RE: Patch "drm/amdgpu/gfx11: need acquire mutex before access CP_VMID_RESET v2" has been added to the 6.6-stable tree

RE: Patch "drm/amdgpu/gfx11: need acquire mutex before access CP_VMID_RESET v2" has been added to the 6.6-stable tree

[Deucher, Alexander]

[Public]

> -----Original Message-----
> From: Sasha Levin <sashal@kernel.org>
> Sent: Wednesday, August 21, 2024 9:33 AM
> To: stable-commits@vger.kernel.org; Xiao, Jack <Jack.Xiao@amd.com>
> Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Koenig, Christian
> <Christian.Koenig@amd.com>; Pan, Xinhui <Xinhui.Pan@amd.com>; David
> Airlie <airlied@gmail.com>; Daniel Vetter <daniel@ffwll.ch>
> Subject: Patch "drm/amdgpu/gfx11: need acquire mutex before access
> CP_VMID_RESET v2" has been added to the 6.6-stable tree
>
> This is a note to let you know that I've just added the patch titled
>
>     drm/amdgpu/gfx11: need acquire mutex before access CP_VMID_RESET v2
>
> to the 6.6-stable tree which can be found at:
>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-
> queue.git;a=summary
>
> The filename of the patch is:
>      drm-amdgpu-gfx11-need-acquire-mutex-before-access-cp.patch
> and it can be found in the queue-6.6 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree, please let
> <stable@vger.kernel.org> know about it.
>

This patch is not stable material.  Please drop for stable.

Thanks,

Alex

>
>
> commit 72516630230bee2668c491fdafcac27c565a5ad5
> Author: Jack Xiao <Jack.Xiao@amd.com>
> Date:   Tue Dec 19 17:10:34 2023 +0800
>
>     drm/amdgpu/gfx11: need acquire mutex before access CP_VMID_RESET v2
>
>     [ Upstream commit 4b5c5f5ad38b9435518730cc7f8f1e8de9c5cb2f ]
>
>     It's required to take the gfx mutex before access to CP_VMID_RESET,
>     for there is a race condition with CP firmware to write the register.
>
>     v2: add extra code to ensure the mutex releasing is successful.
>
>     Signed-off-by: Jack Xiao <Jack.Xiao@amd.com>
>     Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
>     Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
>     Signed-off-by: Sasha Levin <sashal@kernel.org>
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
> b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
> index c81e98f0d17ff..17a09e96b30fc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
> @@ -4430,11 +4430,43 @@ static int gfx_v11_0_wait_for_idle(void *handle)
>       return -ETIMEDOUT;
>  }
>
> +static int gfx_v11_0_request_gfx_index_mutex(struct amdgpu_device *adev,
> +                                          int req)
> +{
> +     u32 i, tmp, val;
> +
> +     for (i = 0; i < adev->usec_timeout; i++) {
> +             /* Request with MeId=2, PipeId=0 */
> +             tmp = REG_SET_FIELD(0, CP_GFX_INDEX_MUTEX, REQUEST,
> req);
> +             tmp = REG_SET_FIELD(tmp, CP_GFX_INDEX_MUTEX,
> CLIENTID, 4);
> +             WREG32_SOC15(GC, 0, regCP_GFX_INDEX_MUTEX, tmp);
> +
> +             val = RREG32_SOC15(GC, 0, regCP_GFX_INDEX_MUTEX);
> +             if (req) {
> +                     if (val == tmp)
> +                             break;
> +             } else {
> +                     tmp = REG_SET_FIELD(tmp, CP_GFX_INDEX_MUTEX,
> +                                         REQUEST, 1);
> +
> +                     /* unlocked or locked by firmware */
> +                     if (val != tmp)
> +                             break;
> +             }
> +             udelay(1);
> +     }
> +
> +     if (i >= adev->usec_timeout)
> +             return -EINVAL;
> +
> +     return 0;
> +}
> +
>  static int gfx_v11_0_soft_reset(void *handle)  {
>       u32 grbm_soft_reset = 0;
>       u32 tmp;
> -     int i, j, k;
> +     int r, i, j, k;
>       struct amdgpu_device *adev = (struct amdgpu_device *)handle;
>
>       tmp = RREG32_SOC15(GC, 0, regCP_INT_CNTL); @@ -4474,6
> +4506,13 @@ static int gfx_v11_0_soft_reset(void *handle)
>               }
>       }
>
> +     /* Try to acquire the gfx mutex before access to CP_VMID_RESET */
> +     r = gfx_v11_0_request_gfx_index_mutex(adev, 1);
> +     if (r) {
> +             DRM_ERROR("Failed to acquire the gfx mutex during soft
> reset\n");
> +             return r;
> +     }
> +
>       WREG32_SOC15(GC, 0, regCP_VMID_RESET, 0xfffffffe);
>
>       // Read CP_VMID_RESET register three times.
> @@ -4482,6 +4521,13 @@ static int gfx_v11_0_soft_reset(void *handle)
>       RREG32_SOC15(GC, 0, regCP_VMID_RESET);
>       RREG32_SOC15(GC, 0, regCP_VMID_RESET);
>
> +     /* release the gfx mutex */
> +     r = gfx_v11_0_request_gfx_index_mutex(adev, 0);
> +     if (r) {
> +             DRM_ERROR("Failed to release the gfx mutex during soft
> reset\n");
> +             return r;
> +     }
> +
>       for (i = 0; i < adev->usec_timeout; i++) {
>               if (!RREG32_SOC15(GC, 0, regCP_HQD_ACTIVE) &&
>                   !RREG32_SOC15(GC, 0, regCP_GFX_HQD_ACTIVE))

Re: Patch "drm/amdgpu/gfx11: need acquire mutex before access CP_VMID_RESET v2" has been added to the 6.6-stable tree

[Sasha Levin]

On Wed, Aug 21, 2024 at 03:56:53PM +0000, Deucher, Alexander wrote:
>[Public]
>
>> -----Original Message-----
>> From: Sasha Levin <sashal@kernel.org>
>> Sent: Wednesday, August 21, 2024 9:33 AM
>> To: stable-commits@vger.kernel.org; Xiao, Jack <Jack.Xiao@amd.com>
>> Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Koenig, Christian
>> <Christian.Koenig@amd.com>; Pan, Xinhui <Xinhui.Pan@amd.com>; David
>> Airlie <airlied@gmail.com>; Daniel Vetter <daniel@ffwll.ch>
>> Subject: Patch "drm/amdgpu/gfx11: need acquire mutex before access
>> CP_VMID_RESET v2" has been added to the 6.6-stable tree
>>
>> This is a note to let you know that I've just added the patch titled
>>
>>     drm/amdgpu/gfx11: need acquire mutex before access CP_VMID_RESET v2
>>
>> to the 6.6-stable tree which can be found at:
>>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-
>> queue.git;a=summary
>>
>> The filename of the patch is:
>>      drm-amdgpu-gfx11-need-acquire-mutex-before-access-cp.patch
>> and it can be found in the queue-6.6 subdirectory.
>>
>> If you, or anyone else, feels it should not be added to the stable tree, please let
>> <stable@vger.kernel.org> know about it.
>>
>
>This patch is not stable material.  Please drop for stable.

Will do, thanks!

-- 
Thanks,
Sasha