[PATCH] drm/amdgpu: Clear overflow for SRIOV

[Alex Deucher]

On Fri, Apr 11, 2025 at 4:07 AM Emily Deng <Emily.Deng at amd.com> wrote:
>
> For VF, it doesn't have the permission to clear overflow, clear the bit
> by reset.
>
> Signed-off-by: Emily Deng <Emily.Deng at amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c | 10 ++++++++--
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h |  1 +
>  drivers/gpu/drm/amd/amdgpu/ih_v6_0.c   |  6 +++++-
>  drivers/gpu/drm/amd/amdgpu/vega20_ih.c |  6 +++++-
>  4 files changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
> index 901f8b12c672..1c8a40d579c7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
> @@ -227,13 +227,19 @@ int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
>                 ih->rptr &= ih->ptr_mask;
>         }
>
> -       amdgpu_ih_set_rptr(adev, ih);
> +       if (!ih->overflow)
> +               amdgpu_ih_set_rptr(adev, ih);
> +
>         wake_up_all(&ih->wait_process);
>
>         /* make sure wptr hasn't changed while processing */
>         wptr = amdgpu_ih_get_wptr(adev, ih);
>         if (wptr != ih->rptr)
> -               goto restart_ih;
> +               if (!ih->overflow)
> +                       goto restart_ih;
> +
> +       if (ih->overflow)
> +               amdgpu_amdkfd_gpu_reset(adev);

This won't work if KFD is not compiled in your kernel config.

Alex

>
>         return IRQ_HANDLED;
>  }
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h
> index 7d4395a5d8ac..ff76f02d3e96 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h
> @@ -72,6 +72,7 @@ struct amdgpu_ih_ring {
>         /* For waiting on IH processing at checkpoint. */
>         wait_queue_head_t wait_process;
>         uint64_t                processed_timestamp;
> +       bool overflow;
>  };
>
>  /* return true if time stamp t2 is after t1 with 48bit wrap around */
> diff --git a/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c b/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
> index f8a485164437..8d3ae88b96a4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
> @@ -349,6 +349,7 @@ static int ih_v6_0_irq_init(struct amdgpu_device *adev)
>                         if (ret)
>                                 return ret;
>                 }
> +               ih[i]->overflow = false;
>         }
>
>         /* update doorbell range for ih ring 0 */
> @@ -446,7 +447,10 @@ static u32 ih_v6_0_get_wptr(struct amdgpu_device *adev,
>         wptr = RREG32_NO_KIQ(ih_regs->ih_rb_wptr);
>         if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW))
>                 goto out;
> -       wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0);
> +       if (!amdgpu_sriov_vf(adev))
> +               wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0);
> +       else
> +               ih->overflow = true;
>
>         /* When a ring buffer overflow happen start parsing interrupt
>          * from the last not overwritten vector (wptr + 32). Hopefully
> diff --git a/drivers/gpu/drm/amd/amdgpu/vega20_ih.c b/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
> index e9e3b2ed4b7b..2ad209406d17 100644
> --- a/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
> +++ b/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
> @@ -350,6 +350,7 @@ static int vega20_ih_irq_init(struct amdgpu_device *adev)
>                         if (ret)
>                                 return ret;
>                 }
> +               ih[i]->overflow = false;
>         }
>
>         if (!amdgpu_sriov_vf(adev))
> @@ -437,7 +438,10 @@ static u32 vega20_ih_get_wptr(struct amdgpu_device *adev,
>         if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW))
>                 goto out;
>
> -       wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0);
> +       if (!amdgpu_sriov_vf(adev))
> +               wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0);
> +       else
> +               ih->overflow = true;
>
>         /* When a ring buffer overflow happen start parsing interrupt
>          * from the last not overwritten vector (wptr + 32). Hopefully
> --
> 2.34.1
>