Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1106 insertions, 0 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
new file mode 100644
index 000000000..ce0ea446b
--- /dev/null
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
@@ -0,0 +1,1106 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Copyright © 2015 Broadcom
+ */
+
+/**
+ * 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 DMA helper functions to allocate contiguous ranges of
+ * physical memory for our BOs.
+ *
+ * Since the DMA 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 <linux/dma-buf.h>
+
+#include <drm/drm_fourcc.h>
+
+#include "vc4_drv.h"
+#include "uapi/drm/vc4_drm.h"
+
+static const struct drm_gem_object_funcs vc4_gem_object_funcs;
+
+static const char * const bo_type_names[] = {
+	"kernel",
+	"V3D",
+	"V3D shader",
+	"dumb",
+	"binner",
+	"RCL",
+	"BCL",
+	"kernel BO cache",
+};
+
+static bool is_user_label(int label)
+{
+	return label >= VC4_BO_TYPE_COUNT;
+}
+
+static void vc4_bo_stats_print(struct drm_printer *p, struct vc4_dev *vc4)
+{
+	int i;
+
+	for (i = 0; i < vc4->num_labels; i++) {
+		if (!vc4->bo_labels[i].num_allocated)
+			continue;
+
+		drm_printf(p, "%30s: %6dkb BOs (%d)\n",
+			   vc4->bo_labels[i].name,
+			   vc4->bo_labels[i].size_allocated / 1024,
+			   vc4->bo_labels[i].num_allocated);
+	}
+
+	mutex_lock(&vc4->purgeable.lock);
+	if (vc4->purgeable.num)
+		drm_printf(p, "%30s: %6zdkb BOs (%d)\n", "userspace BO cache",
+			   vc4->purgeable.size / 1024, vc4->purgeable.num);
+
+	if (vc4->purgeable.purged_num)
+		drm_printf(p, "%30s: %6zdkb BOs (%d)\n", "total purged BO",
+			   vc4->purgeable.purged_size / 1024,
+			   vc4->purgeable.purged_num);
+	mutex_unlock(&vc4->purgeable.lock);
+}
+
+static 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 drm_printer p = drm_seq_file_printer(m);
+
+	vc4_bo_stats_print(&p, vc4);
+
+	return 0;
+}
+
+/* Takes ownership of *name and returns the appropriate slot for it in
+ * the bo_labels[] array, extending it as necessary.
+ *
+ * This is inefficient and could use a hash table instead of walking
+ * an array and strcmp()ing.  However, the assumption is that user
+ * labeling will be infrequent (scanout buffers and other long-lived
+ * objects, or debug driver builds), so we can live with it for now.
+ */
+static int vc4_get_user_label(struct vc4_dev *vc4, const char *name)
+{
+	int i;
+	int free_slot = -1;
+
+	for (i = 0; i < vc4->num_labels; i++) {
+		if (!vc4->bo_labels[i].name) {
+			free_slot = i;
+		} else if (strcmp(vc4->bo_labels[i].name, name) == 0) {
+			kfree(name);
+			return i;
+		}
+	}
+
+	if (free_slot != -1) {
+		WARN_ON(vc4->bo_labels[free_slot].num_allocated != 0);
+		vc4->bo_labels[free_slot].name = name;
+		return free_slot;
+	} else {
+		u32 new_label_count = vc4->num_labels + 1;
+		struct vc4_label *new_labels =
+			krealloc(vc4->bo_labels,
+				 new_label_count * sizeof(*new_labels),
+				 GFP_KERNEL);
+
+		if (!new_labels) {
+			kfree(name);
+			return -1;
+		}
+
+		free_slot = vc4->num_labels;
+		vc4->bo_labels = new_labels;
+		vc4->num_labels = new_label_count;
+
+		vc4->bo_labels[free_slot].name = name;
+		vc4->bo_labels[free_slot].num_allocated = 0;
+		vc4->bo_labels[free_slot].size_allocated = 0;
+
+		return free_slot;
+	}
+}
+
+static void vc4_bo_set_label(struct drm_gem_object *gem_obj, int label)
+{
+	struct vc4_bo *bo = to_vc4_bo(gem_obj);
+	struct vc4_dev *vc4 = to_vc4_dev(gem_obj->dev);
+
+	lockdep_assert_held(&vc4->bo_lock);
+
+	if (label != -1) {
+		vc4->bo_labels[label].num_allocated++;
+		vc4->bo_labels[label].size_allocated += gem_obj->size;
+	}
+
+	vc4->bo_labels[bo->label].num_allocated--;
+	vc4->bo_labels[bo->label].size_allocated -= gem_obj->size;
+
+	if (vc4->bo_labels[bo->label].num_allocated == 0 &&
+	    is_user_label(bo->label)) {
+		/* Free user BO label slots on last unreference.
+		 * Slots are just where we track the stats for a given
+		 * name, and once a name is unused we can reuse that
+		 * slot.
+		 */
+		kfree(vc4->bo_labels[bo->label].name);
+		vc4->bo_labels[bo->label].name = NULL;
+	}
+
+	bo->label = label;
+}
+
+static uint32_t bo_page_index(size_t size)
+{
+	return (size / PAGE_SIZE) - 1;
+}
+
+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);
+
+	lockdep_assert_held(&vc4->bo_lock);
+
+	vc4_bo_set_label(obj, -1);
+
+	if (bo->validated_shader) {
+		kfree(bo->validated_shader->uniform_addr_offsets);
+		kfree(bo->validated_shader->texture_samples);
+		kfree(bo->validated_shader);
+		bo->validated_shader = NULL;
+	}
+
+	mutex_destroy(&bo->madv_lock);
+	drm_gem_dma_free(&bo->base);
+}
+
+static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
+
+	lockdep_assert_held(&vc4->bo_lock);
+	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];
+}
+
+static 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);
+}
+
+void vc4_bo_add_to_purgeable_pool(struct vc4_bo *bo)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return;
+
+	mutex_lock(&vc4->purgeable.lock);
+	list_add_tail(&bo->size_head, &vc4->purgeable.list);
+	vc4->purgeable.num++;
+	vc4->purgeable.size += bo->base.base.size;
+	mutex_unlock(&vc4->purgeable.lock);
+}
+
+static void vc4_bo_remove_from_purgeable_pool_locked(struct vc4_bo *bo)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return;
+
+	/* list_del_init() is used here because the caller might release
+	 * the purgeable lock in order to acquire the madv one and update the
+	 * madv status.
+	 * During this short period of time a user might decide to mark
+	 * the BO as unpurgeable, and if bo->madv is set to
+	 * VC4_MADV_DONTNEED it will try to remove the BO from the
+	 * purgeable list which will fail if the ->next/prev fields
+	 * are set to LIST_POISON1/LIST_POISON2 (which is what
+	 * list_del() does).
+	 * Re-initializing the list element guarantees that list_del()
+	 * will work correctly even if it's a NOP.
+	 */
+	list_del_init(&bo->size_head);
+	vc4->purgeable.num--;
+	vc4->purgeable.size -= bo->base.base.size;
+}
+
+void vc4_bo_remove_from_purgeable_pool(struct vc4_bo *bo)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
+
+	mutex_lock(&vc4->purgeable.lock);
+	vc4_bo_remove_from_purgeable_pool_locked(bo);
+	mutex_unlock(&vc4->purgeable.lock);
+}
+
+static void vc4_bo_purge(struct drm_gem_object *obj)
+{
+	struct vc4_bo *bo = to_vc4_bo(obj);
+	struct drm_device *dev = obj->dev;
+
+	WARN_ON(!mutex_is_locked(&bo->madv_lock));
+	WARN_ON(bo->madv != VC4_MADV_DONTNEED);
+
+	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
+
+	dma_free_wc(dev->dev, obj->size, bo->base.vaddr, bo->base.dma_addr);
+	bo->base.vaddr = NULL;
+	bo->madv = __VC4_MADV_PURGED;
+}
+
+static void vc4_bo_userspace_cache_purge(struct drm_device *dev)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+
+	mutex_lock(&vc4->purgeable.lock);
+	while (!list_empty(&vc4->purgeable.list)) {
+		struct vc4_bo *bo = list_first_entry(&vc4->purgeable.list,
+						     struct vc4_bo, size_head);
+		struct drm_gem_object *obj = &bo->base.base;
+		size_t purged_size = 0;
+
+		vc4_bo_remove_from_purgeable_pool_locked(bo);
+
+		/* Release the purgeable lock while we're purging the BO so
+		 * that other people can continue inserting things in the
+		 * purgeable pool without having to wait for all BOs to be
+		 * purged.
+		 */
+		mutex_unlock(&vc4->purgeable.lock);
+		mutex_lock(&bo->madv_lock);
+
+		/* Since we released the purgeable pool lock before acquiring
+		 * the BO madv one, the user may have marked the BO as WILLNEED
+		 * and re-used it in the meantime.
+		 * Before purging the BO we need to make sure
+		 * - it is still marked as DONTNEED
+		 * - it has not been re-inserted in the purgeable list
+		 * - it is not used by HW blocks
+		 * If one of these conditions is not met, just skip the entry.
+		 */
+		if (bo->madv == VC4_MADV_DONTNEED &&
+		    list_empty(&bo->size_head) &&
+		    !refcount_read(&bo->usecnt)) {
+			purged_size = bo->base.base.size;
+			vc4_bo_purge(obj);
+		}
+		mutex_unlock(&bo->madv_lock);
+		mutex_lock(&vc4->purgeable.lock);
+
+		if (purged_size) {
+			vc4->purgeable.purged_size += purged_size;
+			vc4->purgeable.purged_num++;
+		}
+	}
+	mutex_unlock(&vc4->purgeable.lock);
+}
+
+static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
+					    uint32_t size,
+					    enum vc4_kernel_bo_type type)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	uint32_t page_index = bo_page_index(size);
+	struct vc4_bo *bo = NULL;
+
+	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:
+	if (bo)
+		vc4_bo_set_label(&bo->base.base, type);
+	mutex_unlock(&vc4->bo_lock);
+	return bo;
+}
+
+/**
+ * vc4_create_object - Implementation of driver->gem_create_object.
+ * @dev: DRM device
+ * @size: Size in bytes of the memory the object will reference
+ *
+ * This lets the DMA 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;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return ERR_PTR(-ENODEV);
+
+	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
+	if (!bo)
+		return ERR_PTR(-ENOMEM);
+
+	bo->madv = VC4_MADV_WILLNEED;
+	refcount_set(&bo->usecnt, 0);
+
+	mutex_init(&bo->madv_lock);
+
+	mutex_lock(&vc4->bo_lock);
+	bo->label = VC4_BO_TYPE_KERNEL;
+	vc4->bo_labels[VC4_BO_TYPE_KERNEL].num_allocated++;
+	vc4->bo_labels[VC4_BO_TYPE_KERNEL].size_allocated += size;
+	mutex_unlock(&vc4->bo_lock);
+
+	bo->base.base.funcs = &vc4_gem_object_funcs;
+
+	return &bo->base.base;
+}
+
+struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
+			     bool allow_unzeroed, enum vc4_kernel_bo_type type)
+{
+	size_t size = roundup(unaligned_size, PAGE_SIZE);
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct drm_gem_dma_object *dma_obj;
+	struct vc4_bo *bo;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return ERR_PTR(-ENODEV);
+
+	if (size == 0)
+		return ERR_PTR(-EINVAL);
+
+	/* First, try to get a vc4_bo from the kernel BO cache. */
+	bo = vc4_bo_get_from_cache(dev, size, type);
+	if (bo) {
+		if (!allow_unzeroed)
+			memset(bo->base.vaddr, 0, bo->base.base.size);
+		return bo;
+	}
+
+	dma_obj = drm_gem_dma_create(dev, size);
+	if (IS_ERR(dma_obj)) {
+		/*
+		 * If we've run out of DMA memory, kill the cache of
+		 * DMA allocations we've got laying around and try again.
+		 */
+		vc4_bo_cache_purge(dev);
+		dma_obj = drm_gem_dma_create(dev, size);
+	}
+
+	if (IS_ERR(dma_obj)) {
+		/*
+		 * Still not enough DMA memory, purge the userspace BO
+		 * cache and retry.
+		 * This is sub-optimal since we purge the whole userspace
+		 * BO cache which forces user that want to re-use the BO to
+		 * restore its initial content.
+		 * Ideally, we should purge entries one by one and retry
+		 * after each to see if DMA allocation succeeds. Or even
+		 * better, try to find an entry with at least the same
+		 * size.
+		 */
+		vc4_bo_userspace_cache_purge(dev);
+		dma_obj = drm_gem_dma_create(dev, size);
+	}
+
+	if (IS_ERR(dma_obj)) {
+		struct drm_printer p = drm_info_printer(vc4->base.dev);
+		DRM_ERROR("Failed to allocate from GEM DMA helper:\n");
+		vc4_bo_stats_print(&p, vc4);
+		return ERR_PTR(-ENOMEM);
+	}
+	bo = to_vc4_bo(&dma_obj->base);
+
+	/* By default, BOs do not support the MADV ioctl. This will be enabled
+	 * only on BOs that are exposed to userspace (V3D, V3D_SHADER and DUMB
+	 * BOs).
+	 */
+	bo->madv = __VC4_MADV_NOTSUPP;
+
+	mutex_lock(&vc4->bo_lock);
+	vc4_bo_set_label(&dma_obj->base, type);
+	mutex_unlock(&vc4->bo_lock);
+
+	return bo;
+}
+
+int vc4_bo_dumb_create(struct drm_file *file_priv,
+		       struct drm_device *dev,
+		       struct drm_mode_create_dumb *args)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_bo *bo = NULL;
+	int ret;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	ret = vc4_dumb_fixup_args(args);
+	if (ret)
+		return ret;
+
+	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_DUMB);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	bo->madv = VC4_MADV_WILLNEED;
+
+	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
+	drm_gem_object_put(&bo->base.base);
+
+	return ret;
+}
+
+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);
+
+	lockdep_assert_held(&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);
+		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.
+ */
+static 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;
+
+	/* Remove the BO from the purgeable list. */
+	mutex_lock(&bo->madv_lock);
+	if (bo->madv == VC4_MADV_DONTNEED && !refcount_read(&bo->usecnt))
+		vc4_bo_remove_from_purgeable_pool(bo);
+	mutex_unlock(&bo->madv_lock);
+
+	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;
+	}
+
+	/* If this object was partially constructed but DMA allocation
+	 * had failed, just free it. Can also happen when the BO has been
+	 * purged.
+	 */
+	if (!bo->base.vaddr) {
+		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->uniform_addr_offsets);
+		kfree(bo->validated_shader->texture_samples);
+		kfree(bo->validated_shader);
+		bo->validated_shader = NULL;
+	}
+
+	/* Reset madv and usecnt before adding the BO to the cache. */
+	bo->madv = __VC4_MADV_NOTSUPP;
+	refcount_set(&bo->usecnt, 0);
+
+	bo->t_format = false;
+	bo->free_time = jiffies;
+	list_add(&bo->size_head, cache_list);
+	list_add(&bo->unref_head, &vc4->bo_cache.time_list);
+
+	vc4_bo_set_label(&bo->base.base, VC4_BO_TYPE_KERNEL_CACHE);
+
+	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->base;
+
+	mutex_lock(&vc4->bo_lock);
+	vc4_bo_cache_free_old(dev);
+	mutex_unlock(&vc4->bo_lock);
+}
+
+int vc4_bo_inc_usecnt(struct vc4_bo *bo)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
+	int ret;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	/* Fast path: if the BO is already retained by someone, no need to
+	 * check the madv status.
+	 */
+	if (refcount_inc_not_zero(&bo->usecnt))
+		return 0;
+
+	mutex_lock(&bo->madv_lock);
+	switch (bo->madv) {
+	case VC4_MADV_WILLNEED:
+		if (!refcount_inc_not_zero(&bo->usecnt))
+			refcount_set(&bo->usecnt, 1);
+		ret = 0;
+		break;
+	case VC4_MADV_DONTNEED:
+		/* We shouldn't use a BO marked as purgeable if at least
+		 * someone else retained its content by incrementing usecnt.
+		 * Luckily the BO hasn't been purged yet, but something wrong
+		 * is happening here. Just throw an error instead of
+		 * authorizing this use case.
+		 */
+	case __VC4_MADV_PURGED:
+		/* We can't use a purged BO. */
+	default:
+		/* Invalid madv value. */
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&bo->madv_lock);
+
+	return ret;
+}
+
+void vc4_bo_dec_usecnt(struct vc4_bo *bo)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return;
+
+	/* Fast path: if the BO is still retained by someone, no need to test
+	 * the madv value.
+	 */
+	if (refcount_dec_not_one(&bo->usecnt))
+		return;
+
+	mutex_lock(&bo->madv_lock);
+	if (refcount_dec_and_test(&bo->usecnt) &&
+	    bo->madv == VC4_MADV_DONTNEED)
+		vc4_bo_add_to_purgeable_pool(bo);
+	mutex_unlock(&bo->madv_lock);
+}
+
+static void vc4_bo_cache_time_timer(struct timer_list *t)
+{
+	struct vc4_dev *vc4 = from_timer(vc4, t, bo_cache.time_timer);
+
+	schedule_work(&vc4->bo_cache.time_work);
+}
+
+static struct dma_buf *vc4_prime_export(struct drm_gem_object *obj, int flags)
+{
+	struct vc4_bo *bo = to_vc4_bo(obj);
+	struct dma_buf *dmabuf;
+	int ret;
+
+	if (bo->validated_shader) {
+		DRM_DEBUG("Attempting to export shader BO\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* Note: as soon as the BO is exported it becomes unpurgeable, because
+	 * noone ever decrements the usecnt even if the reference held by the
+	 * exported BO is released. This shouldn't be a problem since we don't
+	 * expect exported BOs to be marked as purgeable.
+	 */
+	ret = vc4_bo_inc_usecnt(bo);
+	if (ret) {
+		DRM_ERROR("Failed to increment BO usecnt\n");
+		return ERR_PTR(ret);
+	}
+
+	dmabuf = drm_gem_prime_export(obj, flags);
+	if (IS_ERR(dmabuf))
+		vc4_bo_dec_usecnt(bo);
+
+	return dmabuf;
+}
+
+static vm_fault_t vc4_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct drm_gem_object *obj = vma->vm_private_data;
+	struct vc4_bo *bo = to_vc4_bo(obj);
+
+	/* The only reason we would end up here is when user-space accesses
+	 * BO's memory after it's been purged.
+	 */
+	mutex_lock(&bo->madv_lock);
+	WARN_ON(bo->madv != __VC4_MADV_PURGED);
+	mutex_unlock(&bo->madv_lock);
+
+	return VM_FAULT_SIGBUS;
+}
+
+static int vc4_gem_object_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_DEBUG("mmaping of shader BOs for writing not allowed.\n");
+		return -EINVAL;
+	}
+
+	if (bo->madv != VC4_MADV_WILLNEED) {
+		DRM_DEBUG("mmaping of %s BO not allowed\n",
+			  bo->madv == VC4_MADV_DONTNEED ?
+			  "purgeable" : "purged");
+		return -EINVAL;
+	}
+
+	return drm_gem_dma_mmap(&bo->base, vma);
+}
+
+static const struct vm_operations_struct vc4_vm_ops = {
+	.fault = vc4_fault,
+	.open = drm_gem_vm_open,
+	.close = drm_gem_vm_close,
+};
+
+static const struct drm_gem_object_funcs vc4_gem_object_funcs = {
+	.free = vc4_free_object,
+	.export = vc4_prime_export,
+	.get_sg_table = drm_gem_dma_object_get_sg_table,
+	.vmap = drm_gem_dma_object_vmap,
+	.mmap = vc4_gem_object_mmap,
+	.vm_ops = &vc4_vm_ops,
+};
+
+static int vc4_grab_bin_bo(struct vc4_dev *vc4, struct vc4_file *vc4file)
+{
+	if (!vc4->v3d)
+		return -ENODEV;
+
+	if (vc4file->bin_bo_used)
+		return 0;
+
+	return vc4_v3d_bin_bo_get(vc4, &vc4file->bin_bo_used);
+}
+
+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_file *vc4file = file_priv->driver_priv;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_bo *bo = NULL;
+	int ret;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	ret = vc4_grab_bin_bo(vc4, vc4file);
+	if (ret)
+		return 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, VC4_BO_TYPE_V3D);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	bo->madv = VC4_MADV_WILLNEED;
+
+	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
+	drm_gem_object_put(&bo->base.base);
+
+	return ret;
+}
+
+int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
+		      struct drm_file *file_priv)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct drm_vc4_mmap_bo *args = data;
+	struct drm_gem_object *gem_obj;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_DEBUG("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_put(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_file *vc4file = file_priv->driver_priv;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_bo *bo = NULL;
+	int ret;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	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;
+	}
+
+	ret = vc4_grab_bin_bo(vc4, vc4file);
+	if (ret)
+		return ret;
+
+	bo = vc4_bo_create(dev, args->size, true, VC4_BO_TYPE_V3D_SHADER);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	bo->madv = VC4_MADV_WILLNEED;
+
+	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_put(&bo->base.base);
+
+	return ret;
+}
+
+/**
+ * vc4_set_tiling_ioctl() - Sets the tiling modifier for a BO.
+ * @dev: DRM device
+ * @data: ioctl argument
+ * @file_priv: DRM file for this fd
+ *
+ * The tiling state of the BO decides the default modifier of an fb if
+ * no specific modifier was set by userspace, and the return value of
+ * vc4_get_tiling_ioctl() (so that userspace can treat a BO it
+ * received from dmabuf as the same tiling format as the producer
+ * used).
+ */
+int vc4_set_tiling_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct drm_vc4_set_tiling *args = data;
+	struct drm_gem_object *gem_obj;
+	struct vc4_bo *bo;
+	bool t_format;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	if (args->flags != 0)
+		return -EINVAL;
+
+	switch (args->modifier) {
+	case DRM_FORMAT_MOD_NONE:
+		t_format = false;
+		break;
+	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
+		t_format = true;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
+		return -ENOENT;
+	}
+	bo = to_vc4_bo(gem_obj);
+	bo->t_format = t_format;
+
+	drm_gem_object_put(gem_obj);
+
+	return 0;
+}
+
+/**
+ * vc4_get_tiling_ioctl() - Gets the tiling modifier for a BO.
+ * @dev: DRM device
+ * @data: ioctl argument
+ * @file_priv: DRM file for this fd
+ *
+ * Returns the tiling modifier for a BO as set by vc4_set_tiling_ioctl().
+ */
+int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct drm_vc4_get_tiling *args = data;
+	struct drm_gem_object *gem_obj;
+	struct vc4_bo *bo;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	if (args->flags != 0 || args->modifier != 0)
+		return -EINVAL;
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
+		return -ENOENT;
+	}
+	bo = to_vc4_bo(gem_obj);
+
+	if (bo->t_format)
+		args->modifier = DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
+	else
+		args->modifier = DRM_FORMAT_MOD_NONE;
+
+	drm_gem_object_put(gem_obj);
+
+	return 0;
+}
+
+int vc4_bo_debugfs_init(struct drm_minor *minor)
+{
+	struct drm_device *drm = minor->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(drm);
+	int ret;
+
+	if (!vc4->v3d)
+		return -ENODEV;
+
+	ret = vc4_debugfs_add_file(minor, "bo_stats",
+				   vc4_bo_stats_debugfs, NULL);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused);
+int vc4_bo_cache_init(struct drm_device *dev)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	int ret;
+	int i;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	/* Create the initial set of BO labels that the kernel will
+	 * use.  This lets us avoid a bunch of string reallocation in
+	 * the kernel's draw and BO allocation paths.
+	 */
+	vc4->bo_labels = kcalloc(VC4_BO_TYPE_COUNT, sizeof(*vc4->bo_labels),
+				 GFP_KERNEL);
+	if (!vc4->bo_labels)
+		return -ENOMEM;
+	vc4->num_labels = VC4_BO_TYPE_COUNT;
+
+	BUILD_BUG_ON(ARRAY_SIZE(bo_type_names) != VC4_BO_TYPE_COUNT);
+	for (i = 0; i < VC4_BO_TYPE_COUNT; i++)
+		vc4->bo_labels[i].name = bo_type_names[i];
+
+	ret = drmm_mutex_init(dev, &vc4->bo_lock);
+	if (ret) {
+		kfree(vc4->bo_labels);
+		return ret;
+	}
+
+	INIT_LIST_HEAD(&vc4->bo_cache.time_list);
+
+	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
+	timer_setup(&vc4->bo_cache.time_timer, vc4_bo_cache_time_timer, 0);
+
+	return drmm_add_action_or_reset(dev, vc4_bo_cache_destroy, NULL);
+}
+
+static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	int i;
+
+	del_timer(&vc4->bo_cache.time_timer);
+	cancel_work_sync(&vc4->bo_cache.time_work);
+
+	vc4_bo_cache_purge(dev);
+
+	for (i = 0; i < vc4->num_labels; i++) {
+		if (vc4->bo_labels[i].num_allocated) {
+			DRM_ERROR("Destroying BO cache with %d %s "
+				  "BOs still allocated\n",
+				  vc4->bo_labels[i].num_allocated,
+				  vc4->bo_labels[i].name);
+		}
+
+		if (is_user_label(i))
+			kfree(vc4->bo_labels[i].name);
+	}
+	kfree(vc4->bo_labels);
+}
+
+int vc4_label_bo_ioctl(struct drm_device *dev, void *data,
+		       struct drm_file *file_priv)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct drm_vc4_label_bo *args = data;
+	char *name;
+	struct drm_gem_object *gem_obj;
+	int ret = 0, label;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	if (!args->len)
+		return -EINVAL;
+
+	name = strndup_user(u64_to_user_ptr(args->name), args->len + 1);
+	if (IS_ERR(name))
+		return PTR_ERR(name);
+
+	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);
+		kfree(name);
+		return -ENOENT;
+	}
+
+	mutex_lock(&vc4->bo_lock);
+	label = vc4_get_user_label(vc4, name);
+	if (label != -1)
+		vc4_bo_set_label(gem_obj, label);
+	else
+		ret = -ENOMEM;
+	mutex_unlock(&vc4->bo_lock);
+
+	drm_gem_object_put(gem_obj);
+
+	return ret;
+}