[PATCH 7/7] drm/amd/amdgpu: Remove deprecated SDMA reset callback mechanism

[Jesse.zhang@amd.com]

From: "Jesse.zhang at amd.com" <Jesse.zhang at amd.com>

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 at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c | 24 ------------------------
 drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h |  8 --------
 drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c | 12 ------------
 3 files changed, 44 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
index c01154313a92..e88fa0f84bb8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
@@ -506,30 +506,6 @@ void amdgpu_sdma_sysfs_reset_mask_fini(struct amdgpu_device *adev)
 	}
 }
 
-/**
- * amdgpu_sdma_register_on_reset_callbacks - Register SDMA reset callbacks
- * @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)
 {
 	u32 soft_reset;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
index 965169320065..1b6d304c6074 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
@@ -98,13 +98,6 @@ 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;
@@ -168,7 +161,6 @@ 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, bool suspend_user_queues);
 
 #define amdgpu_emit_copy_buffer(adev, ib, s, d, b, t) (adev)->mman.buffer_funcs->emit_copy_buffer((ib),  (s), (d), (b), (t))
diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c b/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c
index c1f7ccff9c4e..cb3148324e90 100644
--- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c
+++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c
@@ -106,7 +106,6 @@ static void sdma_v4_4_2_set_buffer_funcs(struct amdgpu_device *adev);
 static void sdma_v4_4_2_set_vm_pte_funcs(struct amdgpu_device *adev);
 static void sdma_v4_4_2_set_irq_funcs(struct amdgpu_device *adev);
 static void sdma_v4_4_2_set_ras_funcs(struct amdgpu_device *adev);
-static void sdma_v4_4_2_set_engine_reset_funcs(struct amdgpu_device *adev);
 static void sdma_v4_4_2_update_reset_mask(struct amdgpu_device *adev);
 
 static u32 sdma_v4_4_2_get_reg_offset(struct amdgpu_device *adev,
@@ -1353,7 +1352,6 @@ static int sdma_v4_4_2_early_init(struct amdgpu_ip_block *ip_block)
 	sdma_v4_4_2_set_vm_pte_funcs(adev);
 	sdma_v4_4_2_set_irq_funcs(adev);
 	sdma_v4_4_2_set_ras_funcs(adev);
-	sdma_v4_4_2_set_engine_reset_funcs(adev);
 
 	return 0;
 }
@@ -1728,16 +1726,6 @@ static int sdma_v4_4_2_restore_queue(struct amdgpu_device *adev, uint32_t instan
 	return sdma_v4_4_2_inst_start(adev, inst_mask, true);
 }
 
-static struct sdma_on_reset_funcs sdma_v4_4_2_engine_reset_funcs = {
-	.pre_reset = sdma_v4_4_2_stop_queue,
-	.post_reset = sdma_v4_4_2_restore_queue,
-};
-
-static void sdma_v4_4_2_set_engine_reset_funcs(struct amdgpu_device *adev)
-{
-	amdgpu_sdma_register_on_reset_callbacks(adev, &sdma_v4_4_2_engine_reset_funcs);
-}
-
 static int sdma_v4_4_2_set_trap_irq_state(struct amdgpu_device *adev,
 					struct amdgpu_irq_src *source,
 					unsigned type,
-- 
2.25.1