[PATCH AUTOSEL 6.10 12/34] drm/amdgpu: Add lock around VF RLCG interface

Sasha Levin
2024-07-28T15:43:36Z

From: Victor Skvortsov <victor.skvortsov@amd.com>

[ Upstream commit e864180ee49b4d30e640fd1e1d852b86411420c9 ]

flush_gpu_tlb may be called from another thread while
device_gpu_recover is running.

Both of these threads access registers through the VF
RLCG interface during VF Full Access. Add a lock around this interface
to prevent race conditions between these threads.

Signed-off-by: Victor Skvortsov <victor.skvortsov@amd.com>
Reviewed-by: Zhigang Luo <zhigang.luo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 1 +
drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 6 ++++++
drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h | 2 ++
3 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 33f791d92ddf3..eb4a1f4318333 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4048,6 +4048,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
mutex_init(&adev->grbm_idx_mutex);
mutex_init(&adev->mn_lock);
mutex_init(&adev->virt.vf_errors.lock);
+ mutex_init(&adev->virt.rlcg_reg_lock);
hash_init(adev->mn_hash);
mutex_init(&adev->psp.mutex);
mutex_init(&adev->notifier_lock);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
index 54ab51a4ada77..972a58f0f4924 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
@@ -980,6 +980,9 @@ u32 amdgpu_virt_rlcg_reg_rw(struct amdgpu_device *adev, u32 offset, u32 v, u32 f
scratch_reg1 = (void __iomem *)adev->rmmio + 4 * reg_access_ctrl->scratch_reg1;
scratch_reg2 = (void __iomem *)adev->rmmio + 4 * reg_access_ctrl->scratch_reg2;
scratch_reg3 = (void __iomem *)adev->rmmio + 4 * reg_access_ctrl->scratch_reg3;
+
+ mutex_lock(&adev->virt.rlcg_reg_lock);
+
if (reg_access_ctrl->spare_int)
spare_int = (void __iomem *)adev->rmmio + 4 * reg_access_ctrl->spare_int;

@@ -1036,6 +1039,9 @@ u32 amdgpu_virt_rlcg_reg_rw(struct amdgpu_device *adev, u32 offset, u32 v, u32 f
}

ret = readl(scratch_reg0);
+
+ mutex_unlock(&adev->virt.rlcg_reg_lock);
+
return ret;
}

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h
index 642f1fd287d83..0ec246c74570c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h
@@ -272,6 +272,8 @@ struct amdgpu_virt {

/* the ucode id to signal the autoload */
uint32_t autoload_ucode_id;
+
+ struct mutex rlcg_reg_lock;
};

struct amdgpu_video_codec_info;
--
2.43.0