[PATCH 6/8] drm/amd/display: Set DC options from modifiers.
Daniel Vetter
daniel at ffwll.ch
Mon Aug 10 12:28:20 UTC 2020
On Wed, Aug 05, 2020 at 09:32:10AM +0200, daniel at ffwll.ch wrote:
> On Tue, Aug 04, 2020 at 11:31:17PM +0200, Bas Nieuwenhuizen wrote:
> > This sets the DC tiling options from the modifier, if modifiers
> > are used for the FB. This patch by itself does not expose the
> > support yet though.
> >
> > There is not much validation yet to limit the scope of this
> > patch, but the current validation is at the same level as
> > the BO metadata path.
> >
> > Signed-off-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
> > ---
> > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 109 +++++++++++++++++-
> > 1 file changed, 103 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > index 6ef7f2f8acab..ac913b8f10ef 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > @@ -3754,6 +3754,93 @@ fill_gfx9_plane_attributes_from_flags(struct amdgpu_device *adev,
> > return 0;
> > }
> >
> > +static bool
> > +modifier_has_dcc(uint64_t modifier)
> > +{
> > + return IS_AMD_FMT_MOD(modifier) && AMD_FMT_MOD_GET(DCC, modifier);
> > +}
> > +
> > +static unsigned
> > +modifier_gfx9_swizzle_mode(uint64_t modifier)
> > +{
> > + if (modifier == DRM_FORMAT_MOD_LINEAR)
> > + return 0;
> > +
> > + return AMD_FMT_MOD_GET(TILE, modifier);
> > +}
> > +
> > +static void
> > +fill_gfx9_tiling_info_from_modifier(const struct amdgpu_device *adev,
> > + union dc_tiling_info *tiling_info,
> > + uint64_t modifier)
> > +{
> > + unsigned int mod_bank_xor_bits = AMD_FMT_MOD_GET(BANK_XOR_BITS, modifier);
> > + unsigned int mod_pipe_xor_bits = AMD_FMT_MOD_GET(PIPE_XOR_BITS, modifier);
> > + unsigned int pkrs_log2 = AMD_FMT_MOD_GET(PACKERS, modifier);
> > + unsigned int pipes_log2 = min(4u, mod_pipe_xor_bits);
> > +
> > + fill_gfx9_tiling_info_from_device(adev, tiling_info);
> > +
> > + if (!IS_AMD_FMT_MOD(modifier))
> > + return;
> > +
> > + tiling_info->gfx9.num_pipes = 1u << pipes_log2;
> > + tiling_info->gfx9.num_shader_engines = 1u << (mod_pipe_xor_bits - pipes_log2);
> > +
> > + if (adev->family >= AMDGPU_FAMILY_NV) {
> > + tiling_info->gfx9.num_pkrs = 1u << pkrs_log2;
> > + } else {
> > + tiling_info->gfx9.num_banks = 1u << mod_bank_xor_bits;
> > +
> > + /* for DCC we know it isn't rb aligned, so rb_per_se doesn't matter. */
> > + }
> > +}
> > +
> > +static void
> > +block_alignment(unsigned int blocksize_log2, unsigned int *width, unsigned int *height)
> > +{
> > + unsigned int height_log2 = blocksize_log2 / 2;
> > + unsigned int width_log2 = blocksize_log2 - height_log2;
> > +
> > + *width = 1u << width_log2;
> > + *height = 1u << height_log2;
> > +}
> > +
> > +static int
> > +fill_gfx9_plane_attributes_from_modifiers(struct amdgpu_device *adev,
> > + const struct amdgpu_framebuffer *afb,
> > + const enum surface_pixel_format format,
> > + const enum dc_rotation_angle rotation,
> > + const struct plane_size *plane_size,
> > + union dc_tiling_info *tiling_info,
> > + struct dc_plane_dcc_param *dcc,
> > + struct dc_plane_address *address,
> > + const bool force_disable_dcc)
> > +{
> > + const uint64_t modifier = afb->base.modifier;
> > + int ret;
> > +
> > + fill_gfx9_tiling_info_from_modifier(adev, tiling_info, modifier);
> > + tiling_info->gfx9.swizzle = modifier_gfx9_swizzle_mode(modifier);
> > +
> > + if (modifier_has_dcc(modifier) && !force_disable_dcc) {
> > + uint64_t dcc_address = afb->address + afb->base.offsets[1];
> > +
> > + dcc->enable = 1;
> > + dcc->meta_pitch = afb->base.pitches[1];
> > + dcc->independent_64b_blks = AMD_FMT_MOD_GET(DCC_INDEPENDENT_64B, modifier);
> > +
> > + address->grph.meta_addr.low_part = lower_32_bits(dcc_address);
> > + address->grph.meta_addr.high_part = upper_32_bits(dcc_address);
> > + }
> > +
> > + ret = validate_dcc(adev, format, rotation, tiling_info, dcc, address, plane_size);
> > + if (ret)
> > + return ret;
> > +
> > + return 0;
> > +}
> > +
> > static int
> > fill_plane_buffer_attributes(struct amdgpu_device *adev,
> > const struct amdgpu_framebuffer *afb,
> > @@ -3823,12 +3910,22 @@ fill_plane_buffer_attributes(struct amdgpu_device *adev,
> >
> >
> > if (adev->family >= AMDGPU_FAMILY_AI) {
> > - ret = fill_gfx9_plane_attributes_from_flags(adev, afb, format, rotation,
> > - plane_size, tiling_info, dcc,
> > - address, tiling_flags,
> > - force_disable_dcc);
> > - if (ret)
> > - return ret;
> > + if (afb->base.flags & DRM_MODE_FB_MODIFIERS) {
> > + ret = fill_gfx9_plane_attributes_from_modifiers(adev, afb, format,
> > + rotation, plane_size,
> > + tiling_info, dcc,
> > + address,
> > + force_disable_dcc);
> > + if (ret)
> > + return ret;
> > + } else {
> > + ret = fill_gfx9_plane_attributes_from_flags(adev, afb, format, rotation,
> > + plane_size, tiling_info, dcc,
> > + address, tiling_flags,
> > + force_disable_dcc);
> > + if (ret)
> > + return ret;
>
> So what we've done in i915, but might be too cumbersome with the amdgpu
> modifiers, is to map legacy tiling information into modifiers once, at the
> beginning of addfb. So in amdgpu_display_user_framebuffer_create(). And
> once modifiers are filled in, you ofc set the DRM_MODE_FB_MODIFIERS flag
> too in the fb.
>
> Then all the display code only works with modifiers, instead of having a
> mix and possible confusion, with breakage when people only test the legacy
> path. Which I kinda expect to happen, since amd probably runs with their
> own ddx in their CI rig only.
>
> This also avoids a bunch of layering and locking unprettiness, since
> display code doesn't need to dig around in gem_bo side of things. On that,
> there's another amdgpu_bo_get_tiling_flags in amdgpu_dm_commit_planes
> which probably shouldn't be there, and should use computed stuff from
> plane state or fb (I changed it to a lockless version to just hack around
> locking issues, but still there).
>
> This hopefully/eventually should allow us to entirely phase out the legacy
> magic tiling blob attached to bo (we've pulled the trigger on that for
> intel now, would have needed to extend the uapi to keep it working was a
> good excuse).
Ok just learned that amdgpu hat set/get_tiling, so I'm upgrading my idea
here to a very strong recommendation, i.e. please do this except if
there's and amd ddx which somehow wants to change tiling mode while a fb
exists, and expects this to propagate.
In i915 we even disallow the set_tiling ioctl with an error if an fb
exists, just to make sure userspace behaves. Even if userspace uses
set_tiling, this way we can at least enforce the same semantics of "client
can't pull compositor over the table with a set_tiling at the wrong time"
of modifiers.
-Daniel
>
> Cheers, Daniel
>
> > + }
> > } else {
> > fill_gfx8_tiling_info_from_flags(tiling_info, tiling_flags);
> > }
> > --
> > 2.28.0
> >
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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