drivers/gpu/drm/armada/armada_gem.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (C) 2012 Russell King
  *
  * 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.
  */
 #include <linux/dma-buf.h>
 #include <linux/dma-mapping.h>
 #include <linux/shmem_fs.h>
 #include <drm/drmP.h>
 #include "armada_drm.h"
 #include "armada_gem.h"
 #include <drm/armada_drm.h>
 #include "armada_ioctlP.h"

 static int armada_gem_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct armada_gem_object *obj = drm_to_armada_gem(vma->vm_private_data);
 	unsigned long addr = (unsigned long)vmf->virtual_address;
 	unsigned long pfn = obj->phys_addr >> PAGE_SHIFT;
 	int ret;

 	pfn += (addr - vma->vm_start) >> PAGE_SHIFT;
 	ret = vm_insert_pfn(vma, addr, pfn);

 	switch (ret) {
 	case 0:
 	case -EBUSY:
 		return VM_FAULT_NOPAGE;
 	case -ENOMEM:
 		return VM_FAULT_OOM;
 	default:
 		return VM_FAULT_SIGBUS;
 	}
 }

 const struct vm_operations_struct armada_gem_vm_ops = {
 	.fault	= armada_gem_vm_fault,
 	.open	= drm_gem_vm_open,
 	.close	= drm_gem_vm_close,
 };

 static size_t roundup_gem_size(size_t size)
 {
 	return roundup(size, PAGE_SIZE);
 }

 void armada_gem_free_object(struct drm_gem_object *obj)
 {
 	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
 	struct armada_private *priv = obj->dev->dev_private;

 	DRM_DEBUG_DRIVER("release obj %p\n", dobj);

 	drm_gem_free_mmap_offset(&dobj->obj);

 	might_lock(&priv->linear_lock);

 	if (dobj->page) {
 		/* page backed memory */
 		unsigned int order = get_order(dobj->obj.size);
 		__free_pages(dobj->page, order);
 	} else if (dobj->linear) {
 		/* linear backed memory */
 		mutex_lock(&priv->linear_lock);
 		drm_mm_remove_node(dobj->linear);
 		mutex_unlock(&priv->linear_lock);
 		kfree(dobj->linear);
 		if (dobj->addr)
 			iounmap(dobj->addr);
 	}

 	if (dobj->obj.import_attach) {
 		/* We only ever display imported data */
 		if (dobj->sgt)
 			dma_buf_unmap_attachment(dobj->obj.import_attach,
 						 dobj->sgt, DMA_TO_DEVICE);
 		drm_prime_gem_destroy(&dobj->obj, NULL);
 	}

 	drm_gem_object_release(&dobj->obj);

 	kfree(dobj);
 }

 int
 armada_gem_linear_back(struct drm_device *dev, struct armada_gem_object *obj)
 {
 	struct armada_private *priv = dev->dev_private;
 	size_t size = obj->obj.size;

 	if (obj->page || obj->linear)
 		return 0;

 	/*
 	 * If it is a small allocation (typically cursor, which will
 	 * be 32x64 or 64x32 ARGB pixels) try to get it from the system.
 	 * Framebuffers will never be this small (our minimum size for
 	 * framebuffers is larger than this anyway.)  Such objects are
 	 * only accessed by the CPU so we don't need any special handing
 	 * here.
 	 */
 	if (size <= 8192) {
 		unsigned int order = get_order(size);
 		struct page *p = alloc_pages(GFP_KERNEL, order);

 		if (p) {
 			obj->addr = page_address(p);
 			obj->phys_addr = page_to_phys(p);
 			obj->page = p;

 			memset(obj->addr, 0, PAGE_ALIGN(size));
 		}
 	}

 	/*
 	 * We could grab something from CMA if it's enabled, but that
 	 * involves building in a problem:
 	 *
 	 * CMA's interface uses dma_alloc_coherent(), which provides us
 	 * with an CPU virtual address and a device address.
 	 *
 	 * The CPU virtual address may be either an address in the kernel
 	 * direct mapped region (for example, as it would be on x86) or
 	 * it may be remapped into another part of kernel memory space
 	 * (eg, as it would be on ARM.)  This means virt_to_phys() on the
 	 * returned virtual address is invalid depending on the architecture
 	 * implementation.
 	 *
 	 * The device address may also not be a physical address; it may
 	 * be that there is some kind of remapping between the device and
 	 * system RAM, which makes the use of the device address also
 	 * unsafe to re-use as a physical address.
 	 *
 	 * This makes DRM usage of dma_alloc_coherent() in a generic way
 	 * at best very questionable and unsafe.
 	 */

 	/* Otherwise, grab it from our linear allocation */
 	if (!obj->page) {
 		struct drm_mm_node *node;
 		unsigned align = min_t(unsigned, size, SZ_2M);
 		void __iomem *ptr;
 		int ret;

 		node = kzalloc(sizeof(*node), GFP_KERNEL);
 		if (!node)
 			return -ENOSPC;

 		mutex_lock(&priv->linear_lock);
 		ret = drm_mm_insert_node(&priv->linear, node, size, align,
 					 DRM_MM_SEARCH_DEFAULT);
 		mutex_unlock(&priv->linear_lock);
 		if (ret) {
 			kfree(node);
 			return ret;
 		}

 		obj->linear = node;

 		/* Ensure that the memory we're returning is cleared. */
 		ptr = ioremap_wc(obj->linear->start, size);
 		if (!ptr) {
 			mutex_lock(&priv->linear_lock);
 			drm_mm_remove_node(obj->linear);
 			mutex_unlock(&priv->linear_lock);
 			kfree(obj->linear);
 			obj->linear = NULL;
 			return -ENOMEM;
 		}

 		memset_io(ptr, 0, size);
 		iounmap(ptr);

 		obj->phys_addr = obj->linear->start;
 		obj->dev_addr = obj->linear->start;
 	}

 	DRM_DEBUG_DRIVER("obj %p phys %#llx dev %#llx\n", obj,
 			 (unsigned long long)obj->phys_addr,
 			 (unsigned long long)obj->dev_addr);

 	return 0;
 }

 void *
 armada_gem_map_object(struct drm_device *dev, struct armada_gem_object *dobj)
 {
 	/* only linear objects need to be ioremap'd */
 	if (!dobj->addr && dobj->linear)
 		dobj->addr = ioremap_wc(dobj->phys_addr, dobj->obj.size);
 	return dobj->addr;
 }

 struct armada_gem_object *
 armada_gem_alloc_private_object(struct drm_device *dev, size_t size)
 {
 	struct armada_gem_object *obj;

 	size = roundup_gem_size(size);

 	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 	if (!obj)
 		return NULL;

 	drm_gem_private_object_init(dev, &obj->obj, size);
 	obj->dev_addr = DMA_ERROR_CODE;

 	DRM_DEBUG_DRIVER("alloc private obj %p size %zu\n", obj, size);

 	return obj;
 }

 struct armada_gem_object *armada_gem_alloc_object(struct drm_device *dev,
 	size_t size)
 {
 	struct armada_gem_object *obj;
 	struct address_space *mapping;

 	size = roundup_gem_size(size);

 	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 	if (!obj)
 		return NULL;

 	if (drm_gem_object_init(dev, &obj->obj, size)) {
 		kfree(obj);
 		return NULL;
 	}

 	obj->dev_addr = DMA_ERROR_CODE;

 	mapping = file_inode(obj->obj.filp)->i_mapping;
 	mapping_set_gfp_mask(mapping, GFP_HIGHUSER | __GFP_RECLAIMABLE);

 	DRM_DEBUG_DRIVER("alloc obj %p size %zu\n", obj, size);

 	return obj;
 }

 /* Dumb alloc support */
 int armada_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 	struct drm_mode_create_dumb *args)
 {
 	struct armada_gem_object *dobj;
 	u32 handle;
 	size_t size;
 	int ret;

 	args->pitch = armada_pitch(args->width, args->bpp);
 	args->size = size = args->pitch * args->height;

 	dobj = armada_gem_alloc_private_object(dev, size);
 	if (dobj == NULL)
 		return -ENOMEM;

 	ret = armada_gem_linear_back(dev, dobj);
 	if (ret)
 		goto err;

 	ret = drm_gem_handle_create(file, &dobj->obj, &handle);
 	if (ret)
 		goto err;

 	args->handle = handle;

 	/* drop reference from allocate - handle holds it now */
 	DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
  err:
 	drm_gem_object_unreference_unlocked(&dobj->obj);
 	return ret;
 }

 int armada_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
 	uint32_t handle, uint64_t *offset)
 {
 	struct armada_gem_object *obj;
 	int ret = 0;

 	obj = armada_gem_object_lookup(dev, file, handle);
 	if (!obj) {
 		DRM_ERROR("failed to lookup gem object\n");
 		return -EINVAL;
 	}

 	/* Don't allow imported objects to be mapped */
 	if (obj->obj.import_attach) {
 		ret = -EINVAL;
 		goto err_unref;
 	}

 	ret = drm_gem_create_mmap_offset(&obj->obj);
 	if (ret == 0) {
 		*offset = drm_vma_node_offset_addr(&obj->obj.vma_node);
 		DRM_DEBUG_DRIVER("handle %#x offset %llx\n", handle, *offset);
 	}

  err_unref:
 	drm_gem_object_unreference_unlocked(&obj->obj);

 	return ret;
 }

 int armada_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
 	uint32_t handle)
 {
 	return drm_gem_handle_delete(file, handle);
 }

 /* Private driver gem ioctls */
 int armada_gem_create_ioctl(struct drm_device *dev, void *data,
 	struct drm_file *file)
 {
 	struct drm_armada_gem_create *args = data;
 	struct armada_gem_object *dobj;
 	size_t size;
 	u32 handle;
 	int ret;

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

 	size = args->size;

 	dobj = armada_gem_alloc_object(dev, size);
 	if (dobj == NULL)
 		return -ENOMEM;

 	ret = drm_gem_handle_create(file, &dobj->obj, &handle);
 	if (ret)
 		goto err;

 	args->handle = handle;

 	/* drop reference from allocate - handle holds it now */
 	DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
  err:
 	drm_gem_object_unreference_unlocked(&dobj->obj);
 	return ret;
 }

 /* Map a shmem-backed object into process memory space */
 int armada_gem_mmap_ioctl(struct drm_device *dev, void *data,
 	struct drm_file *file)
 {
 	struct drm_armada_gem_mmap *args = data;
 	struct armada_gem_object *dobj;
 	unsigned long addr;

 	dobj = armada_gem_object_lookup(dev, file, args->handle);
 	if (dobj == NULL)
 		return -ENOENT;

 	if (!dobj->obj.filp) {
 		drm_gem_object_unreference_unlocked(&dobj->obj);
 		return -EINVAL;
 	}

 	addr = vm_mmap(dobj->obj.filp, 0, args->size, PROT_READ | PROT_WRITE,
 		       MAP_SHARED, args->offset);
 	drm_gem_object_unreference_unlocked(&dobj->obj);
 	if (IS_ERR_VALUE(addr))
 		return addr;

 	args->addr = addr;

 	return 0;
 }

 int armada_gem_pwrite_ioctl(struct drm_device *dev, void *data,
 	struct drm_file *file)
 {
 	struct drm_armada_gem_pwrite *args = data;
 	struct armada_gem_object *dobj;
 	char __user *ptr;
 	int ret;

 	DRM_DEBUG_DRIVER("handle %u off %u size %u ptr 0x%llx\n",
 		args->handle, args->offset, args->size, args->ptr);

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

 	ptr = (char __user *)(uintptr_t)args->ptr;

 	if (!access_ok(VERIFY_READ, ptr, args->size))
 		return -EFAULT;

 	ret = fault_in_multipages_readable(ptr, args->size);
 	if (ret)
 		return ret;

 	dobj = armada_gem_object_lookup(dev, file, args->handle);
 	if (dobj == NULL)
 		return -ENOENT;

 	/* Must be a kernel-mapped object */
 	if (!dobj->addr)
 		return -EINVAL;

 	if (args->offset > dobj->obj.size ||
 	    args->size > dobj->obj.size - args->offset) {
 		DRM_ERROR("invalid size: object size %u\n", dobj->obj.size);
 		ret = -EINVAL;
 		goto unref;
 	}

 	if (copy_from_user(dobj->addr + args->offset, ptr, args->size)) {
 		ret = -EFAULT;
 	} else if (dobj->update) {
 		dobj->update(dobj->update_data);
 		ret = 0;
 	}

  unref:
 	drm_gem_object_unreference_unlocked(&dobj->obj);
 	return ret;
 }

 /* Prime support */
 struct sg_table *
 armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
 	enum dma_data_direction dir)
 {
 	struct drm_gem_object *obj = attach->dmabuf->priv;
 	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
 	struct scatterlist *sg;
 	struct sg_table *sgt;
 	int i, num;

 	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
 	if (!sgt)
 		return NULL;

 	if (dobj->obj.filp) {
 		struct address_space *mapping;
 		int count;

 		count = dobj->obj.size / PAGE_SIZE;
 		if (sg_alloc_table(sgt, count, GFP_KERNEL))
 			goto free_sgt;

 		mapping = file_inode(dobj->obj.filp)->i_mapping;

 		for_each_sg(sgt->sgl, sg, count, i) {
 			struct page *page;

 			page = shmem_read_mapping_page(mapping, i);
 			if (IS_ERR(page)) {
 				num = i;
 				goto release;
 			}

 			sg_set_page(sg, page, PAGE_SIZE, 0);
 		}

 		if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0) {
 			num = sgt->nents;
 			goto release;
 		}
 	} else if (dobj->page) {
 		/* Single contiguous page */
 		if (sg_alloc_table(sgt, 1, GFP_KERNEL))
 			goto free_sgt;

 		sg_set_page(sgt->sgl, dobj->page, dobj->obj.size, 0);

 		if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
 			goto free_table;
 	} else if (dobj->linear) {
 		/* Single contiguous physical region - no struct page */
 		if (sg_alloc_table(sgt, 1, GFP_KERNEL))
 			goto free_sgt;
 		sg_dma_address(sgt->sgl) = dobj->dev_addr;
 		sg_dma_len(sgt->sgl) = dobj->obj.size;
 	} else {
 		goto free_sgt;
 	}
 	return sgt;

  release:
 	for_each_sg(sgt->sgl, sg, num, i)
 		put_page(sg_page(sg));
  free_table:
 	sg_free_table(sgt);
  free_sgt:
 	kfree(sgt);
 	return NULL;
 }

 static void armada_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
 	struct sg_table *sgt, enum dma_data_direction dir)
 {
 	struct drm_gem_object *obj = attach->dmabuf->priv;
 	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
 	int i;

 	if (!dobj->linear)
 		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);

 	if (dobj->obj.filp) {
 		struct scatterlist *sg;
 		for_each_sg(sgt->sgl, sg, sgt->nents, i)
 			put_page(sg_page(sg));
 	}

 	sg_free_table(sgt);
 	kfree(sgt);
 }

 static void *armada_gem_dmabuf_no_kmap(struct dma_buf *buf, unsigned long n)
 {
 	return NULL;
 }

 static void
 armada_gem_dmabuf_no_kunmap(struct dma_buf *buf, unsigned long n, void *addr)
 {
 }

 static int
 armada_gem_dmabuf_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
 {
 	return -EINVAL;
 }

 static const struct dma_buf_ops armada_gem_prime_dmabuf_ops = {
 	.map_dma_buf	= armada_gem_prime_map_dma_buf,
 	.unmap_dma_buf	= armada_gem_prime_unmap_dma_buf,
 	.release	= drm_gem_dmabuf_release,
 	.kmap_atomic	= armada_gem_dmabuf_no_kmap,
 	.kunmap_atomic	= armada_gem_dmabuf_no_kunmap,
 	.kmap		= armada_gem_dmabuf_no_kmap,
 	.kunmap		= armada_gem_dmabuf_no_kunmap,
 	.mmap		= armada_gem_dmabuf_mmap,
 };

 struct dma_buf *
 armada_gem_prime_export(struct drm_device *dev, struct drm_gem_object *obj,
 	int flags)
 {
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

 	exp_info.ops = &armada_gem_prime_dmabuf_ops;
 	exp_info.size = obj->size;
 	exp_info.flags = O_RDWR;
 	exp_info.priv = obj;

 	return dma_buf_export(&exp_info);
 }

 struct drm_gem_object *
 armada_gem_prime_import(struct drm_device *dev, struct dma_buf *buf)
 {
 	struct dma_buf_attachment *attach;
 	struct armada_gem_object *dobj;

 	if (buf->ops == &armada_gem_prime_dmabuf_ops) {
 		struct drm_gem_object *obj = buf->priv;
 		if (obj->dev == dev) {
 			/*
 			 * Importing our own dmabuf(s) increases the
 			 * refcount on the gem object itself.
 			 */
 			drm_gem_object_reference(obj);
 			return obj;
 		}
 	}

 	attach = dma_buf_attach(buf, dev->dev);
 	if (IS_ERR(attach))
 		return ERR_CAST(attach);

 	dobj = armada_gem_alloc_private_object(dev, buf->size);
 	if (!dobj) {
 		dma_buf_detach(buf, attach);
 		return ERR_PTR(-ENOMEM);
 	}

 	dobj->obj.import_attach = attach;
 	get_dma_buf(buf);

 	/*
 	 * Don't call dma_buf_map_attachment() here - it maps the
 	 * scatterlist immediately for DMA, and this is not always
 	 * an appropriate thing to do.
 	 */
 	return &dobj->obj;
 }

 int armada_gem_map_import(struct armada_gem_object *dobj)
 {
 	int ret;

 	dobj->sgt = dma_buf_map_attachment(dobj->obj.import_attach,
 					  DMA_TO_DEVICE);
 	if (!dobj->sgt) {
 		DRM_ERROR("dma_buf_map_attachment() returned NULL\n");
 		return -EINVAL;
 	}
 	if (IS_ERR(dobj->sgt)) {
 		ret = PTR_ERR(dobj->sgt);
 		dobj->sgt = NULL;
 		DRM_ERROR("dma_buf_map_attachment() error: %d\n", ret);
 		return ret;
 	}
 	if (dobj->sgt->nents > 1) {
 		DRM_ERROR("dma_buf_map_attachment() returned an (unsupported) scattered list\n");
 		return -EINVAL;
 	}
 	if (sg_dma_len(dobj->sgt->sgl) < dobj->obj.size) {
 		DRM_ERROR("dma_buf_map_attachment() returned a small buffer\n");
 		return -EINVAL;
 	}
 	dobj->dev_addr = sg_dma_address(dobj->sgt->sgl);
 	return 0;
 }
	/*
	* Copyright (C) 2012 Russell King
	*
	* 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.
	*/
	#include <linux/dma-buf.h>
	#include <linux/dma-mapping.h>
	#include <linux/shmem_fs.h>
	#include <drm/drmP.h>
	#include "armada_drm.h"
	#include "armada_gem.h"
	#include <drm/armada_drm.h>
	#include "armada_ioctlP.h"

	static int armada_gem_vm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	struct armada_gem_object *obj = drm_to_armada_gem(vma->vm_private_data);
	unsigned long addr = (unsigned long)vmf->virtual_address;
	unsigned long pfn = obj->phys_addr >> PAGE_SHIFT;
	int ret;

	pfn += (addr - vma->vm_start) >> PAGE_SHIFT;
	ret = vm_insert_pfn(vma, addr, pfn);

	switch (ret) {
	case 0:
	case -EBUSY:
	return VM_FAULT_NOPAGE;
	case -ENOMEM:
	return VM_FAULT_OOM;
	default:
	return VM_FAULT_SIGBUS;
	}
	}

	const struct vm_operations_struct armada_gem_vm_ops = {
	.fault = armada_gem_vm_fault,
	.open = drm_gem_vm_open,
	.close = drm_gem_vm_close,
	};

	static size_t roundup_gem_size(size_t size)
	{
	return roundup(size, PAGE_SIZE);
	}

	void armada_gem_free_object(struct drm_gem_object *obj)
	{
	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
	struct armada_private *priv = obj->dev->dev_private;

	DRM_DEBUG_DRIVER("release obj %p\n", dobj);

	drm_gem_free_mmap_offset(&dobj->obj);

	might_lock(&priv->linear_lock);

	if (dobj->page) {
	/* page backed memory */
	unsigned int order = get_order(dobj->obj.size);
	__free_pages(dobj->page, order);
	} else if (dobj->linear) {
	/* linear backed memory */
	mutex_lock(&priv->linear_lock);
	drm_mm_remove_node(dobj->linear);
	mutex_unlock(&priv->linear_lock);
	kfree(dobj->linear);
	if (dobj->addr)
	iounmap(dobj->addr);
	}

	if (dobj->obj.import_attach) {
	/* We only ever display imported data */
	if (dobj->sgt)
	dma_buf_unmap_attachment(dobj->obj.import_attach,
	dobj->sgt, DMA_TO_DEVICE);
	drm_prime_gem_destroy(&dobj->obj, NULL);
	}

	drm_gem_object_release(&dobj->obj);

	kfree(dobj);
	}

	int
	armada_gem_linear_back(struct drm_device dev, struct armada_gem_object obj)
	{
	struct armada_private *priv = dev->dev_private;
	size_t size = obj->obj.size;

	if (obj->page \|\| obj->linear)
	return 0;

	/*
	* If it is a small allocation (typically cursor, which will
	* be 32x64 or 64x32 ARGB pixels) try to get it from the system.
	* Framebuffers will never be this small (our minimum size for
	* framebuffers is larger than this anyway.) Such objects are
	* only accessed by the CPU so we don't need any special handing
	* here.
	*/
	if (size <= 8192) {
	unsigned int order = get_order(size);
	struct page *p = alloc_pages(GFP_KERNEL, order);

	if (p) {
	obj->addr = page_address(p);
	obj->phys_addr = page_to_phys(p);
	obj->page = p;

	memset(obj->addr, 0, PAGE_ALIGN(size));
	}
	}

	/*
	* We could grab something from CMA if it's enabled, but that
	* involves building in a problem:
	*
	* CMA's interface uses dma_alloc_coherent(), which provides us
	* with an CPU virtual address and a device address.
	*
	* The CPU virtual address may be either an address in the kernel
	* direct mapped region (for example, as it would be on x86) or
	* it may be remapped into another part of kernel memory space
	* (eg, as it would be on ARM.) This means virt_to_phys() on the
	* returned virtual address is invalid depending on the architecture
	* implementation.
	*
	* The device address may also not be a physical address; it may
	* be that there is some kind of remapping between the device and
	* system RAM, which makes the use of the device address also
	* unsafe to re-use as a physical address.
	*
	* This makes DRM usage of dma_alloc_coherent() in a generic way
	* at best very questionable and unsafe.
	*/

	/* Otherwise, grab it from our linear allocation */
	if (!obj->page) {
	struct drm_mm_node *node;
	unsigned align = min_t(unsigned, size, SZ_2M);
	void __iomem *ptr;
	int ret;

	node = kzalloc(sizeof(*node), GFP_KERNEL);
	if (!node)
	return -ENOSPC;

	mutex_lock(&priv->linear_lock);
	ret = drm_mm_insert_node(&priv->linear, node, size, align,
	DRM_MM_SEARCH_DEFAULT);
	mutex_unlock(&priv->linear_lock);
	if (ret) {
	kfree(node);
	return ret;
	}

	obj->linear = node;

	/* Ensure that the memory we're returning is cleared. */
	ptr = ioremap_wc(obj->linear->start, size);
	if (!ptr) {
	mutex_lock(&priv->linear_lock);
	drm_mm_remove_node(obj->linear);
	mutex_unlock(&priv->linear_lock);
	kfree(obj->linear);
	obj->linear = NULL;
	return -ENOMEM;
	}

	memset_io(ptr, 0, size);
	iounmap(ptr);

	obj->phys_addr = obj->linear->start;
	obj->dev_addr = obj->linear->start;
	}

	DRM_DEBUG_DRIVER("obj %p phys %#llx dev %#llx\n", obj,
	(unsigned long long)obj->phys_addr,
	(unsigned long long)obj->dev_addr);

	return 0;
	}

	void *
	armada_gem_map_object(struct drm_device dev, struct armada_gem_object dobj)
	{
	/* only linear objects need to be ioremap'd */
	if (!dobj->addr && dobj->linear)
	dobj->addr = ioremap_wc(dobj->phys_addr, dobj->obj.size);
	return dobj->addr;
	}

	struct armada_gem_object *
	armada_gem_alloc_private_object(struct drm_device *dev, size_t size)
	{
	struct armada_gem_object *obj;

	size = roundup_gem_size(size);

	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
	if (!obj)
	return NULL;

	drm_gem_private_object_init(dev, &obj->obj, size);
	obj->dev_addr = DMA_ERROR_CODE;

	DRM_DEBUG_DRIVER("alloc private obj %p size %zu\n", obj, size);

	return obj;
	}

	struct armada_gem_object armada_gem_alloc_object(struct drm_device dev,
	size_t size)
	{
	struct armada_gem_object *obj;
	struct address_space *mapping;

	size = roundup_gem_size(size);

	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
	if (!obj)
	return NULL;

	if (drm_gem_object_init(dev, &obj->obj, size)) {
	kfree(obj);
	return NULL;
	}

	obj->dev_addr = DMA_ERROR_CODE;

	mapping = file_inode(obj->obj.filp)->i_mapping;
	mapping_set_gfp_mask(mapping, GFP_HIGHUSER \| __GFP_RECLAIMABLE);

	DRM_DEBUG_DRIVER("alloc obj %p size %zu\n", obj, size);

	return obj;
	}

	/* Dumb alloc support */
	int armada_gem_dumb_create(struct drm_file file, struct drm_device dev,
	struct drm_mode_create_dumb *args)
	{
	struct armada_gem_object *dobj;
	u32 handle;
	size_t size;
	int ret;

	args->pitch = armada_pitch(args->width, args->bpp);
	args->size = size = args->pitch * args->height;

	dobj = armada_gem_alloc_private_object(dev, size);
	if (dobj == NULL)
	return -ENOMEM;

	ret = armada_gem_linear_back(dev, dobj);
	if (ret)
	goto err;

	ret = drm_gem_handle_create(file, &dobj->obj, &handle);
	if (ret)
	goto err;

	args->handle = handle;

	/* drop reference from allocate - handle holds it now */
	DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
	err:
	drm_gem_object_unreference_unlocked(&dobj->obj);
	return ret;
	}

	int armada_gem_dumb_map_offset(struct drm_file file, struct drm_device dev,
	uint32_t handle, uint64_t *offset)
	{
	struct armada_gem_object *obj;
	int ret = 0;

	obj = armada_gem_object_lookup(dev, file, handle);
	if (!obj) {
	DRM_ERROR("failed to lookup gem object\n");
	return -EINVAL;
	}

	/* Don't allow imported objects to be mapped */
	if (obj->obj.import_attach) {
	ret = -EINVAL;
	goto err_unref;
	}

	ret = drm_gem_create_mmap_offset(&obj->obj);
	if (ret == 0) {
	*offset = drm_vma_node_offset_addr(&obj->obj.vma_node);
	DRM_DEBUG_DRIVER("handle %#x offset %llx\n", handle, *offset);
	}

	err_unref:
	drm_gem_object_unreference_unlocked(&obj->obj);

	return ret;
	}

	int armada_gem_dumb_destroy(struct drm_file file, struct drm_device dev,
	uint32_t handle)
	{
	return drm_gem_handle_delete(file, handle);
	}

	/* Private driver gem ioctls */
	int armada_gem_create_ioctl(struct drm_device dev, void data,
	struct drm_file *file)
	{
	struct drm_armada_gem_create *args = data;
	struct armada_gem_object *dobj;
	size_t size;
	u32 handle;
	int ret;

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

	size = args->size;

	dobj = armada_gem_alloc_object(dev, size);
	if (dobj == NULL)
	return -ENOMEM;

	ret = drm_gem_handle_create(file, &dobj->obj, &handle);
	if (ret)
	goto err;

	args->handle = handle;

	/* drop reference from allocate - handle holds it now */
	DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
	err:
	drm_gem_object_unreference_unlocked(&dobj->obj);
	return ret;
	}

	/* Map a shmem-backed object into process memory space */
	int armada_gem_mmap_ioctl(struct drm_device dev, void data,
	struct drm_file *file)
	{
	struct drm_armada_gem_mmap *args = data;
	struct armada_gem_object *dobj;
	unsigned long addr;

	dobj = armada_gem_object_lookup(dev, file, args->handle);
	if (dobj == NULL)
	return -ENOENT;

	if (!dobj->obj.filp) {
	drm_gem_object_unreference_unlocked(&dobj->obj);
	return -EINVAL;
	}

	addr = vm_mmap(dobj->obj.filp, 0, args->size, PROT_READ \| PROT_WRITE,
	MAP_SHARED, args->offset);
	drm_gem_object_unreference_unlocked(&dobj->obj);
	if (IS_ERR_VALUE(addr))
	return addr;

	args->addr = addr;

	return 0;
	}

	int armada_gem_pwrite_ioctl(struct drm_device dev, void data,
	struct drm_file *file)
	{
	struct drm_armada_gem_pwrite *args = data;
	struct armada_gem_object *dobj;
	char __user *ptr;
	int ret;

	DRM_DEBUG_DRIVER("handle %u off %u size %u ptr 0x%llx\n",
	args->handle, args->offset, args->size, args->ptr);

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

	ptr = (char __user *)(uintptr_t)args->ptr;

	if (!access_ok(VERIFY_READ, ptr, args->size))
	return -EFAULT;

	ret = fault_in_multipages_readable(ptr, args->size);
	if (ret)
	return ret;

	dobj = armada_gem_object_lookup(dev, file, args->handle);
	if (dobj == NULL)
	return -ENOENT;

	/* Must be a kernel-mapped object */
	if (!dobj->addr)
	return -EINVAL;

	if (args->offset > dobj->obj.size \|\|
	args->size > dobj->obj.size - args->offset) {
	DRM_ERROR("invalid size: object size %u\n", dobj->obj.size);
	ret = -EINVAL;
	goto unref;
	}

	if (copy_from_user(dobj->addr + args->offset, ptr, args->size)) {
	ret = -EFAULT;
	} else if (dobj->update) {
	dobj->update(dobj->update_data);
	ret = 0;
	}

	unref:
	drm_gem_object_unreference_unlocked(&dobj->obj);
	return ret;
	}

	/* Prime support */
	struct sg_table *
	armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
	enum dma_data_direction dir)
	{
	struct drm_gem_object *obj = attach->dmabuf->priv;
	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
	struct scatterlist *sg;
	struct sg_table *sgt;
	int i, num;

	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
	if (!sgt)
	return NULL;

	if (dobj->obj.filp) {
	struct address_space *mapping;
	int count;

	count = dobj->obj.size / PAGE_SIZE;
	if (sg_alloc_table(sgt, count, GFP_KERNEL))
	goto free_sgt;

	mapping = file_inode(dobj->obj.filp)->i_mapping;

	for_each_sg(sgt->sgl, sg, count, i) {
	struct page *page;

	page = shmem_read_mapping_page(mapping, i);
	if (IS_ERR(page)) {
	num = i;
	goto release;
	}

	sg_set_page(sg, page, PAGE_SIZE, 0);
	}

	if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0) {
	num = sgt->nents;
	goto release;
	}
	} else if (dobj->page) {
	/* Single contiguous page */
	if (sg_alloc_table(sgt, 1, GFP_KERNEL))
	goto free_sgt;

	sg_set_page(sgt->sgl, dobj->page, dobj->obj.size, 0);

	if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
	goto free_table;
	} else if (dobj->linear) {
	/* Single contiguous physical region - no struct page */
	if (sg_alloc_table(sgt, 1, GFP_KERNEL))
	goto free_sgt;
	sg_dma_address(sgt->sgl) = dobj->dev_addr;
	sg_dma_len(sgt->sgl) = dobj->obj.size;
	} else {
	goto free_sgt;
	}
	return sgt;

	release:
	for_each_sg(sgt->sgl, sg, num, i)
	put_page(sg_page(sg));
	free_table:
	sg_free_table(sgt);
	free_sgt:
	kfree(sgt);
	return NULL;
	}

	static void armada_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
	struct sg_table *sgt, enum dma_data_direction dir)
	{
	struct drm_gem_object *obj = attach->dmabuf->priv;
	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
	int i;

	if (!dobj->linear)
	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);

	if (dobj->obj.filp) {
	struct scatterlist *sg;
	for_each_sg(sgt->sgl, sg, sgt->nents, i)
	put_page(sg_page(sg));
	}

	sg_free_table(sgt);
	kfree(sgt);
	}

	static void armada_gem_dmabuf_no_kmap(struct dma_buf buf, unsigned long n)
	{
	return NULL;
	}

	static void
	armada_gem_dmabuf_no_kunmap(struct dma_buf buf, unsigned long n, void addr)
	{
	}

	static int
	armada_gem_dmabuf_mmap(struct dma_buf buf, struct vm_area_struct vma)
	{
	return -EINVAL;
	}

	static const struct dma_buf_ops armada_gem_prime_dmabuf_ops = {
	.map_dma_buf = armada_gem_prime_map_dma_buf,
	.unmap_dma_buf = armada_gem_prime_unmap_dma_buf,
	.release = drm_gem_dmabuf_release,
	.kmap_atomic = armada_gem_dmabuf_no_kmap,
	.kunmap_atomic = armada_gem_dmabuf_no_kunmap,
	.kmap = armada_gem_dmabuf_no_kmap,
	.kunmap = armada_gem_dmabuf_no_kunmap,
	.mmap = armada_gem_dmabuf_mmap,
	};

	struct dma_buf *
	armada_gem_prime_export(struct drm_device dev, struct drm_gem_object obj,
	int flags)
	{
	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

	exp_info.ops = &armada_gem_prime_dmabuf_ops;
	exp_info.size = obj->size;
	exp_info.flags = O_RDWR;
	exp_info.priv = obj;

	return dma_buf_export(&exp_info);
	}

	struct drm_gem_object *
	armada_gem_prime_import(struct drm_device dev, struct dma_buf buf)
	{
	struct dma_buf_attachment *attach;
	struct armada_gem_object *dobj;

	if (buf->ops == &armada_gem_prime_dmabuf_ops) {
	struct drm_gem_object *obj = buf->priv;
	if (obj->dev == dev) {
	/*
	* Importing our own dmabuf(s) increases the
	* refcount on the gem object itself.
	*/
	drm_gem_object_reference(obj);
	return obj;
	}
	}

	attach = dma_buf_attach(buf, dev->dev);
	if (IS_ERR(attach))
	return ERR_CAST(attach);

	dobj = armada_gem_alloc_private_object(dev, buf->size);
	if (!dobj) {
	dma_buf_detach(buf, attach);
	return ERR_PTR(-ENOMEM);
	}

	dobj->obj.import_attach = attach;
	get_dma_buf(buf);

	/*
	* Don't call dma_buf_map_attachment() here - it maps the
	* scatterlist immediately for DMA, and this is not always
	* an appropriate thing to do.
	*/
	return &dobj->obj;
	}

	int armada_gem_map_import(struct armada_gem_object *dobj)
	{
	int ret;

	dobj->sgt = dma_buf_map_attachment(dobj->obj.import_attach,
	DMA_TO_DEVICE);
	if (!dobj->sgt) {
	DRM_ERROR("dma_buf_map_attachment() returned NULL\n");
	return -EINVAL;
	}
	if (IS_ERR(dobj->sgt)) {
	ret = PTR_ERR(dobj->sgt);
	dobj->sgt = NULL;
	DRM_ERROR("dma_buf_map_attachment() error: %d\n", ret);
	return ret;
	}
	if (dobj->sgt->nents > 1) {
	DRM_ERROR("dma_buf_map_attachment() returned an (unsupported) scattered list\n");
	return -EINVAL;
	}
	if (sg_dma_len(dobj->sgt->sgl) < dobj->obj.size) {
	DRM_ERROR("dma_buf_map_attachment() returned a small buffer\n");
	return -EINVAL;
	}
	dobj->dev_addr = sg_dma_address(dobj->sgt->sgl);
	return 0;
	}