drm/amdgpu:remove old sdma reset callback mechanism

This patch removes the deprecated SDMA reset callback mechanism, which was previously used to register pre-reset and post-reset callbacks for SDMA engine resets.
 The callback mechanism has been replaced with a more direct and efficient approach using `stop_queue` and `start_queue` functions in the ring's function table.

The SDMA reset callback mechanism allowed KFD and AMDGPU to register pre-reset and post-reset functions for handling SDMA engine resets.
However, this approach added unnecessary complexity and was no longer needed after the introduction of the `stop_queue` and `start_queue` functions in the ring's function table.

1. **Remove Callback Mechanism**:
   - Removed the `amdgpu_sdma_register_on_reset_callbacks` function and its associated data structures (`sdma_on_reset_funcs`).
   - Removed the callback registration logic from the SDMA v4.4.2 initialization code.

2. **Clean Up Related Code**:
   - Removed the `sdma_v4_4_2_set_engine_reset_funcs` function, which was used to register the callbacks.
   - Removed the `sdma_v4_4_2_engine_reset_funcs` structure, which contained the pre-reset and post-reset callback functions.

Signed-off-by: Jesse Zhang <jesse.zhang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 0 insertions, 25 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
index f456a5a12bb7..6716ac281c49 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
@@ -531,31 +531,6 @@ bool amdgpu_sdma_is_shared_inv_eng(struct amdgpu_device *adev, struct amdgpu_rin
 		return false;
 }
 
-/**
- * amdgpu_sdma_register_on_reset_callbacks - Register SDMA reset callbacks
- * @adev: Pointer to the AMDGPU device
- * @funcs: Pointer to the callback structure containing pre_reset and post_reset functions
- *
- * This function allows KFD and AMDGPU to register their own callbacks for handling
- * pre-reset and post-reset operations for engine reset. These are needed because engine
- * reset will stop all queues on that engine.
- */
-void amdgpu_sdma_register_on_reset_callbacks(struct amdgpu_device *adev, struct sdma_on_reset_funcs *funcs)
-{
-	if (!funcs)
-		return;
-
-	/* Ensure the reset_callback_list is initialized */
-	if (!adev->sdma.reset_callback_list.next) {
-		INIT_LIST_HEAD(&adev->sdma.reset_callback_list);
-	}
-	/* Initialize the list node in the callback structure */
-	INIT_LIST_HEAD(&funcs->list);
-
-	/* Add the callback structure to the global list */
-	list_add_tail(&funcs->list, &adev->sdma.reset_callback_list);
-}
-
 static int amdgpu_sdma_soft_reset(struct amdgpu_device *adev, u32 instance_id)
 {
 	struct amdgpu_sdma_instance *sdma_instance = &adev->sdma.instance[instance_id];