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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Wed, 24 May 2023 11:28:45 -0400
Message-ID: <CADnq5_N7W8_c6tcFDkEEM_shXr0GJV+YJfJ8y4YC=2ufRHRX5g@mail.gmail.com>
Subject: Re: [PATCH] drm/amdgpu: Enable GCVM_CONTEXT1_CNTL after page table
 addr is set.
To:     ghostfly233 <ghostfly23333@gmail.com>
Cc:     alexander.deucher@amd.com, christian.koenig@amd.com,
        Xinhui.Pan@amd.com, daniel@ffwll.ch, airlied@gmail.com,
        linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org
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On Wed, May 24, 2023 at 11:25=E2=80=AFAM ghostfly233 <ghostfly23333@gmail.c=
om> 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@gmail.com>
> ---
>  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/a=
md/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 amdg=
pu_device *adev)
>
>         for (i =3D 0; i <=3D 14; i++) {
>                 tmp =3D RREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_CNTL, =
i);
> -               tmp =3D REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL, ENABLE_CON=
TEXT, 1);
> +               tmp =3D REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL, ENABLE_CON=
TEXT, 0);
>                 tmp =3D REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL, PAGE_TABLE=
_DEPTH,
>                                     adev->vm_manager.num_level);
>                 tmp =3D REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL,
> @@ -333,6 +333,9 @@ static void gfxhub_v2_1_setup_vmid_config(struct amdg=
pu_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_pf=
n - 1));
> +               tmp =3D REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL, ENABLE_CON=
TEXT, 1);
> +               WREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_CNTL,
> +                                   i * hub->ctx_distance, tmp);
>         }
>
>         hub->vm_cntx_cntl =3D tmp;
> --
> 2.34.1
>