[Mesa-dev] [PATCH 23/34] i965: Add logic for allocating BO with CCS

[Jason Ekstrand]

On Wed, Jan 25, 2017 at 10:36 AM, Pohjolainen, Topi <
topi.pohjolainen at gmail.com> wrote:

> On Mon, Jan 23, 2017 at 10:21:46PM -0800, Ben Widawsky wrote:
> > This patch provides the support (and comments) for allocating the BO
> > with space for the CCS buffer just underneath it.
> >
> > This patch was originally titled:
> > "i965: Create correctly sized mcs for an image"
> >
> > In order to make things more bisectable, reviewable, and to have the
> > CCS_MODIFIER token saved for the last patch, this patch now does less so
> > it was renamed.
> >
> > v2: Leave "image+mod" (Topi)
> >
> > Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> > Acked-by: Daniel Stone <daniels at collabora.com>
> > Reviewed-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
> > ---
> >  src/mesa/drivers/dri/i965/intel_screen.c | 34
> ++++++++++++++++++++++++++++----
> >  1 file changed, 30 insertions(+), 4 deletions(-)
> >
> > diff --git a/src/mesa/drivers/dri/i965/intel_screen.c
> b/src/mesa/drivers/dri/i965/intel_screen.c
> > index 8ec33ce5df..971013f2dd 100644
> > --- a/src/mesa/drivers/dri/i965/intel_screen.c
> > +++ b/src/mesa/drivers/dri/i965/intel_screen.c
> > @@ -607,6 +607,7 @@ create_image_with_modifier(struct intel_screen
> *screen,
> >     uint32_t requested_tiling = 0, tiling = I915_TILING_X;
> >     unsigned long pitch;
> >     unsigned tiled_height = 0;
> > +   unsigned ccs_height = 0;
> >
> >     switch (modifier) {
> >     case I915_FORMAT_MOD_Y_TILED:
> > @@ -628,9 +629,33 @@ create_image_with_modifier(struct intel_screen
> *screen,
> >        break;
> >     }
> >
> > -   image->bo = drm_intel_bo_alloc_tiled(screen->bufmgr, "image+mod",
> > -                                        width, tiled_height, cpp,
> &tiling,
> > -                                        &pitch, 0);
> > +   /*
> > +    * CCS width is always going to be less than or equal to the image's
> width.
> > +    * All we need to do is make sure we add extra rows (height) for the
> CCS.
> > +    *
> > +    * A pair of CCS bits correspond to 8x4 pixels, and must be cacheline
> > +    * granularity. Each CCS tile is laid out in 8b strips, which
> corresponds to
> > +    * 1024x512 pixel region. In memory, it looks like the following:
> > +    *
> > +    * ?????????????????????????????????????????????????????????
> > +    * ???                 ???
> > +    * ???                 ???
> > +    * ???                 ???
> > +    * ???      Image      ???
> > +    * ???                 ???
> > +    * ???                 ???
> > +    * ???xxxxxxxxxxxxxxxxx???
> > +    * ?????????????????????????????????????????????????????????
> > +    * ???     ???           |
> > +    * ???ccs  ???  unused   |
> > +    * ?????????????????????-----------???
> > +    * <------pitch------>
> > +    */
> > +   cpp = _mesa_get_format_bytes(image->format);
> > +   image->bo = drm_intel_bo_alloc_tiled(screen->bufmgr,
> > +                                        ccs_height ? "image+ccs" :
> "image+mod",
> > +                                        width, tiled_height +
> ccs_height,
> > +                                        cpp, &tiling, &pitch, 0);
> >     if (image->bo == NULL)
> >        return false;
> >
> > @@ -647,7 +672,8 @@ create_image_with_modifier(struct intel_screen
> *screen,
> >     if (image->planar_format)
> >        assert(image->planar_format->nplanes == 1);
> >
> > -   image->aux_offset = 0; /* y_tiled_height * pitch; */
> > +   if (ccs_height)
> > +      image->aux_offset = tiled_height * pitch /* + mt->offset */;
>
> I think it would be clearer to drop the comment about mt->offset and
> assert here also. How do you feel?
>
>       if (ccs_height) {
>          assert(mt->offset == 0);
>          image->aux_offset = tiled_height * pitch;
>       }
>

That's nicer.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20170131/030c8d67/attachment-0001.html>