drivers/gpu/drm/qxl/qxl_release.c - linux - Git at Google

 /*
  * Copyright 2011 Red Hat, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * on the rights to use, copy, modify, merge, publish, distribute, sub
  * license, and/or sell copies of the Software, and to permit persons to whom
  * the Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */

 #include <linux/delay.h>

 #include <trace/events/dma_fence.h>

 #include "qxl_drv.h"
 #include "qxl_object.h"

 /*
  * drawable cmd cache - allocate a bunch of VRAM pages, suballocate
  * into 256 byte chunks for now - gives 16 cmds per page.
  *
  * use an ida to index into the chunks?
  */
 /* manage releaseables */
 /* stack them 16 high for now -drawable object is 191 */
 #define RELEASE_SIZE 256
 #define RELEASES_PER_BO (PAGE_SIZE / RELEASE_SIZE)
 /* put an alloc/dealloc surface cmd into one bo and round up to 128 */
 #define SURFACE_RELEASE_SIZE 128
 #define SURFACE_RELEASES_PER_BO (PAGE_SIZE / SURFACE_RELEASE_SIZE)

 static const int release_size_per_bo[] = { RELEASE_SIZE, SURFACE_RELEASE_SIZE, RELEASE_SIZE };
 static const int releases_per_bo[] = { RELEASES_PER_BO, SURFACE_RELEASES_PER_BO, RELEASES_PER_BO };

 static const char *qxl_get_driver_name(struct dma_fence *fence)
 {
 	return "qxl";
 }

 static const char *qxl_get_timeline_name(struct dma_fence *fence)
 {
 	return "release";
 }

 static long qxl_fence_wait(struct dma_fence *fence, bool intr,
 			   signed long timeout)
 {
 	struct qxl_device *qdev;
 	unsigned long cur, end = jiffies + timeout;

 	qdev = container_of(fence->lock, struct qxl_device, release_lock);

 	if (!wait_event_timeout(qdev->release_event,
 				(dma_fence_is_signaled(fence) ||
 				 (qxl_io_notify_oom(qdev), 0)),
 				timeout))
 		return 0;

 	cur = jiffies;
 	if (time_after(cur, end))
 		return 0;
 	return end - cur;
 }

 static const struct dma_fence_ops qxl_fence_ops = {
 	.get_driver_name = qxl_get_driver_name,
 	.get_timeline_name = qxl_get_timeline_name,
 	.wait = qxl_fence_wait,
 };

 static int
 qxl_release_alloc(struct qxl_device *qdev, int type,
 		  struct qxl_release **ret)
 {
 	struct qxl_release *release;
 	int handle;
 	size_t size = sizeof(*release);

 	release = kmalloc(size, GFP_KERNEL);
 	if (!release) {
 		DRM_ERROR("Out of memory\n");
 		return -ENOMEM;
 	}
 	release->base.ops = NULL;
 	release->type = type;
 	release->release_offset = 0;
 	release->surface_release_id = 0;
 	INIT_LIST_HEAD(&release->bos);

 	idr_preload(GFP_KERNEL);
 	spin_lock(&qdev->release_idr_lock);
 	handle = idr_alloc(&qdev->release_idr, release, 1, 0, GFP_NOWAIT);
 	release->base.seqno = ++qdev->release_seqno;
 	spin_unlock(&qdev->release_idr_lock);
 	idr_preload_end();
 	if (handle < 0) {
 		kfree(release);
 		*ret = NULL;
 		return handle;
 	}
 	*ret = release;
 	DRM_DEBUG_DRIVER("allocated release %d\n", handle);
 	release->id = handle;
 	return handle;
 }

 static void
 qxl_release_free_list(struct qxl_release *release)
 {
 	while (!list_empty(&release->bos)) {
 		struct qxl_bo_list *entry;
 		struct qxl_bo *bo;

 		entry = container_of(release->bos.next,
 				     struct qxl_bo_list, tv.head);
 		bo = to_qxl_bo(entry->tv.bo);
 		qxl_bo_unref(&bo);
 		list_del(&entry->tv.head);
 		kfree(entry);
 	}
 	release->release_bo = NULL;
 }

 void
 qxl_release_free(struct qxl_device *qdev,
 		 struct qxl_release *release)
 {
 	DRM_DEBUG_DRIVER("release %d, type %d\n", release->id, release->type);

 	if (release->surface_release_id)
 		qxl_surface_id_dealloc(qdev, release->surface_release_id);

 	spin_lock(&qdev->release_idr_lock);
 	idr_remove(&qdev->release_idr, release->id);
 	spin_unlock(&qdev->release_idr_lock);

 	if (release->base.ops) {
 		WARN_ON(list_empty(&release->bos));
 		qxl_release_free_list(release);

 		dma_fence_signal(&release->base);
 		dma_fence_put(&release->base);
 	} else {
 		qxl_release_free_list(release);
 		kfree(release);
 	}
 	atomic_dec(&qdev->release_count);
 }

 static int qxl_release_bo_alloc(struct qxl_device *qdev,
 				struct qxl_bo **bo,
 				u32 priority)
 {
 	/* pin releases bo's they are too messy to evict */
 	return qxl_bo_create(qdev, PAGE_SIZE, false, true,
 			     QXL_GEM_DOMAIN_VRAM, priority, NULL, bo);
 }

 int qxl_release_list_add(struct qxl_release *release, struct qxl_bo *bo)
 {
 	struct qxl_bo_list *entry;

 	list_for_each_entry(entry, &release->bos, tv.head) {
 		if (entry->tv.bo == &bo->tbo)
 			return 0;
 	}

 	entry = kmalloc(sizeof(struct qxl_bo_list), GFP_KERNEL);
 	if (!entry)
 		return -ENOMEM;

 	qxl_bo_ref(bo);
 	entry->tv.bo = &bo->tbo;
 	entry->tv.num_shared = 0;
 	list_add_tail(&entry->tv.head, &release->bos);
 	return 0;
 }

 static int qxl_release_validate_bo(struct qxl_bo *bo)
 {
 	struct ttm_operation_ctx ctx = { true, false };
 	int ret;

 	if (!bo->tbo.pin_count) {
 		qxl_ttm_placement_from_domain(bo, bo->type);
 		ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
 		if (ret)
 			return ret;
 	}

 	ret = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
 	if (ret)
 		return ret;

 	/* allocate a surface for reserved + validated buffers */
 	ret = qxl_bo_check_id(to_qxl(bo->tbo.base.dev), bo);
 	if (ret)
 		return ret;
 	return 0;
 }

 int qxl_release_reserve_list(struct qxl_release *release, bool no_intr)
 {
 	int ret;
 	struct qxl_bo_list *entry;

 	/* if only one object on the release its the release itself
 	   since these objects are pinned no need to reserve */
 	if (list_is_singular(&release->bos))
 		return 0;

 	ret = ttm_eu_reserve_buffers(&release->ticket, &release->bos,
 				     !no_intr, NULL);
 	if (ret)
 		return ret;

 	list_for_each_entry(entry, &release->bos, tv.head) {
 		struct qxl_bo *bo = to_qxl_bo(entry->tv.bo);

 		ret = qxl_release_validate_bo(bo);
 		if (ret) {
 			ttm_eu_backoff_reservation(&release->ticket, &release->bos);
 			return ret;
 		}
 	}
 	return 0;
 }

 void qxl_release_backoff_reserve_list(struct qxl_release *release)
 {
 	/* if only one object on the release its the release itself
 	   since these objects are pinned no need to reserve */
 	if (list_is_singular(&release->bos))
 		return;

 	ttm_eu_backoff_reservation(&release->ticket, &release->bos);
 }

 int qxl_alloc_surface_release_reserved(struct qxl_device *qdev,
 				       enum qxl_surface_cmd_type surface_cmd_type,
 				       struct qxl_release *create_rel,
 				       struct qxl_release **release)
 {
 	if (surface_cmd_type == QXL_SURFACE_CMD_DESTROY && create_rel) {
 		int idr_ret;
 		struct qxl_bo *bo;
 		union qxl_release_info *info;

 		/* stash the release after the create command */
 		idr_ret = qxl_release_alloc(qdev, QXL_RELEASE_SURFACE_CMD, release);
 		if (idr_ret < 0)
 			return idr_ret;
 		bo = create_rel->release_bo;

 		(*release)->release_bo = bo;
 		(*release)->release_offset = create_rel->release_offset + 64;

 		qxl_release_list_add(*release, bo);

 		info = qxl_release_map(qdev, *release);
 		info->id = idr_ret;
 		qxl_release_unmap(qdev, *release, info);
 		return 0;
 	}

 	return qxl_alloc_release_reserved(qdev, sizeof(struct qxl_surface_cmd),
 					 QXL_RELEASE_SURFACE_CMD, release, NULL);
 }

 int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
 				       int type, struct qxl_release **release,
 				       struct qxl_bo **rbo)
 {
 	struct qxl_bo *bo, *free_bo = NULL;
 	int idr_ret;
 	int ret = 0;
 	union qxl_release_info *info;
 	int cur_idx;
 	u32 priority;

 	if (type == QXL_RELEASE_DRAWABLE) {
 		cur_idx = 0;
 		priority = 0;
 	} else if (type == QXL_RELEASE_SURFACE_CMD) {
 		cur_idx = 1;
 		priority = 1;
 	} else if (type == QXL_RELEASE_CURSOR_CMD) {
 		cur_idx = 2;
 		priority = 1;
 	}
 	else {
 		DRM_ERROR("got illegal type: %d\n", type);
 		return -EINVAL;
 	}

 	idr_ret = qxl_release_alloc(qdev, type, release);
 	if (idr_ret < 0) {
 		if (rbo)
 			*rbo = NULL;
 		return idr_ret;
 	}
 	atomic_inc(&qdev->release_count);

 	mutex_lock(&qdev->release_mutex);
 	if (qdev->current_release_bo_offset[cur_idx] + 1 >= releases_per_bo[cur_idx]) {
 		free_bo = qdev->current_release_bo[cur_idx];
 		qdev->current_release_bo_offset[cur_idx] = 0;
 		qdev->current_release_bo[cur_idx] = NULL;
 	}
 	if (!qdev->current_release_bo[cur_idx]) {
 		ret = qxl_release_bo_alloc(qdev, &qdev->current_release_bo[cur_idx], priority);
 		if (ret) {
 			mutex_unlock(&qdev->release_mutex);
 			if (free_bo) {
 				qxl_bo_unpin(free_bo);
 				qxl_bo_unref(&free_bo);
 			}
 			qxl_release_free(qdev, *release);
 			return ret;
 		}
 	}

 	bo = qxl_bo_ref(qdev->current_release_bo[cur_idx]);

 	(*release)->release_bo = bo;
 	(*release)->release_offset = qdev->current_release_bo_offset[cur_idx] * release_size_per_bo[cur_idx];
 	qdev->current_release_bo_offset[cur_idx]++;

 	if (rbo)
 		*rbo = bo;

 	mutex_unlock(&qdev->release_mutex);
 	if (free_bo) {
 		qxl_bo_unpin(free_bo);
 		qxl_bo_unref(&free_bo);
 	}

 	ret = qxl_release_list_add(*release, bo);
 	qxl_bo_unref(&bo);
 	if (ret) {
 		qxl_release_free(qdev, *release);
 		return ret;
 	}

 	info = qxl_release_map(qdev, *release);
 	info->id = idr_ret;
 	qxl_release_unmap(qdev, *release, info);

 	return ret;
 }

 struct qxl_release *qxl_release_from_id_locked(struct qxl_device *qdev,
 						   uint64_t id)
 {
 	struct qxl_release *release;

 	spin_lock(&qdev->release_idr_lock);
 	release = idr_find(&qdev->release_idr, id);
 	spin_unlock(&qdev->release_idr_lock);
 	if (!release) {
 		DRM_ERROR("failed to find id in release_idr\n");
 		return NULL;
 	}

 	return release;
 }

 union qxl_release_info *qxl_release_map(struct qxl_device *qdev,
 					struct qxl_release *release)
 {
 	void *ptr;
 	union qxl_release_info *info;
 	struct qxl_bo *bo = release->release_bo;

 	ptr = qxl_bo_kmap_atomic_page(qdev, bo, release->release_offset & PAGE_MASK);
 	if (!ptr)
 		return NULL;
 	info = ptr + (release->release_offset & ~PAGE_MASK);
 	return info;
 }

 void qxl_release_unmap(struct qxl_device *qdev,
 		       struct qxl_release *release,
 		       union qxl_release_info *info)
 {
 	struct qxl_bo *bo = release->release_bo;
 	void *ptr;

 	ptr = ((void *)info) - (release->release_offset & ~PAGE_MASK);
 	qxl_bo_kunmap_atomic_page(qdev, bo, ptr);
 }

 void qxl_release_fence_buffer_objects(struct qxl_release *release)
 {
 	struct ttm_buffer_object *bo;
 	struct ttm_device *bdev;
 	struct ttm_validate_buffer *entry;
 	struct qxl_device *qdev;

 	/* if only one object on the release its the release itself
 	   since these objects are pinned no need to reserve */
 	if (list_is_singular(&release->bos) || list_empty(&release->bos))
 		return;

 	bo = list_first_entry(&release->bos, struct ttm_validate_buffer, head)->bo;
 	bdev = bo->bdev;
 	qdev = container_of(bdev, struct qxl_device, mman.bdev);

 	/*
 	 * Since we never really allocated a context and we don't want to conflict,
 	 * set the highest bits. This will break if we really allow exporting of dma-bufs.
 	 */
 	dma_fence_init(&release->base, &qxl_fence_ops, &qdev->release_lock,
 		       release->id | 0xf0000000, release->base.seqno);
 	trace_dma_fence_emit(&release->base);

 	list_for_each_entry(entry, &release->bos, head) {
 		bo = entry->bo;

 		dma_resv_add_fence(bo->base.resv, &release->base,
 				   DMA_RESV_USAGE_READ);
 		ttm_bo_move_to_lru_tail_unlocked(bo);
 		dma_resv_unlock(bo->base.resv);
 	}
 	ww_acquire_fini(&release->ticket);
 }
	/*
	* Copyright 2011 Red Hat, Inc.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* on the rights to use, copy, modify, merge, publish, distribute, sub
	* license, and/or sell copies of the Software, and to permit persons to whom
	* the Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice (including the next
	* paragraph) shall be included in all copies or substantial portions of the
	* Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
	* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/

	#include <linux/delay.h>

	#include <trace/events/dma_fence.h>

	#include "qxl_drv.h"
	#include "qxl_object.h"

	/*
	* drawable cmd cache - allocate a bunch of VRAM pages, suballocate
	* into 256 byte chunks for now - gives 16 cmds per page.
	*
	* use an ida to index into the chunks?
	*/
	/* manage releaseables */
	/* stack them 16 high for now -drawable object is 191 */
	#define RELEASE_SIZE 256
	#define RELEASES_PER_BO (PAGE_SIZE / RELEASE_SIZE)
	/* put an alloc/dealloc surface cmd into one bo and round up to 128 */
	#define SURFACE_RELEASE_SIZE 128
	#define SURFACE_RELEASES_PER_BO (PAGE_SIZE / SURFACE_RELEASE_SIZE)

	static const int release_size_per_bo[] = { RELEASE_SIZE, SURFACE_RELEASE_SIZE, RELEASE_SIZE };
	static const int releases_per_bo[] = { RELEASES_PER_BO, SURFACE_RELEASES_PER_BO, RELEASES_PER_BO };

	static const char qxl_get_driver_name(struct dma_fence fence)
	{
	return "qxl";
	}

	static const char qxl_get_timeline_name(struct dma_fence fence)
	{
	return "release";
	}

	static long qxl_fence_wait(struct dma_fence *fence, bool intr,
	signed long timeout)
	{
	struct qxl_device *qdev;
	unsigned long cur, end = jiffies + timeout;

	qdev = container_of(fence->lock, struct qxl_device, release_lock);

	if (!wait_event_timeout(qdev->release_event,
	(dma_fence_is_signaled(fence) \|\|
	(qxl_io_notify_oom(qdev), 0)),
	timeout))
	return 0;

	cur = jiffies;
	if (time_after(cur, end))
	return 0;
	return end - cur;
	}

	static const struct dma_fence_ops qxl_fence_ops = {
	.get_driver_name = qxl_get_driver_name,
	.get_timeline_name = qxl_get_timeline_name,
	.wait = qxl_fence_wait,
	};

	static int
	qxl_release_alloc(struct qxl_device *qdev, int type,
	struct qxl_release **ret)
	{
	struct qxl_release *release;
	int handle;
	size_t size = sizeof(*release);

	release = kmalloc(size, GFP_KERNEL);
	if (!release) {
	DRM_ERROR("Out of memory\n");
	return -ENOMEM;
	}
	release->base.ops = NULL;
	release->type = type;
	release->release_offset = 0;
	release->surface_release_id = 0;
	INIT_LIST_HEAD(&release->bos);

	idr_preload(GFP_KERNEL);
	spin_lock(&qdev->release_idr_lock);
	handle = idr_alloc(&qdev->release_idr, release, 1, 0, GFP_NOWAIT);
	release->base.seqno = ++qdev->release_seqno;
	spin_unlock(&qdev->release_idr_lock);
	idr_preload_end();
	if (handle < 0) {
	kfree(release);
	*ret = NULL;
	return handle;
	}
	*ret = release;
	DRM_DEBUG_DRIVER("allocated release %d\n", handle);
	release->id = handle;
	return handle;
	}

	static void
	qxl_release_free_list(struct qxl_release *release)
	{
	while (!list_empty(&release->bos)) {
	struct qxl_bo_list *entry;
	struct qxl_bo *bo;

	entry = container_of(release->bos.next,
	struct qxl_bo_list, tv.head);
	bo = to_qxl_bo(entry->tv.bo);
	qxl_bo_unref(&bo);
	list_del(&entry->tv.head);
	kfree(entry);
	}
	release->release_bo = NULL;
	}

	void
	qxl_release_free(struct qxl_device *qdev,
	struct qxl_release *release)
	{
	DRM_DEBUG_DRIVER("release %d, type %d\n", release->id, release->type);

	if (release->surface_release_id)
	qxl_surface_id_dealloc(qdev, release->surface_release_id);

	spin_lock(&qdev->release_idr_lock);
	idr_remove(&qdev->release_idr, release->id);
	spin_unlock(&qdev->release_idr_lock);

	if (release->base.ops) {
	WARN_ON(list_empty(&release->bos));
	qxl_release_free_list(release);

	dma_fence_signal(&release->base);
	dma_fence_put(&release->base);
	} else {
	qxl_release_free_list(release);
	kfree(release);
	}
	atomic_dec(&qdev->release_count);
	}

	static int qxl_release_bo_alloc(struct qxl_device *qdev,
	struct qxl_bo **bo,
	u32 priority)
	{
	/* pin releases bo's they are too messy to evict */
	return qxl_bo_create(qdev, PAGE_SIZE, false, true,
	QXL_GEM_DOMAIN_VRAM, priority, NULL, bo);
	}

	int qxl_release_list_add(struct qxl_release release, struct qxl_bo bo)
	{
	struct qxl_bo_list *entry;

	list_for_each_entry(entry, &release->bos, tv.head) {
	if (entry->tv.bo == &bo->tbo)
	return 0;
	}

	entry = kmalloc(sizeof(struct qxl_bo_list), GFP_KERNEL);
	if (!entry)
	return -ENOMEM;

	qxl_bo_ref(bo);
	entry->tv.bo = &bo->tbo;
	entry->tv.num_shared = 0;
	list_add_tail(&entry->tv.head, &release->bos);
	return 0;
	}

	static int qxl_release_validate_bo(struct qxl_bo *bo)
	{
	struct ttm_operation_ctx ctx = { true, false };
	int ret;

	if (!bo->tbo.pin_count) {
	qxl_ttm_placement_from_domain(bo, bo->type);
	ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
	if (ret)
	return ret;
	}

	ret = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
	if (ret)
	return ret;

	/* allocate a surface for reserved + validated buffers */
	ret = qxl_bo_check_id(to_qxl(bo->tbo.base.dev), bo);
	if (ret)
	return ret;
	return 0;
	}

	int qxl_release_reserve_list(struct qxl_release *release, bool no_intr)
	{
	int ret;
	struct qxl_bo_list *entry;

	/* if only one object on the release its the release itself
	since these objects are pinned no need to reserve */
	if (list_is_singular(&release->bos))
	return 0;

	ret = ttm_eu_reserve_buffers(&release->ticket, &release->bos,
	!no_intr, NULL);
	if (ret)
	return ret;

	list_for_each_entry(entry, &release->bos, tv.head) {
	struct qxl_bo *bo = to_qxl_bo(entry->tv.bo);

	ret = qxl_release_validate_bo(bo);
	if (ret) {
	ttm_eu_backoff_reservation(&release->ticket, &release->bos);
	return ret;
	}
	}
	return 0;
	}

	void qxl_release_backoff_reserve_list(struct qxl_release *release)
	{
	/* if only one object on the release its the release itself
	since these objects are pinned no need to reserve */
	if (list_is_singular(&release->bos))
	return;

	ttm_eu_backoff_reservation(&release->ticket, &release->bos);
	}

	int qxl_alloc_surface_release_reserved(struct qxl_device *qdev,
	enum qxl_surface_cmd_type surface_cmd_type,
	struct qxl_release *create_rel,
	struct qxl_release **release)
	{
	if (surface_cmd_type == QXL_SURFACE_CMD_DESTROY && create_rel) {
	int idr_ret;
	struct qxl_bo *bo;
	union qxl_release_info *info;

	/* stash the release after the create command */
	idr_ret = qxl_release_alloc(qdev, QXL_RELEASE_SURFACE_CMD, release);
	if (idr_ret < 0)
	return idr_ret;
	bo = create_rel->release_bo;

	(*release)->release_bo = bo;
	(*release)->release_offset = create_rel->release_offset + 64;

	qxl_release_list_add(*release, bo);

	info = qxl_release_map(qdev, *release);
	info->id = idr_ret;
	qxl_release_unmap(qdev, *release, info);
	return 0;
	}

	return qxl_alloc_release_reserved(qdev, sizeof(struct qxl_surface_cmd),
	QXL_RELEASE_SURFACE_CMD, release, NULL);
	}

	int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
	int type, struct qxl_release **release,
	struct qxl_bo **rbo)
	{
	struct qxl_bo bo, free_bo = NULL;
	int idr_ret;
	int ret = 0;
	union qxl_release_info *info;
	int cur_idx;
	u32 priority;

	if (type == QXL_RELEASE_DRAWABLE) {
	cur_idx = 0;
	priority = 0;
	} else if (type == QXL_RELEASE_SURFACE_CMD) {
	cur_idx = 1;
	priority = 1;
	} else if (type == QXL_RELEASE_CURSOR_CMD) {
	cur_idx = 2;
	priority = 1;
	}
	else {
	DRM_ERROR("got illegal type: %d\n", type);
	return -EINVAL;
	}

	idr_ret = qxl_release_alloc(qdev, type, release);
	if (idr_ret < 0) {
	if (rbo)
	*rbo = NULL;
	return idr_ret;
	}
	atomic_inc(&qdev->release_count);

	mutex_lock(&qdev->release_mutex);
	if (qdev->current_release_bo_offset[cur_idx] + 1 >= releases_per_bo[cur_idx]) {
	free_bo = qdev->current_release_bo[cur_idx];
	qdev->current_release_bo_offset[cur_idx] = 0;
	qdev->current_release_bo[cur_idx] = NULL;
	}
	if (!qdev->current_release_bo[cur_idx]) {
	ret = qxl_release_bo_alloc(qdev, &qdev->current_release_bo[cur_idx], priority);
	if (ret) {
	mutex_unlock(&qdev->release_mutex);
	if (free_bo) {
	qxl_bo_unpin(free_bo);
	qxl_bo_unref(&free_bo);
	}
	qxl_release_free(qdev, *release);
	return ret;
	}
	}

	bo = qxl_bo_ref(qdev->current_release_bo[cur_idx]);

	(*release)->release_bo = bo;
	(release)->release_offset = qdev->current_release_bo_offset[cur_idx] release_size_per_bo[cur_idx];
	qdev->current_release_bo_offset[cur_idx]++;

	if (rbo)
	*rbo = bo;

	mutex_unlock(&qdev->release_mutex);
	if (free_bo) {
	qxl_bo_unpin(free_bo);
	qxl_bo_unref(&free_bo);
	}

	ret = qxl_release_list_add(*release, bo);
	qxl_bo_unref(&bo);
	if (ret) {
	qxl_release_free(qdev, *release);
	return ret;
	}

	info = qxl_release_map(qdev, *release);
	info->id = idr_ret;
	qxl_release_unmap(qdev, *release, info);

	return ret;
	}

	struct qxl_release qxl_release_from_id_locked(struct qxl_device qdev,
	uint64_t id)
	{
	struct qxl_release *release;

	spin_lock(&qdev->release_idr_lock);
	release = idr_find(&qdev->release_idr, id);
	spin_unlock(&qdev->release_idr_lock);
	if (!release) {
	DRM_ERROR("failed to find id in release_idr\n");
	return NULL;
	}

	return release;
	}

	union qxl_release_info qxl_release_map(struct qxl_device qdev,
	struct qxl_release *release)
	{
	void *ptr;
	union qxl_release_info *info;
	struct qxl_bo *bo = release->release_bo;

	ptr = qxl_bo_kmap_atomic_page(qdev, bo, release->release_offset & PAGE_MASK);
	if (!ptr)
	return NULL;
	info = ptr + (release->release_offset & ~PAGE_MASK);
	return info;
	}

	void qxl_release_unmap(struct qxl_device *qdev,
	struct qxl_release *release,
	union qxl_release_info *info)
	{
	struct qxl_bo *bo = release->release_bo;
	void *ptr;

	ptr = ((void *)info) - (release->release_offset & ~PAGE_MASK);
	qxl_bo_kunmap_atomic_page(qdev, bo, ptr);
	}

	void qxl_release_fence_buffer_objects(struct qxl_release *release)
	{
	struct ttm_buffer_object *bo;
	struct ttm_device *bdev;
	struct ttm_validate_buffer *entry;
	struct qxl_device *qdev;

	/* if only one object on the release its the release itself
	since these objects are pinned no need to reserve */
	if (list_is_singular(&release->bos) \|\| list_empty(&release->bos))
	return;

	bo = list_first_entry(&release->bos, struct ttm_validate_buffer, head)->bo;
	bdev = bo->bdev;
	qdev = container_of(bdev, struct qxl_device, mman.bdev);

	/*
	* Since we never really allocated a context and we don't want to conflict,
	* set the highest bits. This will break if we really allow exporting of dma-bufs.
	*/
	dma_fence_init(&release->base, &qxl_fence_ops, &qdev->release_lock,
	release->id \| 0xf0000000, release->base.seqno);
	trace_dma_fence_emit(&release->base);

	list_for_each_entry(entry, &release->bos, head) {
	bo = entry->bo;

	dma_resv_add_fence(bo->base.resv, &release->base,
	DMA_RESV_USAGE_READ);
	ttm_bo_move_to_lru_tail_unlocked(bo);
	dma_resv_unlock(bo->base.resv);
	}
	ww_acquire_fini(&release->ticket);
	}