* RE: Patch "drm/amdgpu/gfx11: need acquire mutex before access CP_VMID_RESET v2" has been added to the 6.6-stable tree
[not found] <20240821133314.1666552-1-sashal@kernel.org>
@ 2024-08-21 15:56 ` Deucher, Alexander
2024-08-23 12:33 ` Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: Deucher, Alexander @ 2024-08-21 15:56 UTC (permalink / raw)
To: stable@vger.kernel.org, stable-commits@vger.kernel.org,
Xiao, Jack
Cc: Koenig, Christian, Pan, Xinhui, David Airlie, Daniel Vetter
[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))
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