Re: [PATCH] drm/amdgpu: always flush the TLB on gfx8

[Alex Deucher <alexdeucher@xxxxxxxxx>]

On Fri, Jun 3, 2022 at 9:05 AM Christian König
<ckoenig.leichtzumerken@xxxxxxxxx> wrote:
>
> The TLB on GFX8 stores each block of 8 PTEs where any of the valid bits
> are set.
>
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>

Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 9596c22fded6..b747488c28ad 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -847,6 +847,11 @@ int amdgpu_vm_update_range(struct amdgpu_device *adev, struct amdgpu_vm *vm,
>         flush_tlb |= adev->gmc.xgmi.num_physical_nodes &&
>                      adev->ip_versions[GC_HWIP][0] == IP_VERSION(9, 4, 0);
>
> +       /*
> +        * On GFX8 and older any 8 PTE block with a valid bit set enters the TLB
> +        */
> +       flush_tlb |= adev->ip_versions[GC_HWIP][0] < IP_VERSION(9, 0, 0);
> +
>         memset(&params, 0, sizeof(params));
>         params.adev = adev;
>         params.vm = vm;
> --
> 2.25.1
>