Re: [PATCH] drm/amdgpu: Enable GCVM_CONTEXT1_CNTL after page table addr is set.

[Alex Deucher]

On Wed, May 24, 2023 at 11:25 AM ghostfly233 <ghostfly23333@xxxxxxxxx> wrote:
>
> In gfxhub_v2_1_setup_vmid_config(), the GCVM_CONTEXT1_CNTL reg is
> enabled before related GCVM_CONTEXT1_PAGE_TABLE_START_ADDR and
> GCVM_CONTEXT1_PAGE_TABLE_END_ADDR regs are written, which may
> cause undefined behavior.
>
> This patch enable GCVM_CONNTEXT1_CNTL after page table addresses are set,
> so that it can ensure no undefined behavior will happen.

Please update all of the gfxhub and mmhub files with this change.

Alex

>
> Signed-off-by: Zibin Liu <ghostfly23333@xxxxxxxxx>
> ---
>  drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c b/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c
> index 4aacbbec31e2..791afc8e9e85 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c
> @@ -297,7 +297,7 @@ static void gfxhub_v2_1_setup_vmid_config(struct amdgpu_device *adev)
>
>         for (i = 0; i <= 14; i++) {
>                 tmp = RREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_CNTL, i);
> -               tmp = REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL, ENABLE_CONTEXT, 1);
> +               tmp = REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL, ENABLE_CONTEXT, 0);
>                 tmp = REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL, PAGE_TABLE_DEPTH,
>                                     adev->vm_manager.num_level);
>                 tmp = REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL,
> @@ -333,6 +333,9 @@ static void gfxhub_v2_1_setup_vmid_config(struct amdgpu_device *adev)
>                 WREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_PAGE_TABLE_END_ADDR_HI32,
>                                     i * hub->ctx_addr_distance,
>                                     upper_32_bits(adev->vm_manager.max_pfn - 1));
> +               tmp = REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL, ENABLE_CONTEXT, 1);
> +               WREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_CNTL,
> +                                   i * hub->ctx_distance, tmp);
>         }
>
>         hub->vm_cntx_cntl = tmp;
> --
> 2.34.1
>