1 files changed, 386 insertions, 257 deletions

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 35138f8a375c..dc94a27710e5 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -10,7 +10,6 @@
 #include <linux/shmem_fs.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
-#include <linux/module.h>
 
 #ifdef CONFIG_X86
 #include <asm/set_memory.h>
@@ -19,11 +18,12 @@
 #include <drm/drm.h>
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
+#include <drm/drm_dumb_buffers.h>
 #include <drm/drm_gem_shmem_helper.h>
 #include <drm/drm_prime.h>
 #include <drm/drm_print.h>
 
-MODULE_IMPORT_NS(DMA_BUF);
+MODULE_IMPORT_NS("DMA_BUF");
 
 /**
  * DOC: overview
@@ -49,27 +49,12 @@ static const struct drm_gem_object_funcs drm_gem_shmem_funcs = {
 	.vm_ops = &drm_gem_shmem_vm_ops,
 };
 
-static struct drm_gem_shmem_object *
-__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
+static int __drm_gem_shmem_init(struct drm_device *dev, struct drm_gem_shmem_object *shmem,
+				size_t size, bool private, struct vfsmount *gemfs)
 {
-	struct drm_gem_shmem_object *shmem;
-	struct drm_gem_object *obj;
+	struct drm_gem_object *obj = &shmem->base;
 	int ret = 0;
 
-	size = PAGE_ALIGN(size);
-
-	if (dev->driver->gem_create_object) {
-		obj = dev->driver->gem_create_object(dev, size);
-		if (IS_ERR(obj))
-			return ERR_CAST(obj);
-		shmem = to_drm_gem_shmem_obj(obj);
-	} else {
-		shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
-		if (!shmem)
-			return ERR_PTR(-ENOMEM);
-		obj = &shmem->base;
-	}
-
 	if (!obj->funcs)
 		obj->funcs = &drm_gem_shmem_funcs;
 
@@ -77,17 +62,17 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
 		drm_gem_private_object_init(dev, obj, size);
 		shmem->map_wc = false; /* dma-buf mappings use always writecombine */
 	} else {
-		ret = drm_gem_object_init(dev, obj, size);
+		ret = drm_gem_object_init_with_mnt(dev, obj, size, gemfs);
+	}
+	if (ret) {
+		drm_gem_private_object_fini(obj);
+		return ret;
 	}
-	if (ret)
-		goto err_free;
 
 	ret = drm_gem_create_mmap_offset(obj);
 	if (ret)
 		goto err_release;
 
-	mutex_init(&shmem->pages_lock);
-	mutex_init(&shmem->vmap_lock);
 	INIT_LIST_HEAD(&shmem->madv_list);
 
 	if (!private) {
@@ -102,14 +87,55 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
 				     __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
 	}
 
-	return shmem;
-
+	return 0;
 err_release:
 	drm_gem_object_release(obj);
-err_free:
-	kfree(obj);
+	return ret;
+}
 
-	return ERR_PTR(ret);
+/**
+ * drm_gem_shmem_init - Initialize an allocated object.
+ * @dev: DRM device
+ * @obj: The allocated shmem GEM object.
+ *
+ * Returns:
+ * 0 on success, or a negative error code on failure.
+ */
+int drm_gem_shmem_init(struct drm_device *dev, struct drm_gem_shmem_object *shmem, size_t size)
+{
+	return __drm_gem_shmem_init(dev, shmem, size, false, NULL);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_init);
+
+static struct drm_gem_shmem_object *
+__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private,
+		       struct vfsmount *gemfs)
+{
+	struct drm_gem_shmem_object *shmem;
+	struct drm_gem_object *obj;
+	int ret = 0;
+
+	size = PAGE_ALIGN(size);
+
+	if (dev->driver->gem_create_object) {
+		obj = dev->driver->gem_create_object(dev, size);
+		if (IS_ERR(obj))
+			return ERR_CAST(obj);
+		shmem = to_drm_gem_shmem_obj(obj);
+	} else {
+		shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
+		if (!shmem)
+			return ERR_PTR(-ENOMEM);
+		obj = &shmem->base;
+	}
+
+	ret = __drm_gem_shmem_init(dev, shmem, size, private, gemfs);
+	if (ret) {
+		kfree(obj);
+		return ERR_PTR(ret);
+	}
+
+	return shmem;
 }
 /**
  * drm_gem_shmem_create - Allocate an object with the given size
@@ -124,26 +150,49 @@ err_free:
  */
 struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size)
 {
-	return __drm_gem_shmem_create(dev, size, false);
+	return __drm_gem_shmem_create(dev, size, false, NULL);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_create);
 
 /**
- * drm_gem_shmem_free - Free resources associated with a shmem GEM object
- * @shmem: shmem GEM object to free
+ * drm_gem_shmem_create_with_mnt - Allocate an object with the given size in a
+ * given mountpoint
+ * @dev: DRM device
+ * @size: Size of the object to allocate
+ * @gemfs: tmpfs mount where the GEM object will be created
  *
- * This function cleans up the GEM object state and frees the memory used to
- * store the object itself.
+ * This function creates a shmem GEM object in a given tmpfs mountpoint.
+ *
+ * Returns:
+ * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative
+ * error code on failure.
  */
-void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
+struct drm_gem_shmem_object *drm_gem_shmem_create_with_mnt(struct drm_device *dev,
+							   size_t size,
+							   struct vfsmount *gemfs)
 {
-	struct drm_gem_object *obj = &shmem->base;
+	return __drm_gem_shmem_create(dev, size, false, gemfs);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_create_with_mnt);
 
-	WARN_ON(shmem->vmap_use_count);
+/**
+ * drm_gem_shmem_release - Release resources associated with a shmem GEM object.
+ * @shmem: shmem GEM object
+ *
+ * This function cleans up the GEM object state, but does not free the memory used to store the
+ * object itself. This function is meant to be a dedicated helper for the Rust GEM bindings.
+ */
+void drm_gem_shmem_release(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
 
-	if (obj->import_attach) {
+	if (drm_gem_is_imported(obj)) {
 		drm_prime_gem_destroy(obj, shmem->sgt);
 	} else {
+		dma_resv_lock(shmem->base.resv, NULL);
+
+		drm_WARN_ON(obj->dev, refcount_read(&shmem->vmap_use_count));
+
 		if (shmem->sgt) {
 			dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
 					  DMA_BIDIRECTIONAL, 0);
@@ -151,14 +200,28 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
 			kfree(shmem->sgt);
 		}
 		if (shmem->pages)
-			drm_gem_shmem_put_pages(shmem);
-	}
+			drm_gem_shmem_put_pages_locked(shmem);
 
-	WARN_ON(shmem->pages_use_count);
+		drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_use_count));
+		drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_pin_count));
+
+		dma_resv_unlock(shmem->base.resv);
+	}
 
 	drm_gem_object_release(obj);
-	mutex_destroy(&shmem->pages_lock);
-	mutex_destroy(&shmem->vmap_lock);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_release);
+
+/**
+ * drm_gem_shmem_free - Free resources associated with a shmem GEM object
+ * @shmem: shmem GEM object to free
+ *
+ * This function cleans up the GEM object state and frees the memory used to
+ * store the object itself.
+ */
+void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
+{
+	drm_gem_shmem_release(shmem);
 	kfree(shmem);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_free);
@@ -168,13 +231,15 @@ static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
 	struct drm_gem_object *obj = &shmem->base;
 	struct page **pages;
 
-	if (shmem->pages_use_count++ > 0)
+	dma_resv_assert_held(shmem->base.resv);
+
+	if (refcount_inc_not_zero(&shmem->pages_use_count))
 		return 0;
 
 	pages = drm_gem_get_pages(obj);
 	if (IS_ERR(pages)) {
-		DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages));
-		shmem->pages_use_count = 0;
+		drm_dbg_kms(obj->dev, "Failed to get pages (%ld)\n",
+			    PTR_ERR(pages));
 		return PTR_ERR(pages);
 	}
 
@@ -190,69 +255,64 @@ static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
 
 	shmem->pages = pages;
 
+	refcount_set(&shmem->pages_use_count, 1);
+
 	return 0;
 }
 
 /*
- * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object
+ * drm_gem_shmem_put_pages_locked - Decrease use count on the backing pages for a shmem GEM object
  * @shmem: shmem GEM object
  *
- * This function makes sure that backing pages exists for the shmem GEM object
- * and increases the use count.
- *
- * Returns:
- * 0 on success or a negative error code on failure.
+ * This function decreases the use count and puts the backing pages when use drops to zero.
  */
-int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
+void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
 {
-	int ret;
+	struct drm_gem_object *obj = &shmem->base;
 
-	WARN_ON(shmem->base.import_attach);
+	dma_resv_assert_held(shmem->base.resv);
 
-	ret = mutex_lock_interruptible(&shmem->pages_lock);
-	if (ret)
-		return ret;
-	ret = drm_gem_shmem_get_pages_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
+	if (refcount_dec_and_test(&shmem->pages_use_count)) {
+#ifdef CONFIG_X86
+		if (shmem->map_wc)
+			set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT);
+#endif
 
-	return ret;
+		drm_gem_put_pages(obj, shmem->pages,
+				  shmem->pages_mark_dirty_on_put,
+				  shmem->pages_mark_accessed_on_put);
+		shmem->pages = NULL;
+	}
 }
-EXPORT_SYMBOL(drm_gem_shmem_get_pages);
+EXPORT_SYMBOL_GPL(drm_gem_shmem_put_pages_locked);
 
-static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
+int drm_gem_shmem_pin_locked(struct drm_gem_shmem_object *shmem)
 {
-	struct drm_gem_object *obj = &shmem->base;
+	int ret;
 
-	if (WARN_ON_ONCE(!shmem->pages_use_count))
-		return;
+	dma_resv_assert_held(shmem->base.resv);
 
-	if (--shmem->pages_use_count > 0)
-		return;
+	drm_WARN_ON(shmem->base.dev, drm_gem_is_imported(&shmem->base));
 
-#ifdef CONFIG_X86
-	if (shmem->map_wc)
-		set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT);
-#endif
+	if (refcount_inc_not_zero(&shmem->pages_pin_count))
+		return 0;
+
+	ret = drm_gem_shmem_get_pages_locked(shmem);
+	if (!ret)
+		refcount_set(&shmem->pages_pin_count, 1);
 
-	drm_gem_put_pages(obj, shmem->pages,
-			  shmem->pages_mark_dirty_on_put,
-			  shmem->pages_mark_accessed_on_put);
-	shmem->pages = NULL;
+	return ret;
 }
+EXPORT_SYMBOL(drm_gem_shmem_pin_locked);
 
-/*
- * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object
- * @shmem: shmem GEM object
- *
- * This function decreases the use count and puts the backing pages when use drops to zero.
- */
-void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
+void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem)
 {
-	mutex_lock(&shmem->pages_lock);
-	drm_gem_shmem_put_pages_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_assert_held(shmem->base.resv);
+
+	if (refcount_dec_and_test(&shmem->pages_pin_count))
+		drm_gem_shmem_put_pages_locked(shmem);
 }
-EXPORT_SYMBOL(drm_gem_shmem_put_pages);
+EXPORT_SYMBOL(drm_gem_shmem_unpin_locked);
 
 /**
  * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object
@@ -266,11 +326,23 @@ EXPORT_SYMBOL(drm_gem_shmem_put_pages);
  */
 int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem)
 {
-	WARN_ON(shmem->base.import_attach);
+	struct drm_gem_object *obj = &shmem->base;
+	int ret;
 
-	return drm_gem_shmem_get_pages(shmem);
+	drm_WARN_ON(obj->dev, drm_gem_is_imported(obj));
+
+	if (refcount_inc_not_zero(&shmem->pages_pin_count))
+		return 0;
+
+	ret = dma_resv_lock_interruptible(shmem->base.resv, NULL);
+	if (ret)
+		return ret;
+	ret = drm_gem_shmem_pin_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
+	return ret;
 }
-EXPORT_SYMBOL(drm_gem_shmem_pin);
+EXPORT_SYMBOL_GPL(drm_gem_shmem_pin);
 
 /**
  * drm_gem_shmem_unpin - Unpin backing pages for a shmem GEM object
@@ -281,139 +353,120 @@ EXPORT_SYMBOL(drm_gem_shmem_pin);
  */
 void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem)
 {
-	WARN_ON(shmem->base.import_attach);
+	struct drm_gem_object *obj = &shmem->base;
+
+	drm_WARN_ON(obj->dev, drm_gem_is_imported(obj));
+
+	if (refcount_dec_not_one(&shmem->pages_pin_count))
+		return;
 
-	drm_gem_shmem_put_pages(shmem);
+	dma_resv_lock(shmem->base.resv, NULL);
+	drm_gem_shmem_unpin_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
 }
-EXPORT_SYMBOL(drm_gem_shmem_unpin);
+EXPORT_SYMBOL_GPL(drm_gem_shmem_unpin);
 
-static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
-				     struct iosys_map *map)
+/*
+ * drm_gem_shmem_vmap_locked - Create a virtual mapping for a shmem GEM object
+ * @shmem: shmem GEM object
+ * @map: Returns the kernel virtual address of the SHMEM GEM object's backing
+ *       store.
+ *
+ * This function makes sure that a contiguous kernel virtual address mapping
+ * exists for the buffer backing the shmem GEM object. It hides the differences
+ * between dma-buf imported and natively allocated objects.
+ *
+ * Acquired mappings should be cleaned up by calling drm_gem_shmem_vunmap_locked().
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
+			      struct iosys_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	int ret = 0;
 
-	if (shmem->vmap_use_count++ > 0) {
-		iosys_map_set_vaddr(map, shmem->vaddr);
-		return 0;
-	}
+	dma_resv_assert_held(obj->resv);
 
-	if (obj->import_attach) {
+	if (drm_gem_is_imported(obj)) {
 		ret = dma_buf_vmap(obj->import_attach->dmabuf, map);
-		if (!ret) {
-			if (WARN_ON(map->is_iomem)) {
-				dma_buf_vunmap(obj->import_attach->dmabuf, map);
-				ret = -EIO;
-				goto err_put_pages;
-			}
-			shmem->vaddr = map->vaddr;
-		}
 	} else {
 		pgprot_t prot = PAGE_KERNEL;
 
-		ret = drm_gem_shmem_get_pages(shmem);
+		dma_resv_assert_held(shmem->base.resv);
+
+		if (refcount_inc_not_zero(&shmem->vmap_use_count)) {
+			iosys_map_set_vaddr(map, shmem->vaddr);
+			return 0;
+		}
+
+		ret = drm_gem_shmem_pin_locked(shmem);
 		if (ret)
-			goto err_zero_use;
+			return ret;
 
 		if (shmem->map_wc)
 			prot = pgprot_writecombine(prot);
 		shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
 				    VM_MAP, prot);
-		if (!shmem->vaddr)
+		if (!shmem->vaddr) {
 			ret = -ENOMEM;
-		else
+		} else {
 			iosys_map_set_vaddr(map, shmem->vaddr);
+			refcount_set(&shmem->vmap_use_count, 1);
+		}
 	}
 
 	if (ret) {
-		DRM_DEBUG_KMS("Failed to vmap pages, error %d\n", ret);
+		drm_dbg_kms(obj->dev, "Failed to vmap pages, error %d\n", ret);
 		goto err_put_pages;
 	}
 
 	return 0;
 
 err_put_pages:
-	if (!obj->import_attach)
-		drm_gem_shmem_put_pages(shmem);
-err_zero_use:
-	shmem->vmap_use_count = 0;
+	if (!drm_gem_is_imported(obj))
+		drm_gem_shmem_unpin_locked(shmem);
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(drm_gem_shmem_vmap_locked);
 
 /*
- * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object
+ * drm_gem_shmem_vunmap_locked - Unmap a virtual mapping for a shmem GEM object
  * @shmem: shmem GEM object
- * @map: Returns the kernel virtual address of the SHMEM GEM object's backing
- *       store.
- *
- * This function makes sure that a contiguous kernel virtual address mapping
- * exists for the buffer backing the shmem GEM object. It hides the differences
- * between dma-buf imported and natively allocated objects.
+ * @map: Kernel virtual address where the SHMEM GEM object was mapped
  *
- * Acquired mappings should be cleaned up by calling drm_gem_shmem_vunmap().
+ * This function cleans up a kernel virtual address mapping acquired by
+ * drm_gem_shmem_vmap_locked(). The mapping is only removed when the use count
+ * drops to zero.
  *
- * Returns:
- * 0 on success or a negative error code on failure.
+ * This function hides the differences between dma-buf imported and natively
+ * allocated objects.
  */
-int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
-		       struct iosys_map *map)
-{
-	int ret;
-
-	ret = mutex_lock_interruptible(&shmem->vmap_lock);
-	if (ret)
-		return ret;
-	ret = drm_gem_shmem_vmap_locked(shmem, map);
-	mutex_unlock(&shmem->vmap_lock);
-
-	return ret;
-}
-EXPORT_SYMBOL(drm_gem_shmem_vmap);
-
-static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
-					struct iosys_map *map)
+void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
+				 struct iosys_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
-	if (WARN_ON_ONCE(!shmem->vmap_use_count))
-		return;
-
-	if (--shmem->vmap_use_count > 0)
-		return;
+	dma_resv_assert_held(obj->resv);
 
-	if (obj->import_attach) {
+	if (drm_gem_is_imported(obj)) {
 		dma_buf_vunmap(obj->import_attach->dmabuf, map);
 	} else {
-		vunmap(shmem->vaddr);
-		drm_gem_shmem_put_pages(shmem);
-	}
+		dma_resv_assert_held(shmem->base.resv);
 
-	shmem->vaddr = NULL;
-}
+		if (refcount_dec_and_test(&shmem->vmap_use_count)) {
+			vunmap(shmem->vaddr);
+			shmem->vaddr = NULL;
 
-/*
- * drm_gem_shmem_vunmap - Unmap a virtual mapping for a shmem GEM object
- * @shmem: shmem GEM object
- * @map: Kernel virtual address where the SHMEM GEM object was mapped
- *
- * This function cleans up a kernel virtual address mapping acquired by
- * drm_gem_shmem_vmap(). The mapping is only removed when the use count drops to
- * zero.
- *
- * This function hides the differences between dma-buf imported and natively
- * allocated objects.
- */
-void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
-			  struct iosys_map *map)
-{
-	mutex_lock(&shmem->vmap_lock);
-	drm_gem_shmem_vunmap_locked(shmem, map);
-	mutex_unlock(&shmem->vmap_lock);
+			drm_gem_shmem_unpin_locked(shmem);
+		}
+	}
 }
-EXPORT_SYMBOL(drm_gem_shmem_vunmap);
+EXPORT_SYMBOL_GPL(drm_gem_shmem_vunmap_locked);
 
-static struct drm_gem_shmem_object *
+static int
 drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
 				 struct drm_device *dev, size_t size,
 				 uint32_t *handle)
@@ -423,7 +476,7 @@ drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
 
 	shmem = drm_gem_shmem_create(dev, size);
 	if (IS_ERR(shmem))
-		return shmem;
+		return PTR_ERR(shmem);
 
 	/*
 	 * Allocate an id of idr table where the obj is registered
@@ -432,36 +485,34 @@ drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
 	ret = drm_gem_handle_create(file_priv, &shmem->base, handle);
 	/* drop reference from allocate - handle holds it now. */
 	drm_gem_object_put(&shmem->base);
-	if (ret)
-		return ERR_PTR(ret);
 
-	return shmem;
+	return ret;
 }
 
 /* Update madvise status, returns true if not purged, else
  * false or -errno.
  */
-int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
+int drm_gem_shmem_madvise_locked(struct drm_gem_shmem_object *shmem, int madv)
 {
-	mutex_lock(&shmem->pages_lock);
+	dma_resv_assert_held(shmem->base.resv);
 
 	if (shmem->madv >= 0)
 		shmem->madv = madv;
 
 	madv = shmem->madv;
 
-	mutex_unlock(&shmem->pages_lock);
-
 	return (madv >= 0);
 }
-EXPORT_SYMBOL(drm_gem_shmem_madvise);
+EXPORT_SYMBOL_GPL(drm_gem_shmem_madvise_locked);
 
 void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	struct drm_device *dev = obj->dev;
 
-	WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
+	dma_resv_assert_held(shmem->base.resv);
+
+	drm_WARN_ON(obj->dev, !drm_gem_shmem_is_purgeable(shmem));
 
 	dma_unmap_sgtable(dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
 	sg_free_table(shmem->sgt);
@@ -484,18 +535,7 @@ void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
 
 	invalidate_mapping_pages(file_inode(obj->filp)->i_mapping, 0, (loff_t)-1);
 }
-EXPORT_SYMBOL(drm_gem_shmem_purge_locked);
-
-bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
-{
-	if (!mutex_trylock(&shmem->pages_lock))
-		return false;
-	drm_gem_shmem_purge_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
-
-	return true;
-}
-EXPORT_SYMBOL(drm_gem_shmem_purge);
+EXPORT_SYMBOL_GPL(drm_gem_shmem_purge_locked);
 
 /**
  * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object
@@ -517,23 +557,13 @@ EXPORT_SYMBOL(drm_gem_shmem_purge);
 int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,
 			      struct drm_mode_create_dumb *args)
 {
-	u32 min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
-	struct drm_gem_shmem_object *shmem;
-
-	if (!args->pitch || !args->size) {
-		args->pitch = min_pitch;
-		args->size = PAGE_ALIGN(args->pitch * args->height);
-	} else {
-		/* ensure sane minimum values */
-		if (args->pitch < min_pitch)
-			args->pitch = min_pitch;
-		if (args->size < args->pitch * args->height)
-			args->size = PAGE_ALIGN(args->pitch * args->height);
-	}
+	int ret;
 
-	shmem = drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle);
+	ret = drm_mode_size_dumb(dev, args, SZ_8, 0);
+	if (ret)
+		return ret;
 
-	return PTR_ERR_OR_ZERO(shmem);
+	return drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create);
 
@@ -550,10 +580,10 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
 	/* We don't use vmf->pgoff since that has the fake offset */
 	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
 
-	mutex_lock(&shmem->pages_lock);
+	dma_resv_lock(shmem->base.resv, NULL);
 
 	if (page_offset >= num_pages ||
-	    WARN_ON_ONCE(!shmem->pages) ||
+	    drm_WARN_ON_ONCE(obj->dev, !shmem->pages) ||
 	    shmem->madv < 0) {
 		ret = VM_FAULT_SIGBUS;
 	} else {
@@ -562,7 +592,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
 		ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page));
 	}
 
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 	return ret;
 }
@@ -571,12 +601,20 @@ static void drm_gem_shmem_vm_open(struct vm_area_struct *vma)
 {
 	struct drm_gem_object *obj = vma->vm_private_data;
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
-	int ret;
 
-	WARN_ON(shmem->base.import_attach);
+	drm_WARN_ON(obj->dev, drm_gem_is_imported(obj));
 
-	ret = drm_gem_shmem_get_pages(shmem);
-	WARN_ON_ONCE(ret != 0);
+	dma_resv_lock(shmem->base.resv, NULL);
+
+	/*
+	 * We should have already pinned the pages when the buffer was first
+	 * mmap'd, vm_open() just grabs an additional reference for the new
+	 * mm the vma is getting copied into (ie. on fork()).
+	 */
+	drm_WARN_ON_ONCE(obj->dev,
+			 !refcount_inc_not_zero(&shmem->pages_use_count));
+
+	dma_resv_unlock(shmem->base.resv);
 
 	drm_gem_vm_open(vma);
 }
@@ -586,7 +624,10 @@ static void drm_gem_shmem_vm_close(struct vm_area_struct *vma)
 	struct drm_gem_object *obj = vma->vm_private_data;
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
-	drm_gem_shmem_put_pages(shmem);
+	dma_resv_lock(shmem->base.resv, NULL);
+	drm_gem_shmem_put_pages_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
 	drm_gem_vm_close(vma);
 }
 
@@ -613,21 +654,34 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct
 	struct drm_gem_object *obj = &shmem->base;
 	int ret;
 
-	if (obj->import_attach) {
-		/* Drop the reference drm_gem_mmap_obj() acquired.*/
-		drm_gem_object_put(obj);
+	if (drm_gem_is_imported(obj)) {
+		/* Reset both vm_ops and vm_private_data, so we don't end up with
+		 * vm_ops pointing to our implementation if the dma-buf backend
+		 * doesn't set those fields.
+		 */
 		vma->vm_private_data = NULL;
+		vma->vm_ops = NULL;
 
-		return dma_buf_mmap(obj->dma_buf, vma, 0);
-	}
+		ret = dma_buf_mmap(obj->dma_buf, vma, 0);
+
+		/* Drop the reference drm_gem_mmap_obj() acquired.*/
+		if (!ret)
+			drm_gem_object_put(obj);
 
-	ret = drm_gem_shmem_get_pages(shmem);
-	if (ret) {
-		drm_gem_vm_close(vma);
 		return ret;
 	}
 
-	vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
+	if (is_cow_mapping(vma->vm_flags))
+		return -EINVAL;
+
+	dma_resv_lock(shmem->base.resv, NULL);
+	ret = drm_gem_shmem_get_pages_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
+	if (ret)
+		return ret;
+
+	vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 	if (shmem->map_wc)
 		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
@@ -645,11 +699,15 @@ EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap);
 void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
 			      struct drm_printer *p, unsigned int indent)
 {
-	drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count);
-	drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count);
+	if (drm_gem_is_imported(&shmem->base))
+		return;
+
+	drm_printf_indent(p, indent, "pages_pin_count=%u\n", refcount_read(&shmem->pages_pin_count));
+	drm_printf_indent(p, indent, "pages_use_count=%u\n", refcount_read(&shmem->pages_use_count));
+	drm_printf_indent(p, indent, "vmap_use_count=%u\n", refcount_read(&shmem->vmap_use_count));
 	drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr);
 }
-EXPORT_SYMBOL(drm_gem_shmem_print_info);
+EXPORT_SYMBOL_GPL(drm_gem_shmem_print_info);
 
 /**
  * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned
@@ -669,29 +727,13 @@ struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
-	WARN_ON(shmem->base.import_attach);
+	drm_WARN_ON(obj->dev, drm_gem_is_imported(obj));
 
 	return drm_prime_pages_to_sg(obj->dev, shmem->pages, obj->size >> PAGE_SHIFT);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
 
-/**
- * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a
- *				 scatter/gather table for a shmem GEM object.
- * @shmem: shmem GEM object
- *
- * This function returns a scatter/gather table suitable for driver usage. If
- * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg
- * table created.
- *
- * This is the main function for drivers to get at backing storage, and it hides
- * and difference between dma-buf imported and natively allocated objects.
- * drm_gem_shmem_get_sg_table() should not be directly called by drivers.
- *
- * Returns:
- * A pointer to the scatter/gather table of pinned pages or errno on failure.
- */
-struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
+static struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	int ret;
@@ -700,9 +742,9 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
 	if (shmem->sgt)
 		return shmem->sgt;
 
-	WARN_ON(obj->import_attach);
+	drm_WARN_ON(obj->dev, drm_gem_is_imported(obj));
 
-	ret = drm_gem_shmem_get_pages(shmem);
+	ret = drm_gem_shmem_get_pages_locked(shmem);
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -724,9 +766,39 @@ err_free_sgt:
 	sg_free_table(sgt);
 	kfree(sgt);
 err_put_pages:
-	drm_gem_shmem_put_pages(shmem);
+	drm_gem_shmem_put_pages_locked(shmem);
 	return ERR_PTR(ret);
 }
+
+/**
+ * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a
+ *				 scatter/gather table for a shmem GEM object.
+ * @shmem: shmem GEM object
+ *
+ * This function returns a scatter/gather table suitable for driver usage. If
+ * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg
+ * table created.
+ *
+ * This is the main function for drivers to get at backing storage, and it hides
+ * and difference between dma-buf imported and natively allocated objects.
+ * drm_gem_shmem_get_sg_table() should not be directly called by drivers.
+ *
+ * Returns:
+ * A pointer to the scatter/gather table of pinned pages or errno on failure.
+ */
+struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
+{
+	int ret;
+	struct sg_table *sgt;
+
+	ret = dma_resv_lock_interruptible(shmem->base.resv, NULL);
+	if (ret)
+		return ERR_PTR(ret);
+	sgt = drm_gem_shmem_get_pages_sgt_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
+	return sgt;
+}
 EXPORT_SYMBOL_GPL(drm_gem_shmem_get_pages_sgt);
 
 /**
@@ -752,18 +824,75 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
 	size_t size = PAGE_ALIGN(attach->dmabuf->size);
 	struct drm_gem_shmem_object *shmem;
 
-	shmem = __drm_gem_shmem_create(dev, size, true);
+	shmem = __drm_gem_shmem_create(dev, size, true, NULL);
 	if (IS_ERR(shmem))
 		return ERR_CAST(shmem);
 
 	shmem->sgt = sgt;
 
-	DRM_DEBUG_PRIME("size = %zu\n", size);
+	drm_dbg_prime(dev, "size = %zu\n", size);
 
 	return &shmem->base;
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);
 
+/**
+ * drm_gem_shmem_prime_import_no_map - Import dmabuf without mapping its sg_table
+ * @dev: Device to import into
+ * @dma_buf: dma-buf object to import
+ *
+ * Drivers that use the shmem helpers but also wants to import dmabuf without
+ * mapping its sg_table can use this as their &drm_driver.gem_prime_import
+ * implementation.
+ */
+struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
+							 struct dma_buf *dma_buf)
+{
+	struct dma_buf_attachment *attach;
+	struct drm_gem_shmem_object *shmem;
+	struct drm_gem_object *obj;
+	size_t size;
+	int ret;
+
+	if (drm_gem_is_prime_exported_dma_buf(dev, dma_buf)) {
+		/*
+		 * Importing dmabuf exported from our own gem increases
+		 * refcount on gem itself instead of f_count of dmabuf.
+		 */
+		obj = dma_buf->priv;
+		drm_gem_object_get(obj);
+		return obj;
+	}
+
+	attach = dma_buf_attach(dma_buf, dev->dev);
+	if (IS_ERR(attach))
+		return ERR_CAST(attach);
+
+	get_dma_buf(dma_buf);
+
+	size = PAGE_ALIGN(attach->dmabuf->size);
+
+	shmem = __drm_gem_shmem_create(dev, size, true, NULL);
+	if (IS_ERR(shmem)) {
+		ret = PTR_ERR(shmem);
+		goto fail_detach;
+	}
+
+	drm_dbg_prime(dev, "size = %zu\n", size);
+
+	shmem->base.import_attach = attach;
+	shmem->base.resv = dma_buf->resv;
+
+	return &shmem->base;
+
+fail_detach:
+	dma_buf_detach(dma_buf, attach);
+	dma_buf_put(dma_buf);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_no_map);
+
 MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
-MODULE_IMPORT_NS(DMA_BUF);
+MODULE_IMPORT_NS("DMA_BUF");
 MODULE_LICENSE("GPL v2");