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, 8 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
index 59778b978eb5..5605921212f0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
@@ -109,13 +109,6 @@ struct amdgpu_sdma_ras {
 	struct amdgpu_ras_block_object ras_block;
 };
 
-struct sdma_on_reset_funcs {
-	int (*pre_reset)(struct amdgpu_device *adev, uint32_t instance_id);
-	int (*post_reset)(struct amdgpu_device *adev, uint32_t instance_id);
-	/* Linked list node to store this structure in a list; */
-	struct list_head list;
-};
-
 struct amdgpu_sdma {
 	struct amdgpu_sdma_instance instance[AMDGPU_MAX_SDMA_INSTANCES];
 	struct amdgpu_irq_src	trap_irq;
@@ -178,7 +171,6 @@ struct amdgpu_buffer_funcs {
 				 uint32_t byte_count);
 };
 
-void amdgpu_sdma_register_on_reset_callbacks(struct amdgpu_device *adev, struct sdma_on_reset_funcs *funcs);
 int amdgpu_sdma_reset_engine(struct amdgpu_device *adev, uint32_t instance_id);
 
 #define amdgpu_emit_copy_buffer(adev, ib, s, d, b, t) (adev)->mman.buffer_funcs->emit_copy_buffer((ib),  (s), (d), (b), (t))