cursorq.qlock);
276 	do {
277 		virtqueue_disable_cb(vgdev->cursorq.vq);
278 		reclaim_vbufs(vgdev->cursorq.vq, &reclaim_list);
279 	} while (!virtqueue_enable_cb(vgdev->cursorq.vq));
280 	spin_unlock(&vgdev->cursorq.qlock);
281 
282 	list_for_each_entry_safe(entry, tmp, &reclaim_list, list) {
283 		list_del(&entry->list);
284 		free_vbuf(vgdev, entry);
285 	}
286 	wake_up(&vgdev->cursorq.ack_queue);
287 }
288 
289 static int virtio_gpu_queue_ctrl_buffer(struct virtio_gpu_device *vgdev,
290 					struct virtio_gpu_vbuffer *vbuf)
291 {
292 	struct virtqueue *vq = vgdev->ctrlq.vq;
293 	struct scatterlist *sgs[3], vcmd, vout, vresp;
294 	int outcnt = 0, incnt = 0;
295 	int ret;
296 
297 	if (!vgdev->vqs_ready)
298 		return -ENODEV;
299 
300 	sg_init_one(&vcmd, vbuf->buf, vbuf->size);
301 	sgs[outcnt+incnt] = &vcmd;
302 	outcnt++;
303 
304 	if (vbuf->data_size) {
305 		sg_init_one(&vout, vbuf->data_buf, vbuf->data_size);
306 		sgs[outcnt + incnt] = &vout;
307 		outcnt++;
308 	}
309 
310 	if (vbuf->resp_size) {
311 		sg_init_one(&vresp, vbuf->resp_buf, vbuf->resp_size);
312 		sgs[outcnt + incnt] = &vresp;
313 		incnt++;
314 	}
315 
316 	spin_lock(&vgdev->ctrlq.qlock);
317 retry:
318 	ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
319 	if (ret == -ENOSPC) {
320 		spin_unlock(&vgdev->ctrlq.qlock);
321 		wait_event(vgdev->ctrlq.ack_queue, vq->num_free);
322 		spin_lock(&vgdev->ctrlq.qlock);
323 		goto retry;
324 	} else {
325 		virtqueue_kick(vq);
326 	}
327 	spin_unlock(&vgdev->ctrlq.qlock);
328 
329 	if (!ret)
330 		ret = vq->num_free;
331 	return ret;
332 }
333 
334 static int virtio_gpu_queue_cursor(struct virtio_gpu_device *vgdev,
335 				   struct virtio_gpu_vbuffer *vbuf)
336 {
337 	struct virtqueue *vq = vgdev->cursorq.vq;
338 	struct scatterlist *sgs[1], ccmd;
339 	int ret;
340 	int outcnt;
341 
342 	if (!vgdev->vqs_ready)
343 		return -ENODEV;
344 
345 	sg_init_one(&ccmd, vbuf->buf, vbuf->size);
346 	sgs[0] = &ccmd;
347 	outcnt = 1;
348 
349 	spin_lock(&vgdev->cursorq.qlock);
350 retry:
351 	ret = virtqueue_add_sgs(vq, sgs, outcnt, 0, vbuf, GFP_ATOMIC);
352 	if (ret == -ENOSPC) {
353 		spin_unlock(&vgdev->cursorq.qlock);
354 		wait_event(vgdev->cursorq.ack_queue, vq->num_free);
355 		spin_lock(&vgdev->cursorq.qlock);
356 		goto retry;
357 	} else {
358 		virtqueue_kick(vq);
359 	}
360 
361 	spin_unlock(&vgdev->cursorq.qlock);
362 
363 	if (!ret)
364 		ret = vq->num_free;
365 	return ret;
366 }
367 
368 /* just create gem objects for userspace and long lived objects,
369    just use dma_alloced pages for the queue objects? */
370 
371 /* create a basic resource */
372 void virtio_gpu_cmd_create_resource(struct virtio_gpu_device *vgdev,
373 				    uint32_t resource_id,
374 				    uint32_t format,
375 				    uint32_t width,
376 				    uint32_t height)
377 {
378 	struct virtio_gpu_resource_create_2d *cmd_p;
379 	struct virtio_gpu_vbuffer *vbuf;
380 
381 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
382 	memset(cmd_p, 0, sizeof(*cmd_p));
383 
384 	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_CREATE_2D);
385 	cmd_p->resource_id = cpu_to_le32(resource_id);
386 	cmd_p->format = cpu_to_le32(format);
387 	cmd_p->width = cpu_to_le32(width);
388 	cmd_p->height = cpu_to_le32(height);
389 
390 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
391 }
392 
393 void virtio_gpu_cmd_unref_resource(struct virtio_gpu_device *vgdev,
394 				   uint32_t resource_id)
395 {
396 	struct virtio_gpu_resource_unref *cmd_p;
397 	struct virtio_gpu_vbuffer *vbuf;
398 
399 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
400 	memset(cmd_p, 0, sizeof(*cmd_p));
401 
402 	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_UNREF);
403 	cmd_p->resource_id = cpu_to_le32(resource_id);
404 
405 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
406 }
407 
408 void virtio_gpu_cmd_resource_inval_backing(struct virtio_gpu_device *vgdev,
409 					   uint32_t resource_id)
410 {
411 	struct virtio_gpu_resource_detach_backing *cmd_p;
412 	struct virtio_gpu_vbuffer *vbuf;
413 
414 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
415 	memset(cmd_p, 0, sizeof(*cmd_p));
416 
417 	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING);
418 	cmd_p->resource_id = cpu_to_le32(resource_id);
419 
420 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
421 }
422 
423 void virtio_gpu_cmd_set_scanout(struct virtio_gpu_device *vgdev,
424 				uint32_t scanout_id, uint32_t resource_id,
425 				uint32_t width, uint32_t height,
426 				uint32_t x, uint32_t y)
427 {
428 	struct virtio_gpu_set_scanout *cmd_p;
429 	struct virtio_gpu_vbuffer *vbuf;
430 
431 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
432 	memset(cmd_p, 0, sizeof(*cmd_p));
433 
434 	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_SET_SCANOUT);
435 	cmd_p->resource_id = cpu_to_le32(resource_id);
436 	cmd_p->scanout_id = cpu_to_le32(scanout_id);
437 	cmd_p->r.width = cpu_to_le32(width);
438 	cmd_p->r.height = cpu_to_le32(height);
439 	cmd_p->r.x = cpu_to_le32(x);
440 	cmd_p->r.y = cpu_to_le32(y);
441 
442 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
443 }
444 
445 void virtio_gpu_cmd_resource_flush(struct virtio_gpu_device *vgdev,
446 				   uint32_t resource_id,
447 				   uint32_t x, uint32_t y,
448 				   uint32_t width, uint32_t height)
449 {
450 	struct virtio_gpu_resource_flush *cmd_p;
451 	struct virtio_gpu_vbuffer *vbuf;
452 
453 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
454 	memset(cmd_p, 0, sizeof(*cmd_p));
455 
456 	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_FLUSH);
457 	cmd_p->resource_id = cpu_to_le32(resource_id);
458 	cmd_p->r.width = cpu_to_le32(width);
459 	cmd_p->r.height = cpu_to_le32(height);
460 	cmd_p->r.x = cpu_to_le32(x);
461 	cmd_p->r.y = cpu_to_le32(y);
462 
463 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
464 }
465 
466 void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
467 					uint32_t resource_id, uint64_t offset,
468 					__le32 width, __le32 height,
469 					__le32 x, __le32 y,
470 					struct virtio_gpu_fence **fence)
471 {
472 	struct virtio_gpu_transfer_to_host_2d *cmd_p;
473 	struct virtio_gpu_vbuffer *vbuf;
474 
475 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
476 	memset(cmd_p, 0, sizeof(*cmd_p));
477 
478 	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D);
479 	cmd_p->resource_id = cpu_to_le32(resource_id);
480 	cmd_p->offset = cpu_to_le64(offset);
481 	cmd_p->r.width = width;
482 	cmd_p->r.height = height;
483 	cmd_p->r.x = x;
484 	cmd_p->r.y = y;
485 
486 	if (fence)
487 		virtio_gpu_fence_emit(vgdev, &cmd_p->hdr, fence);
488 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
489 }
490 
491 static void
492 virtio_gpu_cmd_resource_attach_backing(struct virtio_gpu_device *vgdev,
493 				       uint32_t resource_id,
494 				       struct virtio_gpu_mem_entry *ents,
495 				       uint32_t nents,
496 				       struct virtio_gpu_fence **fence)
497 {
498 	struct virtio_gpu_resource_attach_backing *cmd_p;
499 	struct virtio_gpu_vbuffer *vbuf;
500 
501 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
502 	memset(cmd_p, 0, sizeof(*cmd_p));
503 
504 	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING);
505 	cmd_p->resource_id = cpu_to_le32(resource_id);
506 	cmd_p->nr_entries = cpu_to_le32(nents);
507 
508 	vbuf->data_buf = ents;
509 	vbuf->data_size = sizeof(*ents) * nents;
510 
511 	if (fence)
512 		virtio_gpu_fence_emit(vgdev, &cmd_p->hdr, fence);
513 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
514 }
515 
516 static void virtio_gpu_cmd_get_display_info_cb(struct virtio_gpu_device *vgdev,
517 					       struct virtio_gpu_vbuffer *vbuf)
518 {
519 	struct virtio_gpu_resp_display_info *resp =
520 		(struct virtio_gpu_resp_display_info *)vbuf->resp_buf;
521 	int i;
522 
523 	spin_lock(&vgdev->display_info_lock);
524 	for (i = 0; i < vgdev->num_scanouts; i++) {
525 		vgdev->outputs[i].info = resp->pmodes[i];
526 		if (resp->pmodes[i].enabled) {
527 			DRM_DEBUG("output %d: %dx%d+%d+%d", i,
528 				  le32_to_cpu(resp->pmodes[i].r.width),
529 				  le32_to_cpu(resp->pmodes[i].r.height),
530 				  le32_to_cpu(resp->pmodes[i].r.x),
531 				  le32_to_cpu(resp->pmodes[i].r.y));
532 		} else {
533 			DRM_DEBUG("output %d: disabled", i);
534 		}
535 	}
536 
537 	spin_unlock(&vgdev->display_info_lock);
538 	wake_up(&vgdev->resp_wq);
539 
540 	if (!drm_helper_hpd_irq_event(vgdev->ddev))
541 		drm_kms_helper_hotplug_event(vgdev->ddev);
542 }
543 
544 int virtio_gpu_cmd_get_display_info(struct virtio_gpu_device *vgdev)
545 {
546 	struct virtio_gpu_ctrl_hdr *cmd_p;
547 	struct virtio_gpu_vbuffer *vbuf;
548 	void *resp_buf;
549 
550 	resp_buf = kzalloc(sizeof(struct virtio_gpu_resp_display_info),
551 			   GFP_KERNEL);
552 	if (!resp_buf)
553 		return -ENOMEM;
554 
555 	cmd_p = virtio_gpu_alloc_cmd_resp
556 		(vgdev, &virtio_gpu_cmd_get_display_info_cb, &vbuf,
557 		 sizeof(*cmd_p), sizeof(struct virtio_gpu_resp_display_info),
558 		 resp_buf);
559 	memset(cmd_p, 0, sizeof(*cmd_p));
560 
561 	cmd_p->type = cpu_to_le32(VIRTIO_GPU_CMD_GET_DISPLAY_INFO);
562 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
563 	return 0;
564 }
565 
566 int virtio_gpu_object_attach(struct virtio_gpu_device *vgdev,
567 			     struct virtio_gpu_object *obj,
568 			     uint32_t resource_id,
569 			     struct virtio_gpu_fence **fence)
570 {
571 	struct virtio_gpu_mem_entry *ents;
572 	struct scatterlist *sg;
573 	int si;
574 
575 	if (!obj->pages) {
576 		int ret;
577 		ret = virtio_gpu_object_get_sg_table(vgdev, obj);
578 		if (ret)
579 			return ret;
580 	}
581 
582 	/* gets freed when the ring has consumed it */
583 	ents = kmalloc_array(obj->pages->nents,
584 			     sizeof(struct virtio_gpu_mem_entry),
585 			     GFP_KERNEL);
586 	if (!ents) {
587 		DRM_ERROR("failed to allocate ent list\n");
588 		return -ENOMEM;
589 	}
590 
591 	for_each_sg(obj->pages->sgl, sg, obj->pages->nents, si) {
592 		ents[si].addr = cpu_to_le64(sg_phys(sg));
593 		ents[si].length = cpu_to_le32(sg->length);
594 		ents[si].padding = 0;
595 	}
596 
597 	virtio_gpu_cmd_resource_attach_backing(vgdev, resource_id,
598 					       ents, obj->pages->nents,
599 					       fence);
600 	obj->hw_res_handle = resource_id;
601 	return 0;
602 }
603 
604 void virtio_gpu_cursor_ping(struct virtio_gpu_device *vgdev,
605 			    struct virtio_gpu_output *output)
606 {
607 	struct virtio_gpu_vbuffer *vbuf;
608 	struct virtio_gpu_update_cursor *cur_p;
609 
610 	output->cursor.pos.scanout_id = cpu_to_le32(output->index);
611 	cur_p = virtio_gpu_alloc_cursor(vgdev, &vbuf);
612 	memcpy(cur_p, &output->cursor, sizeof(output->cursor));
613 	virtio_gpu_queue_cursor(vgdev, vbuf);
614 }
615