drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c - linux - Git at Google

 /*
  * SPDX-License-Identifier: MIT
  *
  * Copyright 2012 Red Hat Inc
  */

 #include <linux/dma-buf.h>
 #include <linux/highmem.h>
 #include <linux/dma-resv.h>

 #include "i915_drv.h"
 #include "i915_gem_object.h"
 #include "i915_scatterlist.h"

 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
 {
 	return to_intel_bo(buf->priv);
 }

 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
 					     enum dma_data_direction dir)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
 	struct sg_table *st;
 	struct scatterlist *src, *dst;
 	int ret, i;

 	ret = i915_gem_object_pin_pages(obj);
 	if (ret)
 		goto err;

 	/* Copy sg so that we make an independent mapping */
 	st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
 	if (st == NULL) {
 		ret = -ENOMEM;
 		goto err_unpin_pages;
 	}

 	ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
 	if (ret)
 		goto err_free;

 	src = obj->mm.pages->sgl;
 	dst = st->sgl;
 	for (i = 0; i < obj->mm.pages->nents; i++) {
 		sg_set_page(dst, sg_page(src), src->length, 0);
 		dst = sg_next(dst);
 		src = sg_next(src);
 	}

 	ret = dma_map_sgtable(attachment->dev, st, dir, DMA_ATTR_SKIP_CPU_SYNC);
 	if (ret)
 		goto err_free_sg;

 	return st;

 err_free_sg:
 	sg_free_table(st);
 err_free:
 	kfree(st);
 err_unpin_pages:
 	i915_gem_object_unpin_pages(obj);
 err:
 	return ERR_PTR(ret);
 }

 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
 				   struct sg_table *sg,
 				   enum dma_data_direction dir)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);

 	dma_unmap_sgtable(attachment->dev, sg, dir, DMA_ATTR_SKIP_CPU_SYNC);
 	sg_free_table(sg);
 	kfree(sg);

 	i915_gem_object_unpin_pages(obj);
 }

 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

 	return i915_gem_object_pin_map(obj, I915_MAP_WB);
 }

 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

 	i915_gem_object_flush_map(obj);
 	i915_gem_object_unpin_map(obj);
 }

 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 	int ret;

 	if (obj->base.size < vma->vm_end - vma->vm_start)
 		return -EINVAL;

 	if (!obj->base.filp)
 		return -ENODEV;

 	ret = call_mmap(obj->base.filp, vma);
 	if (ret)
 		return ret;

 	fput(vma->vm_file);
 	vma->vm_file = get_file(obj->base.filp);

 	return 0;
 }

 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 	bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 	int err;

 	err = i915_gem_object_pin_pages(obj);
 	if (err)
 		return err;

 	err = i915_gem_object_lock_interruptible(obj, NULL);
 	if (err)
 		goto out;

 	err = i915_gem_object_set_to_cpu_domain(obj, write);
 	i915_gem_object_unlock(obj);

 out:
 	i915_gem_object_unpin_pages(obj);
 	return err;
 }

 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 	int err;

 	err = i915_gem_object_pin_pages(obj);
 	if (err)
 		return err;

 	err = i915_gem_object_lock_interruptible(obj, NULL);
 	if (err)
 		goto out;

 	err = i915_gem_object_set_to_gtt_domain(obj, false);
 	i915_gem_object_unlock(obj);

 out:
 	i915_gem_object_unpin_pages(obj);
 	return err;
 }

 static const struct dma_buf_ops i915_dmabuf_ops =  {
 	.map_dma_buf = i915_gem_map_dma_buf,
 	.unmap_dma_buf = i915_gem_unmap_dma_buf,
 	.release = drm_gem_dmabuf_release,
 	.mmap = i915_gem_dmabuf_mmap,
 	.vmap = i915_gem_dmabuf_vmap,
 	.vunmap = i915_gem_dmabuf_vunmap,
 	.begin_cpu_access = i915_gem_begin_cpu_access,
 	.end_cpu_access = i915_gem_end_cpu_access,
 };

 struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags)
 {
 	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

 	exp_info.ops = &i915_dmabuf_ops;
 	exp_info.size = gem_obj->size;
 	exp_info.flags = flags;
 	exp_info.priv = gem_obj;
 	exp_info.resv = obj->base.resv;

 	if (obj->ops->dmabuf_export) {
 		int ret = obj->ops->dmabuf_export(obj);
 		if (ret)
 			return ERR_PTR(ret);
 	}

 	return drm_gem_dmabuf_export(gem_obj->dev, &exp_info);
 }

 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 {
 	struct sg_table *pages;
 	unsigned int sg_page_sizes;

 	pages = dma_buf_map_attachment(obj->base.import_attach,
 				       DMA_BIDIRECTIONAL);
 	if (IS_ERR(pages))
 		return PTR_ERR(pages);

 	sg_page_sizes = i915_sg_page_sizes(pages->sgl);

 	__i915_gem_object_set_pages(obj, pages, sg_page_sizes);

 	return 0;
 }

 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
 					     struct sg_table *pages)
 {
 	dma_buf_unmap_attachment(obj->base.import_attach, pages,
 				 DMA_BIDIRECTIONAL);
 }

 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 	.name = "i915_gem_object_dmabuf",
 	.get_pages = i915_gem_object_get_pages_dmabuf,
 	.put_pages = i915_gem_object_put_pages_dmabuf,
 };

 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 					     struct dma_buf *dma_buf)
 {
 	static struct lock_class_key lock_class;
 	struct dma_buf_attachment *attach;
 	struct drm_i915_gem_object *obj;
 	int ret;

 	/* is this one of own objects? */
 	if (dma_buf->ops == &i915_dmabuf_ops) {
 		obj = dma_buf_to_obj(dma_buf);
 		/* is it from our device? */
 		if (obj->base.dev == dev) {
 			/*
 			 * Importing dmabuf exported from out own gem increases
 			 * refcount on gem itself instead of f_count of dmabuf.
 			 */
 			return &i915_gem_object_get(obj)->base;
 		}
 	}

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

 	get_dma_buf(dma_buf);

 	obj = i915_gem_object_alloc();
 	if (obj == NULL) {
 		ret = -ENOMEM;
 		goto fail_detach;
 	}

 	drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 	i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops, &lock_class);
 	obj->base.import_attach = attach;
 	obj->base.resv = dma_buf->resv;

 	/* We use GTT as shorthand for a coherent domain, one that is
 	 * neither in the GPU cache nor in the CPU cache, where all
 	 * writes are immediately visible in memory. (That's not strictly
 	 * true, but it's close! There are internal buffers such as the
 	 * write-combined buffer or a delay through the chipset for GTT
 	 * writes that do require us to treat GTT as a separate cache domain.)
 	 */
 	obj->read_domains = I915_GEM_DOMAIN_GTT;
 	obj->write_domain = 0;

 	return &obj->base;

 fail_detach:
 	dma_buf_detach(dma_buf, attach);
 	dma_buf_put(dma_buf);

 	return ERR_PTR(ret);
 }

 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 #include "selftests/mock_dmabuf.c"
 #include "selftests/i915_gem_dmabuf.c"
 #endif
	/*
	* SPDX-License-Identifier: MIT
	*
	* Copyright 2012 Red Hat Inc
	*/

	#include <linux/dma-buf.h>
	#include <linux/highmem.h>
	#include <linux/dma-resv.h>

	#include "i915_drv.h"
	#include "i915_gem_object.h"
	#include "i915_scatterlist.h"

	static struct drm_i915_gem_object dma_buf_to_obj(struct dma_buf buf)
	{
	return to_intel_bo(buf->priv);
	}

	static struct sg_table i915_gem_map_dma_buf(struct dma_buf_attachment attachment,
	enum dma_data_direction dir)
	{
	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
	struct sg_table *st;
	struct scatterlist src, dst;
	int ret, i;

	ret = i915_gem_object_pin_pages(obj);
	if (ret)
	goto err;

	/* Copy sg so that we make an independent mapping */
	st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
	if (st == NULL) {
	ret = -ENOMEM;
	goto err_unpin_pages;
	}

	ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
	if (ret)
	goto err_free;

	src = obj->mm.pages->sgl;
	dst = st->sgl;
	for (i = 0; i < obj->mm.pages->nents; i++) {
	sg_set_page(dst, sg_page(src), src->length, 0);
	dst = sg_next(dst);
	src = sg_next(src);
	}

	ret = dma_map_sgtable(attachment->dev, st, dir, DMA_ATTR_SKIP_CPU_SYNC);
	if (ret)
	goto err_free_sg;

	return st;

	err_free_sg:
	sg_free_table(st);
	err_free:
	kfree(st);
	err_unpin_pages:
	i915_gem_object_unpin_pages(obj);
	err:
	return ERR_PTR(ret);
	}

	static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
	struct sg_table *sg,
	enum dma_data_direction dir)
	{
	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);

	dma_unmap_sgtable(attachment->dev, sg, dir, DMA_ATTR_SKIP_CPU_SYNC);
	sg_free_table(sg);
	kfree(sg);

	i915_gem_object_unpin_pages(obj);
	}

	static void i915_gem_dmabuf_vmap(struct dma_buf dma_buf)
	{
	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

	return i915_gem_object_pin_map(obj, I915_MAP_WB);
	}

	static void i915_gem_dmabuf_vunmap(struct dma_buf dma_buf, void vaddr)
	{
	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

	i915_gem_object_flush_map(obj);
	i915_gem_object_unpin_map(obj);
	}

	static int i915_gem_dmabuf_mmap(struct dma_buf dma_buf, struct vm_area_struct vma)
	{
	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
	int ret;

	if (obj->base.size < vma->vm_end - vma->vm_start)
	return -EINVAL;

	if (!obj->base.filp)
	return -ENODEV;

	ret = call_mmap(obj->base.filp, vma);
	if (ret)
	return ret;

	fput(vma->vm_file);
	vma->vm_file = get_file(obj->base.filp);

	return 0;
	}

	static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
	{
	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
	bool write = (direction == DMA_BIDIRECTIONAL \|\| direction == DMA_TO_DEVICE);
	int err;

	err = i915_gem_object_pin_pages(obj);
	if (err)
	return err;

	err = i915_gem_object_lock_interruptible(obj, NULL);
	if (err)
	goto out;

	err = i915_gem_object_set_to_cpu_domain(obj, write);
	i915_gem_object_unlock(obj);

	out:
	i915_gem_object_unpin_pages(obj);
	return err;
	}

	static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
	{
	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
	int err;

	err = i915_gem_object_pin_pages(obj);
	if (err)
	return err;

	err = i915_gem_object_lock_interruptible(obj, NULL);
	if (err)
	goto out;

	err = i915_gem_object_set_to_gtt_domain(obj, false);
	i915_gem_object_unlock(obj);

	out:
	i915_gem_object_unpin_pages(obj);
	return err;
	}

	static const struct dma_buf_ops i915_dmabuf_ops = {
	.map_dma_buf = i915_gem_map_dma_buf,
	.unmap_dma_buf = i915_gem_unmap_dma_buf,
	.release = drm_gem_dmabuf_release,
	.mmap = i915_gem_dmabuf_mmap,
	.vmap = i915_gem_dmabuf_vmap,
	.vunmap = i915_gem_dmabuf_vunmap,
	.begin_cpu_access = i915_gem_begin_cpu_access,
	.end_cpu_access = i915_gem_end_cpu_access,
	};

	struct dma_buf i915_gem_prime_export(struct drm_gem_object gem_obj, int flags)
	{
	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

	exp_info.ops = &i915_dmabuf_ops;
	exp_info.size = gem_obj->size;
	exp_info.flags = flags;
	exp_info.priv = gem_obj;
	exp_info.resv = obj->base.resv;

	if (obj->ops->dmabuf_export) {
	int ret = obj->ops->dmabuf_export(obj);
	if (ret)
	return ERR_PTR(ret);
	}

	return drm_gem_dmabuf_export(gem_obj->dev, &exp_info);
	}

	static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
	{
	struct sg_table *pages;
	unsigned int sg_page_sizes;

	pages = dma_buf_map_attachment(obj->base.import_attach,
	DMA_BIDIRECTIONAL);
	if (IS_ERR(pages))
	return PTR_ERR(pages);

	sg_page_sizes = i915_sg_page_sizes(pages->sgl);

	__i915_gem_object_set_pages(obj, pages, sg_page_sizes);

	return 0;
	}

	static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
	struct sg_table *pages)
	{
	dma_buf_unmap_attachment(obj->base.import_attach, pages,
	DMA_BIDIRECTIONAL);
	}

	static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
	.name = "i915_gem_object_dmabuf",
	.get_pages = i915_gem_object_get_pages_dmabuf,
	.put_pages = i915_gem_object_put_pages_dmabuf,
	};

	struct drm_gem_object i915_gem_prime_import(struct drm_device dev,
	struct dma_buf *dma_buf)
	{
	static struct lock_class_key lock_class;
	struct dma_buf_attachment *attach;
	struct drm_i915_gem_object *obj;
	int ret;

	/* is this one of own objects? */
	if (dma_buf->ops == &i915_dmabuf_ops) {
	obj = dma_buf_to_obj(dma_buf);
	/* is it from our device? */
	if (obj->base.dev == dev) {
	/*
	* Importing dmabuf exported from out own gem increases
	* refcount on gem itself instead of f_count of dmabuf.
	*/
	return &i915_gem_object_get(obj)->base;
	}
	}

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

	get_dma_buf(dma_buf);

	obj = i915_gem_object_alloc();
	if (obj == NULL) {
	ret = -ENOMEM;
	goto fail_detach;
	}

	drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
	i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops, &lock_class);
	obj->base.import_attach = attach;
	obj->base.resv = dma_buf->resv;

	/* We use GTT as shorthand for a coherent domain, one that is
	* neither in the GPU cache nor in the CPU cache, where all
	* writes are immediately visible in memory. (That's not strictly
	* true, but it's close! There are internal buffers such as the
	* write-combined buffer or a delay through the chipset for GTT
	* writes that do require us to treat GTT as a separate cache domain.)
	*/
	obj->read_domains = I915_GEM_DOMAIN_GTT;
	obj->write_domain = 0;

	return &obj->base;

	fail_detach:
	dma_buf_detach(dma_buf, attach);
	dma_buf_put(dma_buf);

	return ERR_PTR(ret);
	}

	#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
	#include "selftests/mock_dmabuf.c"
	#include "selftests/i915_gem_dmabuf.c"
	#endif