[Feat] Unquantized Linear to nz and control all nz-cast (#3356)

### What this PR does / why we need it?
Currently, when executing to the Linear layer of models in vLLM-Ascend,
the weights format is ND in unquantized case and skipped ascend case.
This PR supplements the execution logic for Linear layer. We use a new
global variable: VLLM_ASCEND_ENABLE_NZ. When VLLM_ASCEND_ENABLE_NZ=1 and
CANN version is 8.3, the weights of the Linear layer will be converted
to FRACTAL_NZ, in both unquantized case and skipped ascend case. We also
use VLLM_ASCEND_ENABLE_NZ to control the existing NZ conversion, such as
w8a8-quantized case.

### Does this PR introduce _any_ user-facing change?
Add a new global variable VLLM_ASCEND_ENABLE_NZ. If you want to use NZ
format, you should set VLLM_ASCEND_ENABLE_NZ=1.

### How was this patch tested?

- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0

Signed-off-by: anon189Ty <Stari_Falcon@outlook.com>

vllm_ascend/ops/linear.py

@@ -24,17 +24,29 @@ from typing import Optional, Union
 
 import torch
 import torch.nn as nn
+import torch_npu
 from torch.nn.parameter import Parameter
 from vllm.distributed import divide
 from vllm.model_executor.layers.linear import (  # noqa
     WEIGHT_LOADER_V2_SUPPORTED, ColumnParallelLinear, LinearBase,
     MergedColumnParallelLinear, QKVParallelLinear, QuantizeMethodBase,
-    RowParallelLinear, UnquantizedLinearMethod)
+    ReplicatedLinear, RowParallelLinear, UnquantizedLinearMethod)
 from vllm.model_executor.layers.quantization.base_config import \
     QuantizationConfig
 from vllm.model_executor.utils import set_weight_attrs
 
-from vllm_ascend.ops.linear_op import get_parallel_op
+from vllm_ascend.ops.linear_op import get_parallel_op, get_replicated_op
+from vllm_ascend.utils import ACL_FORMAT_FRACTAL_NZ, is_enable_nz
+
+
+class AscendUnquantizedLinearMethod(UnquantizedLinearMethod):
+    """Linear method without quantization"""
+
+    def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
+        super().process_weights_after_loading(layer)
+        if is_enable_nz() and torch.version.cann.startswith("8.3"):
+            layer.weight.data = torch_npu.npu_format_cast(
+                layer.weight.data, ACL_FORMAT_FRACTAL_NZ)
 
 
 # TODO(realliujiaxu): Remove this class after linear of vllm supports custom comm group
@@ -65,7 +77,7 @@ class AscendLinearBase(LinearBase):
         self.prefix = prefix
         if quant_config is None:
             self.quant_method: Optional[
-                QuantizeMethodBase] = UnquantizedLinearMethod()
+                QuantizeMethodBase] = AscendUnquantizedLinearMethod()
         else:
             self.quant_method = quant_config.get_quant_method(self,
                                                               prefix=prefix)
@@ -364,3 +376,81 @@ class AscendColumnParallelLinear(ColumnParallelLinear):
             return self.custom_op.apply(input_)
 
         return super().forward(input_)
+
+
+class AscendReplicatedLinear(ReplicatedLinear):
+    """Ascend Replicated linear layer.
+
+    Args:
+        input_size: input dimension of the linear layer.
+        output_size: output dimension of the linear layer.
+        bias: If true, add bias.
+        skip_bias_add: If true, skip adding bias but instead return it.
+        params_dtype: Data type for the parameters.
+        quant_config: Quantization configure.
+        prefix: The name of the layer in the state dict, including all parents
+                        (e.g. model.layers.0.qkv_proj)
+        return_bias: If true, return bias together with outputs in forward pass.
+        disable_tp: Take no effect for replicated linear layers.
+    """
+
+    def __init__(
+        self,
+        input_size: int,
+        output_size: int,
+        bias: bool = True,
+        skip_bias_add: bool = False,
+        params_dtype: Optional[torch.dtype] = None,
+        quant_config: Optional[QuantizationConfig] = None,
+        prefix: str = "",
+        *,
+        return_bias: bool = True,
+        disable_tp: bool = False,
+    ):
+        self.custom_op = get_replicated_op(disable_tp, prefix, self)
+        # If MergedReplicatedLinear, use output size of each partition.
+        if hasattr(self, "output_sizes"):
+            self.output_partition_sizes = self.output_sizes
+        else:
+            self.output_partition_sizes = [output_size]
+
+        AscendLinearBase.__init__(self,
+                                  input_size,
+                                  output_size,
+                                  skip_bias_add,
+                                  params_dtype,
+                                  quant_config,
+                                  prefix=prefix,
+                                  return_bias=return_bias,
+                                  disable_tp=disable_tp)
+
+        # All the linear layer supports quant method.
+        assert self.quant_method is not None
+        self.quant_method.create_weights(self,
+                                         self.input_size, [self.output_size],
+                                         self.input_size,
+                                         self.output_size,
+                                         self.params_dtype,
+                                         weight_loader=self.weight_loader)
+
+        if bias:
+            self.bias = Parameter(
+                torch.empty(self.output_size, dtype=self.params_dtype))
+            set_weight_attrs(self.bias, {
+                "output_dim": 0,
+                "weight_loader": self.weight_loader,
+            })
+        else:
+            self.register_parameter("bias", None)
+
+        if self.custom_op is not None:
+            self.custom_op.update_attrs()
+
+    def forward(
+        self,
+        input_,
+    ) -> Union[torch.Tensor, tuple[torch.Tensor, Optional[Parameter]]]:
+        if self.custom_op is not None:
+            return self.custom_op.apply(input_)
+
+        return super().forward(input_)