xref: /linux/drivers/gpu/drm/i915/gvt/dmabuf.c (revision 9557b4376d02088a33e5f4116bcc324d35a3b64c)
1 /*
2  * Copyright 2017 Intel Corporation. All rights reserved.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21  * DEALINGS IN THE SOFTWARE.
22  *
23  * Authors:
24  *    Zhiyuan Lv <zhiyuan.lv@intel.com>
25  *
26  * Contributors:
27  *    Xiaoguang Chen
28  *    Tina Zhang <tina.zhang@intel.com>
29  */
30 
31 #include <linux/dma-buf.h>
32 #include <linux/mdev.h>
33 
34 #include <drm/drm_fourcc.h>
35 #include <drm/drm_plane.h>
36 
37 #include "gem/i915_gem_dmabuf.h"
38 
39 #include "i915_drv.h"
40 #include "gvt.h"
41 
42 #include "display/skl_universal_plane_regs.h"
43 
44 #define GEN8_DECODE_PTE(pte) (pte & GENMASK_ULL(63, 12))
45 
46 static int vgpu_gem_get_pages(struct drm_i915_gem_object *obj)
47 {
48 	struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
49 	struct intel_vgpu *vgpu;
50 	struct sg_table *st;
51 	struct scatterlist *sg;
52 	int i, j, ret;
53 	gen8_pte_t __iomem *gtt_entries;
54 	struct intel_vgpu_fb_info *fb_info;
55 	unsigned int page_num; /* limited by sg_alloc_table */
56 
57 	if (overflows_type(obj->base.size >> PAGE_SHIFT, page_num))
58 		return -E2BIG;
59 
60 	page_num = obj->base.size >> PAGE_SHIFT;
61 	fb_info = (struct intel_vgpu_fb_info *)obj->gvt_info;
62 	if (drm_WARN_ON(&dev_priv->drm, !fb_info))
63 		return -ENODEV;
64 
65 	vgpu = fb_info->obj->vgpu;
66 	if (drm_WARN_ON(&dev_priv->drm, !vgpu))
67 		return -ENODEV;
68 
69 	st = kmalloc(sizeof(*st), GFP_KERNEL);
70 	if (unlikely(!st))
71 		return -ENOMEM;
72 
73 	ret = sg_alloc_table(st, page_num, GFP_KERNEL);
74 	if (ret) {
75 		kfree(st);
76 		return ret;
77 	}
78 	gtt_entries = (gen8_pte_t __iomem *)to_gt(dev_priv)->ggtt->gsm +
79 		(fb_info->start >> PAGE_SHIFT);
80 	for_each_sg(st->sgl, sg, page_num, i) {
81 		dma_addr_t dma_addr =
82 			GEN8_DECODE_PTE(readq(&gtt_entries[i]));
83 		if (intel_gvt_dma_pin_guest_page(vgpu, dma_addr)) {
84 			ret = -EINVAL;
85 			goto out;
86 		}
87 
88 		sg->offset = 0;
89 		sg->length = PAGE_SIZE;
90 		sg_dma_len(sg) = PAGE_SIZE;
91 		sg_dma_address(sg) = dma_addr;
92 	}
93 
94 	__i915_gem_object_set_pages(obj, st);
95 out:
96 	if (ret) {
97 		dma_addr_t dma_addr;
98 
99 		for_each_sg(st->sgl, sg, i, j) {
100 			dma_addr = sg_dma_address(sg);
101 			if (dma_addr)
102 				intel_gvt_dma_unmap_guest_page(vgpu, dma_addr);
103 		}
104 		sg_free_table(st);
105 		kfree(st);
106 	}
107 
108 	return ret;
109 
110 }
111 
112 static void vgpu_gem_put_pages(struct drm_i915_gem_object *obj,
113 		struct sg_table *pages)
114 {
115 	struct scatterlist *sg;
116 
117 	if (obj->base.dma_buf) {
118 		struct intel_vgpu_fb_info *fb_info = obj->gvt_info;
119 		struct intel_vgpu_dmabuf_obj *obj = fb_info->obj;
120 		struct intel_vgpu *vgpu = obj->vgpu;
121 		int i;
122 
123 		for_each_sg(pages->sgl, sg, fb_info->size, i)
124 			intel_gvt_dma_unmap_guest_page(vgpu,
125 					       sg_dma_address(sg));
126 	}
127 
128 	sg_free_table(pages);
129 	kfree(pages);
130 }
131 
132 static void dmabuf_gem_object_free(struct kref *kref)
133 {
134 	struct intel_vgpu_dmabuf_obj *obj =
135 		container_of(kref, struct intel_vgpu_dmabuf_obj, kref);
136 	struct intel_vgpu *vgpu = obj->vgpu;
137 	struct list_head *pos;
138 	struct intel_vgpu_dmabuf_obj *dmabuf_obj;
139 
140 	if (vgpu && test_bit(INTEL_VGPU_STATUS_ACTIVE, vgpu->status) &&
141 	    !list_empty(&vgpu->dmabuf_obj_list_head)) {
142 		list_for_each(pos, &vgpu->dmabuf_obj_list_head) {
143 			dmabuf_obj = list_entry(pos, struct intel_vgpu_dmabuf_obj, list);
144 			if (dmabuf_obj == obj) {
145 				list_del(pos);
146 				idr_remove(&vgpu->object_idr,
147 					   dmabuf_obj->dmabuf_id);
148 				kfree(dmabuf_obj->info);
149 				kfree(dmabuf_obj);
150 				break;
151 			}
152 		}
153 	} else {
154 		/* Free the orphan dmabuf_objs here */
155 		kfree(obj->info);
156 		kfree(obj);
157 	}
158 }
159 
160 
161 static inline void dmabuf_obj_get(struct intel_vgpu_dmabuf_obj *obj)
162 {
163 	kref_get(&obj->kref);
164 }
165 
166 static inline void dmabuf_obj_put(struct intel_vgpu_dmabuf_obj *obj)
167 {
168 	kref_put(&obj->kref, dmabuf_gem_object_free);
169 }
170 
171 static void vgpu_gem_release(struct drm_i915_gem_object *gem_obj)
172 {
173 
174 	struct intel_vgpu_fb_info *fb_info = gem_obj->gvt_info;
175 	struct intel_vgpu_dmabuf_obj *obj = fb_info->obj;
176 	struct intel_vgpu *vgpu = obj->vgpu;
177 
178 	if (vgpu) {
179 		mutex_lock(&vgpu->dmabuf_lock);
180 		gem_obj->base.dma_buf = NULL;
181 		dmabuf_obj_put(obj);
182 		mutex_unlock(&vgpu->dmabuf_lock);
183 	} else {
184 		/* vgpu is NULL, as it has been removed already */
185 		gem_obj->base.dma_buf = NULL;
186 		dmabuf_obj_put(obj);
187 	}
188 }
189 
190 static const struct drm_i915_gem_object_ops intel_vgpu_gem_ops = {
191 	.name = "i915_gem_object_vgpu",
192 	.flags = I915_GEM_OBJECT_IS_PROXY,
193 	.get_pages = vgpu_gem_get_pages,
194 	.put_pages = vgpu_gem_put_pages,
195 	.release = vgpu_gem_release,
196 };
197 
198 static struct drm_i915_gem_object *vgpu_create_gem(struct drm_device *dev,
199 		struct intel_vgpu_fb_info *info)
200 {
201 	static struct lock_class_key lock_class;
202 	struct drm_i915_private *dev_priv = to_i915(dev);
203 	struct drm_i915_gem_object *obj;
204 
205 	obj = i915_gem_object_alloc();
206 	if (obj == NULL)
207 		return NULL;
208 
209 	drm_gem_private_object_init(dev, &obj->base,
210 		roundup(info->size, PAGE_SIZE));
211 	i915_gem_object_init(obj, &intel_vgpu_gem_ops, &lock_class, 0);
212 	i915_gem_object_set_readonly(obj);
213 
214 	obj->read_domains = I915_GEM_DOMAIN_GTT;
215 	obj->write_domain = 0;
216 	if (GRAPHICS_VER(dev_priv) >= 9) {
217 		unsigned int tiling_mode = 0;
218 		unsigned int stride = 0;
219 
220 		switch (info->drm_format_mod) {
221 		case DRM_FORMAT_MOD_LINEAR:
222 			tiling_mode = I915_TILING_NONE;
223 			break;
224 		case I915_FORMAT_MOD_X_TILED:
225 			tiling_mode = I915_TILING_X;
226 			stride = info->stride;
227 			break;
228 		case I915_FORMAT_MOD_Y_TILED:
229 		case I915_FORMAT_MOD_Yf_TILED:
230 			tiling_mode = I915_TILING_Y;
231 			stride = info->stride;
232 			break;
233 		default:
234 			gvt_dbg_core("invalid drm_format_mod %llx for tiling\n",
235 				     info->drm_format_mod);
236 		}
237 		obj->tiling_and_stride = tiling_mode | stride;
238 	} else {
239 		obj->tiling_and_stride = info->drm_format_mod ?
240 					I915_TILING_X : 0;
241 	}
242 
243 	return obj;
244 }
245 
246 static bool validate_hotspot(struct intel_vgpu_cursor_plane_format *c)
247 {
248 	if (c && c->x_hot <= c->width && c->y_hot <= c->height)
249 		return true;
250 	else
251 		return false;
252 }
253 
254 static int vgpu_get_plane_info(struct drm_device *dev,
255 		struct intel_vgpu *vgpu,
256 		struct intel_vgpu_fb_info *info,
257 		int plane_id)
258 {
259 	struct intel_vgpu_primary_plane_format p;
260 	struct intel_vgpu_cursor_plane_format c;
261 	int ret, tile_height = 1;
262 
263 	memset(info, 0, sizeof(*info));
264 
265 	if (plane_id == DRM_PLANE_TYPE_PRIMARY) {
266 		ret = intel_vgpu_decode_primary_plane(vgpu, &p);
267 		if (ret)
268 			return ret;
269 		info->start = p.base;
270 		info->start_gpa = p.base_gpa;
271 		info->width = p.width;
272 		info->height = p.height;
273 		info->stride = p.stride;
274 		info->drm_format = p.drm_format;
275 
276 		switch (p.tiled) {
277 		case PLANE_CTL_TILED_LINEAR:
278 			info->drm_format_mod = DRM_FORMAT_MOD_LINEAR;
279 			break;
280 		case PLANE_CTL_TILED_X:
281 			info->drm_format_mod = I915_FORMAT_MOD_X_TILED;
282 			tile_height = 8;
283 			break;
284 		case PLANE_CTL_TILED_Y:
285 			info->drm_format_mod = I915_FORMAT_MOD_Y_TILED;
286 			tile_height = 32;
287 			break;
288 		case PLANE_CTL_TILED_YF:
289 			info->drm_format_mod = I915_FORMAT_MOD_Yf_TILED;
290 			tile_height = 32;
291 			break;
292 		default:
293 			gvt_vgpu_err("invalid tiling mode: %x\n", p.tiled);
294 		}
295 	} else if (plane_id == DRM_PLANE_TYPE_CURSOR) {
296 		ret = intel_vgpu_decode_cursor_plane(vgpu, &c);
297 		if (ret)
298 			return ret;
299 		info->start = c.base;
300 		info->start_gpa = c.base_gpa;
301 		info->width = c.width;
302 		info->height = c.height;
303 		info->stride = c.width * (c.bpp / 8);
304 		info->drm_format = c.drm_format;
305 		info->drm_format_mod = 0;
306 		info->x_pos = c.x_pos;
307 		info->y_pos = c.y_pos;
308 
309 		if (validate_hotspot(&c)) {
310 			info->x_hot = c.x_hot;
311 			info->y_hot = c.y_hot;
312 		} else {
313 			info->x_hot = UINT_MAX;
314 			info->y_hot = UINT_MAX;
315 		}
316 	} else {
317 		gvt_vgpu_err("invalid plane id:%d\n", plane_id);
318 		return -EINVAL;
319 	}
320 
321 	info->size = info->stride * roundup(info->height, tile_height);
322 	if (info->size == 0) {
323 		gvt_vgpu_err("fb size is zero\n");
324 		return -EINVAL;
325 	}
326 
327 	if (info->start & (PAGE_SIZE - 1)) {
328 		gvt_vgpu_err("Not aligned fb address:0x%llx\n", info->start);
329 		return -EFAULT;
330 	}
331 
332 	if (!intel_gvt_ggtt_validate_range(vgpu, info->start, info->size)) {
333 		gvt_vgpu_err("invalid gma addr\n");
334 		return -EFAULT;
335 	}
336 
337 	return 0;
338 }
339 
340 static struct intel_vgpu_dmabuf_obj *
341 pick_dmabuf_by_info(struct intel_vgpu *vgpu,
342 		    struct intel_vgpu_fb_info *latest_info)
343 {
344 	struct list_head *pos;
345 	struct intel_vgpu_fb_info *fb_info;
346 	struct intel_vgpu_dmabuf_obj *dmabuf_obj = NULL;
347 	struct intel_vgpu_dmabuf_obj *ret = NULL;
348 
349 	list_for_each(pos, &vgpu->dmabuf_obj_list_head) {
350 		dmabuf_obj = list_entry(pos, struct intel_vgpu_dmabuf_obj, list);
351 		if (!dmabuf_obj->info)
352 			continue;
353 
354 		fb_info = (struct intel_vgpu_fb_info *)dmabuf_obj->info;
355 		if ((fb_info->start == latest_info->start) &&
356 		    (fb_info->start_gpa == latest_info->start_gpa) &&
357 		    (fb_info->size == latest_info->size) &&
358 		    (fb_info->drm_format_mod == latest_info->drm_format_mod) &&
359 		    (fb_info->drm_format == latest_info->drm_format) &&
360 		    (fb_info->width == latest_info->width) &&
361 		    (fb_info->height == latest_info->height)) {
362 			ret = dmabuf_obj;
363 			break;
364 		}
365 	}
366 
367 	return ret;
368 }
369 
370 static struct intel_vgpu_dmabuf_obj *
371 pick_dmabuf_by_num(struct intel_vgpu *vgpu, u32 id)
372 {
373 	struct list_head *pos;
374 	struct intel_vgpu_dmabuf_obj *dmabuf_obj = NULL;
375 	struct intel_vgpu_dmabuf_obj *ret = NULL;
376 
377 	list_for_each(pos, &vgpu->dmabuf_obj_list_head) {
378 		dmabuf_obj = list_entry(pos, struct intel_vgpu_dmabuf_obj, list);
379 		if (dmabuf_obj->dmabuf_id == id) {
380 			ret = dmabuf_obj;
381 			break;
382 		}
383 	}
384 
385 	return ret;
386 }
387 
388 static void update_fb_info(struct vfio_device_gfx_plane_info *gvt_dmabuf,
389 		      struct intel_vgpu_fb_info *fb_info)
390 {
391 	gvt_dmabuf->drm_format = fb_info->drm_format;
392 	gvt_dmabuf->drm_format_mod = fb_info->drm_format_mod;
393 	gvt_dmabuf->width = fb_info->width;
394 	gvt_dmabuf->height = fb_info->height;
395 	gvt_dmabuf->stride = fb_info->stride;
396 	gvt_dmabuf->size = fb_info->size;
397 	gvt_dmabuf->x_pos = fb_info->x_pos;
398 	gvt_dmabuf->y_pos = fb_info->y_pos;
399 	gvt_dmabuf->x_hot = fb_info->x_hot;
400 	gvt_dmabuf->y_hot = fb_info->y_hot;
401 }
402 
403 int intel_vgpu_query_plane(struct intel_vgpu *vgpu, void *args)
404 {
405 	struct drm_device *dev = &vgpu->gvt->gt->i915->drm;
406 	struct vfio_device_gfx_plane_info *gfx_plane_info = args;
407 	struct intel_vgpu_dmabuf_obj *dmabuf_obj;
408 	struct intel_vgpu_fb_info fb_info;
409 	int ret = 0;
410 
411 	if (gfx_plane_info->flags == (VFIO_GFX_PLANE_TYPE_DMABUF |
412 				       VFIO_GFX_PLANE_TYPE_PROBE))
413 		return ret;
414 	else if ((gfx_plane_info->flags & ~VFIO_GFX_PLANE_TYPE_DMABUF) ||
415 			(!gfx_plane_info->flags))
416 		return -EINVAL;
417 
418 	ret = vgpu_get_plane_info(dev, vgpu, &fb_info,
419 					gfx_plane_info->drm_plane_type);
420 	if (ret != 0)
421 		goto out;
422 
423 	mutex_lock(&vgpu->dmabuf_lock);
424 	/* If exists, pick up the exposed dmabuf_obj */
425 	dmabuf_obj = pick_dmabuf_by_info(vgpu, &fb_info);
426 	if (dmabuf_obj) {
427 		update_fb_info(gfx_plane_info, &fb_info);
428 		gfx_plane_info->dmabuf_id = dmabuf_obj->dmabuf_id;
429 
430 		/* This buffer may be released between query_plane ioctl and
431 		 * get_dmabuf ioctl. Add the refcount to make sure it won't
432 		 * be released between the two ioctls.
433 		 */
434 		if (!dmabuf_obj->initref) {
435 			dmabuf_obj->initref = true;
436 			dmabuf_obj_get(dmabuf_obj);
437 		}
438 		ret = 0;
439 		gvt_dbg_dpy("vgpu%d: re-use dmabuf_obj ref %d, id %d\n",
440 			    vgpu->id, kref_read(&dmabuf_obj->kref),
441 			    gfx_plane_info->dmabuf_id);
442 		mutex_unlock(&vgpu->dmabuf_lock);
443 		goto out;
444 	}
445 
446 	mutex_unlock(&vgpu->dmabuf_lock);
447 
448 	/* Need to allocate a new one*/
449 	dmabuf_obj = kmalloc(sizeof(struct intel_vgpu_dmabuf_obj), GFP_KERNEL);
450 	if (unlikely(!dmabuf_obj)) {
451 		gvt_vgpu_err("alloc dmabuf_obj failed\n");
452 		ret = -ENOMEM;
453 		goto out;
454 	}
455 
456 	dmabuf_obj->info = kmalloc(sizeof(struct intel_vgpu_fb_info),
457 				   GFP_KERNEL);
458 	if (unlikely(!dmabuf_obj->info)) {
459 		gvt_vgpu_err("allocate intel vgpu fb info failed\n");
460 		ret = -ENOMEM;
461 		goto out_free_dmabuf;
462 	}
463 	memcpy(dmabuf_obj->info, &fb_info, sizeof(struct intel_vgpu_fb_info));
464 
465 	((struct intel_vgpu_fb_info *)dmabuf_obj->info)->obj = dmabuf_obj;
466 
467 	dmabuf_obj->vgpu = vgpu;
468 
469 	ret = idr_alloc(&vgpu->object_idr, dmabuf_obj, 1, 0, GFP_NOWAIT);
470 	if (ret < 0)
471 		goto out_free_info;
472 	gfx_plane_info->dmabuf_id = ret;
473 	dmabuf_obj->dmabuf_id = ret;
474 
475 	dmabuf_obj->initref = true;
476 
477 	kref_init(&dmabuf_obj->kref);
478 
479 	update_fb_info(gfx_plane_info, &fb_info);
480 
481 	INIT_LIST_HEAD(&dmabuf_obj->list);
482 	mutex_lock(&vgpu->dmabuf_lock);
483 	list_add_tail(&dmabuf_obj->list, &vgpu->dmabuf_obj_list_head);
484 	mutex_unlock(&vgpu->dmabuf_lock);
485 
486 	gvt_dbg_dpy("vgpu%d: %s new dmabuf_obj ref %d, id %d\n", vgpu->id,
487 		    __func__, kref_read(&dmabuf_obj->kref), ret);
488 
489 	return 0;
490 
491 out_free_info:
492 	kfree(dmabuf_obj->info);
493 out_free_dmabuf:
494 	kfree(dmabuf_obj);
495 out:
496 	/* ENODEV means plane isn't ready, which might be a normal case. */
497 	return (ret == -ENODEV) ? 0 : ret;
498 }
499 
500 /* To associate an exposed dmabuf with the dmabuf_obj */
501 int intel_vgpu_get_dmabuf(struct intel_vgpu *vgpu, unsigned int dmabuf_id)
502 {
503 	struct drm_device *dev = &vgpu->gvt->gt->i915->drm;
504 	struct intel_vgpu_dmabuf_obj *dmabuf_obj;
505 	struct drm_i915_gem_object *obj;
506 	struct dma_buf *dmabuf;
507 	int dmabuf_fd;
508 	int ret = 0;
509 
510 	mutex_lock(&vgpu->dmabuf_lock);
511 
512 	dmabuf_obj = pick_dmabuf_by_num(vgpu, dmabuf_id);
513 	if (dmabuf_obj == NULL) {
514 		gvt_vgpu_err("invalid dmabuf id:%d\n", dmabuf_id);
515 		ret = -EINVAL;
516 		goto out;
517 	}
518 
519 	obj = vgpu_create_gem(dev, dmabuf_obj->info);
520 	if (obj == NULL) {
521 		gvt_vgpu_err("create gvt gem obj failed\n");
522 		ret = -ENOMEM;
523 		goto out;
524 	}
525 
526 	obj->gvt_info = dmabuf_obj->info;
527 
528 	dmabuf = i915_gem_prime_export(&obj->base, DRM_CLOEXEC | DRM_RDWR);
529 	if (IS_ERR(dmabuf)) {
530 		gvt_vgpu_err("export dma-buf failed\n");
531 		ret = PTR_ERR(dmabuf);
532 		goto out_free_gem;
533 	}
534 
535 	ret = dma_buf_fd(dmabuf, DRM_CLOEXEC | DRM_RDWR);
536 	if (ret < 0) {
537 		gvt_vgpu_err("create dma-buf fd failed ret:%d\n", ret);
538 		goto out_free_dmabuf;
539 	}
540 	dmabuf_fd = ret;
541 
542 	dmabuf_obj_get(dmabuf_obj);
543 
544 	if (dmabuf_obj->initref) {
545 		dmabuf_obj->initref = false;
546 		dmabuf_obj_put(dmabuf_obj);
547 	}
548 
549 	mutex_unlock(&vgpu->dmabuf_lock);
550 
551 	gvt_dbg_dpy("vgpu%d: dmabuf:%d, dmabuf ref %d, fd:%d\n"
552 		    "        file count: %ld, GEM ref: %d\n",
553 		    vgpu->id, dmabuf_obj->dmabuf_id,
554 		    kref_read(&dmabuf_obj->kref),
555 		    dmabuf_fd,
556 		    file_count(dmabuf->file),
557 		    kref_read(&obj->base.refcount));
558 
559 	i915_gem_object_put(obj);
560 
561 	return dmabuf_fd;
562 
563 out_free_dmabuf:
564 	dma_buf_put(dmabuf);
565 out_free_gem:
566 	i915_gem_object_put(obj);
567 out:
568 	mutex_unlock(&vgpu->dmabuf_lock);
569 	return ret;
570 }
571 
572 void intel_vgpu_dmabuf_cleanup(struct intel_vgpu *vgpu)
573 {
574 	struct list_head *pos, *n;
575 	struct intel_vgpu_dmabuf_obj *dmabuf_obj;
576 
577 	mutex_lock(&vgpu->dmabuf_lock);
578 	list_for_each_safe(pos, n, &vgpu->dmabuf_obj_list_head) {
579 		dmabuf_obj = list_entry(pos, struct intel_vgpu_dmabuf_obj, list);
580 		dmabuf_obj->vgpu = NULL;
581 
582 		idr_remove(&vgpu->object_idr, dmabuf_obj->dmabuf_id);
583 		list_del(pos);
584 
585 		/* dmabuf_obj might be freed in dmabuf_obj_put */
586 		if (dmabuf_obj->initref) {
587 			dmabuf_obj->initref = false;
588 			dmabuf_obj_put(dmabuf_obj);
589 		}
590 
591 	}
592 	mutex_unlock(&vgpu->dmabuf_lock);
593 }
594