[PATCH v2 1/2] drm/amdgpu: Move HDP remapping earlier during init

Alex Deucher alexdeucher at gmail.com
Tue Aug 30 13:48:11 UTC 2022


On Tue, Aug 30, 2022 at 12:05 AM Lazar, Lijo <lijo.lazar at amd.com> wrote:
>
>
>
> On 8/29/2022 10:20 PM, Alex Deucher wrote:
> > On Mon, Aug 29, 2022 at 4:18 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 Unsupported Request error reported through AER during
> >> driver load. The error happens as a write happens to the remap offset
> >> before real remapping is done.
> >>
> >> 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%7C0882d00080124386814a08da89de9bcd%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637973886457404198%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=dC%2BCY22cfix1VCcQINrvNWI5XW%2BYV5lleJX3Ju9A6Iw%3D&reserved=0
> >>
> >> The error was unnoticed before and got visible because of the commit
> >> referenced below. This doesn't fix anything in the commit below, rather
> >> fixes the issue in amdgpu exposed by the commit. The reference is only
> >> to associate this commit with below one so that both go together.
> >>
> >> Fixes: 8795e182b02d ("PCI/portdrv: Don't disable AER reporting in get_port_device_capability()")
> >>
> >> Reported-by: Tom Seewald <tseewald at gmail.com>
> >> Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
> >> Cc: stable at vger.kernel.org
> >
> > How about something like the attached patch rather than these two
> > patches?  It's a bit bigger but seems cleaner and more defensive in my
> > opinion.
> >
>
> Whenever device goes to suspend/reset and then comes back, remap offset
> has to be set back to 0 to make sure it doesn't use the wrong offset
> when the register assumes default values again.
>
> To avoid the if-check in hdp_flush (which is more frequent), another way
> is to initialize the remap offset to default offset during early init
> and hw fini/suspend sequences. It won't be obvious (even with this
> patch) as to when remap offset vs default offset is used though.

On resume, the common IP is resumed first so it will always be set.
The only case that is a problem is init because we init GMC out of
order.  We could init common before GMC in amdgpu_device_ip_init().  I
think that should be fine, but I wasn't sure if there might be some
fallout from that on certain cards.

Alex

>
> Thanks,
> Lijo
>
> > Alex
> >
> >> ---
> >> v2:
> >>          Take care of IP resume cases (Alex Deucher)
> >>          Add NULL check to nbio.funcs to cover older (GFXv8) ASICs (Felix Kuehling)
> >>          Add more details in commit message and associate with AER patch (Bjorn
> >> Helgaas)
> >>
> >>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 24 ++++++++++++++++++++++
> >>   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, 24 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..e420118769a5 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >> @@ -2334,6 +2334,26 @@ static int amdgpu_device_init_schedulers(struct amdgpu_device *adev)
> >>          return 0;
> >>   }
> >>
> >> +/**
> >> + * amdgpu_device_prepare_ip - prepare IPs for hardware initialization
> >> + *
> >> + * @adev: amdgpu_device pointer
> >> + *
> >> + * Any common hardware initialization sequence that needs to be done before
> >> + * hw init of individual IPs is performed here. This is different from the
> >> + * 'common block' which initializes a set of IPs.
> >> + */
> >> +static void amdgpu_device_prepare_ip(struct amdgpu_device *adev)
> >> +{
> >> +       /* Remap HDP registers to a hole in mmio space, for the purpose
> >> +        * of exposing those registers to process space. This needs to be
> >> +        * done before hw init of ip blocks to take care of HDP flush
> >> +        * operations through registers during hw_init.
> >> +        */
> >> +       if (adev->nbio.funcs && adev->nbio.funcs->remap_hdp_registers &&
> >> +           !amdgpu_sriov_vf(adev))
> >> +               adev->nbio.funcs->remap_hdp_registers(adev);
> >> +}
> >>
> >>   /**
> >>    * amdgpu_device_ip_init - run init for hardware IPs
> >> @@ -2376,6 +2396,8 @@ static int amdgpu_device_ip_init(struct amdgpu_device *adev)
> >>                                  DRM_ERROR("amdgpu_vram_scratch_init failed %d\n", r);
> >>                                  goto init_failed;
> >>                          }
> >> +
> >> +                       amdgpu_device_prepare_ip(adev);
> >>                          r = adev->ip_blocks[i].version->funcs->hw_init((void *)adev);
> >>                          if (r) {
> >>                                  DRM_ERROR("hw_init %d failed %d\n", i, r);
> >> @@ -3058,6 +3080,7 @@ static int amdgpu_device_ip_reinit_early_sriov(struct amdgpu_device *adev)
> >>                  AMD_IP_BLOCK_TYPE_IH,
> >>          };
> >>
> >> +       amdgpu_device_prepare_ip(adev);
> >>          for (i = 0; i < adev->num_ip_blocks; i++) {
> >>                  int j;
> >>                  struct amdgpu_ip_block *block;
> >> @@ -3139,6 +3162,7 @@ static int amdgpu_device_ip_resume_phase1(struct amdgpu_device *adev)
> >>   {
> >>          int i, r;
> >>
> >> +       amdgpu_device_prepare_ip(adev);
> >>          for (i = 0; i < adev->num_ip_blocks; i++) {
> >>                  if (!adev->ip_blocks[i].status.valid || adev->ip_blocks[i].status.hw)
> >>                          continue;
> >> 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
> >>


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