[ascend] convert kv cache to nd format in ascend graph mode

lmdeploy/pytorch/backends/dlinfer/ascend/graph_runner.py

@@ -1,15 +1,20 @@
 # Copyright (c) OpenMMLab. All rights reserved.
 import warnings
 from importlib import import_module
+from typing import List
 
 import torch
 import torch.distributed
+import torch_npu
 
 from lmdeploy.pytorch.config import BackendConfig, CacheConfig, ModelConfig
+from lmdeploy.pytorch.model_inputs import StepContext
 from lmdeploy.utils import get_logger
 
 from ...graph_runner import GraphRunner
 
+ACL_FORMAT_ND = 2
+
 logger = get_logger('lmdeploy')
 
 
@@ -110,3 +115,31 @@ def allocate_gpu_cache_mark_static(self):
             return gpu_cache
 
         setattr(cache_engine_class, func_str, allocate_gpu_cache_mark_static)
+
+    def _convert_kv_format(self,
+                           past_key_values: List[List[torch.Tensor]]) -> None:
+        """Convert key/value caches to ACL_FORMAT_ND format if needed."""
+        # Check format of first KV cache
+        if torch_npu.get_npu_format(past_key_values[0][0]) == ACL_FORMAT_ND:
+            return
+
+        # Convert all KV caches to ACL_FORMAT_ND
+        for layer_kv in past_key_values:
+            key_cache, value_cache = layer_kv
+            torch_npu.npu_format_cast(key_cache, ACL_FORMAT_ND)
+            torch_npu.npu_format_cast(value_cache, ACL_FORMAT_ND)
+
+    def prepare_inputs_for_generation(
+        self,
+        past_key_values: List[List[torch.Tensor]],
+        inputs_embeds: torch.Tensor = None,
+        context: StepContext = None,
+    ):
+        """prepare inputs."""
+        if self.enable_graph:
+            self._convert_kv_format(past_key_values)
+        return self.model.prepare_inputs_for_generation(
+            past_key_values=past_key_values,
+            inputs_embeds=inputs_embeds,
+            context=context,
+        )