The drm prime also can support it like GEM CMA supports to cache mapping. It doesn't allow multiple mappings for one attachment.

Signed-off-by: Joonyoung Shim jy0922.shim@samsung.com --- drivers/gpu/drm/drm_prime.c | 54 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 50 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index d92853e..ac48038 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -62,15 +62,29 @@ struct drm_prime_member { struct dma_buf *dma_buf; uint32_t handle; }; + +struct drm_prime_attachment { + struct sg_table *sgt; + enum dma_data_direction dir; +}; + static int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle);

static int drm_gem_map_attach(struct dma_buf *dma_buf, struct device *target_dev, struct dma_buf_attachment *attach) { + struct drm_prime_attachment *prime_attach; struct drm_gem_object *obj = dma_buf->priv; struct drm_device *dev = obj->dev;

+ prime_attach = kzalloc(sizeof(*prime_attach), GFP_KERNEL); + if (!prime_attach) + return -ENOMEM; + + prime_attach->dir = DMA_NONE; + attach->priv = prime_attach; + if (!dev->driver->gem_prime_pin) return 0;

@@ -80,25 +94,59 @@ static int drm_gem_map_attach(struct dma_buf *dma_buf, static void drm_gem_map_detach(struct dma_buf *dma_buf, struct dma_buf_attachment *attach) { + struct drm_prime_attachment *prime_attach = attach->priv; struct drm_gem_object *obj = dma_buf->priv; struct drm_device *dev = obj->dev; + struct sg_table *sgt;

if (dev->driver->gem_prime_unpin) dev->driver->gem_prime_unpin(obj); + + if (!prime_attach) + return; + + sgt = prime_attach->sgt; + + if (prime_attach->dir != DMA_NONE) + dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, + prime_attach->dir); + + sg_free_table(sgt); + kfree(sgt); + kfree(prime_attach); + attach->priv = NULL; }

static struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach, enum dma_data_direction dir) { + struct drm_prime_attachment *prime_attach = attach->priv; struct drm_gem_object *obj = attach->dmabuf->priv; struct sg_table *sgt;

+ if (WARN_ON(dir == DMA_NONE || !prime_attach)) + return ERR_PTR(-EINVAL); + + /* return the cached mapping when possible */ + if (prime_attach->dir == dir) + return prime_attach->sgt; + + /* + * two mappings with different directions for the same attachment are + * not allowed + */ + if (WARN_ON(prime_attach->dir != DMA_NONE)) + return ERR_PTR(-EBUSY); + mutex_lock(&obj->dev->struct_mutex);

sgt = obj->dev->driver->gem_prime_get_sg_table(obj);

- if (!IS_ERR_OR_NULL(sgt)) + if (!IS_ERR_OR_NULL(sgt)) { dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir); + prime_attach->sgt = sgt; + prime_attach->dir = dir; + }

mutex_unlock(&obj->dev->struct_mutex); return sgt; @@ -107,9 +155,7 @@ static struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach, static void drm_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); + /* nothing to be done here */ }

static void drm_gem_dmabuf_release(struct dma_buf *dma_buf)