[MUSA][4/N] Add common device utilities, distributed backend, and custom op wiring (#17246)

Signed-off-by: Xiaodong Ye <xiaodong.ye@mthreads.com>

python/sglang/srt/layers/rotary_embedding.py

@@ -20,6 +20,7 @@ from sglang.srt.utils import (
     is_cpu,
     is_cuda,
     is_hip,
+    is_musa,
     is_npu,
     is_xpu,
 )
@@ -31,6 +32,7 @@ _is_npu = is_npu()
 _is_cpu_amx_available = cpu_has_amx_support()
 _is_cpu = is_cpu()
 _is_xpu = is_xpu()
+_is_musa = is_musa()
 
 if _is_cuda:
     from sgl_kernel import FusedSetKVBufferArg, apply_rope_with_cos_sin_cache_inplace
@@ -119,6 +121,7 @@ class RotaryEmbedding(MultiPlatformOp):
             and not (_is_cpu)
             and not (_is_xpu)
             and not (_is_npu)
+            and not (_is_musa)
         ):
             if _is_cuda or _is_hip:
                 from sgl_kernel import rotary_embedding