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drm/exynos: add dmabuf attach/detach callbacks.

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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: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
This commit is contained in:
Inki Dae 2012-11-28 19:09:31 +09:00 committed by Inki Dae
parent ae9dace290
commit a7b362fb3b
1 changed files with 73 additions and 31 deletions
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104
drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
View file

@ -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 sgt;
return 0;
}
err_free_sgt:
kfree(sgt);
sgt = NULL;
out:
return NULL;
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;
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,