drivers/gpu/drm/vc4/vc4_bo.c - kernel/msm-4.19 - Gitiles

 /*
  *  Copyright © 2015 Broadcom
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 /* DOC: VC4 GEM BO management support.
  *
  * The VC4 GPU architecture (both scanout and rendering) has direct
  * access to system memory with no MMU in between.  To support it, we
  * use the GEM CMA helper functions to allocate contiguous ranges of
  * physical memory for our BOs.
  *
  * Since the CMA allocator is very slow, we keep a cache of recently
  * freed BOs around so that the kernel's allocation of objects for 3D
  * rendering can return quickly.
  */

 #include "vc4_drv.h"
 #include "uapi/drm/vc4_drm.h"

 static void vc4_bo_stats_dump(struct vc4_dev *vc4)
 {
 	DRM_INFO("num bos allocated: %d\n",
 		 vc4->bo_stats.num_allocated);
 	DRM_INFO("size bos allocated: %dkb\n",
 		 vc4->bo_stats.size_allocated / 1024);
 	DRM_INFO("num bos used: %d\n",
 		 vc4->bo_stats.num_allocated - vc4->bo_stats.num_cached);
 	DRM_INFO("size bos used: %dkb\n",
 		 (vc4->bo_stats.size_allocated -
 		  vc4->bo_stats.size_cached) / 1024);
 	DRM_INFO("num bos cached: %d\n",
 		 vc4->bo_stats.num_cached);
 	DRM_INFO("size bos cached: %dkb\n",
 		 vc4->bo_stats.size_cached / 1024);
 }

 #ifdef CONFIG_DEBUG_FS
 int vc4_bo_stats_debugfs(struct seq_file *m, void *unused)
 {
 	struct drm_info_node *node = (struct drm_info_node *)m->private;
 	struct drm_device *dev = node->minor->dev;
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct vc4_bo_stats stats;

 	/* Take a snapshot of the current stats with the lock held. */
 	mutex_lock(&vc4->bo_lock);
 	stats = vc4->bo_stats;
 	mutex_unlock(&vc4->bo_lock);

 	seq_printf(m, "num bos allocated: %d\n",
 		   stats.num_allocated);
 	seq_printf(m, "size bos allocated: %dkb\n",
 		   stats.size_allocated / 1024);
 	seq_printf(m, "num bos used: %d\n",
 		   stats.num_allocated - stats.num_cached);
 	seq_printf(m, "size bos used: %dkb\n",
 		   (stats.size_allocated - stats.size_cached) / 1024);
 	seq_printf(m, "num bos cached: %d\n",
 		   stats.num_cached);
 	seq_printf(m, "size bos cached: %dkb\n",
 		   stats.size_cached / 1024);

 	return 0;
 }
 #endif

 static uint32_t bo_page_index(size_t size)
 {
 	return (size / PAGE_SIZE) - 1;
 }

 /* Must be called with bo_lock held. */
 static void vc4_bo_destroy(struct vc4_bo *bo)
 {
 	struct drm_gem_object *obj = &bo->base.base;
 	struct vc4_dev *vc4 = to_vc4_dev(obj->dev);

 	if (bo->validated_shader) {
 		kfree(bo->validated_shader->texture_samples);
 		kfree(bo->validated_shader);
 		bo->validated_shader = NULL;
 	}

 	vc4->bo_stats.num_allocated--;
 	vc4->bo_stats.size_allocated -= obj->size;
 	drm_gem_cma_free_object(obj);
 }

 /* Must be called with bo_lock held. */
 static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
 {
 	struct drm_gem_object *obj = &bo->base.base;
 	struct vc4_dev *vc4 = to_vc4_dev(obj->dev);

 	vc4->bo_stats.num_cached--;
 	vc4->bo_stats.size_cached -= obj->size;

 	list_del(&bo->unref_head);
 	list_del(&bo->size_head);
 }

 static struct list_head *vc4_get_cache_list_for_size(struct drm_device *dev,
 						     size_t size)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	uint32_t page_index = bo_page_index(size);

 	if (vc4->bo_cache.size_list_size <= page_index) {
 		uint32_t new_size = max(vc4->bo_cache.size_list_size * 2,
 					page_index + 1);
 		struct list_head *new_list;
 		uint32_t i;

 		new_list = kmalloc_array(new_size, sizeof(struct list_head),
 					 GFP_KERNEL);
 		if (!new_list)
 			return NULL;

 		/* Rebase the old cached BO lists to their new list
 		 * head locations.
 		 */
 		for (i = 0; i < vc4->bo_cache.size_list_size; i++) {
 			struct list_head *old_list =
 				&vc4->bo_cache.size_list[i];

 			if (list_empty(old_list))
 				INIT_LIST_HEAD(&new_list[i]);
 			else
 				list_replace(old_list, &new_list[i]);
 		}
 		/* And initialize the brand new BO list heads. */
 		for (i = vc4->bo_cache.size_list_size; i < new_size; i++)
 			INIT_LIST_HEAD(&new_list[i]);

 		kfree(vc4->bo_cache.size_list);
 		vc4->bo_cache.size_list = new_list;
 		vc4->bo_cache.size_list_size = new_size;
 	}

 	return &vc4->bo_cache.size_list[page_index];
 }

 void vc4_bo_cache_purge(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);

 	mutex_lock(&vc4->bo_lock);
 	while (!list_empty(&vc4->bo_cache.time_list)) {
 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
 						    struct vc4_bo, unref_head);
 		vc4_bo_remove_from_cache(bo);
 		vc4_bo_destroy(bo);
 	}
 	mutex_unlock(&vc4->bo_lock);
 }

 static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
 					    uint32_t size)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	uint32_t page_index = bo_page_index(size);
 	struct vc4_bo *bo = NULL;

 	size = roundup(size, PAGE_SIZE);

 	mutex_lock(&vc4->bo_lock);
 	if (page_index >= vc4->bo_cache.size_list_size)
 		goto out;

 	if (list_empty(&vc4->bo_cache.size_list[page_index]))
 		goto out;

 	bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
 			      struct vc4_bo, size_head);
 	vc4_bo_remove_from_cache(bo);
 	kref_init(&bo->base.base.refcount);

 out:
 	mutex_unlock(&vc4->bo_lock);
 	return bo;
 }

 /**
  * vc4_gem_create_object - Implementation of driver->gem_create_object.
  *
  * This lets the CMA helpers allocate object structs for us, and keep
  * our BO stats correct.
  */
 struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct vc4_bo *bo;

 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
 	if (!bo)
 		return ERR_PTR(-ENOMEM);

 	mutex_lock(&vc4->bo_lock);
 	vc4->bo_stats.num_allocated++;
 	vc4->bo_stats.size_allocated += size;
 	mutex_unlock(&vc4->bo_lock);

 	return &bo->base.base;
 }

 struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
 			     bool from_cache)
 {
 	size_t size = roundup(unaligned_size, PAGE_SIZE);
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct drm_gem_cma_object *cma_obj;

 	if (size == 0)
 		return ERR_PTR(-EINVAL);

 	/* First, try to get a vc4_bo from the kernel BO cache. */
 	if (from_cache) {
 		struct vc4_bo *bo = vc4_bo_get_from_cache(dev, size);

 		if (bo)
 			return bo;
 	}

 	cma_obj = drm_gem_cma_create(dev, size);
 	if (IS_ERR(cma_obj)) {
 		/*
 		 * If we've run out of CMA memory, kill the cache of
 		 * CMA allocations we've got laying around and try again.
 		 */
 		vc4_bo_cache_purge(dev);

 		cma_obj = drm_gem_cma_create(dev, size);
 		if (IS_ERR(cma_obj)) {
 			DRM_ERROR("Failed to allocate from CMA:\n");
 			vc4_bo_stats_dump(vc4);
 			return ERR_PTR(-ENOMEM);
 		}
 	}

 	return to_vc4_bo(&cma_obj->base);
 }

 int vc4_dumb_create(struct drm_file *file_priv,
 		    struct drm_device *dev,
 		    struct drm_mode_create_dumb *args)
 {
 	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
 	struct vc4_bo *bo = NULL;
 	int ret;

 	if (args->pitch < min_pitch)
 		args->pitch = min_pitch;

 	if (args->size < args->pitch * args->height)
 		args->size = args->pitch * args->height;

 	bo = vc4_bo_create(dev, args->size, false);
 	if (IS_ERR(bo))
 		return PTR_ERR(bo);

 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
 	drm_gem_object_unreference_unlocked(&bo->base.base);

 	return ret;
 }

 /* Must be called with bo_lock held. */
 static void vc4_bo_cache_free_old(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	unsigned long expire_time = jiffies - msecs_to_jiffies(1000);

 	while (!list_empty(&vc4->bo_cache.time_list)) {
 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
 						    struct vc4_bo, unref_head);
 		if (time_before(expire_time, bo->free_time)) {
 			mod_timer(&vc4->bo_cache.time_timer,
 				  round_jiffies_up(jiffies +
 						   msecs_to_jiffies(1000)));
 			return;
 		}

 		vc4_bo_remove_from_cache(bo);
 		vc4_bo_destroy(bo);
 	}
 }

 /* Called on the last userspace/kernel unreference of the BO.  Returns
  * it to the BO cache if possible, otherwise frees it.
  */
 void vc4_free_object(struct drm_gem_object *gem_bo)
 {
 	struct drm_device *dev = gem_bo->dev;
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct vc4_bo *bo = to_vc4_bo(gem_bo);
 	struct list_head *cache_list;

 	mutex_lock(&vc4->bo_lock);
 	/* If the object references someone else's memory, we can't cache it.
 	 */
 	if (gem_bo->import_attach) {
 		vc4_bo_destroy(bo);
 		goto out;
 	}

 	/* Don't cache if it was publicly named. */
 	if (gem_bo->name) {
 		vc4_bo_destroy(bo);
 		goto out;
 	}

 	cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
 	if (!cache_list) {
 		vc4_bo_destroy(bo);
 		goto out;
 	}

 	if (bo->validated_shader) {
 		kfree(bo->validated_shader->texture_samples);
 		kfree(bo->validated_shader);
 		bo->validated_shader = NULL;
 	}

 	bo->free_time = jiffies;
 	list_add(&bo->size_head, cache_list);
 	list_add(&bo->unref_head, &vc4->bo_cache.time_list);

 	vc4->bo_stats.num_cached++;
 	vc4->bo_stats.size_cached += gem_bo->size;

 	vc4_bo_cache_free_old(dev);

 out:
 	mutex_unlock(&vc4->bo_lock);
 }

 static void vc4_bo_cache_time_work(struct work_struct *work)
 {
 	struct vc4_dev *vc4 =
 		container_of(work, struct vc4_dev, bo_cache.time_work);
 	struct drm_device *dev = vc4->dev;

 	mutex_lock(&vc4->bo_lock);
 	vc4_bo_cache_free_old(dev);
 	mutex_unlock(&vc4->bo_lock);
 }

 static void vc4_bo_cache_time_timer(unsigned long data)
 {
 	struct drm_device *dev = (struct drm_device *)data;
 	struct vc4_dev *vc4 = to_vc4_dev(dev);

 	schedule_work(&vc4->bo_cache.time_work);
 }

 struct dma_buf *
 vc4_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags)
 {
 	struct vc4_bo *bo = to_vc4_bo(obj);

 	if (bo->validated_shader) {
 		DRM_ERROR("Attempting to export shader BO\n");
 		return ERR_PTR(-EINVAL);
 	}

 	return drm_gem_prime_export(dev, obj, flags);
 }

 int vc4_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	struct drm_gem_object *gem_obj;
 	struct vc4_bo *bo;
 	int ret;

 	ret = drm_gem_mmap(filp, vma);
 	if (ret)
 		return ret;

 	gem_obj = vma->vm_private_data;
 	bo = to_vc4_bo(gem_obj);

 	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
 		DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
 		return -EINVAL;
 	}

 	/*
 	 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
 	 * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
 	 * the whole buffer.
 	 */
 	vma->vm_flags &= ~VM_PFNMAP;
 	vma->vm_pgoff = 0;

 	ret = dma_mmap_wc(bo->base.base.dev->dev, vma, bo->base.vaddr,
 			  bo->base.paddr, vma->vm_end - vma->vm_start);
 	if (ret)
 		drm_gem_vm_close(vma);

 	return ret;
 }

 int vc4_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 {
 	struct vc4_bo *bo = to_vc4_bo(obj);

 	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
 		DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
 		return -EINVAL;
 	}

 	return drm_gem_cma_prime_mmap(obj, vma);
 }

 void *vc4_prime_vmap(struct drm_gem_object *obj)
 {
 	struct vc4_bo *bo = to_vc4_bo(obj);

 	if (bo->validated_shader) {
 		DRM_ERROR("mmaping of shader BOs not allowed.\n");
 		return ERR_PTR(-EINVAL);
 	}

 	return drm_gem_cma_prime_vmap(obj);
 }

 int vc4_create_bo_ioctl(struct drm_device *dev, void *data,
 			struct drm_file *file_priv)
 {
 	struct drm_vc4_create_bo *args = data;
 	struct vc4_bo *bo = NULL;
 	int ret;

 	/*
 	 * We can't allocate from the BO cache, because the BOs don't
 	 * get zeroed, and that might leak data between users.
 	 */
 	bo = vc4_bo_create(dev, args->size, false);
 	if (IS_ERR(bo))
 		return PTR_ERR(bo);

 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
 	drm_gem_object_unreference_unlocked(&bo->base.base);

 	return ret;
 }

 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
 		      struct drm_file *file_priv)
 {
 	struct drm_vc4_mmap_bo *args = data;
 	struct drm_gem_object *gem_obj;

 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
 	if (!gem_obj) {
 		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
 		return -EINVAL;
 	}

 	/* The mmap offset was set up at BO allocation time. */
 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);

 	drm_gem_object_unreference_unlocked(gem_obj);
 	return 0;
 }

 int
 vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
 			   struct drm_file *file_priv)
 {
 	struct drm_vc4_create_shader_bo *args = data;
 	struct vc4_bo *bo = NULL;
 	int ret;

 	if (args->size == 0)
 		return -EINVAL;

 	if (args->size % sizeof(u64) != 0)
 		return -EINVAL;

 	if (args->flags != 0) {
 		DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
 		return -EINVAL;
 	}

 	if (args->pad != 0) {
 		DRM_INFO("Pad set: 0x%08x\n", args->pad);
 		return -EINVAL;
 	}

 	bo = vc4_bo_create(dev, args->size, true);
 	if (IS_ERR(bo))
 		return PTR_ERR(bo);

 	if (copy_from_user(bo->base.vaddr,
 			     (void __user *)(uintptr_t)args->data,
 			     args->size)) {
 		ret = -EFAULT;
 		goto fail;
 	}
 	/* Clear the rest of the memory from allocating from the BO
 	 * cache.
 	 */
 	memset(bo->base.vaddr + args->size, 0,
 	       bo->base.base.size - args->size);

 	bo->validated_shader = vc4_validate_shader(&bo->base);
 	if (!bo->validated_shader) {
 		ret = -EINVAL;
 		goto fail;
 	}

 	/* We have to create the handle after validation, to avoid
 	 * races for users to do doing things like mmap the shader BO.
 	 */
 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);

  fail:
 	drm_gem_object_unreference_unlocked(&bo->base.base);

 	return ret;
 }

 void vc4_bo_cache_init(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);

 	mutex_init(&vc4->bo_lock);

 	INIT_LIST_HEAD(&vc4->bo_cache.time_list);

 	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
 	setup_timer(&vc4->bo_cache.time_timer,
 		    vc4_bo_cache_time_timer,
 		    (unsigned long)dev);
 }

 void vc4_bo_cache_destroy(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);

 	del_timer(&vc4->bo_cache.time_timer);
 	cancel_work_sync(&vc4->bo_cache.time_work);

 	vc4_bo_cache_purge(dev);

 	if (vc4->bo_stats.num_allocated) {
 		DRM_ERROR("Destroying BO cache while BOs still allocated:\n");
 		vc4_bo_stats_dump(vc4);
 	}
 }
	/*
	* Copyright © 2015 Broadcom
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	/* DOC: VC4 GEM BO management support.
	*
	* The VC4 GPU architecture (both scanout and rendering) has direct
	* access to system memory with no MMU in between. To support it, we
	* use the GEM CMA helper functions to allocate contiguous ranges of
	* physical memory for our BOs.
	*
	* Since the CMA allocator is very slow, we keep a cache of recently
	* freed BOs around so that the kernel's allocation of objects for 3D
	* rendering can return quickly.
	*/

	#include "vc4_drv.h"
	#include "uapi/drm/vc4_drm.h"

	static void vc4_bo_stats_dump(struct vc4_dev *vc4)
	{
	DRM_INFO("num bos allocated: %d\n",
	vc4->bo_stats.num_allocated);
	DRM_INFO("size bos allocated: %dkb\n",
	vc4->bo_stats.size_allocated / 1024);
	DRM_INFO("num bos used: %d\n",
	vc4->bo_stats.num_allocated - vc4->bo_stats.num_cached);
	DRM_INFO("size bos used: %dkb\n",
	(vc4->bo_stats.size_allocated -
	vc4->bo_stats.size_cached) / 1024);
	DRM_INFO("num bos cached: %d\n",
	vc4->bo_stats.num_cached);
	DRM_INFO("size bos cached: %dkb\n",
	vc4->bo_stats.size_cached / 1024);
	}

	#ifdef CONFIG_DEBUG_FS
	int vc4_bo_stats_debugfs(struct seq_file m, void unused)
	{
	struct drm_info_node node = (struct drm_info_node )m->private;
	struct drm_device *dev = node->minor->dev;
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	struct vc4_bo_stats stats;

	/* Take a snapshot of the current stats with the lock held. */
	mutex_lock(&vc4->bo_lock);
	stats = vc4->bo_stats;
	mutex_unlock(&vc4->bo_lock);

	seq_printf(m, "num bos allocated: %d\n",
	stats.num_allocated);
	seq_printf(m, "size bos allocated: %dkb\n",
	stats.size_allocated / 1024);
	seq_printf(m, "num bos used: %d\n",
	stats.num_allocated - stats.num_cached);
	seq_printf(m, "size bos used: %dkb\n",
	(stats.size_allocated - stats.size_cached) / 1024);
	seq_printf(m, "num bos cached: %d\n",
	stats.num_cached);
	seq_printf(m, "size bos cached: %dkb\n",
	stats.size_cached / 1024);

	return 0;
	}
	#endif

	static uint32_t bo_page_index(size_t size)
	{
	return (size / PAGE_SIZE) - 1;
	}

	/* Must be called with bo_lock held. */
	static void vc4_bo_destroy(struct vc4_bo *bo)
	{
	struct drm_gem_object *obj = &bo->base.base;
	struct vc4_dev *vc4 = to_vc4_dev(obj->dev);

	if (bo->validated_shader) {
	kfree(bo->validated_shader->texture_samples);
	kfree(bo->validated_shader);
	bo->validated_shader = NULL;
	}

	vc4->bo_stats.num_allocated--;
	vc4->bo_stats.size_allocated -= obj->size;
	drm_gem_cma_free_object(obj);
	}

	/* Must be called with bo_lock held. */
	static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
	{
	struct drm_gem_object *obj = &bo->base.base;
	struct vc4_dev *vc4 = to_vc4_dev(obj->dev);

	vc4->bo_stats.num_cached--;
	vc4->bo_stats.size_cached -= obj->size;

	list_del(&bo->unref_head);
	list_del(&bo->size_head);
	}

	static struct list_head vc4_get_cache_list_for_size(struct drm_device dev,
	size_t size)
	{
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	uint32_t page_index = bo_page_index(size);

	if (vc4->bo_cache.size_list_size <= page_index) {
	uint32_t new_size = max(vc4->bo_cache.size_list_size * 2,
	page_index + 1);
	struct list_head *new_list;
	uint32_t i;

	new_list = kmalloc_array(new_size, sizeof(struct list_head),
	GFP_KERNEL);
	if (!new_list)
	return NULL;

	/* Rebase the old cached BO lists to their new list
	* head locations.
	*/
	for (i = 0; i < vc4->bo_cache.size_list_size; i++) {
	struct list_head *old_list =
	&vc4->bo_cache.size_list[i];

	if (list_empty(old_list))
	INIT_LIST_HEAD(&new_list[i]);
	else
	list_replace(old_list, &new_list[i]);
	}
	/* And initialize the brand new BO list heads. */
	for (i = vc4->bo_cache.size_list_size; i < new_size; i++)
	INIT_LIST_HEAD(&new_list[i]);

	kfree(vc4->bo_cache.size_list);
	vc4->bo_cache.size_list = new_list;
	vc4->bo_cache.size_list_size = new_size;
	}

	return &vc4->bo_cache.size_list[page_index];
	}

	void vc4_bo_cache_purge(struct drm_device *dev)
	{
	struct vc4_dev *vc4 = to_vc4_dev(dev);

	mutex_lock(&vc4->bo_lock);
	while (!list_empty(&vc4->bo_cache.time_list)) {
	struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
	struct vc4_bo, unref_head);
	vc4_bo_remove_from_cache(bo);
	vc4_bo_destroy(bo);
	}
	mutex_unlock(&vc4->bo_lock);
	}

	static struct vc4_bo vc4_bo_get_from_cache(struct drm_device dev,
	uint32_t size)
	{
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	uint32_t page_index = bo_page_index(size);
	struct vc4_bo *bo = NULL;

	size = roundup(size, PAGE_SIZE);

	mutex_lock(&vc4->bo_lock);
	if (page_index >= vc4->bo_cache.size_list_size)
	goto out;

	if (list_empty(&vc4->bo_cache.size_list[page_index]))
	goto out;

	bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
	struct vc4_bo, size_head);
	vc4_bo_remove_from_cache(bo);
	kref_init(&bo->base.base.refcount);

	out:
	mutex_unlock(&vc4->bo_lock);
	return bo;
	}

	/**
	* vc4_gem_create_object - Implementation of driver->gem_create_object.
	*
	* This lets the CMA helpers allocate object structs for us, and keep
	* our BO stats correct.
	*/
	struct drm_gem_object vc4_create_object(struct drm_device dev, size_t size)
	{
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	struct vc4_bo *bo;

	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
	if (!bo)
	return ERR_PTR(-ENOMEM);

	mutex_lock(&vc4->bo_lock);
	vc4->bo_stats.num_allocated++;
	vc4->bo_stats.size_allocated += size;
	mutex_unlock(&vc4->bo_lock);

	return &bo->base.base;
	}

	struct vc4_bo vc4_bo_create(struct drm_device dev, size_t unaligned_size,
	bool from_cache)
	{
	size_t size = roundup(unaligned_size, PAGE_SIZE);
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	struct drm_gem_cma_object *cma_obj;

	if (size == 0)
	return ERR_PTR(-EINVAL);

	/* First, try to get a vc4_bo from the kernel BO cache. */
	if (from_cache) {
	struct vc4_bo *bo = vc4_bo_get_from_cache(dev, size);

	if (bo)
	return bo;
	}

	cma_obj = drm_gem_cma_create(dev, size);
	if (IS_ERR(cma_obj)) {
	/*
	* If we've run out of CMA memory, kill the cache of
	* CMA allocations we've got laying around and try again.
	*/
	vc4_bo_cache_purge(dev);

	cma_obj = drm_gem_cma_create(dev, size);
	if (IS_ERR(cma_obj)) {
	DRM_ERROR("Failed to allocate from CMA:\n");
	vc4_bo_stats_dump(vc4);
	return ERR_PTR(-ENOMEM);
	}
	}

	return to_vc4_bo(&cma_obj->base);
	}

	int vc4_dumb_create(struct drm_file *file_priv,
	struct drm_device *dev,
	struct drm_mode_create_dumb *args)
	{
	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
	struct vc4_bo *bo = NULL;
	int ret;

	if (args->pitch < min_pitch)
	args->pitch = min_pitch;

	if (args->size < args->pitch * args->height)
	args->size = args->pitch * args->height;

	bo = vc4_bo_create(dev, args->size, false);
	if (IS_ERR(bo))
	return PTR_ERR(bo);

	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
	drm_gem_object_unreference_unlocked(&bo->base.base);

	return ret;
	}

	/* Must be called with bo_lock held. */
	static void vc4_bo_cache_free_old(struct drm_device *dev)
	{
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	unsigned long expire_time = jiffies - msecs_to_jiffies(1000);

	while (!list_empty(&vc4->bo_cache.time_list)) {
	struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
	struct vc4_bo, unref_head);
	if (time_before(expire_time, bo->free_time)) {
	mod_timer(&vc4->bo_cache.time_timer,
	round_jiffies_up(jiffies +
	msecs_to_jiffies(1000)));
	return;
	}

	vc4_bo_remove_from_cache(bo);
	vc4_bo_destroy(bo);
	}
	}

	/* Called on the last userspace/kernel unreference of the BO. Returns
	* it to the BO cache if possible, otherwise frees it.
	*/
	void vc4_free_object(struct drm_gem_object *gem_bo)
	{
	struct drm_device *dev = gem_bo->dev;
	struct vc4_dev *vc4 = to_vc4_dev(dev);
	struct vc4_bo *bo = to_vc4_bo(gem_bo);
	struct list_head *cache_list;

	mutex_lock(&vc4->bo_lock);
	/* If the object references someone else's memory, we can't cache it.
	*/
	if (gem_bo->import_attach) {
	vc4_bo_destroy(bo);
	goto out;
	}

	/* Don't cache if it was publicly named. */
	if (gem_bo->name) {
	vc4_bo_destroy(bo);
	goto out;
	}

	cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
	if (!cache_list) {
	vc4_bo_destroy(bo);
	goto out;
	}

	if (bo->validated_shader) {
	kfree(bo->validated_shader->texture_samples);
	kfree(bo->validated_shader);
	bo->validated_shader = NULL;
	}

	bo->free_time = jiffies;
	list_add(&bo->size_head, cache_list);
	list_add(&bo->unref_head, &vc4->bo_cache.time_list);

	vc4->bo_stats.num_cached++;
	vc4->bo_stats.size_cached += gem_bo->size;

	vc4_bo_cache_free_old(dev);

	out:
	mutex_unlock(&vc4->bo_lock);
	}

	static void vc4_bo_cache_time_work(struct work_struct *work)
	{
	struct vc4_dev *vc4 =
	container_of(work, struct vc4_dev, bo_cache.time_work);
	struct drm_device *dev = vc4->dev;

	mutex_lock(&vc4->bo_lock);
	vc4_bo_cache_free_old(dev);
	mutex_unlock(&vc4->bo_lock);
	}

	static void vc4_bo_cache_time_timer(unsigned long data)
	{
	struct drm_device dev = (struct drm_device )data;
	struct vc4_dev *vc4 = to_vc4_dev(dev);

	schedule_work(&vc4->bo_cache.time_work);
	}

	struct dma_buf *
	vc4_prime_export(struct drm_device dev, struct drm_gem_object obj, int flags)
	{
	struct vc4_bo *bo = to_vc4_bo(obj);

	if (bo->validated_shader) {
	DRM_ERROR("Attempting to export shader BO\n");
	return ERR_PTR(-EINVAL);
	}

	return drm_gem_prime_export(dev, obj, flags);
	}

	int vc4_mmap(struct file filp, struct vm_area_struct vma)
	{
	struct drm_gem_object *gem_obj;
	struct vc4_bo *bo;
	int ret;

	ret = drm_gem_mmap(filp, vma);
	if (ret)
	return ret;

	gem_obj = vma->vm_private_data;
	bo = to_vc4_bo(gem_obj);

	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
	DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
	return -EINVAL;
	}

	/*
	* Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
	* vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
	* the whole buffer.
	*/
	vma->vm_flags &= ~VM_PFNMAP;
	vma->vm_pgoff = 0;

	ret = dma_mmap_wc(bo->base.base.dev->dev, vma, bo->base.vaddr,
	bo->base.paddr, vma->vm_end - vma->vm_start);
	if (ret)
	drm_gem_vm_close(vma);

	return ret;
	}

	int vc4_prime_mmap(struct drm_gem_object obj, struct vm_area_struct vma)
	{
	struct vc4_bo *bo = to_vc4_bo(obj);

	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
	DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
	return -EINVAL;
	}

	return drm_gem_cma_prime_mmap(obj, vma);
	}

	void vc4_prime_vmap(struct drm_gem_object obj)
	{
	struct vc4_bo *bo = to_vc4_bo(obj);

	if (bo->validated_shader) {
	DRM_ERROR("mmaping of shader BOs not allowed.\n");
	return ERR_PTR(-EINVAL);
	}

	return drm_gem_cma_prime_vmap(obj);
	}

	int vc4_create_bo_ioctl(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	struct drm_vc4_create_bo *args = data;
	struct vc4_bo *bo = NULL;
	int ret;

	/*
	* We can't allocate from the BO cache, because the BOs don't
	* get zeroed, and that might leak data between users.
	*/
	bo = vc4_bo_create(dev, args->size, false);
	if (IS_ERR(bo))
	return PTR_ERR(bo);

	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
	drm_gem_object_unreference_unlocked(&bo->base.base);

	return ret;
	}

	int vc4_mmap_bo_ioctl(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	struct drm_vc4_mmap_bo *args = data;
	struct drm_gem_object *gem_obj;

	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
	if (!gem_obj) {
	DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
	return -EINVAL;
	}

	/* The mmap offset was set up at BO allocation time. */
	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);

	drm_gem_object_unreference_unlocked(gem_obj);
	return 0;
	}

	int
	vc4_create_shader_bo_ioctl(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	struct drm_vc4_create_shader_bo *args = data;
	struct vc4_bo *bo = NULL;
	int ret;

	if (args->size == 0)
	return -EINVAL;

	if (args->size % sizeof(u64) != 0)
	return -EINVAL;

	if (args->flags != 0) {
	DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
	return -EINVAL;
	}

	if (args->pad != 0) {
	DRM_INFO("Pad set: 0x%08x\n", args->pad);
	return -EINVAL;
	}

	bo = vc4_bo_create(dev, args->size, true);
	if (IS_ERR(bo))
	return PTR_ERR(bo);

	if (copy_from_user(bo->base.vaddr,
	(void __user *)(uintptr_t)args->data,
	args->size)) {
	ret = -EFAULT;
	goto fail;
	}
	/* Clear the rest of the memory from allocating from the BO
	* cache.
	*/
	memset(bo->base.vaddr + args->size, 0,
	bo->base.base.size - args->size);

	bo->validated_shader = vc4_validate_shader(&bo->base);
	if (!bo->validated_shader) {
	ret = -EINVAL;
	goto fail;
	}

	/* We have to create the handle after validation, to avoid
	* races for users to do doing things like mmap the shader BO.
	*/
	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);

	fail:
	drm_gem_object_unreference_unlocked(&bo->base.base);

	return ret;
	}

	void vc4_bo_cache_init(struct drm_device *dev)
	{
	struct vc4_dev *vc4 = to_vc4_dev(dev);

	mutex_init(&vc4->bo_lock);

	INIT_LIST_HEAD(&vc4->bo_cache.time_list);

	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
	setup_timer(&vc4->bo_cache.time_timer,
	vc4_bo_cache_time_timer,
	(unsigned long)dev);
	}

	void vc4_bo_cache_destroy(struct drm_device *dev)
	{
	struct vc4_dev *vc4 = to_vc4_dev(dev);

	del_timer(&vc4->bo_cache.time_timer);
	cancel_work_sync(&vc4->bo_cache.time_work);

	vc4_bo_cache_purge(dev);

	if (vc4->bo_stats.num_allocated) {
	DRM_ERROR("Destroying BO cache while BOs still allocated:\n");
	vc4_bo_stats_dump(vc4);
	}
	}