[PATCH 1/2] drm/amdgpu: Move HDP remapping earlier during init

[Alex Deucher]

On Thu, Aug 25, 2022 at 10:22 AM Lazar, Lijo <lijo.lazar at amd.com> wrote:
>
>
>
> On 8/25/2022 7:37 PM, Alex Deucher wrote:
> > On Thu, Aug 25, 2022 at 4:58 AM Lijo Lazar <lijo.lazar at amd.com> wrote:
> >>
> >> HDP flush is used early in the init sequence as part of memory controller
> >> block initialization. Hence remapping of HDP registers needed for flush
> >> needs to happen earlier.
> >>
> >> This also fixes the AER error reported as Unsupported Request during
> >> driver load.
> >>
> >> Link: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.kernel.org%2Fshow_bug.cgi%3Fid%3D216373&data=05%7C01%7Clijo.lazar%40amd.com%7Caeec5a5e8ec7402e546708da86a31e41%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637970332414985963%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=EQuUjHTaVPSKZdCUhL6iI4EJ56UMhKTLl86uVpSL8AU%3D&reserved=0
> >>
> >> Reported-by: Tom Seewald <tseewald at gmail.com>
> >> Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
> >> ---
> >>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 9 +++++++++
> >>   drivers/gpu/drm/amd/amdgpu/nv.c            | 6 ------
> >>   drivers/gpu/drm/amd/amdgpu/soc15.c         | 6 ------
> >>   drivers/gpu/drm/amd/amdgpu/soc21.c         | 6 ------
> >>   4 files changed, 9 insertions(+), 18 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >> index ce7d117efdb5..53d753e94a71 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >> @@ -2376,6 +2376,15 @@ static int amdgpu_device_ip_init(struct amdgpu_device *adev)
> >>                                  DRM_ERROR("amdgpu_vram_scratch_init failed %d\n", r);
> >>                                  goto init_failed;
> >>                          }
> >> +
> >> +                       /* remap HDP registers to a hole in mmio space,
> >> +                        * for the purpose of expose those registers
> >> +                        * to process space. This is needed for any early HDP
> >> +                        * flush operation during gmc initialization.
> >> +                        */
> >> +                       if (adev->nbio.funcs->remap_hdp_registers && !amdgpu_sriov_vf(adev))
> >> +                               adev->nbio.funcs->remap_hdp_registers(adev);
> >> +
> >
> > We probably also need this in ip_resume() as well to handle the
> > suspend and resume case.  Thinking about this more, maybe it's easier
> > to just track whether the remap has happened yet and use the old or
> > new offset based on that.
>
> If we can use the default offset without a remap, does it make sense to
> remap? What about calling the same in ip_resume?

The remap is necessary so that userspace drivers can access this to
flush the HDP registers when they need to since normally it's in a
non-accessible region of the MMIO space.  I'm fine with updating it in
ip_resume as well.

Alex


>
> Thanks,
> Lijo
>
> >
> > Alex
> >
> >
> >>                          r = adev->ip_blocks[i].version->funcs->hw_init((void *)adev);
> >>                          if (r) {
> >>                                  DRM_ERROR("hw_init %d failed %d\n", i, r);
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/nv.c b/drivers/gpu/drm/amd/amdgpu/nv.c
> >> index b3fba8dea63c..3ac7fef74277 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/nv.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/nv.c
> >> @@ -1032,12 +1032,6 @@ static int nv_common_hw_init(void *handle)
> >>          nv_program_aspm(adev);
> >>          /* setup nbio registers */
> >>          adev->nbio.funcs->init_registers(adev);
> >> -       /* remap HDP registers to a hole in mmio space,
> >> -        * for the purpose of expose those registers
> >> -        * to process space
> >> -        */
> >> -       if (adev->nbio.funcs->remap_hdp_registers && !amdgpu_sriov_vf(adev))
> >> -               adev->nbio.funcs->remap_hdp_registers(adev);
> >>          /* enable the doorbell aperture */
> >>          nv_enable_doorbell_aperture(adev, true);
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/soc15.c b/drivers/gpu/drm/amd/amdgpu/soc15.c
> >> index fde6154f2009..a0481e37d7cf 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/soc15.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/soc15.c
> >> @@ -1240,12 +1240,6 @@ static int soc15_common_hw_init(void *handle)
> >>          soc15_program_aspm(adev);
> >>          /* setup nbio registers */
> >>          adev->nbio.funcs->init_registers(adev);
> >> -       /* remap HDP registers to a hole in mmio space,
> >> -        * for the purpose of expose those registers
> >> -        * to process space
> >> -        */
> >> -       if (adev->nbio.funcs->remap_hdp_registers && !amdgpu_sriov_vf(adev))
> >> -               adev->nbio.funcs->remap_hdp_registers(adev);
> >>
> >>          /* enable the doorbell aperture */
> >>          soc15_enable_doorbell_aperture(adev, true);
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/soc21.c b/drivers/gpu/drm/amd/amdgpu/soc21.c
> >> index 55284b24f113..16b447055102 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/soc21.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/soc21.c
> >> @@ -660,12 +660,6 @@ static int soc21_common_hw_init(void *handle)
> >>          soc21_program_aspm(adev);
> >>          /* setup nbio registers */
> >>          adev->nbio.funcs->init_registers(adev);
> >> -       /* remap HDP registers to a hole in mmio space,
> >> -        * for the purpose of expose those registers
> >> -        * to process space
> >> -        */
> >> -       if (adev->nbio.funcs->remap_hdp_registers)
> >> -               adev->nbio.funcs->remap_hdp_registers(adev);
> >>          /* enable the doorbell aperture */
> >>          soc21_enable_doorbell_aperture(adev, true);
> >>
> >> --
> >> 2.25.1
> >>