drivers/gpu/drm/exynos/exynos_drm_dmabuf.c - maze/linux - Git at Google

 /* exynos_drm_dmabuf.c
  *
  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
  * Author: Inki Dae <inki.dae@samsung.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */

 #include <drm/drmP.h>
 #include <drm/exynos_drm.h>
 #include "exynos_drm_drv.h"
 #include "exynos_drm_gem.h"

 #include <linux/dma-buf.h>

 static struct sg_table *exynos_pages_to_sg(struct page **pages, int nr_pages,
 		unsigned int page_size)
 {
 	struct sg_table *sgt = NULL;
 	struct scatterlist *sgl;
 	int i, ret;

 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 	if (!sgt)
 		goto out;

 	ret = sg_alloc_table(sgt, nr_pages, GFP_KERNEL);
 	if (ret)
 		goto err_free_sgt;

 	if (page_size < PAGE_SIZE)
 		page_size = PAGE_SIZE;

 	for_each_sg(sgt->sgl, sgl, nr_pages, i)
 		sg_set_page(sgl, pages[i], page_size, 0);

 	return sgt;

 err_free_sgt:
 	kfree(sgt);
 	sgt = NULL;
 out:
 	return NULL;
 }

 static struct sg_table *
 		exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,
 					enum dma_data_direction dir)
 {
 	struct exynos_drm_gem_obj *gem_obj = attach->dmabuf->priv;
 	struct drm_device *dev = gem_obj->base.dev;
 	struct exynos_drm_gem_buf *buf;
 	struct sg_table *sgt = NULL;
 	unsigned int npages;
 	int nents;

 	DRM_DEBUG_PRIME("%s\n", __FILE__);

 	mutex_lock(&dev->struct_mutex);

 	buf = gem_obj->buffer;

 	/* there should always be pages allocated. */
 	if (!buf->pages) {
 		DRM_ERROR("pages is null.\n");
 		goto err_unlock;
 	}

 	npages = buf->size / buf->page_size;

 	sgt = exynos_pages_to_sg(buf->pages, npages, buf->page_size);
 	if (!sgt) {
 		DRM_DEBUG_PRIME("exynos_pages_to_sg returned NULL!\n");
 		goto err_unlock;
 	}
 	nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);

 	DRM_DEBUG_PRIME("npages = %d buffer size = 0x%lx page_size = 0x%lx\n",
 			npages, buf->size, buf->page_size);

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

 static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 						struct sg_table *sgt,
 						enum dma_data_direction dir)
 {
 	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
 	sg_free_table(sgt);
 	kfree(sgt);
 	sgt = NULL;
 }

 static void exynos_dmabuf_release(struct dma_buf *dmabuf)
 {
 	struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;

 	DRM_DEBUG_PRIME("%s\n", __FILE__);

 	/*
 	 * exynos_dmabuf_release() call means that file object's
 	 * f_count is 0 and it calls drm_gem_object_handle_unreference()
 	 * to drop the references that these values had been increased
 	 * at drm_prime_handle_to_fd()
 	 */
 	if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
 		exynos_gem_obj->base.export_dma_buf = NULL;

 		/*
 		 * drop this gem object refcount to release allocated buffer
 		 * and resources.
 		 */
 		drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
 	}
 }

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

 	return NULL;
 }

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

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

 	return NULL;
 }

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

 static int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf,
 	struct vm_area_struct *vma)
 {
 	return -ENOTTY;
 }

 static struct dma_buf_ops exynos_dmabuf_ops = {
 	.map_dma_buf		= exynos_gem_map_dma_buf,
 	.unmap_dma_buf		= exynos_gem_unmap_dma_buf,
 	.kmap			= exynos_gem_dmabuf_kmap,
 	.kmap_atomic		= exynos_gem_dmabuf_kmap_atomic,
 	.kunmap			= exynos_gem_dmabuf_kunmap,
 	.kunmap_atomic		= exynos_gem_dmabuf_kunmap_atomic,
 	.mmap			= exynos_gem_dmabuf_mmap,
 	.release		= exynos_dmabuf_release,
 };

 struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
 				struct drm_gem_object *obj, int flags)
 {
 	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);

 	return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
 				exynos_gem_obj->base.size, 0600);
 }

 struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 				struct dma_buf *dma_buf)
 {
 	struct dma_buf_attachment *attach;
 	struct sg_table *sgt;
 	struct scatterlist *sgl;
 	struct exynos_drm_gem_obj *exynos_gem_obj;
 	struct exynos_drm_gem_buf *buffer;
 	struct page *page;
 	int ret;

 	DRM_DEBUG_PRIME("%s\n", __FILE__);

 	/* is this one of own objects? */
 	if (dma_buf->ops == &exynos_dmabuf_ops) {
 		struct drm_gem_object *obj;

 		exynos_gem_obj = dma_buf->priv;
 		obj = &exynos_gem_obj->base;

 		/* is it from our device? */
 		if (obj->dev == drm_dev) {
 			drm_gem_object_reference(obj);
 			return obj;
 		}
 	}

 	attach = dma_buf_attach(dma_buf, drm_dev->dev);
 	if (IS_ERR(attach))
 		return ERR_PTR(-EINVAL);


 	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR_OR_NULL(sgt)) {
 		ret = PTR_ERR(sgt);
 		goto err_buf_detach;
 	}

 	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 	if (!buffer) {
 		DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
 		ret = -ENOMEM;
 		goto err_unmap_attach;
 	}

 	buffer->pages = kzalloc(sizeof(*page) * sgt->nents, GFP_KERNEL);
 	if (!buffer->pages) {
 		DRM_ERROR("failed to allocate pages.\n");
 		ret = -ENOMEM;
 		goto err_free_buffer;
 	}

 	exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
 	if (!exynos_gem_obj) {
 		ret = -ENOMEM;
 		goto err_free_pages;
 	}

 	sgl = sgt->sgl;

 	if (sgt->nents == 1) {
 		buffer->dma_addr = sg_dma_address(sgt->sgl);
 		buffer->size = sg_dma_len(sgt->sgl);

 		/* always physically continuous memory if sgt->nents is 1. */
 		exynos_gem_obj->flags |= EXYNOS_BO_CONTIG;
 	} else {
 		unsigned int i = 0;

 		buffer->dma_addr = sg_dma_address(sgl);
 		while (i < sgt->nents) {
 			buffer->pages[i] = sg_page(sgl);
 			buffer->size += sg_dma_len(sgl);
 			sgl = sg_next(sgl);
 			i++;
 		}

 		exynos_gem_obj->flags |= EXYNOS_BO_NONCONTIG;
 	}

 	exynos_gem_obj->buffer = buffer;
 	buffer->sgt = sgt;
 	exynos_gem_obj->base.import_attach = attach;

 	DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
 								buffer->size);

 	return &exynos_gem_obj->base;

 err_free_pages:
 	kfree(buffer->pages);
 	buffer->pages = NULL;
 err_free_buffer:
 	kfree(buffer);
 	buffer = NULL;
 err_unmap_attach:
 	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 err_buf_detach:
 	dma_buf_detach(dma_buf, attach);
 	return ERR_PTR(ret);
 }

 MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
 MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
 MODULE_LICENSE("GPL");
	/* exynos_drm_dmabuf.c
	*
	* Copyright (c) 2012 Samsung Electronics Co., Ltd.
	* Author: Inki Dae <inki.dae@samsung.com>
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice (including the next
	* paragraph) shall be included in all copies or substantial portions of the
	* Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
	* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
	* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
	* OTHER DEALINGS IN THE SOFTWARE.
	*/

	#include <drm/drmP.h>
	#include <drm/exynos_drm.h>
	#include "exynos_drm_drv.h"
	#include "exynos_drm_gem.h"

	#include <linux/dma-buf.h>

	static struct sg_table exynos_pages_to_sg(struct page *pages, int nr_pages,
	unsigned int page_size)
	{
	struct sg_table *sgt = NULL;
	struct scatterlist *sgl;
	int i, ret;

	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
	if (!sgt)
	goto out;

	ret = sg_alloc_table(sgt, nr_pages, GFP_KERNEL);
	if (ret)
	goto err_free_sgt;

	if (page_size < PAGE_SIZE)
	page_size = PAGE_SIZE;

	for_each_sg(sgt->sgl, sgl, nr_pages, i)
	sg_set_page(sgl, pages[i], page_size, 0);

	return sgt;

	err_free_sgt:
	kfree(sgt);
	sgt = NULL;
	out:
	return NULL;
	}

	static struct sg_table *
	exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,
	enum dma_data_direction dir)
	{
	struct exynos_drm_gem_obj *gem_obj = attach->dmabuf->priv;
	struct drm_device *dev = gem_obj->base.dev;
	struct exynos_drm_gem_buf *buf;
	struct sg_table *sgt = NULL;
	unsigned int npages;
	int nents;

	DRM_DEBUG_PRIME("%s\n", __FILE__);

	mutex_lock(&dev->struct_mutex);

	buf = gem_obj->buffer;

	/* there should always be pages allocated. */
	if (!buf->pages) {
	DRM_ERROR("pages is null.\n");
	goto err_unlock;
	}

	npages = buf->size / buf->page_size;

	sgt = exynos_pages_to_sg(buf->pages, npages, buf->page_size);
	if (!sgt) {
	DRM_DEBUG_PRIME("exynos_pages_to_sg returned NULL!\n");
	goto err_unlock;
	}
	nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);

	DRM_DEBUG_PRIME("npages = %d buffer size = 0x%lx page_size = 0x%lx\n",
	npages, buf->size, buf->page_size);

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

	static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
	struct sg_table *sgt,
	enum dma_data_direction dir)
	{
	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
	sg_free_table(sgt);
	kfree(sgt);
	sgt = NULL;
	}

	static void exynos_dmabuf_release(struct dma_buf *dmabuf)
	{
	struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;

	DRM_DEBUG_PRIME("%s\n", __FILE__);

	/*
	* exynos_dmabuf_release() call means that file object's
	* f_count is 0 and it calls drm_gem_object_handle_unreference()
	* to drop the references that these values had been increased
	* at drm_prime_handle_to_fd()
	*/
	if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
	exynos_gem_obj->base.export_dma_buf = NULL;

	/*
	* drop this gem object refcount to release allocated buffer
	* and resources.
	*/
	drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
	}
	}

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

	return NULL;
	}

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

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

	return NULL;
	}

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

	static int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf,
	struct vm_area_struct *vma)
	{
	return -ENOTTY;
	}

	static struct dma_buf_ops exynos_dmabuf_ops = {
	.map_dma_buf = exynos_gem_map_dma_buf,
	.unmap_dma_buf = exynos_gem_unmap_dma_buf,
	.kmap = exynos_gem_dmabuf_kmap,
	.kmap_atomic = exynos_gem_dmabuf_kmap_atomic,
	.kunmap = exynos_gem_dmabuf_kunmap,
	.kunmap_atomic = exynos_gem_dmabuf_kunmap_atomic,
	.mmap = exynos_gem_dmabuf_mmap,
	.release = exynos_dmabuf_release,
	};

	struct dma_buf exynos_dmabuf_prime_export(struct drm_device drm_dev,
	struct drm_gem_object *obj, int flags)
	{
	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);

	return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
	exynos_gem_obj->base.size, 0600);
	}

	struct drm_gem_object exynos_dmabuf_prime_import(struct drm_device drm_dev,
	struct dma_buf *dma_buf)
	{
	struct dma_buf_attachment *attach;
	struct sg_table *sgt;
	struct scatterlist *sgl;
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct exynos_drm_gem_buf *buffer;
	struct page *page;
	int ret;

	DRM_DEBUG_PRIME("%s\n", __FILE__);

	/* is this one of own objects? */
	if (dma_buf->ops == &exynos_dmabuf_ops) {
	struct drm_gem_object *obj;

	exynos_gem_obj = dma_buf->priv;
	obj = &exynos_gem_obj->base;

	/* is it from our device? */
	if (obj->dev == drm_dev) {
	drm_gem_object_reference(obj);
	return obj;
	}
	}

	attach = dma_buf_attach(dma_buf, drm_dev->dev);
	if (IS_ERR(attach))
	return ERR_PTR(-EINVAL);


	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
	if (IS_ERR_OR_NULL(sgt)) {
	ret = PTR_ERR(sgt);
	goto err_buf_detach;
	}

	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
	if (!buffer) {
	DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
	ret = -ENOMEM;
	goto err_unmap_attach;
	}

	buffer->pages = kzalloc(sizeof(page) sgt->nents, GFP_KERNEL);
	if (!buffer->pages) {
	DRM_ERROR("failed to allocate pages.\n");
	ret = -ENOMEM;
	goto err_free_buffer;
	}

	exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
	if (!exynos_gem_obj) {
	ret = -ENOMEM;
	goto err_free_pages;
	}

	sgl = sgt->sgl;

	if (sgt->nents == 1) {
	buffer->dma_addr = sg_dma_address(sgt->sgl);
	buffer->size = sg_dma_len(sgt->sgl);

	/* always physically continuous memory if sgt->nents is 1. */
	exynos_gem_obj->flags \|= EXYNOS_BO_CONTIG;
	} else {
	unsigned int i = 0;

	buffer->dma_addr = sg_dma_address(sgl);
	while (i < sgt->nents) {
	buffer->pages[i] = sg_page(sgl);
	buffer->size += sg_dma_len(sgl);
	sgl = sg_next(sgl);
	i++;
	}

	exynos_gem_obj->flags \|= EXYNOS_BO_NONCONTIG;
	}

	exynos_gem_obj->buffer = buffer;
	buffer->sgt = sgt;
	exynos_gem_obj->base.import_attach = attach;

	DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
	buffer->size);

	return &exynos_gem_obj->base;

	err_free_pages:
	kfree(buffer->pages);
	buffer->pages = NULL;
	err_free_buffer:
	kfree(buffer);
	buffer = NULL;
	err_unmap_attach:
	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
	err_buf_detach:
	dma_buf_detach(dma_buf, attach);
	return ERR_PTR(ret);
	}

	MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
	MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
	MODULE_LICENSE("GPL");