[deliverable/linux.git] / drivers / gpu / drm / drm_gem_cma_helper.c

/*
 * drm gem CMA (contiguous memory allocator) helper functions
 *
 * Copyright (C) 2012 Sascha Hauer, Pengutronix
 *
 * Based on Samsung Exynos code
 *
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 *
 * 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.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/export.h>
#include <linux/dma-buf.h>
#include <linux/dma-mapping.h>

#include <drm/drmP.h>
#include <drm/drm.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_vma_manager.h>

/*
 * __drm_gem_cma_create - Create a GEM CMA object without allocating memory
 * @drm: The drm device
 * @size: The GEM object size
 *
 * This function creates and initializes a GEM CMA object of the given size, but
 * doesn't allocate any memory to back the object.
 *
 * Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure.
 */
static struct drm_gem_cma_object *
__drm_gem_cma_create(struct drm_device *drm, unsigned int size)
{
	struct drm_gem_cma_object *cma_obj;
	struct drm_gem_object *gem_obj;
	int ret;

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

	gem_obj = &cma_obj->base;

	ret = drm_gem_object_init(drm, gem_obj, size);
	if (ret)
		goto error;

	ret = drm_gem_create_mmap_offset(gem_obj);
	if (ret) {
		drm_gem_object_release(gem_obj);
		goto error;
	}

	return cma_obj;

error:
	kfree(cma_obj);
	return ERR_PTR(ret);
}

/*
 * drm_gem_cma_create - allocate an object with the given size
 *
 * returns a struct drm_gem_cma_object* on success or ERR_PTR values
 * on failure.
 */
struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
		unsigned int size)
{
	struct drm_gem_cma_object *cma_obj;
	struct sg_table *sgt = NULL;
	int ret;

	size = round_up(size, PAGE_SIZE);

	cma_obj = __drm_gem_cma_create(drm, size);
	if (IS_ERR(cma_obj))
		return cma_obj;

	cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size,
			&cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN);
	if (!cma_obj->vaddr) {
		dev_err(drm->dev, "failed to allocate buffer with size %d\n",
			size);
		ret = -ENOMEM;
		goto error;
	}

	sgt = kzalloc(sizeof(*cma_obj->sgt), GFP_KERNEL);
	if (sgt == NULL) {
		ret = -ENOMEM;
		goto error;
	}

	ret = dma_get_sgtable(drm->dev, sgt, cma_obj->vaddr,
			      cma_obj->paddr, size);
	if (ret < 0)
		goto error;

	cma_obj->sgt = sgt;

	return cma_obj;

error:
	kfree(sgt);
	drm_gem_cma_free_object(&cma_obj->base);
	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_create);

/*
 * drm_gem_cma_create_with_handle - allocate an object with the given
 * size and create a gem handle on it
 *
 * returns a struct drm_gem_cma_object* on success or ERR_PTR values
 * on failure.
 */
static struct drm_gem_cma_object *drm_gem_cma_create_with_handle(
		struct drm_file *file_priv,
		struct drm_device *drm, unsigned int size,
		unsigned int *handle)
{
	struct drm_gem_cma_object *cma_obj;
	struct drm_gem_object *gem_obj;
	int ret;

	cma_obj = drm_gem_cma_create(drm, size);
	if (IS_ERR(cma_obj))
		return cma_obj;

	gem_obj = &cma_obj->base;

	/*
	 * allocate a id of idr table where the obj is registered
	 * and handle has the id what user can see.
	 */
	ret = drm_gem_handle_create(file_priv, gem_obj, handle);
	if (ret)
		goto err_handle_create;

	/* drop reference from allocate - handle holds it now. */
	drm_gem_object_unreference_unlocked(gem_obj);

	return cma_obj;

err_handle_create:
	drm_gem_cma_free_object(gem_obj);

	return ERR_PTR(ret);
}

/*
 * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback
 * function
 */
void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
{
	struct drm_gem_cma_object *cma_obj;

	drm_gem_free_mmap_offset(gem_obj);

	cma_obj = to_drm_gem_cma_obj(gem_obj);

	if (cma_obj->vaddr) {
		dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
				      cma_obj->vaddr, cma_obj->paddr);
		if (cma_obj->sgt) {
			sg_free_table(cma_obj->sgt);
			kfree(cma_obj->sgt);
		}
	} else if (gem_obj->import_attach) {
		drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
	}

	drm_gem_object_release(gem_obj);

	kfree(cma_obj);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_free_object);

/*
 * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback
 * function
 *
 * This aligns the pitch and size arguments to the minimum required. wrap
 * this into your own function if you need bigger alignment.
 */
int drm_gem_cma_dumb_create(struct drm_file *file_priv,
		struct drm_device *dev, struct drm_mode_create_dumb *args)
{
	struct drm_gem_cma_object *cma_obj;
	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);

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

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

	cma_obj = drm_gem_cma_create_with_handle(file_priv, dev,
			args->size, &args->handle);
	return PTR_ERR_OR_ZERO(cma_obj);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);

/*
 * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback
 * function
 */
int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
		struct drm_device *drm, uint32_t handle, uint64_t *offset)
{
	struct drm_gem_object *gem_obj;

	mutex_lock(&drm->struct_mutex);

	gem_obj = drm_gem_object_lookup(drm, file_priv, handle);
	if (!gem_obj) {
		dev_err(drm->dev, "failed to lookup gem object\n");
		mutex_unlock(&drm->struct_mutex);
		return -EINVAL;
	}

	*offset = drm_vma_node_offset_addr(&gem_obj->vma_node);

	drm_gem_object_unreference(gem_obj);

	mutex_unlock(&drm->struct_mutex);

	return 0;
}
EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset);

const struct vm_operations_struct drm_gem_cma_vm_ops = {
	.open = drm_gem_vm_open,
	.close = drm_gem_vm_close,
};
EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops);

static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj,
				struct vm_area_struct *vma)
{
	int ret;

	ret = remap_pfn_range(vma, vma->vm_start, cma_obj->paddr >> PAGE_SHIFT,
			vma->vm_end - vma->vm_start, vma->vm_page_prot);
	if (ret)
		drm_gem_vm_close(vma);

	return ret;
}

/*
 * drm_gem_cma_mmap - (struct file_operation)->mmap callback function
 */
int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma)
{
	struct drm_gem_cma_object *cma_obj;
	struct drm_gem_object *gem_obj;
	int ret;

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

	gem_obj = vma->vm_private_data;
	cma_obj = to_drm_gem_cma_obj(gem_obj);

	return drm_gem_cma_mmap_obj(cma_obj, vma);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);

#ifdef CONFIG_DEBUG_FS
void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m)
{
	struct drm_gem_object *obj = &cma_obj->base;
	struct drm_device *dev = obj->dev;
	uint64_t off;

	WARN_ON(!mutex_is_locked(&dev->struct_mutex));

	off = drm_vma_node_start(&obj->vma_node);

	seq_printf(m, "%2d (%2d) %08llx %08Zx %p %d",
			obj->name, obj->refcount.refcount.counter,
			off, cma_obj->paddr, cma_obj->vaddr, obj->size);

	seq_printf(m, "\n");
}
EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
#endif

/* low-level interface prime helpers */
struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj)
{
	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
	struct sg_table *sgt;
	int ret;

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

	ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr,
			      cma_obj->paddr, obj->size);
	if (ret < 0)
		goto out;

	return sgt;

out:
	kfree(sgt);
	return NULL;
}
EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table);

struct drm_gem_object *
drm_gem_cma_prime_import_sg_table(struct drm_device *dev, size_t size,
				  struct sg_table *sgt)
{
	struct drm_gem_cma_object *cma_obj;

	if (sgt->nents != 1)
		return ERR_PTR(-EINVAL);

	/* Create a CMA GEM buffer. */
	cma_obj = __drm_gem_cma_create(dev, size);
	if (IS_ERR(cma_obj))
		return ERR_PTR(PTR_ERR(cma_obj));

	cma_obj->paddr = sg_dma_address(sgt->sgl);
	cma_obj->sgt = sgt;

	DRM_DEBUG_PRIME("dma_addr = 0x%x, size = %zu\n", cma_obj->paddr, size);

	return &cma_obj->base;
}
EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table);

int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
			   struct vm_area_struct *vma)
{
	struct drm_gem_cma_object *cma_obj;
	struct drm_device *dev = obj->dev;
	int ret;

	mutex_lock(&dev->struct_mutex);
	ret = drm_gem_mmap_obj(obj, obj->size, vma);
	mutex_unlock(&dev->struct_mutex);
	if (ret < 0)
		return ret;

	cma_obj = to_drm_gem_cma_obj(obj);
	return drm_gem_cma_mmap_obj(cma_obj, vma);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);

void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
{
	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);

	return cma_obj->vaddr;
}
EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);

void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
{
	/* Nothing to do */
}
EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);
Commit	Line	Data
b9d47450 SH	1	/*
	2	* drm gem CMA (contiguous memory allocator) helper functions
	3	*
	4	* Copyright (C) 2012 Sascha Hauer, Pengutronix
	5	*
	6	* Based on Samsung Exynos code
	7	*
	8	* Copyright (c) 2011 Samsung Electronics Co., Ltd.
	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* as published by the Free Software Foundation; either version 2
	13	* of the License, or (at your option) any later version.
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*/
	19
	20	#include <linux/mm.h>
	21	#include <linux/slab.h>
	22	#include <linux/mutex.h>
	23	#include <linux/export.h>
71d7282a	24	#include <linux/dma-buf.h>
b9d47450 SH	25	#include <linux/dma-mapping.h>
	26
	27	#include <drm/drmP.h>
	28	#include <drm/drm.h>
	29	#include <drm/drm_gem_cma_helper.h>
0de23977	30	#include <drm/drm_vma_manager.h>
b9d47450	31
b9d47450	32	/*
a5ed8940 LP	33	* __drm_gem_cma_create - Create a GEM CMA object without allocating memory
	34	* @drm: The drm device
	35	* @size: The GEM object size
b9d47450	36	*
a5ed8940 LP	37	* This function creates and initializes a GEM CMA object of the given size, but
	38	* doesn't allocate any memory to back the object.
	39	*
	40	* Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure.
b9d47450	41	*/
a5ed8940 LP	42	static struct drm_gem_cma_object *
a5ed8940 LP	43	__drm_gem_cma_create(struct drm_device *drm, unsigned int size)
b9d47450 SH	44	{
	45	struct drm_gem_cma_object *cma_obj;
	46	struct drm_gem_object *gem_obj;
	47	int ret;
	48
b9d47450 SH	49	cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
	50	if (!cma_obj)
	51	return ERR_PTR(-ENOMEM);
	52
b9d47450 SH	53	gem_obj = &cma_obj->base;
	54
	55	ret = drm_gem_object_init(drm, gem_obj, size);
	56	if (ret)
a5ed8940	57	goto error;
b9d47450 SH	58
b9d47450 SH	59	ret = drm_gem_create_mmap_offset(gem_obj);
a5ed8940 LP	60	if (ret) {
	61	drm_gem_object_release(gem_obj);
	62	goto error;
	63	}
b9d47450 SH	64
	65	return cma_obj;
	66
a5ed8940 LP	67	error:
	68	kfree(cma_obj);
	69	return ERR_PTR(ret);
	70	}
b9d47450	71
a5ed8940 LP	72	/*
	73	* drm_gem_cma_create - allocate an object with the given size
	74	*
	75	* returns a struct drm_gem_cma_object* on success or ERR_PTR values
	76	* on failure.
	77	*/
	78	struct drm_gem_cma_object drm_gem_cma_create(struct drm_device drm,
	79	unsigned int size)
	80	{
	81	struct drm_gem_cma_object *cma_obj;
71d7282a LP	82	struct sg_table *sgt = NULL;
71d7282a LP	83	int ret;
b9d47450	84
a5ed8940	85	size = round_up(size, PAGE_SIZE);
b9d47450	86
a5ed8940 LP	87	cma_obj = __drm_gem_cma_create(drm, size);
	88	if (IS_ERR(cma_obj))
	89	return cma_obj;
	90
	91	cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size,
	92	&cma_obj->paddr, GFP_KERNEL \| __GFP_NOWARN);
	93	if (!cma_obj->vaddr) {
	94	dev_err(drm->dev, "failed to allocate buffer with size %d\n",
	95	size);
71d7282a LP	96	ret = -ENOMEM;
	97	goto error;
	98	}
	99
	100	sgt = kzalloc(sizeof(*cma_obj->sgt), GFP_KERNEL);
	101	if (sgt == NULL) {
	102	ret = -ENOMEM;
	103	goto error;
a5ed8940 LP	104	}
a5ed8940 LP	105
71d7282a LP	106	ret = dma_get_sgtable(drm->dev, sgt, cma_obj->vaddr,
	107	cma_obj->paddr, size);
	108	if (ret < 0)
	109	goto error;
	110
	111	cma_obj->sgt = sgt;
	112
a5ed8940	113	return cma_obj;
71d7282a LP	114
	115	error:
	116	kfree(sgt);
	117	drm_gem_cma_free_object(&cma_obj->base);
	118	return ERR_PTR(ret);
b9d47450 SH	119	}
	120	EXPORT_SYMBOL_GPL(drm_gem_cma_create);
	121
	122	/*
	123	* drm_gem_cma_create_with_handle - allocate an object with the given
	124	* size and create a gem handle on it
	125	*
	126	* returns a struct drm_gem_cma_object* on success or ERR_PTR values
	127	* on failure.
	128	*/
	129	static struct drm_gem_cma_object *drm_gem_cma_create_with_handle(
	130	struct drm_file *file_priv,
	131	struct drm_device *drm, unsigned int size,
	132	unsigned int *handle)
	133	{
	134	struct drm_gem_cma_object *cma_obj;
	135	struct drm_gem_object *gem_obj;
	136	int ret;
	137
	138	cma_obj = drm_gem_cma_create(drm, size);
	139	if (IS_ERR(cma_obj))
	140	return cma_obj;
	141
	142	gem_obj = &cma_obj->base;
	143
	144	/*
	145	* allocate a id of idr table where the obj is registered
	146	* and handle has the id what user can see.
	147	*/
	148	ret = drm_gem_handle_create(file_priv, gem_obj, handle);
	149	if (ret)
	150	goto err_handle_create;
	151
	152	/* drop reference from allocate - handle holds it now. */
	153	drm_gem_object_unreference_unlocked(gem_obj);
	154
	155	return cma_obj;
	156
	157	err_handle_create:
	158	drm_gem_cma_free_object(gem_obj);
	159
	160	return ERR_PTR(ret);
	161	}
	162
	163	/*
	164	* drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback
	165	* function
	166	*/
	167	void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
	168	{
	169	struct drm_gem_cma_object *cma_obj;
	170
0de23977	171	drm_gem_free_mmap_offset(gem_obj);
b9d47450	172
b9d47450 SH	173	cma_obj = to_drm_gem_cma_obj(gem_obj);
b9d47450 SH	174
71d7282a	175	if (cma_obj->vaddr) {
a5ed8940 LP	176	dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
a5ed8940 LP	177	cma_obj->vaddr, cma_obj->paddr);
71d7282a LP	178	if (cma_obj->sgt) {
	179	sg_free_table(cma_obj->sgt);
	180	kfree(cma_obj->sgt);
	181	}
	182	} else if (gem_obj->import_attach) {
	183	drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
	184	}
a5ed8940 LP	185
a5ed8940 LP	186	drm_gem_object_release(gem_obj);
b9d47450 SH	187
	188	kfree(cma_obj);
	189	}
	190	EXPORT_SYMBOL_GPL(drm_gem_cma_free_object);
	191
	192	/*
	193	* drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback
	194	* function
	195	*
	196	* This aligns the pitch and size arguments to the minimum required. wrap
	197	* this into your own function if you need bigger alignment.
	198	*/
	199	int drm_gem_cma_dumb_create(struct drm_file *file_priv,
	200	struct drm_device dev, struct drm_mode_create_dumb args)
	201	{
	202	struct drm_gem_cma_object *cma_obj;
	203	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
	204
	205	if (args->pitch < min_pitch)
	206	args->pitch = min_pitch;
	207
	208	if (args->size < args->pitch * args->height)
	209	args->size = args->pitch * args->height;
	210
	211	cma_obj = drm_gem_cma_create_with_handle(file_priv, dev,
	212	args->size, &args->handle);
b03cda51	213	return PTR_ERR_OR_ZERO(cma_obj);
b9d47450 SH	214	}
	215	EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);
	216
	217	/*
	218	* drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback
	219	* function
	220	*/
	221	int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
	222	struct drm_device drm, uint32_t handle, uint64_t offset)
	223	{
	224	struct drm_gem_object *gem_obj;
	225
	226	mutex_lock(&drm->struct_mutex);
	227
	228	gem_obj = drm_gem_object_lookup(drm, file_priv, handle);
	229	if (!gem_obj) {
	230	dev_err(drm->dev, "failed to lookup gem object\n");
	231	mutex_unlock(&drm->struct_mutex);
	232	return -EINVAL;
	233	}
	234
0de23977	235	*offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
b9d47450 SH	236
	237	drm_gem_object_unreference(gem_obj);
	238
	239	mutex_unlock(&drm->struct_mutex);
	240
	241	return 0;
	242	}
	243	EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset);
	244
	245	const struct vm_operations_struct drm_gem_cma_vm_ops = {
	246	.open = drm_gem_vm_open,
	247	.close = drm_gem_vm_close,
	248	};
	249	EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops);
	250
ebaf9e03 LP	251	static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj,
	252	struct vm_area_struct *vma)
	253	{
	254	int ret;
	255
	256	ret = remap_pfn_range(vma, vma->vm_start, cma_obj->paddr >> PAGE_SHIFT,
	257	vma->vm_end - vma->vm_start, vma->vm_page_prot);
	258	if (ret)
	259	drm_gem_vm_close(vma);
	260
	261	return ret;
	262	}
	263
b9d47450 SH	264	/*
	265	* drm_gem_cma_mmap - (struct file_operation)->mmap callback function
	266	*/
	267	int drm_gem_cma_mmap(struct file filp, struct vm_area_struct vma)
	268	{
b9d47450	269	struct drm_gem_cma_object *cma_obj;
ebaf9e03	270	struct drm_gem_object *gem_obj;
b9d47450 SH	271	int ret;
	272
	273	ret = drm_gem_mmap(filp, vma);
	274	if (ret)
	275	return ret;
	276
	277	gem_obj = vma->vm_private_data;
	278	cma_obj = to_drm_gem_cma_obj(gem_obj);
	279
ebaf9e03	280	return drm_gem_cma_mmap_obj(cma_obj, vma);
b9d47450 SH	281	}
	282	EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);
	283
6f646095 RC	284	#ifdef CONFIG_DEBUG_FS
	285	void drm_gem_cma_describe(struct drm_gem_cma_object cma_obj, struct seq_file m)
	286	{
	287	struct drm_gem_object *obj = &cma_obj->base;
	288	struct drm_device *dev = obj->dev;
0de23977	289	uint64_t off;
6f646095 RC	290
	291	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
	292
0de23977	293	off = drm_vma_node_start(&obj->vma_node);
6f646095 RC	294
	295	seq_printf(m, "%2d (%2d) %08llx %08Zx %p %d",
	296	obj->name, obj->refcount.refcount.counter,
	297	off, cma_obj->paddr, cma_obj->vaddr, obj->size);
	298
	299	seq_printf(m, "\n");
	300	}
	301	EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
	302	#endif
71d7282a	303
78467dc5 JS	304	/* low-level interface prime helpers */
	305	struct sg_table drm_gem_cma_prime_get_sg_table(struct drm_gem_object obj)
	306	{
	307	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
	308	struct sg_table *sgt;
	309	int ret;
	310
	311	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
	312	if (!sgt)
	313	return NULL;
	314
	315	ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr,
	316	cma_obj->paddr, obj->size);
	317	if (ret < 0)
	318	goto out;
	319
	320	return sgt;
	321
	322	out:
	323	kfree(sgt);
	324	return NULL;
	325	}
	326	EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table);
	327
	328	struct drm_gem_object *
	329	drm_gem_cma_prime_import_sg_table(struct drm_device *dev, size_t size,
	330	struct sg_table *sgt)
	331	{
	332	struct drm_gem_cma_object *cma_obj;
	333
	334	if (sgt->nents != 1)
	335	return ERR_PTR(-EINVAL);
	336
	337	/* Create a CMA GEM buffer. */
	338	cma_obj = __drm_gem_cma_create(dev, size);
	339	if (IS_ERR(cma_obj))
	340	return ERR_PTR(PTR_ERR(cma_obj));
	341
	342	cma_obj->paddr = sg_dma_address(sgt->sgl);
	343	cma_obj->sgt = sgt;
	344
	345	DRM_DEBUG_PRIME("dma_addr = 0x%x, size = %zu\n", cma_obj->paddr, size);
	346
	347	return &cma_obj->base;
	348	}
	349	EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table);
	350
	351	int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
	352	struct vm_area_struct *vma)
	353	{
	354	struct drm_gem_cma_object *cma_obj;
	355	struct drm_device *dev = obj->dev;
	356	int ret;
	357
	358	mutex_lock(&dev->struct_mutex);
	359	ret = drm_gem_mmap_obj(obj, obj->size, vma);
	360	mutex_unlock(&dev->struct_mutex);
	361	if (ret < 0)
	362	return ret;
	363
	364	cma_obj = to_drm_gem_cma_obj(obj);
	365	return drm_gem_cma_mmap_obj(cma_obj, vma);
	366	}
	367	EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
368
369	void drm_gem_cma_prime_vmap(struct drm_gem_object obj)
370	{
371	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
372
373	return cma_obj->vaddr;
374	}
375	EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
376
377	void drm_gem_cma_prime_vunmap(struct drm_gem_object obj, void vaddr)
378	{
379	/* Nothing to do */
380	}
381	EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);