1 files changed, 255 insertions, 589 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index 24c22a8c3364..b9b2f000072d 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -1,108 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* exynos_drm_gem.c
  *
  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
  * Author: Inki Dae <inki.dae@samsung.com>
- *
- * This program is free software; you can redistribute  it and/or modify it
- * under  the terms of  the GNU General  Public License as published by the
- * Free Software Foundation;  either version 2 of the  License, or (at your
- * option) any later version.
  */
 
-#include <drm/drmP.h>
 
+#include <linux/dma-buf.h>
 #include <linux/shmem_fs.h>
+#include <linux/module.h>
+
+#include <drm/drm_dumb_buffers.h>
+#include <drm/drm_prime.h>
+#include <drm/drm_print.h>
+#include <drm/drm_vma_manager.h>
 #include <drm/exynos_drm.h>
 
 #include "exynos_drm_drv.h"
 #include "exynos_drm_gem.h"
-#include "exynos_drm_buf.h"
 
-static unsigned int convert_to_vm_err_msg(int msg)
-{
-	unsigned int out_msg;
-
-	switch (msg) {
-	case 0:
-	case -ERESTARTSYS:
-	case -EINTR:
-		out_msg = VM_FAULT_NOPAGE;
-		break;
-
-	case -ENOMEM:
-		out_msg = VM_FAULT_OOM;
-		break;
-
-	default:
-		out_msg = VM_FAULT_SIGBUS;
-		break;
-	}
+MODULE_IMPORT_NS("DMA_BUF");
 
-	return out_msg;
-}
+static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
 
-static int check_gem_flags(unsigned int flags)
+static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem, bool kvmap)
 {
-	if (flags & ~(EXYNOS_BO_MASK)) {
-		DRM_ERROR("invalid flags.\n");
-		return -EINVAL;
-	}
+	struct drm_device *dev = exynos_gem->base.dev;
+	unsigned long attr = 0;
 
-	return 0;
-}
+	if (exynos_gem->dma_addr) {
+		DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "already allocated.\n");
+		return 0;
+	}
 
-static void update_vm_cache_attr(struct exynos_drm_gem_obj *obj,
-					struct vm_area_struct *vma)
-{
-	DRM_DEBUG_KMS("flags = 0x%x\n", obj->flags);
+	/*
+	 * if EXYNOS_BO_CONTIG, fully physically contiguous memory
+	 * region will be allocated else physically contiguous
+	 * as possible.
+	 */
+	if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
+		attr |= DMA_ATTR_FORCE_CONTIGUOUS;
 
-	/* non-cachable as default. */
-	if (obj->flags & EXYNOS_BO_CACHABLE)
-		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-	else if (obj->flags & EXYNOS_BO_WC)
-		vma->vm_page_prot =
-			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
-	else
-		vma->vm_page_prot =
-			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
-}
+	/*
+	 * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
+	 * else cachable mapping.
+	 */
+	if (exynos_gem->flags & EXYNOS_BO_WC ||
+			!(exynos_gem->flags & EXYNOS_BO_CACHABLE))
+		attr |= DMA_ATTR_WRITE_COMBINE;
+
+	/* FBDev emulation requires kernel mapping */
+	if (!kvmap)
+		attr |= DMA_ATTR_NO_KERNEL_MAPPING;
+
+	exynos_gem->dma_attrs = attr;
+	exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
+					     &exynos_gem->dma_addr, GFP_KERNEL,
+					     exynos_gem->dma_attrs);
+	if (!exynos_gem->cookie) {
+		DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate buffer.\n");
+		return -ENOMEM;
+	}
 
-static unsigned long roundup_gem_size(unsigned long size, unsigned int flags)
-{
-	/* TODO */
+	if (kvmap)
+		exynos_gem->kvaddr = exynos_gem->cookie;
 
-	return roundup(size, PAGE_SIZE);
+	DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "dma_addr(0x%lx), size(0x%lx)\n",
+			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
+	return 0;
 }
 
-static int exynos_drm_gem_map_buf(struct drm_gem_object *obj,
-					struct vm_area_struct *vma,
-					unsigned long f_vaddr,
-					pgoff_t page_offset)
+static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
-	struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
-	struct scatterlist *sgl;
-	unsigned long pfn;
-	int i;
-
-	if (!buf->sgt)
-		return -EINTR;
-
-	if (page_offset >= (buf->size >> PAGE_SHIFT)) {
-		DRM_ERROR("invalid page offset\n");
-		return -EINVAL;
-	}
+	struct drm_device *dev = exynos_gem->base.dev;
 
-	sgl = buf->sgt->sgl;
-	for_each_sg(buf->sgt->sgl, sgl, buf->sgt->nents, i) {
-		if (page_offset < (sgl->length >> PAGE_SHIFT))
-			break;
-		page_offset -=	(sgl->length >> PAGE_SHIFT);
+	if (!exynos_gem->dma_addr) {
+		DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr is invalid.\n");
+		return;
 	}
 
-	pfn = __phys_to_pfn(sg_phys(sgl)) + page_offset;
+	DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr(0x%lx), size(0x%lx)\n",
+			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
 
-	return vm_insert_mixed(vma, f_vaddr, pfn);
+	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
+			(dma_addr_t)exynos_gem->dma_addr,
+			exynos_gem->dma_attrs);
 }
 
 static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
@@ -119,23 +101,20 @@ static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
 	if (ret)
 		return ret;
 
-	DRM_DEBUG_KMS("gem handle = 0x%x\n", *handle);
+	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "gem handle = 0x%x\n", *handle);
 
 	/* drop reference from allocate - handle holds it now. */
-	drm_gem_object_unreference_unlocked(obj);
+	drm_gem_object_put(obj);
 
 	return 0;
 }
 
-void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
+void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem)
 {
-	struct drm_gem_object *obj;
-	struct exynos_drm_gem_buf *buf;
+	struct drm_gem_object *obj = &exynos_gem->base;
 
-	obj = &exynos_gem_obj->base;
-	buf = exynos_gem_obj->buffer;
-
-	DRM_DEBUG_KMS("handle count = %d\n", atomic_read(&obj->handle_count));
+	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "handle count = %d\n",
+			  obj->handle_count);
 
 	/*
 	 * do not release memory region from exporter.
@@ -144,651 +123,338 @@ void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
 	 * once dmabuf's refcount becomes 0.
 	 */
 	if (obj->import_attach)
-		goto out;
-
-	exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags, buf);
-
-out:
-	exynos_drm_fini_buf(obj->dev, buf);
-	exynos_gem_obj->buffer = NULL;
-
-	if (obj->map_list.map)
-		drm_gem_free_mmap_offset(obj);
+		drm_prime_gem_destroy(obj, exynos_gem->sgt);
+	else
+		exynos_drm_free_buf(exynos_gem);
 
 	/* release file pointer to gem object. */
 	drm_gem_object_release(obj);
 
-	kfree(exynos_gem_obj);
-	exynos_gem_obj = NULL;
+	kfree(exynos_gem);
 }
 
-unsigned long exynos_drm_gem_get_size(struct drm_device *dev,
-						unsigned int gem_handle,
-						struct drm_file *file_priv)
-{
-	struct exynos_drm_gem_obj *exynos_gem_obj;
-	struct drm_gem_object *obj;
-
-	obj = drm_gem_object_lookup(dev, file_priv, gem_handle);
-	if (!obj) {
-		DRM_ERROR("failed to lookup gem object.\n");
-		return 0;
-	}
-
-	exynos_gem_obj = to_exynos_gem_obj(obj);
-
-	drm_gem_object_unreference_unlocked(obj);
-
-	return exynos_gem_obj->buffer->size;
-}
+static const struct vm_operations_struct exynos_drm_gem_vm_ops = {
+	.open = drm_gem_vm_open,
+	.close = drm_gem_vm_close,
+};
 
+static const struct drm_gem_object_funcs exynos_drm_gem_object_funcs = {
+	.free = exynos_drm_gem_free_object,
+	.get_sg_table = exynos_drm_gem_prime_get_sg_table,
+	.mmap = exynos_drm_gem_mmap,
+	.vm_ops = &exynos_drm_gem_vm_ops,
+};
 
-struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
-						      unsigned long size)
+static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
+						  unsigned long size)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj;
+	struct exynos_drm_gem *exynos_gem;
 	struct drm_gem_object *obj;
 	int ret;
 
-	exynos_gem_obj = kzalloc(sizeof(*exynos_gem_obj), GFP_KERNEL);
-	if (!exynos_gem_obj) {
-		DRM_ERROR("failed to allocate exynos gem object\n");
-		return NULL;
-	}
+	exynos_gem = kzalloc(sizeof(*exynos_gem), GFP_KERNEL);
+	if (!exynos_gem)
+		return ERR_PTR(-ENOMEM);
 
-	exynos_gem_obj->size = size;
-	obj = &exynos_gem_obj->base;
+	exynos_gem->size = size;
+	obj = &exynos_gem->base;
+
+	obj->funcs = &exynos_drm_gem_object_funcs;
 
 	ret = drm_gem_object_init(dev, obj, size);
 	if (ret < 0) {
-		DRM_ERROR("failed to initialize gem object\n");
-		kfree(exynos_gem_obj);
-		return NULL;
+		DRM_DEV_ERROR(dev->dev, "failed to initialize gem object\n");
+		kfree(exynos_gem);
+		return ERR_PTR(ret);
+	}
+
+	ret = drm_gem_create_mmap_offset(obj);
+	if (ret < 0) {
+		drm_gem_object_release(obj);
+		kfree(exynos_gem);
+		return ERR_PTR(ret);
 	}
 
-	DRM_DEBUG_KMS("created file object = 0x%x\n", (unsigned int)obj->filp);
+	DRM_DEV_DEBUG_KMS(dev->dev, "created file object = %p\n", obj->filp);
 
-	return exynos_gem_obj;
+	return exynos_gem;
 }
 
-struct exynos_drm_gem_obj *exynos_drm_gem_create(struct drm_device *dev,
-						unsigned int flags,
-						unsigned long size)
+struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
+					     unsigned int flags,
+					     unsigned long size,
+					     bool kvmap)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj;
-	struct exynos_drm_gem_buf *buf;
+	struct exynos_drm_gem *exynos_gem;
 	int ret;
 
-	if (!size) {
-		DRM_ERROR("invalid size.\n");
+	if (flags & ~(EXYNOS_BO_MASK)) {
+		DRM_DEV_ERROR(dev->dev,
+			      "invalid GEM buffer flags: %u\n", flags);
 		return ERR_PTR(-EINVAL);
 	}
 
-	size = roundup_gem_size(size, flags);
+	if (!size) {
+		DRM_DEV_ERROR(dev->dev, "invalid GEM buffer size: %lu\n", size);
+		return ERR_PTR(-EINVAL);
+	}
 
-	ret = check_gem_flags(flags);
-	if (ret)
-		return ERR_PTR(ret);
+	size = roundup(size, PAGE_SIZE);
 
-	buf = exynos_drm_init_buf(dev, size);
-	if (!buf)
-		return ERR_PTR(-ENOMEM);
+	exynos_gem = exynos_drm_gem_init(dev, size);
+	if (IS_ERR(exynos_gem))
+		return exynos_gem;
 
-	exynos_gem_obj = exynos_drm_gem_init(dev, size);
-	if (!exynos_gem_obj) {
-		ret = -ENOMEM;
-		goto err_fini_buf;
+	if (!is_drm_iommu_supported(dev) && (flags & EXYNOS_BO_NONCONTIG)) {
+		/*
+		 * when no IOMMU is available, all allocated buffers are
+		 * contiguous anyway, so drop EXYNOS_BO_NONCONTIG flag
+		 */
+		flags &= ~EXYNOS_BO_NONCONTIG;
+		DRM_WARN("Non-contiguous allocation is not supported without IOMMU, falling back to contiguous buffer\n");
 	}
 
-	exynos_gem_obj->buffer = buf;
-
 	/* set memory type and cache attribute from user side. */
-	exynos_gem_obj->flags = flags;
+	exynos_gem->flags = flags;
 
-	ret = exynos_drm_alloc_buf(dev, buf, flags);
-	if (ret < 0)
-		goto err_gem_fini;
-
-	return exynos_gem_obj;
+	ret = exynos_drm_alloc_buf(exynos_gem, kvmap);
+	if (ret < 0) {
+		drm_gem_object_release(&exynos_gem->base);
+		kfree(exynos_gem);
+		return ERR_PTR(ret);
+	}
 
-err_gem_fini:
-	drm_gem_object_release(&exynos_gem_obj->base);
-	kfree(exynos_gem_obj);
-err_fini_buf:
-	exynos_drm_fini_buf(dev, buf);
-	return ERR_PTR(ret);
+	return exynos_gem;
 }
 
 int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
 				struct drm_file *file_priv)
 {
 	struct drm_exynos_gem_create *args = data;
-	struct exynos_drm_gem_obj *exynos_gem_obj;
+	struct exynos_drm_gem *exynos_gem;
 	int ret;
 
-	exynos_gem_obj = exynos_drm_gem_create(dev, args->flags, args->size);
-	if (IS_ERR(exynos_gem_obj))
-		return PTR_ERR(exynos_gem_obj);
+	exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size, false);
+	if (IS_ERR(exynos_gem))
+		return PTR_ERR(exynos_gem);
 
-	ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
-			&args->handle);
+	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
+					   &args->handle);
 	if (ret) {
-		exynos_drm_gem_destroy(exynos_gem_obj);
+		exynos_drm_gem_destroy(exynos_gem);
 		return ret;
 	}
 
 	return 0;
 }
 
-dma_addr_t *exynos_drm_gem_get_dma_addr(struct drm_device *dev,
-					unsigned int gem_handle,
-					struct drm_file *filp)
+int exynos_drm_gem_map_ioctl(struct drm_device *dev, void *data,
+			     struct drm_file *file_priv)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj;
-	struct drm_gem_object *obj;
-
-	obj = drm_gem_object_lookup(dev, filp, gem_handle);
-	if (!obj) {
-		DRM_ERROR("failed to lookup gem object.\n");
-		return ERR_PTR(-EINVAL);
-	}
-
-	exynos_gem_obj = to_exynos_gem_obj(obj);
+	struct drm_exynos_gem_map *args = data;
 
-	return &exynos_gem_obj->buffer->dma_addr;
+	return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
+				       &args->offset);
 }
 
-void exynos_drm_gem_put_dma_addr(struct drm_device *dev,
-					unsigned int gem_handle,
-					struct drm_file *filp)
+struct exynos_drm_gem *exynos_drm_gem_get(struct drm_file *filp,
+					  unsigned int gem_handle)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj;
 	struct drm_gem_object *obj;
 
-	obj = drm_gem_object_lookup(dev, filp, gem_handle);
-	if (!obj) {
-		DRM_ERROR("failed to lookup gem object.\n");
-		return;
-	}
-
-	exynos_gem_obj = to_exynos_gem_obj(obj);
-
-	drm_gem_object_unreference_unlocked(obj);
-
-	/*
-	 * decrease obj->refcount one more time because we has already
-	 * increased it at exynos_drm_gem_get_dma_addr().
-	 */
-	drm_gem_object_unreference_unlocked(obj);
-}
-
-int exynos_drm_gem_map_offset_ioctl(struct drm_device *dev, void *data,
-				    struct drm_file *file_priv)
-{
-	struct drm_exynos_gem_map_off *args = data;
-
-	DRM_DEBUG_KMS("handle = 0x%x, offset = 0x%lx\n",
-			args->handle, (unsigned long)args->offset);
-
-	if (!(dev->driver->driver_features & DRIVER_GEM)) {
-		DRM_ERROR("does not support GEM.\n");
-		return -ENODEV;
-	}
-
-	return exynos_drm_gem_dumb_map_offset(file_priv, dev, args->handle,
-			&args->offset);
-}
-
-static struct drm_file *exynos_drm_find_drm_file(struct drm_device *drm_dev,
-							struct file *filp)
-{
-	struct drm_file *file_priv;
-
-	/* find current process's drm_file from filelist. */
-	list_for_each_entry(file_priv, &drm_dev->filelist, lhead)
-		if (file_priv->filp == filp)
-			return file_priv;
-
-	WARN_ON(1);
-
-	return ERR_PTR(-EFAULT);
+	obj = drm_gem_object_lookup(filp, gem_handle);
+	if (!obj)
+		return NULL;
+	return to_exynos_gem(obj);
 }
 
-static int exynos_drm_gem_mmap_buffer(struct file *filp,
+static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
 				      struct vm_area_struct *vma)
 {
-	struct drm_gem_object *obj = filp->private_data;
-	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
-	struct drm_device *drm_dev = obj->dev;
-	struct exynos_drm_gem_buf *buffer;
-	struct drm_file *file_priv;
+	struct drm_device *drm_dev = exynos_gem->base.dev;
 	unsigned long vm_size;
 	int ret;
 
-	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
-	vma->vm_private_data = obj;
-	vma->vm_ops = drm_dev->driver->gem_vm_ops;
-
-	/* restore it to driver's fops. */
-	filp->f_op = fops_get(drm_dev->driver->fops);
-
-	file_priv = exynos_drm_find_drm_file(drm_dev, filp);
-	if (IS_ERR(file_priv))
-		return PTR_ERR(file_priv);
-
-	/* restore it to drm_file. */
-	filp->private_data = file_priv;
-
-	update_vm_cache_attr(exynos_gem_obj, vma);
+	vm_flags_clear(vma, VM_PFNMAP);
+	vma->vm_pgoff = 0;
 
 	vm_size = vma->vm_end - vma->vm_start;
 
-	/*
-	 * a buffer contains information to physically continuous memory
-	 * allocated by user request or at framebuffer creation.
-	 */
-	buffer = exynos_gem_obj->buffer;
-
 	/* check if user-requested size is valid. */
-	if (vm_size > buffer->size)
+	if (vm_size > exynos_gem->size)
 		return -EINVAL;
 
-	ret = dma_mmap_attrs(drm_dev->dev, vma, buffer->pages,
-				buffer->dma_addr, buffer->size,
-				&buffer->dma_attrs);
+	ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
+			     exynos_gem->dma_addr, exynos_gem->size,
+			     exynos_gem->dma_attrs);
 	if (ret < 0) {
 		DRM_ERROR("failed to mmap.\n");
 		return ret;
 	}
 
-	/*
-	 * take a reference to this mapping of the object. And this reference
-	 * is unreferenced by the corresponding vm_close call.
-	 */
-	drm_gem_object_reference(obj);
-
-	drm_vm_open_locked(drm_dev, vma);
-
-	return 0;
-}
-
-static const struct file_operations exynos_drm_gem_fops = {
-	.mmap = exynos_drm_gem_mmap_buffer,
-};
-
-int exynos_drm_gem_mmap_ioctl(struct drm_device *dev, void *data,
-			      struct drm_file *file_priv)
-{
-	struct drm_exynos_gem_mmap *args = data;
-	struct drm_gem_object *obj;
-	unsigned long addr;
-
-	if (!(dev->driver->driver_features & DRIVER_GEM)) {
-		DRM_ERROR("does not support GEM.\n");
-		return -ENODEV;
-	}
-
-	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
-	if (!obj) {
-		DRM_ERROR("failed to lookup gem object.\n");
-		return -EINVAL;
-	}
-
-	/*
-	 * We have to use gem object and its fops for specific mmaper,
-	 * but vm_mmap() can deliver only filp. So we have to change
-	 * filp->f_op and filp->private_data temporarily, then restore
-	 * again. So it is important to keep lock until restoration the
-	 * settings to prevent others from misuse of filp->f_op or
-	 * filp->private_data.
-	 */
-	mutex_lock(&dev->struct_mutex);
-
-	/*
-	 * Set specific mmper's fops. And it will be restored by
-	 * exynos_drm_gem_mmap_buffer to dev->driver->fops.
-	 * This is used to call specific mapper temporarily.
-	 */
-	file_priv->filp->f_op = &exynos_drm_gem_fops;
-
-	/*
-	 * Set gem object to private_data so that specific mmaper
-	 * can get the gem object. And it will be restored by
-	 * exynos_drm_gem_mmap_buffer to drm_file.
-	 */
-	file_priv->filp->private_data = obj;
-
-	addr = vm_mmap(file_priv->filp, 0, args->size,
-			PROT_READ | PROT_WRITE, MAP_SHARED, 0);
-
-	drm_gem_object_unreference(obj);
-
-	if (IS_ERR_VALUE(addr)) {
-		/* check filp->f_op, filp->private_data are restored */
-		if (file_priv->filp->f_op == &exynos_drm_gem_fops) {
-			file_priv->filp->f_op = fops_get(dev->driver->fops);
-			file_priv->filp->private_data = file_priv;
-		}
-		mutex_unlock(&dev->struct_mutex);
-		return (int)addr;
-	}
-
-	mutex_unlock(&dev->struct_mutex);
-
-	args->mapped = addr;
-
-	DRM_DEBUG_KMS("mapped = 0x%lx\n", (unsigned long)args->mapped);
-
 	return 0;
 }
 
 int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
 				      struct drm_file *file_priv)
-{	struct exynos_drm_gem_obj *exynos_gem_obj;
+{
+	struct exynos_drm_gem *exynos_gem;
 	struct drm_exynos_gem_info *args = data;
 	struct drm_gem_object *obj;
 
-	mutex_lock(&dev->struct_mutex);
-
-	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
+	obj = drm_gem_object_lookup(file_priv, args->handle);
 	if (!obj) {
-		DRM_ERROR("failed to lookup gem object.\n");
-		mutex_unlock(&dev->struct_mutex);
+		DRM_DEV_ERROR(dev->dev, "failed to lookup gem object.\n");
 		return -EINVAL;
 	}
 
-	exynos_gem_obj = to_exynos_gem_obj(obj);
-
-	args->flags = exynos_gem_obj->flags;
-	args->size = exynos_gem_obj->size;
-
-	drm_gem_object_unreference(obj);
-	mutex_unlock(&dev->struct_mutex);
-
-	return 0;
-}
-
-struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
-{
-	struct vm_area_struct *vma_copy;
-
-	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-	if (!vma_copy)
-		return NULL;
-
-	if (vma->vm_ops && vma->vm_ops->open)
-		vma->vm_ops->open(vma);
-
-	if (vma->vm_file)
-		get_file(vma->vm_file);
-
-	memcpy(vma_copy, vma, sizeof(*vma));
-
-	vma_copy->vm_mm = NULL;
-	vma_copy->vm_next = NULL;
-	vma_copy->vm_prev = NULL;
-
-	return vma_copy;
-}
-
-void exynos_gem_put_vma(struct vm_area_struct *vma)
-{
-	if (!vma)
-		return;
-
-	if (vma->vm_ops && vma->vm_ops->close)
-		vma->vm_ops->close(vma);
-
-	if (vma->vm_file)
-		fput(vma->vm_file);
-
-	kfree(vma);
-}
-
-int exynos_gem_get_pages_from_userptr(unsigned long start,
-						unsigned int npages,
-						struct page **pages,
-						struct vm_area_struct *vma)
-{
-	int get_npages;
-
-	/* the memory region mmaped with VM_PFNMAP. */
-	if (vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
-			unsigned long pfn;
-			int ret = follow_pfn(vma, start, &pfn);
-			if (ret)
-				return ret;
-
-			pages[i] = pfn_to_page(pfn);
-		}
-
-		if (i != npages) {
-			DRM_ERROR("failed to get user_pages.\n");
-			return -EINVAL;
-		}
-
-		return 0;
-	}
-
-	get_npages = get_user_pages(current, current->mm, start,
-					npages, 1, 1, pages, NULL);
-	get_npages = max(get_npages, 0);
-	if (get_npages != npages) {
-		DRM_ERROR("failed to get user_pages.\n");
-		while (get_npages)
-			put_page(pages[--get_npages]);
-		return -EFAULT;
-	}
-
-	return 0;
-}
-
-void exynos_gem_put_pages_to_userptr(struct page **pages,
-					unsigned int npages,
-					struct vm_area_struct *vma)
-{
-	if (!vma_is_io(vma)) {
-		unsigned int i;
-
-		for (i = 0; i < npages; i++) {
-			set_page_dirty_lock(pages[i]);
-
-			/*
-			 * undo the reference we took when populating
-			 * the table.
-			 */
-			put_page(pages[i]);
-		}
-	}
-}
-
-int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
-				struct sg_table *sgt,
-				enum dma_data_direction dir)
-{
-	int nents;
-
-	mutex_lock(&drm_dev->struct_mutex);
-
-	nents = dma_map_sg(drm_dev->dev, sgt->sgl, sgt->nents, dir);
-	if (!nents) {
-		DRM_ERROR("failed to map sgl with dma.\n");
-		mutex_unlock(&drm_dev->struct_mutex);
-		return nents;
-	}
+	exynos_gem = to_exynos_gem(obj);
 
-	mutex_unlock(&drm_dev->struct_mutex);
-	return 0;
-}
+	args->flags = exynos_gem->flags;
+	args->size = exynos_gem->size;
 
-void exynos_gem_unmap_sgt_from_dma(struct drm_device *drm_dev,
-				struct sg_table *sgt,
-				enum dma_data_direction dir)
-{
-	dma_unmap_sg(drm_dev->dev, sgt->sgl, sgt->nents, dir);
-}
+	drm_gem_object_put(obj);
 
-int exynos_drm_gem_init_object(struct drm_gem_object *obj)
-{
 	return 0;
 }
 
 void exynos_drm_gem_free_object(struct drm_gem_object *obj)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj;
-	struct exynos_drm_gem_buf *buf;
-
-	exynos_gem_obj = to_exynos_gem_obj(obj);
-	buf = exynos_gem_obj->buffer;
-
-	if (obj->import_attach)
-		drm_prime_gem_destroy(obj, buf->sgt);
-
-	exynos_drm_gem_destroy(to_exynos_gem_obj(obj));
+	exynos_drm_gem_destroy(to_exynos_gem(obj));
 }
 
 int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
 			       struct drm_device *dev,
 			       struct drm_mode_create_dumb *args)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj;
+	struct exynos_drm_gem *exynos_gem;
+	unsigned int flags;
 	int ret;
 
+	ret = drm_mode_size_dumb(dev, args, 0, 0);
+	if (ret)
+		return ret;
+
 	/*
-	 * alocate memory to be used for framebuffer.
+	 * allocate memory to be used for framebuffer.
 	 * - this callback would be called by user application
 	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
 	 */
 
-	args->pitch = args->width * ((args->bpp + 7) / 8);
-	args->size = args->pitch * args->height;
+	if (is_drm_iommu_supported(dev))
+		flags = EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC;
+	else
+		flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
 
-	exynos_gem_obj = exynos_drm_gem_create(dev, EXYNOS_BO_CONTIG |
-						EXYNOS_BO_WC, args->size);
-	if (IS_ERR(exynos_gem_obj))
-		return PTR_ERR(exynos_gem_obj);
+	exynos_gem = exynos_drm_gem_create(dev, flags, args->size, false);
+	if (IS_ERR(exynos_gem)) {
+		dev_warn(dev->dev, "FB allocation failed.\n");
+		return PTR_ERR(exynos_gem);
+	}
 
-	ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
-			&args->handle);
+	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
+					   &args->handle);
 	if (ret) {
-		exynos_drm_gem_destroy(exynos_gem_obj);
+		exynos_drm_gem_destroy(exynos_gem);
 		return ret;
 	}
 
 	return 0;
 }
 
-int exynos_drm_gem_dumb_map_offset(struct drm_file *file_priv,
-				   struct drm_device *dev, uint32_t handle,
-				   uint64_t *offset)
+static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 {
-	struct drm_gem_object *obj;
-	int ret = 0;
+	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
+	int ret;
 
-	mutex_lock(&dev->struct_mutex);
+	if (obj->import_attach)
+		return dma_buf_mmap(obj->dma_buf, vma, 0);
 
-	/*
-	 * get offset of memory allocated for drm framebuffer.
-	 * - this callback would be called by user application
-	 *	with DRM_IOCTL_MODE_MAP_DUMB command.
-	 */
+	vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
 
-	obj = drm_gem_object_lookup(dev, file_priv, handle);
-	if (!obj) {
-		DRM_ERROR("failed to lookup gem object.\n");
-		ret = -EINVAL;
-		goto unlock;
-	}
+	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "flags = 0x%x\n",
+			  exynos_gem->flags);
 
-	if (!obj->map_list.map) {
-		ret = drm_gem_create_mmap_offset(obj);
-		if (ret)
-			goto out;
-	}
+	/* non-cachable as default. */
+	if (exynos_gem->flags & EXYNOS_BO_CACHABLE)
+		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+	else if (exynos_gem->flags & EXYNOS_BO_WC)
+		vma->vm_page_prot =
+			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+	else
+		vma->vm_page_prot =
+			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
 
-	*offset = (u64)obj->map_list.hash.key << PAGE_SHIFT;
-	DRM_DEBUG_KMS("offset = 0x%lx\n", (unsigned long)*offset);
+	ret = exynos_drm_gem_mmap_buffer(exynos_gem, vma);
+	if (ret)
+		goto err_close_vm;
 
-out:
-	drm_gem_object_unreference(obj);
-unlock:
-	mutex_unlock(&dev->struct_mutex);
 	return ret;
-}
 
-int exynos_drm_gem_dumb_destroy(struct drm_file *file_priv,
-				struct drm_device *dev,
-				unsigned int handle)
-{
-	int ret;
+err_close_vm:
+	drm_gem_vm_close(vma);
 
-	/*
-	 * obj->refcount and obj->handle_count are decreased and
-	 * if both them are 0 then exynos_drm_gem_free_object()
-	 * would be called by callback to release resources.
-	 */
-	ret = drm_gem_handle_delete(file_priv, handle);
-	if (ret < 0) {
-		DRM_ERROR("failed to delete drm_gem_handle.\n");
-		return ret;
-	}
+	return ret;
+}
 
-	return 0;
+/* low-level interface prime helpers */
+struct drm_gem_object *exynos_drm_gem_prime_import(struct drm_device *dev,
+					    struct dma_buf *dma_buf)
+{
+	return drm_gem_prime_import_dev(dev, dma_buf, to_dma_dev(dev));
 }
 
-int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
 {
-	struct drm_gem_object *obj = vma->vm_private_data;
-	struct drm_device *dev = obj->dev;
-	unsigned long f_vaddr;
-	pgoff_t page_offset;
+	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
+	struct drm_device *drm_dev = obj->dev;
+	struct sg_table *sgt;
 	int ret;
 
-	page_offset = ((unsigned long)vmf->virtual_address -
-			vma->vm_start) >> PAGE_SHIFT;
-	f_vaddr = (unsigned long)vmf->virtual_address;
-
-	mutex_lock(&dev->struct_mutex);
-
-	ret = exynos_drm_gem_map_buf(obj, vma, f_vaddr, page_offset);
-	if (ret < 0)
-		DRM_ERROR("failed to map a buffer with user.\n");
+	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return ERR_PTR(-ENOMEM);
 
-	mutex_unlock(&dev->struct_mutex);
+	ret = dma_get_sgtable_attrs(to_dma_dev(drm_dev), sgt, exynos_gem->cookie,
+				    exynos_gem->dma_addr, exynos_gem->size,
+				    exynos_gem->dma_attrs);
+	if (ret) {
+		DRM_ERROR("failed to get sgtable, %d\n", ret);
+		kfree(sgt);
+		return ERR_PTR(ret);
+	}
 
-	return convert_to_vm_err_msg(ret);
+	return sgt;
 }
 
-int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+struct drm_gem_object *
+exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
+				     struct dma_buf_attachment *attach,
+				     struct sg_table *sgt)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj;
-	struct drm_gem_object *obj;
-	int ret;
-
-	/* set vm_area_struct. */
-	ret = drm_gem_mmap(filp, vma);
-	if (ret < 0) {
-		DRM_ERROR("failed to mmap.\n");
-		return ret;
-	}
+	struct exynos_drm_gem *exynos_gem;
 
-	obj = vma->vm_private_data;
-	exynos_gem_obj = to_exynos_gem_obj(obj);
-
-	ret = check_gem_flags(exynos_gem_obj->flags);
-	if (ret) {
-		drm_gem_vm_close(vma);
-		drm_gem_free_mmap_offset(obj);
-		return ret;
+	/* check if the entries in the sg_table are contiguous */
+	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
+		DRM_ERROR("buffer chunks must be mapped contiguously");
+		return ERR_PTR(-EINVAL);
 	}
 
-	vma->vm_flags &= ~VM_PFNMAP;
-	vma->vm_flags |= VM_MIXEDMAP;
+	exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
+	if (IS_ERR(exynos_gem))
+		return ERR_CAST(exynos_gem);
 
-	update_vm_cache_attr(exynos_gem_obj, vma);
+	/*
+	 * Buffer has been mapped as contiguous into DMA address space,
+	 * but if there is IOMMU, it can be either CONTIG or NONCONTIG.
+	 * We assume a simplified logic below:
+	 */
+	if (is_drm_iommu_supported(dev))
+		exynos_gem->flags |= EXYNOS_BO_NONCONTIG;
+	else
+		exynos_gem->flags |= EXYNOS_BO_CONTIG;
 
-	return ret;
+	exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
+	exynos_gem->sgt = sgt;
+	return &exynos_gem->base;
 }