doc: update documentation index (#603)

Lots of APIs are missing from the documentation, this PR fixes the
index.

docs/api/python/activation.rst

@@ -0,0 +1,18 @@
+.. _apiactivation:
+
+flashinfer.activation
+=====================
+
+.. currentmodule:: flashinfer.activation
+
+This module provides a set of activation operations for up/gate layers in transformer MLPs.
+
+Up/Gate output activation
+-------------------------
+
+.. autosummary::
+    :toctree: ../../generated
+
+    silu_and_mul
+    gelu_tanh_and_mul
+    gelu_and_mul

docs/api/python/norm.rst

@@ -11,3 +11,6 @@ Kernels for normalization layers.
     :toctree: _generate
 
     rmsnorm
+    fused_add_rmsnorm
+    gemma_rmsnorm
+    gemma_fused_add_rmsnorm

docs/api/python/page.rst

@@ -14,3 +14,4 @@ Append new K/V tensors to Paged KV-Cache
   :toctree: ../../generated
 
   append_paged_kv_cache
+  get_batch_indices_positions

docs/api/python/rope.rst

@@ -14,3 +14,9 @@ Kernels for applying rotary embeddings.
     apply_llama31_rope_inplace
     apply_rope
     apply_llama31_rope
+    apply_rope_pos_ids
+    apply_rope_pos_ids_inplace
+    apply_llama31_rope_pos_ids
+    apply_llama31_rope_pos_ids_inplace
+    apply_rope_with_cos_sin_cache
+    apply_rope_with_cos_sin_cache_inplace

docs/index.rst

@@ -36,4 +36,5 @@ FlashInfer is a library for Large Language Models that provides high-performance
    api/python/gemm
    api/python/norm
    api/python/rope
+   api/python/activation
    api/python/quantization

python/flashinfer/activation.py

@@ -111,6 +111,8 @@ def _check_shape(input: torch.Tensor, output: torch.Tensor) -> None:
 def silu_and_mul(input: torch.Tensor, out: torch.Tensor = None) -> torch.Tensor:
     r"""Fused SiLU and Mul operation.
 
+    ``silu(input[..., :hidden_size]) * input[..., hidden_size:]``
+
     Parameters
     ----------
     input: torch.Tensor
@@ -141,6 +143,8 @@ def silu_and_mul(input: torch.Tensor, out: torch.Tensor = None) -> torch.Tensor:
 def gelu_tanh_and_mul(input: torch.Tensor, out: torch.Tensor = None) -> torch.Tensor:
     r"""Fused GeLU Tanh and Mul operation.
 
+    ``gelu(tanh(input[..., :hidden_size])) * input[..., hidden_size:]``
+
     Parameters
     ----------
     input: torch.Tensor
@@ -171,6 +175,8 @@ def gelu_tanh_and_mul(input: torch.Tensor, out: torch.Tensor = None) -> torch.Te
 def gelu_and_mul(input: torch.Tensor, out: torch.Tensor = None) -> torch.Tensor:
     r"""Fused GeLU and Mul operation.
 
+    ``gelu(input[..., :hidden_size]) * input[..., hidden_size:]``
+
     Parameters
     ----------
     input: torch.Tensor

python/flashinfer/norm.py

@@ -50,6 +50,8 @@ def rmsnorm(
 ) -> torch.Tensor:
     r"""Root mean square normalization.
 
+    ``out[i] = (input[i] / RMS(input)) * weight[i]``
+
     Parameters
     ----------
     input: torch.Tensor
@@ -92,6 +94,12 @@ def fused_add_rmsnorm(
 ) -> None:
     r"""Fused add root mean square normalization.
 
+    Step 1:
+    ``residual[i] += input[i]``
+
+    Step 2:
+    ``input[i] = (residual[i] / RMS(residual)) * weight[i]``
+
     Parameters
     ----------
     input: torch.Tensor
@@ -119,7 +127,9 @@ def gemma_rmsnorm(
     eps: float = 1e-6,
     out: Optional[torch.Tensor] = None,
 ) -> torch.Tensor:
-    r"""Gemma Root mean square normalization.
+    r"""Gemma-style root mean square normalization.
+
+    ``out[i] = (input[i] / RMS(input)) * (weight[i] + 1)``
 
     Parameters
     ----------
@@ -163,7 +173,13 @@ def _gemma_rmsnorm_fake(
 def gemma_fused_add_rmsnorm(
     input: torch.Tensor, residual: torch.Tensor, weight: torch.Tensor, eps: float = 1e-6
 ) -> None:
-    r"""Gemma Fused add root mean square normalization.
+    r"""Gemma-style fused add root mean square normalization.
+
+    Step 1:
+    ``residual[i] += input[i]``
+
+    Step 2:
+    ``input[i] = (residual[i] / RMS(residual)) * (weight + 1)``
 
     Parameters
     ----------

python/flashinfer/page.py

@@ -151,11 +151,15 @@ def get_batch_indices_positions(
     >>> positions  # the rightmost column index of each row
     tensor([4, 3, 4, 2, 3, 4, 1, 2, 3, 4], device='cuda:0', dtype=torch.int32)
 
-    Notes
-    -----
+    Note
+    ----
     This function is similar to `CSR2COO <https://docs.nvidia.com/cuda/cusparse/#csr2coo>`_
     conversion in cuSPARSE library, with the difference that we are converting from a ragged
     tensor (which don't require a column indices array) to a COO format.
+
+    See Also
+    --------
+    append_paged_kv_cache
     """
     batch_size = append_indptr.size(0) - 1
     batch_indices = torch.empty((nnz,), device=append_indptr.device, dtype=torch.int32)
@@ -305,6 +309,10 @@ def append_paged_kv_cache(
     The function assumes that the space for appended k/v have already been allocated,
     which means :attr:`kv_indices`, :attr:`kv_indptr`, :attr:`kv_last_page_len` has
     incorporated appended k/v.
+
+    See Also
+    --------
+    get_batch_indices_positions
     """
     _check_kv_layout(kv_layout)
     _append_paged_kv_cache_kernel(