[2/n]decouple quantization implementation from vLLM dependency (#8112)

Co-authored-by: walker-ai <yiyun.wyt@antgroup.com>
Co-authored-by: leoneo <1320612015@qq.com>

sgl-kernel/python/sgl_kernel/gemm.py

@@ -1,6 +1,7 @@
-from typing import List, Optional, Tuple
+from typing import Optional, Tuple
 
 import torch
+from sgl_kernel.scalar_type import ScalarType
 from sgl_kernel.utils import _get_cache_buf, get_cuda_stream
 
 
@@ -353,3 +354,62 @@ def scaled_fp4_experts_quant(
     )
     output_scales = output_scales.view(torch.float8_e4m3fn)
     return output, output_scales
+
+
+# GPTQ kernels
+def gptq_marlin_gemm(
+    a: torch.Tensor,
+    c: Optional[torch.Tensor],
+    b_q_weight: torch.Tensor,
+    b_scales: torch.Tensor,
+    global_scale: Optional[torch.Tensor],
+    b_zeros: Optional[torch.Tensor],
+    g_idx: Optional[torch.Tensor],
+    perm: Optional[torch.Tensor],
+    workspace: torch.Tensor,
+    b_q_type: ScalarType,
+    size_m: int,
+    size_n: int,
+    size_k: int,
+    is_k_full: bool = True,
+    use_atomic_add: bool = False,
+    use_fp32_reduce: bool = False,
+    is_zp_float: bool = False,
+) -> torch.Tensor:
+    return torch.ops.sgl_kernel.gptq_marlin_gemm(
+        a,
+        c,
+        b_q_weight,
+        b_scales,
+        global_scale,
+        b_zeros,
+        g_idx,
+        perm,
+        workspace,
+        b_q_type.id,
+        size_m,
+        size_n,
+        size_k,
+        is_k_full,
+        use_atomic_add,
+        use_fp32_reduce,
+        is_zp_float,
+    )
+
+
+def gptq_gemm(
+    a: torch.Tensor,
+    b_q_weight: torch.Tensor,
+    b_gptq_qzeros: torch.Tensor,
+    b_gptq_scales: torch.Tensor,
+    b_g_idx: torch.Tensor,
+    use_shuffle: bool,
+    bit: int,
+) -> torch.Tensor:
+    return torch.ops.sgl_kernel.gptq_gemm(
+        a, b_q_weight, b_gptq_qzeros, b_gptq_scales, b_g_idx, use_shuffle, bit
+    )
+
+
+def gptq_shuffle(q_weight: torch.Tensor, q_perm: torch.Tensor, bit: int) -> None:
+    torch.torch.ops.sgl_kernel.gptq_shuffle(q_weight, q_perm, bit)