drivers/gpu/drm/udl/udl_dmabuf.c - arm/linux - Git at Google

 /*
  * udl_dmabuf.c
  *
  * Copyright (c) 2014 The Chromium OS Authors
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */

 #include <drm/drmP.h>
 #include "udl_drv.h"
 #include <linux/shmem_fs.h>
 #include <linux/dma-buf.h>

 struct udl_drm_dmabuf_attachment {
 	struct sg_table sgt;
 	enum dma_data_direction dir;
 	bool is_mapped;
 };

 static int udl_attach_dma_buf(struct dma_buf *dmabuf,
 			      struct device *dev,
 			      struct dma_buf_attachment *attach)
 {
 	struct udl_drm_dmabuf_attachment *udl_attach;

 	DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
 			attach->dmabuf->size);

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

 	udl_attach->dir = DMA_NONE;
 	attach->priv = udl_attach;

 	return 0;
 }

 static void udl_detach_dma_buf(struct dma_buf *dmabuf,
 			       struct dma_buf_attachment *attach)
 {
 	struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
 	struct sg_table *sgt;

 	if (!udl_attach)
 		return;

 	DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
 			attach->dmabuf->size);

 	sgt = &udl_attach->sgt;

 	if (udl_attach->dir != DMA_NONE)
 		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
 				udl_attach->dir);

 	sg_free_table(sgt);
 	kfree(udl_attach);
 	attach->priv = NULL;
 }

 static struct sg_table *udl_map_dma_buf(struct dma_buf_attachment *attach,
 					enum dma_data_direction dir)
 {
 	struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
 	struct udl_gem_object *obj = to_udl_bo(attach->dmabuf->priv);
 	struct drm_device *dev = obj->base.dev;
 	struct scatterlist *rd, *wr;
 	struct sg_table *sgt = NULL;
 	unsigned int i;
 	int page_count;
 	int nents, ret;

 	DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir=%d\n", dev_name(attach->dev),
 			attach->dmabuf->size, dir);

 	/* just return current sgt if already requested. */
 	if (udl_attach->dir == dir && udl_attach->is_mapped)
 		return &udl_attach->sgt;

 	if (!obj->pages) {
 		ret = udl_gem_get_pages(obj);
 		if (ret) {
 			DRM_ERROR("failed to map pages.\n");
 			return ERR_PTR(ret);
 		}
 	}

 	page_count = obj->base.size / PAGE_SIZE;
 	obj->sg = drm_prime_pages_to_sg(obj->pages, page_count);
 	if (IS_ERR(obj->sg)) {
 		DRM_ERROR("failed to allocate sgt.\n");
 		return ERR_CAST(obj->sg);
 	}

 	sgt = &udl_attach->sgt;

 	ret = sg_alloc_table(sgt, obj->sg->orig_nents, GFP_KERNEL);
 	if (ret) {
 		DRM_ERROR("failed to alloc sgt.\n");
 		return ERR_PTR(-ENOMEM);
 	}

 	mutex_lock(&dev->struct_mutex);

 	rd = obj->sg->sgl;
 	wr = sgt->sgl;
 	for (i = 0; i < sgt->orig_nents; ++i) {
 		sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
 		rd = sg_next(rd);
 		wr = sg_next(wr);
 	}

 	if (dir != DMA_NONE) {
 		nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);
 		if (!nents) {
 			DRM_ERROR("failed to map sgl with iommu.\n");
 			sg_free_table(sgt);
 			sgt = ERR_PTR(-EIO);
 			goto err_unlock;
 		}
 	}

 	udl_attach->is_mapped = true;
 	udl_attach->dir = dir;
 	attach->priv = udl_attach;

 err_unlock:
 	mutex_unlock(&dev->struct_mutex);
 	return sgt;
 }

 static void udl_unmap_dma_buf(struct dma_buf_attachment *attach,
 			      struct sg_table *sgt,
 			      enum dma_data_direction dir)
 {
 	/* Nothing to do. */
 	DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir:%d\n", dev_name(attach->dev),
 			attach->dmabuf->size, dir);
 }

 static void *udl_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 {
 	/* TODO */

 	return NULL;
 }

 static void *udl_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
 				    unsigned long page_num)
 {
 	/* TODO */

 	return NULL;
 }

 static void udl_dmabuf_kunmap(struct dma_buf *dma_buf,
 			      unsigned long page_num, void *addr)
 {
 	/* TODO */
 }

 static void udl_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
 				     unsigned long page_num,
 				     void *addr)
 {
 	/* TODO */
 }

 static int udl_dmabuf_mmap(struct dma_buf *dma_buf,
 			   struct vm_area_struct *vma)
 {
 	/* TODO */

 	return -EINVAL;
 }

 static struct dma_buf_ops udl_dmabuf_ops = {
 	.attach			= udl_attach_dma_buf,
 	.detach			= udl_detach_dma_buf,
 	.map_dma_buf		= udl_map_dma_buf,
 	.unmap_dma_buf		= udl_unmap_dma_buf,
 	.map			= udl_dmabuf_kmap,
 	.map_atomic		= udl_dmabuf_kmap_atomic,
 	.unmap			= udl_dmabuf_kunmap,
 	.unmap_atomic		= udl_dmabuf_kunmap_atomic,
 	.mmap			= udl_dmabuf_mmap,
 	.release		= drm_gem_dmabuf_release,
 };

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

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

 	return drm_gem_dmabuf_export(dev, &exp_info);
 }

 static int udl_prime_create(struct drm_device *dev,
 			    size_t size,
 			    struct sg_table *sg,
 			    struct udl_gem_object **obj_p)
 {
 	struct udl_gem_object *obj;
 	int npages;

 	npages = size / PAGE_SIZE;

 	*obj_p = NULL;
 	obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
 	if (!obj)
 		return -ENOMEM;

 	obj->sg = sg;
 	obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
 	if (obj->pages == NULL) {
 		DRM_ERROR("obj pages is NULL %d\n", npages);
 		return -ENOMEM;
 	}

 	drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);

 	*obj_p = obj;
 	return 0;
 }

 struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
 				struct dma_buf *dma_buf)
 {
 	struct dma_buf_attachment *attach;
 	struct sg_table *sg;
 	struct udl_gem_object *uobj;
 	int ret;

 	/* need to attach */
 	get_device(dev->dev);
 	attach = dma_buf_attach(dma_buf, dev->dev);
 	if (IS_ERR(attach)) {
 		put_device(dev->dev);
 		return ERR_CAST(attach);
 	}

 	get_dma_buf(dma_buf);

 	sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR(sg)) {
 		ret = PTR_ERR(sg);
 		goto fail_detach;
 	}

 	ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
 	if (ret)
 		goto fail_unmap;

 	uobj->base.import_attach = attach;
 	uobj->flags = UDL_BO_WC;

 	return &uobj->base;

 fail_unmap:
 	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
 	dma_buf_put(dma_buf);
 	put_device(dev->dev);
 	return ERR_PTR(ret);
 }
	/*
	* udl_dmabuf.c
	*
	* Copyright (c) 2014 The Chromium OS Authors
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <drm/drmP.h>
	#include "udl_drv.h"
	#include <linux/shmem_fs.h>
	#include <linux/dma-buf.h>

	struct udl_drm_dmabuf_attachment {
	struct sg_table sgt;
	enum dma_data_direction dir;
	bool is_mapped;
	};

	static int udl_attach_dma_buf(struct dma_buf *dmabuf,
	struct device *dev,
	struct dma_buf_attachment *attach)
	{
	struct udl_drm_dmabuf_attachment *udl_attach;

	DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
	attach->dmabuf->size);

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

	udl_attach->dir = DMA_NONE;
	attach->priv = udl_attach;

	return 0;
	}

	static void udl_detach_dma_buf(struct dma_buf *dmabuf,
	struct dma_buf_attachment *attach)
	{
	struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
	struct sg_table *sgt;

	if (!udl_attach)
	return;

	DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
	attach->dmabuf->size);

	sgt = &udl_attach->sgt;

	if (udl_attach->dir != DMA_NONE)
	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
	udl_attach->dir);

	sg_free_table(sgt);
	kfree(udl_attach);
	attach->priv = NULL;
	}

	static struct sg_table udl_map_dma_buf(struct dma_buf_attachment attach,
	enum dma_data_direction dir)
	{
	struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
	struct udl_gem_object *obj = to_udl_bo(attach->dmabuf->priv);
	struct drm_device *dev = obj->base.dev;
	struct scatterlist rd, wr;
	struct sg_table *sgt = NULL;
	unsigned int i;
	int page_count;
	int nents, ret;

	DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir=%d\n", dev_name(attach->dev),
	attach->dmabuf->size, dir);

	/* just return current sgt if already requested. */
	if (udl_attach->dir == dir && udl_attach->is_mapped)
	return &udl_attach->sgt;

	if (!obj->pages) {
	ret = udl_gem_get_pages(obj);
	if (ret) {
	DRM_ERROR("failed to map pages.\n");
	return ERR_PTR(ret);
	}
	}

	page_count = obj->base.size / PAGE_SIZE;
	obj->sg = drm_prime_pages_to_sg(obj->pages, page_count);
	if (IS_ERR(obj->sg)) {
	DRM_ERROR("failed to allocate sgt.\n");
	return ERR_CAST(obj->sg);
	}

	sgt = &udl_attach->sgt;

	ret = sg_alloc_table(sgt, obj->sg->orig_nents, GFP_KERNEL);
	if (ret) {
	DRM_ERROR("failed to alloc sgt.\n");
	return ERR_PTR(-ENOMEM);
	}

	mutex_lock(&dev->struct_mutex);

	rd = obj->sg->sgl;
	wr = sgt->sgl;
	for (i = 0; i < sgt->orig_nents; ++i) {
	sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
	rd = sg_next(rd);
	wr = sg_next(wr);
	}

	if (dir != DMA_NONE) {
	nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);
	if (!nents) {
	DRM_ERROR("failed to map sgl with iommu.\n");
	sg_free_table(sgt);
	sgt = ERR_PTR(-EIO);
	goto err_unlock;
	}
	}

	udl_attach->is_mapped = true;
	udl_attach->dir = dir;
	attach->priv = udl_attach;

	err_unlock:
	mutex_unlock(&dev->struct_mutex);
	return sgt;
	}

	static void udl_unmap_dma_buf(struct dma_buf_attachment *attach,
	struct sg_table *sgt,
	enum dma_data_direction dir)
	{
	/* Nothing to do. */
	DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir:%d\n", dev_name(attach->dev),
	attach->dmabuf->size, dir);
	}

	static void udl_dmabuf_kmap(struct dma_buf dma_buf, unsigned long page_num)
	{
	/* TODO */

	return NULL;
	}

	static void udl_dmabuf_kmap_atomic(struct dma_buf dma_buf,
	unsigned long page_num)
	{
	/* TODO */

	return NULL;
	}

	static void udl_dmabuf_kunmap(struct dma_buf *dma_buf,
	unsigned long page_num, void *addr)
	{
	/* TODO */
	}

	static void udl_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
	unsigned long page_num,
	void *addr)
	{
	/* TODO */
	}

	static int udl_dmabuf_mmap(struct dma_buf *dma_buf,
	struct vm_area_struct *vma)
	{
	/* TODO */

	return -EINVAL;
	}

	static struct dma_buf_ops udl_dmabuf_ops = {
	.attach = udl_attach_dma_buf,
	.detach = udl_detach_dma_buf,
	.map_dma_buf = udl_map_dma_buf,
	.unmap_dma_buf = udl_unmap_dma_buf,
	.map = udl_dmabuf_kmap,
	.map_atomic = udl_dmabuf_kmap_atomic,
	.unmap = udl_dmabuf_kunmap,
	.unmap_atomic = udl_dmabuf_kunmap_atomic,
	.mmap = udl_dmabuf_mmap,
	.release = drm_gem_dmabuf_release,
	};

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

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

	return drm_gem_dmabuf_export(dev, &exp_info);
	}

	static int udl_prime_create(struct drm_device *dev,
	size_t size,
	struct sg_table *sg,
	struct udl_gem_object **obj_p)
	{
	struct udl_gem_object *obj;
	int npages;

	npages = size / PAGE_SIZE;

	*obj_p = NULL;
	obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
	if (!obj)
	return -ENOMEM;

	obj->sg = sg;
	obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
	if (obj->pages == NULL) {
	DRM_ERROR("obj pages is NULL %d\n", npages);
	return -ENOMEM;
	}

	drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);

	*obj_p = obj;
	return 0;
	}

	struct drm_gem_object udl_gem_prime_import(struct drm_device dev,
	struct dma_buf *dma_buf)
	{
	struct dma_buf_attachment *attach;
	struct sg_table *sg;
	struct udl_gem_object *uobj;
	int ret;

	/* need to attach */
	get_device(dev->dev);
	attach = dma_buf_attach(dma_buf, dev->dev);
	if (IS_ERR(attach)) {
	put_device(dev->dev);
	return ERR_CAST(attach);
	}

	get_dma_buf(dma_buf);

	sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
	if (IS_ERR(sg)) {
	ret = PTR_ERR(sg);
	goto fail_detach;
	}

	ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
	if (ret)
	goto fail_unmap;

	uobj->base.import_attach = attach;
	uobj->flags = UDL_BO_WC;

	return &uobj->base;

	fail_unmap:
	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
	fail_detach:
	dma_buf_detach(dma_buf, attach);
	dma_buf_put(dma_buf);
	put_device(dev->dev);
	return ERR_PTR(ret);
	}