[PATCH v6,12/24] media: mediatek: vcodec: add interface to allocate/free secure memory

[Tomasz Figa]

On Mon, Jun 17, 2024 at 3:53 PM Yong Wu (吴勇) <Yong.Wu at mediatek.com> wrote:
>
> On Wed, 2024-06-12 at 14:22 +0900, Tomasz Figa wrote:
> >
> > External email : Please do not click links or open attachments until
> > you have verified the sender or the content.
> >  On Thu, May 16, 2024 at 08:20:50PM +0800, Yunfei Dong wrote:
> > > Need to call dma heap interface to allocate/free secure memory when
> > playing
> > > secure video.
> > >
> > > Signed-off-by: Yunfei Dong <yunfei.dong at mediatek.com>
> > > ---
> > >  .../media/platform/mediatek/vcodec/Kconfig    |   1 +
> > >  .../mediatek/vcodec/common/mtk_vcodec_util.c  | 122
> > +++++++++++++++++-
> > >  .../mediatek/vcodec/common/mtk_vcodec_util.h  |   3 +
> > >  3 files changed, 123 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/media/platform/mediatek/vcodec/Kconfig
> > b/drivers/media/platform/mediatek/vcodec/Kconfig
> > > index bc8292232530..707865703e61 100644
> > > --- a/drivers/media/platform/mediatek/vcodec/Kconfig
> > > +++ b/drivers/media/platform/mediatek/vcodec/Kconfig
> > > @@ -17,6 +17,7 @@ config VIDEO_MEDIATEK_VCODEC
>
> [snip]
>
> > > -void mtk_vcodec_mem_free(void *priv, struct mtk_vcodec_mem *mem)
> > > +static int mtk_vcodec_mem_alloc_sec(struct mtk_vcodec_dec_ctx
> > *ctx, struct mtk_vcodec_mem *mem)
> > > +{
> > > +struct device *dev = &ctx->dev->plat_dev->dev;
> > > +struct dma_buf *dma_buffer;
> > > +struct dma_heap *vdec_heap;
> > > +struct dma_buf_attachment *attach;
> > > +struct sg_table *sgt;
> > > +unsigned long size = mem->size;
> > > +int ret = 0;
> > > +
> > > +if (!size)
> > > +return -EINVAL;
> > > +
> > > +vdec_heap = dma_heap_find("restricted_mtk_cma");
> > > +if (!vdec_heap) {
> > > +mtk_v4l2_vdec_err(ctx, "dma heap find failed!");
> > > +return -EPERM;
> > > +}
> >
> > How is the heap name determined here? My recollection is that the
> > heap
> > name comes from the heap node in the DT, so it may vary depending on
> > the
> > board.
> >
> > Is the heap name documented anywhere in the DT bindings?
> >
> > Shouldn't we rather query DT for a phandle to the right heap?
> >
>
> Hi Tomasz,
>
> This heap name does not come from dt-binding. It is hard-coded in the
> driver[1]. Because the heap driver is a pure SW driver, there is no
> corresponding HW unit, and there is no way to add a dtsi node.
>
> [1]
> https://lore.kernel.org/linux-mediatek/20240515112308.10171-10-yong.wu@mediatek.com/

Okay, I see. Thanks for clarifying.

Best regards,
Tomasz