[feat] Support tp mode for DeepSeek-R1-W4AFP8 (#8118)

Co-authored-by: yuhyao <827623970@qq.com>

python/sglang/srt/models/deepseek_v2.py

@@ -2185,6 +2185,8 @@ class DeepseekV2ForCausalLM(nn.Module):
             disable_reason = "Only Deepseek V3/R1 on NV-platform with capability >= 80 can use shared experts fusion optimization."
         elif get_moe_expert_parallel_world_size() > 1:
             disable_reason = "Deepseek V3/R1 can not use shared experts fusion optimization under expert parallelism."
+        elif self.quant_config.get_name() == "w4afp8":
+            disable_reason = "Deepseek V3/R1 W4AFP8 model uses different quant method for routed experts and shared experts."
 
         if disable_reason is not None:
             global_server_args_dict["disable_shared_experts_fusion"] = True
@@ -2496,6 +2498,9 @@ class DeepseekV2ForCausalLM(nn.Module):
             ckpt_up_proj_name="up_proj",
             num_experts=self.config.n_routed_experts + self.num_fused_shared_experts,
         )
+        # Params for special naming rules in mixed-precision models, for example:
+        # model.layers.xx.mlp.experts.xx.w1.input_scale. For details,
+        # see https://huggingface.co/Barrrrry/DeepSeek-R1-W4AFP8/blob/main.
         if self.quant_config and self.quant_config.get_name() == "w4afp8":
             expert_params_mapping += FusedMoE.make_expert_input_scale_params_mapping(
                 num_experts=self.config.n_routed_experts