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Commit a7b362fb authored by Inki Dae's avatar Inki Dae Committed by Inki Dae
Browse files

drm/exynos: add dmabuf attach/detach callbacks. 



With this patch, When dma_buf_unmap_attachment is called,
the pages of sgt aren't unmapped from iommu table.
Instead, when dma_buf_detach is called, that would be done.

And also removes exynos_get_sgt function used to get clone sgt
and uses attachment's sgt instead. This patch would resolve
performance deterioration issue when v4l2-based driver is using
the buffer imported from gem.

This change is derived from videobuf2-dma-contig.c

Signed-off-by: default avatarInki Dae <inki.dae@samsung.com>
Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
parent ae9dace2

drivers/gpu/drm/exynos/exynos_drm_dmabuf.c

+73 −31
Original line number Diff line number Diff line
@@ -30,63 +30,107 @@ 


#include <linux/dma-buf.h>



static struct sg_table *exynos_get_sgt(struct drm_device *drm_dev,

					struct exynos_drm_gem_buf *buf)

struct exynos_drm_dmabuf_attachment {

	struct sg_table sgt;

	enum dma_data_direction dir;

};



static int exynos_gem_attach_dma_buf(struct dma_buf *dmabuf,

					struct device *dev,

					struct dma_buf_attachment *attach)

{

	struct sg_table *sgt = NULL;

	int ret;

	struct exynos_drm_dmabuf_attachment *exynos_attach;



	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);

	if (!sgt)

		goto out;

	exynos_attach = kzalloc(sizeof(*exynos_attach), GFP_KERNEL);

	if (!exynos_attach)

		return -ENOMEM;



	ret = dma_get_sgtable(drm_dev->dev, sgt, buf->kvaddr,

				buf->dma_addr, buf->size);

	if (ret < 0) {

		DRM_ERROR("failed to get sgtable.\n");

		goto err_free_sgt;

	exynos_attach->dir = DMA_NONE;

	attach->priv = exynos_attach;



	return 0;

}



	return sgt;

static void exynos_gem_detach_dma_buf(struct dma_buf *dmabuf,

					struct dma_buf_attachment *attach)

{

	struct exynos_drm_dmabuf_attachment *exynos_attach = attach->priv;

	struct sg_table *sgt;



err_free_sgt:

	kfree(sgt);

	sgt = NULL;

out:

	return NULL;

	if (!exynos_attach)

		return;



	sgt = &exynos_attach->sgt;



	if (exynos_attach->dir != DMA_NONE)

		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,

				exynos_attach->dir);



	sg_free_table(sgt);

	kfree(exynos_attach);

	attach->priv = NULL;

}



static struct sg_table *

		exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,

					enum dma_data_direction dir)

{

	struct exynos_drm_dmabuf_attachment *exynos_attach = attach->priv;

	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 scatterlist *rd, *wr;

	struct sg_table *sgt = NULL;

	int nents;

	unsigned int i;

	int nents, ret;



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



	if (WARN_ON(dir == DMA_NONE))

		return ERR_PTR(-EINVAL);



	/* just return current sgt if already requested. */

	if (exynos_attach->dir == dir)

		return &exynos_attach->sgt;



	/* reattaching is not allowed. */

	if (WARN_ON(exynos_attach->dir != DMA_NONE))

		return ERR_PTR(-EBUSY);



	buf = gem_obj->buffer;

	if (!buf) {

		DRM_ERROR("buffer is null.\n");

		return sgt;

		return ERR_PTR(-ENOMEM);

	}



	sgt = &exynos_attach->sgt;



	ret = sg_alloc_table(sgt, buf->sgt->orig_nents, GFP_KERNEL);

	if (ret) {

		DRM_ERROR("failed to alloc sgt.\n");

		return ERR_PTR(-ENOMEM);

	}



	mutex_lock(&dev->struct_mutex);



	sgt = exynos_get_sgt(dev, buf);

	if (!sgt)

		goto err_unlock;

	rd = buf->sgt->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);

	}



	nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);

	nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);

	if (!nents) {

		DRM_ERROR("failed to map sgl with iommu.\n");

		sgt = NULL;

		sgt = ERR_PTR(-EIO);

		goto err_unlock;

	}



	exynos_attach->dir = dir;

	attach->priv = exynos_attach;



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



err_unlock:
@@ -98,11 +142,7 @@ 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;

	/* Nothing to do. */

}



static void exynos_dmabuf_release(struct dma_buf *dmabuf)
@@ -164,6 +204,8 @@ static int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf, 
}



static struct dma_buf_ops exynos_dmabuf_ops = {

	.attach			= exynos_gem_attach_dma_buf,

	.detach			= exynos_gem_detach_dma_buf,

	.map_dma_buf		= exynos_gem_map_dma_buf,

	.unmap_dma_buf		= exynos_gem_unmap_dma_buf,

	.kmap			= exynos_gem_dmabuf_kmap,