[PATCH] drm/amdgpu: Enable doorbell selfring if resize BAR successfully

Liu, Aaron Aaron.Liu at amd.com
Tue Apr 25 01:13:32 UTC 2023


[AMD Official Use Only - General]

> -----Original Message-----
> From: Alex Deucher <alexdeucher at gmail.com>
> Sent: Tuesday, April 25, 2023 4:20 AM
> To: Koenig, Christian <Christian.Koenig at amd.com>
> Cc: Xiao, Shane <shane.xiao at amd.com>; Christian König
> <ckoenig.leichtzumerken at gmail.com>; amd-gfx at lists.freedesktop.org;
> Deucher, Alexander <Alexander.Deucher at amd.com>; Zhang, Hawking
> <Hawking.Zhang at amd.com>; Kuehling, Felix <Felix.Kuehling at amd.com>; Hou,
> Xiaomeng (Matthew) <Xiaomeng.Hou at amd.com>; Liu, Aaron
> <Aaron.Liu at amd.com>
> Subject: Re: [PATCH] drm/amdgpu: Enable doorbell selfring if resize BAR
> successfully
>
> On Mon, Apr 24, 2023 at 3:11 PM Christian König <christian.koenig at amd.com>
> wrote:
> >
> > Am 24.04.23 um 16:06 schrieb Xiao, Shane:
> > > [AMD Official Use Only - General]
> > >> -----Original Message-----
> > >> From: Xiao, Shane
> > >> Sent: Monday, April 24, 2023 6:31 PM
> > >> To: Christian König <ckoenig.leichtzumerken at gmail.com>; amd-
> > >> gfx at lists.freedesktop.org; Deucher, Alexander
> > >> <Alexander.Deucher at amd.com>; Zhang, Hawking
> > >> <Hawking.Zhang at amd.com>; Kuehling, Felix <Felix.Kuehling at amd.com>
> > >> Cc: Hou, Xiaomeng (Matthew) <Xiaomeng.Hou at amd.com>; Liu, Aaron
> > >> <Aaron.Liu at amd.com>
> > >> Subject: RE: [PATCH] drm/amdgpu: Enable doorbell selfring if resize
> > >> BAR successfully
> > >>
> > >> [AMD Official Use Only - General]
> > >>> -----Original Message-----
> > >>> From: Christian König <ckoenig.leichtzumerken at gmail.com>
> > >>> Sent: Monday, April 24, 2023 5:07 PM
> > >>> To: Xiao, Shane <shane.xiao at amd.com>;
> > >>> amd-gfx at lists.freedesktop.org; Deucher, Alexander
> > >>> <Alexander.Deucher at amd.com>; Zhang, Hawking
> > >>> <Hawking.Zhang at amd.com>; Kuehling, Felix <Felix.Kuehling at amd.com>
> > >>> Cc: Hou, Xiaomeng (Matthew) <Xiaomeng.Hou at amd.com>; Liu, Aaron
> > >>> <Aaron.Liu at amd.com>
> > >>> Subject: Re: [PATCH] drm/amdgpu: Enable doorbell selfring if
> > >>> resize BAR successfully
> > >>>
> > >>> Am 18.04.23 um 08:54 schrieb Shane Xiao:
> > >>>> [Why]
> > >>>> The selfring doorbell aperture will change when we resize FB BAR
> > >>>> successfully during gmc sw init, we should reorder the sequence
> > >>>> of enabling doorbell selfring aperture.
> > >>> That's a good catch.
> > >>>
> > >>>> [How]
> > >>>> Move enable_doorbell_selfring_aperture from *_common_hw_init to
> > >>>> *_common_late_init.
> > >>> But that sounds like a bad idea. Instead the full call to
> > >>> nv_enable_doorbell_aperture() should be moved around.
> > >> Hi Christian,
> > >>
> > >> Yes,  I get your idea. But as far as I can understand that, the gfx
> > >> hw init will use doorbell.
> > >> If so, we cannot enable doorbell after gfx hw init.
> > > We have come up with two ways to resolve the issue.
> > >
> > > 1) Separate enable_doorbell_aperture and
> > > enable_doorbell_selfring_aperture. However,  the
> enable_doorbell_selfring_aperture should be moved in *_common_ip_funcs-
> >late_init.
> >
> > I'm not an expert for this part of the driver, but of hand that sounds
> > like the right way of doing it.
> >
> > Alex any objections?
>
> Yeah, seems reasonable.
>
> Alex
>
enable_doorbell_aperture and enable_doorbell_selfring_aperture should be in common_*_init instead of gmc_hw_init.
The order of execution of Shane's 1st way is :
1) common_sw_init
2) common_hw_init  -> enable_doorbell_aperture
3) gmc_sw_init -> amdgpu_device_resize_fb_bar                  ///This relies gmc.real_vram_size to determine resize_fb_bar, so moving amdgpu_device_resize_fb_bar to common_sw_init  is not a good idea.
4) gmc_hw_init
5) common_late_init -> enable_doorbell_selfring_aperture

The 1st way looks good to me and reviewed-by me.

> >
> > Regards,
> > Christian.
> >
> > > 2) The full call can be moved to gmc hw init.  But it seems strange to move
> nbio configuration into gmc hw init.
> > >
> > > If neither of the above methods is suitable, could you please give us some
> advice on this issue?
> > >
> > > Best Regards,
> > > Shane
> > >
> > >> Best Regards,
> > >> Shane
> > >>
> > >>> Regards,
> > >>> Christian.
> > >>>
> > >>>> This fixes the potential issue that GPU ring its own doorbell
> > >>>> when this device is in translated mode with iommu is on.
> > >>>>
> > >>>> Signed-off-by: Shane Xiao <shane.xiao at amd.com>
> > >>>> Signed-off-by: Aaron Liu <aaron.liu at amd.com>
> > >>>> Tested-by: Xiaomeng Hou <Xiaomeng.Hou at amd.com>
> > >>>> ---
> > >>>>    drivers/gpu/drm/amd/amdgpu/nv.c    | 4 +++-
> > >>>>    drivers/gpu/drm/amd/amdgpu/soc15.c | 4 +++-
> > >>>>    drivers/gpu/drm/amd/amdgpu/soc21.c | 4 +++-
> > >>>>    3 files changed, 9 insertions(+), 3 deletions(-)
> > >>>>
> > >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/nv.c
> > >>>> b/drivers/gpu/drm/amd/amdgpu/nv.c index
> > >>>> 47420b403871..f4c85634a4c8
> > >>>> 100644
> > >>>> --- a/drivers/gpu/drm/amd/amdgpu/nv.c
> > >>>> +++ b/drivers/gpu/drm/amd/amdgpu/nv.c
> > >>>> @@ -535,7 +535,8 @@ static void
> > >>>> nv_enable_doorbell_aperture(struct
> > >>> amdgpu_device *adev,
> > >>>>                                            bool enable)
> > >>>>    {
> > >>>>            adev->nbio.funcs->enable_doorbell_aperture(adev,
> > >>>> enable);
> > >>>> -  adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>>> enable);
> > >>>> +  if (!enable)
> > >>>> +
> > >>>> + adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>> false);
> > >>>>    }
> > >>>>
> > >>>>    const struct amdgpu_ip_block_version nv_common_ip_block = @@
> > >>>> -999,6
> > >>>> +1000,7 @@ static int nv_common_late_init(void *handle)
> > >>>>                    }
> > >>>>            }
> > >>>>
> > >>>> +  adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>>> + true);
> > >>>>            return 0;
> > >>>>    }
> > >>>>
> > >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/soc15.c
> > >>>> b/drivers/gpu/drm/amd/amdgpu/soc15.c
> > >>>> index bc5dd80f10c1..0202de79a389 100644
> > >>>> --- a/drivers/gpu/drm/amd/amdgpu/soc15.c
> > >>>> +++ b/drivers/gpu/drm/amd/amdgpu/soc15.c
> > >>>> @@ -623,7 +623,8 @@ static void
> > >>>> soc15_enable_doorbell_aperture(struct
> > >>> amdgpu_device *adev,
> > >>>>                                               bool enable)
> > >>>>    {
> > >>>>            adev->nbio.funcs->enable_doorbell_aperture(adev,
> > >>>> enable);
> > >>>> -  adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>>> enable);
> > >>>> +  if (!enable)
> > >>>> +
> > >>>> + adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>> false);
> > >>>>    }
> > >>>>
> > >>>>    const struct amdgpu_ip_block_version vega10_common_ip_block =
> > >>>> @@
> > >>>> -1125,6 +1126,7 @@ static int soc15_common_late_init(void *handle)
> > >>>>            if (amdgpu_sriov_vf(adev))
> > >>>>                    xgpu_ai_mailbox_get_irq(adev);
> > >>>>
> > >>>> +  adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>>> + true);
> > >>>>            return 0;
> > >>>>    }
> > >>>>
> > >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/soc21.c
> > >>>> b/drivers/gpu/drm/amd/amdgpu/soc21.c
> > >>>> index 514bfc705d5a..cd4619085d67 100644
> > >>>> --- a/drivers/gpu/drm/amd/amdgpu/soc21.c
> > >>>> +++ b/drivers/gpu/drm/amd/amdgpu/soc21.c
> > >>>> @@ -454,7 +454,8 @@ static void
> > >>>> soc21_enable_doorbell_aperture(struct
> > >>> amdgpu_device *adev,
> > >>>>                                            bool enable)
> > >>>>    {
> > >>>>            adev->nbio.funcs->enable_doorbell_aperture(adev,
> > >>>> enable);
> > >>>> -  adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>>> enable);
> > >>>> +  if (!enable)
> > >>>> +
> > >>>> + adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>> false);
> > >>>>    }
> > >>>>
> > >>>>    const struct amdgpu_ip_block_version soc21_common_ip_block =
> > >>>> @@
> > >>>> -764,6 +765,7 @@ static int soc21_common_late_init(void *handle)
> > >>>>                            amdgpu_irq_get(adev, &adev-
> > >>>> nbio.ras_err_event_athub_irq, 0);
> > >>>>            }
> > >>>>
> > >>>> +  adev->nbio.funcs->enable_doorbell_selfring_aperture(adev,
> > >>>> + true);
> > >>>>            return 0;
> > >>>>    }
> > >>>>
> >


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