[NVIDIA] Support Cutlass MLA for Blackwell GPUs (#16032)

Signed-off-by: kaixih <kaixih@nvidia.com>

csrc/torch_bindings.cpp

@@ -130,6 +130,13 @@ TORCH_LIBRARY_EXPAND(TORCH_EXTENSION_NAME, ops) {
       ") -> ()");
   ops.impl("advance_step_flashinfer", torch::kCUDA, &advance_step_flashinfer);
 
+  // Compute MLA decode using cutlass.
+  ops.def(
+      "cutlass_mla_decode(Tensor! out, Tensor q_nope, Tensor q_pe,"
+      "                   Tensor kv_c_and_k_pe_cache, Tensor seq_lens,"
+      "                   Tensor page_table, float scale) -> ()");
+  ops.impl("cutlass_mla_decode", torch::kCUDA, &cutlass_mla_decode);
+
   // Layernorm
   // Apply Root Mean Square (RMS) Normalization to the input tensor.
   ops.def(