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ACE-Step/models/customer_attention_processor.py
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2025-04-03 12:25:30 +08:00

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# Copyright 2024 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import inspect
from importlib import import_module
from typing import Callable, Optional, Union, Tuple
import torch
import torch.nn.functional as F
from torch import nn
from diffusers.utils import logging
from diffusers.utils.import_utils import is_xformers_available
from diffusers.utils.torch_utils import maybe_allow_in_graph
import numbers
from diffusers.models.attention_processor import (
AttentionProcessor,
AttnProcessor,
AttnProcessor2_0,
AttnProcessorNPU,
AttnAddedKVProcessor,
AttnAddedKVProcessor2_0,
SlicedAttnProcessor,
SlicedAttnAddedKVProcessor,
XFormersAttnProcessor,
LoRAAttnProcessor,
LoRAAttnProcessor2_0,
LoRAXFormersAttnProcessor,
CustomDiffusionAttnProcessor,
CustomDiffusionAttnProcessor2_0,
CustomDiffusionXFormersAttnProcessor,
XFormersAttnAddedKVProcessor,
LoRAAttnAddedKVProcessor,
SpatialNorm,
xformers
)
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
class RMSNorm(nn.Module):
def __init__(self, dim, eps: float, elementwise_affine: bool = True):
super().__init__()
self.eps = eps
if isinstance(dim, numbers.Integral):
dim = (dim,)
self.dim = torch.Size(dim)
if elementwise_affine:
self.weight = nn.Parameter(torch.ones(dim))
else:
self.weight = None
def forward(self, hidden_states):
input_dtype = hidden_states.dtype
variance = hidden_states.to(torch.float32).pow(2).mean(-1, keepdim=True)
hidden_states = hidden_states * torch.rsqrt(variance + self.eps)
if self.weight is not None:
# convert into half-precision if necessary
if self.weight.dtype in [torch.float16, torch.bfloat16]:
hidden_states = hidden_states.to(self.weight.dtype)
hidden_states = hidden_states * self.weight
else:
hidden_states = hidden_states.to(input_dtype)
return hidden_states
@maybe_allow_in_graph
class Attention(nn.Module):
r"""
A cross attention layer.
Parameters:
query_dim (`int`):
The number of channels in the query.
cross_attention_dim (`int`, *optional*):
The number of channels in the encoder_hidden_states. If not given, defaults to `query_dim`.
heads (`int`, *optional*, defaults to 8):
The number of heads to use for multi-head attention.
dim_head (`int`, *optional*, defaults to 64):
The number of channels in each head.
dropout (`float`, *optional*, defaults to 0.0):
The dropout probability to use.
bias (`bool`, *optional*, defaults to False):
Set to `True` for the query, key, and value linear layers to contain a bias parameter.
upcast_attention (`bool`, *optional*, defaults to False):
Set to `True` to upcast the attention computation to `float32`.
upcast_softmax (`bool`, *optional*, defaults to False):
Set to `True` to upcast the softmax computation to `float32`.
cross_attention_norm (`str`, *optional*, defaults to `None`):
The type of normalization to use for the cross attention. Can be `None`, `layer_norm`, or `group_norm`.
cross_attention_norm_num_groups (`int`, *optional*, defaults to 32):
The number of groups to use for the group norm in the cross attention.
added_kv_proj_dim (`int`, *optional*, defaults to `None`):
The number of channels to use for the added key and value projections. If `None`, no projection is used.
norm_num_groups (`int`, *optional*, defaults to `None`):
The number of groups to use for the group norm in the attention.
spatial_norm_dim (`int`, *optional*, defaults to `None`):
The number of channels to use for the spatial normalization.
out_bias (`bool`, *optional*, defaults to `True`):
Set to `True` to use a bias in the output linear layer.
scale_qk (`bool`, *optional*, defaults to `True`):
Set to `True` to scale the query and key by `1 / sqrt(dim_head)`.
only_cross_attention (`bool`, *optional*, defaults to `False`):
Set to `True` to only use cross attention and not added_kv_proj_dim. Can only be set to `True` if
`added_kv_proj_dim` is not `None`.
eps (`float`, *optional*, defaults to 1e-5):
An additional value added to the denominator in group normalization that is used for numerical stability.
rescale_output_factor (`float`, *optional*, defaults to 1.0):
A factor to rescale the output by dividing it with this value.
residual_connection (`bool`, *optional*, defaults to `False`):
Set to `True` to add the residual connection to the output.
_from_deprecated_attn_block (`bool`, *optional*, defaults to `False`):
Set to `True` if the attention block is loaded from a deprecated state dict.
processor (`AttnProcessor`, *optional*, defaults to `None`):
The attention processor to use. If `None`, defaults to `AttnProcessor2_0` if `torch 2.x` is used and
`AttnProcessor` otherwise.
"""
def __init__(
self,
query_dim: int,
cross_attention_dim: Optional[int] = None,
heads: int = 8,
dim_head: int = 64,
dropout: float = 0.0,
bias: bool = False,
upcast_attention: bool = False,
upcast_softmax: bool = False,
cross_attention_norm: Optional[str] = None,
cross_attention_norm_num_groups: int = 32,
qk_norm: Optional[str] = None, # [layer_norm, group_norm, rms_norm]
added_kv_proj_dim: Optional[int] = None,
norm_num_groups: Optional[int] = None,
spatial_norm_dim: Optional[int] = None,
out_bias: bool = True,
scale_qk: bool = True,
only_cross_attention: bool = False,
eps: float = 1e-5,
rescale_output_factor: float = 1.0,
residual_connection: bool = False,
_from_deprecated_attn_block: bool = False,
processor: Optional["AttnProcessor"] = None,
out_dim: int = None,
context_pre_only=None,
):
super().__init__()
self.inner_dim = out_dim if out_dim is not None else dim_head * heads
self.query_dim = query_dim
self.use_bias = bias
self.is_cross_attention = cross_attention_dim is not None
self.cross_attention_dim = cross_attention_dim if cross_attention_dim is not None else query_dim
self.upcast_attention = upcast_attention
self.upcast_softmax = upcast_softmax
self.rescale_output_factor = rescale_output_factor
self.residual_connection = residual_connection
self.dropout = dropout
self.fused_projections = False
self.out_dim = out_dim if out_dim is not None else query_dim
self.context_pre_only = context_pre_only
# we make use of this private variable to know whether this class is loaded
# with an deprecated state dict so that we can convert it on the fly
self._from_deprecated_attn_block = _from_deprecated_attn_block
self.scale_qk = scale_qk
self.scale = dim_head**-0.5 if self.scale_qk else 1.0
self.heads = out_dim // dim_head if out_dim is not None else heads
# for slice_size > 0 the attention score computation
# is split across the batch axis to save memory
# You can set slice_size with `set_attention_slice`
self.sliceable_head_dim = heads
self.added_kv_proj_dim = added_kv_proj_dim
self.only_cross_attention = only_cross_attention
if self.added_kv_proj_dim is None and self.only_cross_attention:
raise ValueError(
"`only_cross_attention` can only be set to True if `added_kv_proj_dim` is not None. Make sure to set either `only_cross_attention=False` or define `added_kv_proj_dim`."
)
if norm_num_groups is not None:
self.group_norm = nn.GroupNorm(num_channels=query_dim, num_groups=norm_num_groups, eps=eps, affine=True)
else:
self.group_norm = None
if spatial_norm_dim is not None:
self.spatial_norm = SpatialNorm(f_channels=query_dim, zq_channels=spatial_norm_dim)
else:
self.spatial_norm = None
if qk_norm is None:
self.norm_q = None
self.norm_k = None
elif qk_norm == "layer_norm":
self.norm_q = nn.LayerNorm(dim_head, eps=eps)
self.norm_k = nn.LayerNorm(dim_head, eps=eps)
elif qk_norm == "rms_norm":
self.norm_q = RMSNorm(dim_head, eps=eps)
self.norm_k = RMSNorm(dim_head, eps=eps)
else:
raise ValueError(f"unknown qk_norm: {qk_norm}. Should be None or 'layer_norm' or 'rsm_norm'")
if cross_attention_norm is None:
self.norm_cross = None
elif cross_attention_norm == "layer_norm":
self.norm_cross = nn.LayerNorm(self.cross_attention_dim)
elif cross_attention_norm == "group_norm":
if self.added_kv_proj_dim is not None:
# The given `encoder_hidden_states` are initially of shape
# (batch_size, seq_len, added_kv_proj_dim) before being projected
# to (batch_size, seq_len, cross_attention_dim). The norm is applied
# before the projection, so we need to use `added_kv_proj_dim` as
# the number of channels for the group norm.
norm_cross_num_channels = added_kv_proj_dim
else:
norm_cross_num_channels = self.cross_attention_dim
self.norm_cross = nn.GroupNorm(
num_channels=norm_cross_num_channels, num_groups=cross_attention_norm_num_groups, eps=1e-5, affine=True
)
else:
raise ValueError(
f"unknown cross_attention_norm: {cross_attention_norm}. Should be None, 'layer_norm' or 'group_norm'"
)
self.to_q = nn.Linear(query_dim, self.inner_dim, bias=bias)
if not self.only_cross_attention:
# only relevant for the `AddedKVProcessor` classes
self.to_k = nn.Linear(self.cross_attention_dim, self.inner_dim, bias=bias)
self.to_v = nn.Linear(self.cross_attention_dim, self.inner_dim, bias=bias)
else:
self.to_k = None
self.to_v = None
if self.added_kv_proj_dim is not None:
self.add_k_proj = nn.Linear(added_kv_proj_dim, self.inner_dim)
self.add_v_proj = nn.Linear(added_kv_proj_dim, self.inner_dim)
if self.context_pre_only is not None:
self.add_q_proj = nn.Linear(added_kv_proj_dim, self.inner_dim)
self.to_out = nn.ModuleList([])
self.to_out.append(nn.Linear(self.inner_dim, self.out_dim, bias=out_bias))
self.to_out.append(nn.Dropout(dropout))
if self.context_pre_only is not None and not self.context_pre_only and self.added_kv_proj_dim is not None:
self.to_add_out = nn.Linear(self.inner_dim, self.out_dim, bias=out_bias)
if qk_norm is not None and added_kv_proj_dim is not None:
if qk_norm == "fp32_layer_norm":
self.norm_added_q = FP32LayerNorm(dim_head, elementwise_affine=False, bias=False, eps=eps)
self.norm_added_k = FP32LayerNorm(dim_head, elementwise_affine=False, bias=False, eps=eps)
elif qk_norm == "rms_norm":
self.norm_added_q = RMSNorm(dim_head, eps=eps)
self.norm_added_k = RMSNorm(dim_head, eps=eps)
else:
raise ValueError(
f"unknown qk_norm: {qk_norm}. Should be one of `None,'layer_norm','fp32_layer_norm','rms_norm'`"
)
else:
self.norm_added_q = None
self.norm_added_k = None
# set attention processor
# We use the AttnProcessor2_0 by default when torch 2.x is used which uses
# torch.nn.functional.scaled_dot_product_attention for native Flash/memory_efficient_attention
# but only if it has the default `scale` argument. TODO remove scale_qk check when we move to torch 2.1
if processor is None:
processor = (
AttnProcessor2_0() if hasattr(F, "scaled_dot_product_attention") and self.scale_qk else AttnProcessor()
)
self.set_processor(processor)
def set_use_npu_flash_attention(self, use_npu_flash_attention: bool) -> None:
r"""
Set whether to use npu flash attention from `torch_npu` or not.
"""
if use_npu_flash_attention:
processor = AttnProcessorNPU()
else:
# set attention processor
# We use the AttnProcessor2_0 by default when torch 2.x is used which uses
# torch.nn.functional.scaled_dot_product_attention for native Flash/memory_efficient_attention
# but only if it has the default `scale` argument. TODO remove scale_qk check when we move to torch 2.1
processor = (
AttnProcessor2_0() if hasattr(F, "scaled_dot_product_attention") and self.scale_qk else AttnProcessor()
)
self.set_processor(processor)
def set_use_memory_efficient_attention_xformers(
self, use_memory_efficient_attention_xformers: bool, attention_op: Optional[Callable] = None
) -> None:
r"""
Set whether to use memory efficient attention from `xformers` or not.
Args:
use_memory_efficient_attention_xformers (`bool`):
Whether to use memory efficient attention from `xformers` or not.
attention_op (`Callable`, *optional*):
The attention operation to use. Defaults to `None` which uses the default attention operation from
`xformers`.
"""
# is_lora = hasattr(self, "processor") and isinstance(
# self.processor,
# LORA_ATTENTION_PROCESSORS,
# )
is_custom_diffusion = hasattr(self, "processor") and isinstance(
self.processor,
(CustomDiffusionAttnProcessor, CustomDiffusionXFormersAttnProcessor, CustomDiffusionAttnProcessor2_0),
)
is_added_kv_processor = hasattr(self, "processor") and isinstance(
self.processor,
(
AttnAddedKVProcessor,
AttnAddedKVProcessor2_0,
SlicedAttnAddedKVProcessor,
XFormersAttnAddedKVProcessor,
LoRAAttnAddedKVProcessor,
),
)
if use_memory_efficient_attention_xformers:
if is_added_kv_processor and (is_lora or is_custom_diffusion):
raise NotImplementedError(
f"Memory efficient attention is currently not supported for LoRA or custom diffusion for attention processor type {self.processor}"
)
if not is_xformers_available():
raise ModuleNotFoundError(
(
"Refer to https://github.com/facebookresearch/xformers for more information on how to install"
" xformers"
),
name="xformers",
)
elif not torch.cuda.is_available():
raise ValueError(
"torch.cuda.is_available() should be True but is False. xformers' memory efficient attention is"
" only available for GPU "
)
else:
try:
# Make sure we can run the memory efficient attention
_ = xformers.ops.memory_efficient_attention(
torch.randn((1, 2, 40), device="cuda"),
torch.randn((1, 2, 40), device="cuda"),
torch.randn((1, 2, 40), device="cuda"),
)
except Exception as e:
raise e
if is_lora:
# TODO (sayakpaul): should we throw a warning if someone wants to use the xformers
# variant when using PT 2.0 now that we have LoRAAttnProcessor2_0?
processor = LoRAXFormersAttnProcessor(
hidden_size=self.processor.hidden_size,
cross_attention_dim=self.processor.cross_attention_dim,
rank=self.processor.rank,
attention_op=attention_op,
)
processor.load_state_dict(self.processor.state_dict())
processor.to(self.processor.to_q_lora.up.weight.device)
elif is_custom_diffusion:
processor = CustomDiffusionXFormersAttnProcessor(
train_kv=self.processor.train_kv,
train_q_out=self.processor.train_q_out,
hidden_size=self.processor.hidden_size,
cross_attention_dim=self.processor.cross_attention_dim,
attention_op=attention_op,
)
processor.load_state_dict(self.processor.state_dict())
if hasattr(self.processor, "to_k_custom_diffusion"):
processor.to(self.processor.to_k_custom_diffusion.weight.device)
elif is_added_kv_processor:
# TODO(Patrick, Suraj, William) - currently xformers doesn't work for UnCLIP
# which uses this type of cross attention ONLY because the attention mask of format
# [0, ..., -10.000, ..., 0, ...,] is not supported
# throw warning
logger.info(
"Memory efficient attention with `xformers` might currently not work correctly if an attention mask is required for the attention operation."
)
processor = XFormersAttnAddedKVProcessor(attention_op=attention_op)
else:
processor = XFormersAttnProcessor(attention_op=attention_op)
else:
if is_lora:
attn_processor_class = (
LoRAAttnProcessor2_0 if hasattr(F, "scaled_dot_product_attention") else LoRAAttnProcessor
)
processor = attn_processor_class(
hidden_size=self.processor.hidden_size,
cross_attention_dim=self.processor.cross_attention_dim,
rank=self.processor.rank,
)
processor.load_state_dict(self.processor.state_dict())
processor.to(self.processor.to_q_lora.up.weight.device)
elif is_custom_diffusion:
attn_processor_class = (
CustomDiffusionAttnProcessor2_0
if hasattr(F, "scaled_dot_product_attention")
else CustomDiffusionAttnProcessor
)
processor = attn_processor_class(
train_kv=self.processor.train_kv,
train_q_out=self.processor.train_q_out,
hidden_size=self.processor.hidden_size,
cross_attention_dim=self.processor.cross_attention_dim,
)
processor.load_state_dict(self.processor.state_dict())
if hasattr(self.processor, "to_k_custom_diffusion"):
processor.to(self.processor.to_k_custom_diffusion.weight.device)
else:
# set attention processor
# We use the AttnProcessor2_0 by default when torch 2.x is used which uses
# torch.nn.functional.scaled_dot_product_attention for native Flash/memory_efficient_attention
# but only if it has the default `scale` argument. TODO remove scale_qk check when we move to torch 2.1
processor = (
AttnProcessor2_0()
if hasattr(F, "scaled_dot_product_attention") and self.scale_qk
else AttnProcessor()
)
self.set_processor(processor)
def set_attention_slice(self, slice_size: int) -> None:
r"""
Set the slice size for attention computation.
Args:
slice_size (`int`):
The slice size for attention computation.
"""
if slice_size is not None and slice_size > self.sliceable_head_dim:
raise ValueError(f"slice_size {slice_size} has to be smaller or equal to {self.sliceable_head_dim}.")
if slice_size is not None and self.added_kv_proj_dim is not None:
processor = SlicedAttnAddedKVProcessor(slice_size)
elif slice_size is not None:
processor = SlicedAttnProcessor(slice_size)
elif self.added_kv_proj_dim is not None:
processor = AttnAddedKVProcessor()
else:
# set attention processor
# We use the AttnProcessor2_0 by default when torch 2.x is used which uses
# torch.nn.functional.scaled_dot_product_attention for native Flash/memory_efficient_attention
# but only if it has the default `scale` argument. TODO remove scale_qk check when we move to torch 2.1
processor = (
AttnProcessor2_0() if hasattr(F, "scaled_dot_product_attention") and self.scale_qk else AttnProcessor()
)
self.set_processor(processor)
def set_processor(self, processor: "AttnProcessor") -> None:
r"""
Set the attention processor to use.
Args:
processor (`AttnProcessor`):
The attention processor to use.
"""
# if current processor is in `self._modules` and if passed `processor` is not, we need to
# pop `processor` from `self._modules`
if (
hasattr(self, "processor")
and isinstance(self.processor, torch.nn.Module)
and not isinstance(processor, torch.nn.Module)
):
logger.info(f"You are removing possibly trained weights of {self.processor} with {processor}")
self._modules.pop("processor")
self.processor = processor
def get_processor(self, return_deprecated_lora: bool = False) -> "AttentionProcessor":
r"""
Get the attention processor in use.
Args:
return_deprecated_lora (`bool`, *optional*, defaults to `False`):
Set to `True` to return the deprecated LoRA attention processor.
Returns:
"AttentionProcessor": The attention processor in use.
"""
if not return_deprecated_lora:
return self.processor
# TODO(Sayak, Patrick). The rest of the function is needed to ensure backwards compatible
# serialization format for LoRA Attention Processors. It should be deleted once the integration
# with PEFT is completed.
is_lora_activated = {
name: module.lora_layer is not None
for name, module in self.named_modules()
if hasattr(module, "lora_layer")
}
# 1. if no layer has a LoRA activated we can return the processor as usual
if not any(is_lora_activated.values()):
return self.processor
# If doesn't apply LoRA do `add_k_proj` or `add_v_proj`
is_lora_activated.pop("add_k_proj", None)
is_lora_activated.pop("add_v_proj", None)
# 2. else it is not possible that only some layers have LoRA activated
if not all(is_lora_activated.values()):
raise ValueError(
f"Make sure that either all layers or no layers have LoRA activated, but have {is_lora_activated}"
)
# 3. And we need to merge the current LoRA layers into the corresponding LoRA attention processor
non_lora_processor_cls_name = self.processor.__class__.__name__
lora_processor_cls = getattr(import_module(__name__), "LoRA" + non_lora_processor_cls_name)
hidden_size = self.inner_dim
# now create a LoRA attention processor from the LoRA layers
if lora_processor_cls in [LoRAAttnProcessor, LoRAAttnProcessor2_0, LoRAXFormersAttnProcessor]:
kwargs = {
"cross_attention_dim": self.cross_attention_dim,
"rank": self.to_q.lora_layer.rank,
"network_alpha": self.to_q.lora_layer.network_alpha,
"q_rank": self.to_q.lora_layer.rank,
"q_hidden_size": self.to_q.lora_layer.out_features,
"k_rank": self.to_k.lora_layer.rank,
"k_hidden_size": self.to_k.lora_layer.out_features,
"v_rank": self.to_v.lora_layer.rank,
"v_hidden_size": self.to_v.lora_layer.out_features,
"out_rank": self.to_out[0].lora_layer.rank,
"out_hidden_size": self.to_out[0].lora_layer.out_features,
}
if hasattr(self.processor, "attention_op"):
kwargs["attention_op"] = self.processor.attention_op
lora_processor = lora_processor_cls(hidden_size, **kwargs)
lora_processor.to_q_lora.load_state_dict(self.to_q.lora_layer.state_dict())
lora_processor.to_k_lora.load_state_dict(self.to_k.lora_layer.state_dict())
lora_processor.to_v_lora.load_state_dict(self.to_v.lora_layer.state_dict())
lora_processor.to_out_lora.load_state_dict(self.to_out[0].lora_layer.state_dict())
elif lora_processor_cls == LoRAAttnAddedKVProcessor:
lora_processor = lora_processor_cls(
hidden_size,
cross_attention_dim=self.add_k_proj.weight.shape[0],
rank=self.to_q.lora_layer.rank,
network_alpha=self.to_q.lora_layer.network_alpha,
)
lora_processor.to_q_lora.load_state_dict(self.to_q.lora_layer.state_dict())
lora_processor.to_k_lora.load_state_dict(self.to_k.lora_layer.state_dict())
lora_processor.to_v_lora.load_state_dict(self.to_v.lora_layer.state_dict())
lora_processor.to_out_lora.load_state_dict(self.to_out[0].lora_layer.state_dict())
# only save if used
if self.add_k_proj.lora_layer is not None:
lora_processor.add_k_proj_lora.load_state_dict(self.add_k_proj.lora_layer.state_dict())
lora_processor.add_v_proj_lora.load_state_dict(self.add_v_proj.lora_layer.state_dict())
else:
lora_processor.add_k_proj_lora = None
lora_processor.add_v_proj_lora = None
else:
raise ValueError(f"{lora_processor_cls} does not exist.")
return lora_processor
def forward(
self,
hidden_states: torch.Tensor,
encoder_hidden_states: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
**cross_attention_kwargs,
) -> torch.Tensor:
r"""
The forward method of the `Attention` class.
Args:
hidden_states (`torch.Tensor`):
The hidden states of the query.
encoder_hidden_states (`torch.Tensor`, *optional*):
The hidden states of the encoder.
attention_mask (`torch.Tensor`, *optional*):
The attention mask to use. If `None`, no mask is applied.
**cross_attention_kwargs:
Additional keyword arguments to pass along to the cross attention.
Returns:
`torch.Tensor`: The output of the attention layer.
"""
# The `Attention` class can call different attention processors / attention functions
# here we simply pass along all tensors to the selected processor class
# For standard processors that are defined here, `**cross_attention_kwargs` is empty
attn_parameters = set(inspect.signature(self.processor.__call__).parameters.keys())
quiet_attn_parameters = {"ip_adapter_masks"}
unused_kwargs = [
k for k, _ in cross_attention_kwargs.items() if k not in attn_parameters and k not in quiet_attn_parameters
]
if len(unused_kwargs) > 0:
logger.warning(
f"cross_attention_kwargs {unused_kwargs} are not expected by {self.processor.__class__.__name__} and will be ignored."
)
cross_attention_kwargs = {k: w for k, w in cross_attention_kwargs.items() if k in attn_parameters}
return self.processor(
self,
hidden_states,
encoder_hidden_states=encoder_hidden_states,
attention_mask=attention_mask,
**cross_attention_kwargs,
)
def batch_to_head_dim(self, tensor: torch.Tensor) -> torch.Tensor:
r"""
Reshape the tensor from `[batch_size, seq_len, dim]` to `[batch_size // heads, seq_len, dim * heads]`. `heads`
is the number of heads initialized while constructing the `Attention` class.
Args:
tensor (`torch.Tensor`): The tensor to reshape.
Returns:
`torch.Tensor`: The reshaped tensor.
"""
head_size = self.heads
batch_size, seq_len, dim = tensor.shape
tensor = tensor.reshape(batch_size // head_size, head_size, seq_len, dim)
tensor = tensor.permute(0, 2, 1, 3).reshape(batch_size // head_size, seq_len, dim * head_size)
return tensor
def head_to_batch_dim(self, tensor: torch.Tensor, out_dim: int = 3) -> torch.Tensor:
r"""
Reshape the tensor from `[batch_size, seq_len, dim]` to `[batch_size, seq_len, heads, dim // heads]` `heads` is
the number of heads initialized while constructing the `Attention` class.
Args:
tensor (`torch.Tensor`): The tensor to reshape.
out_dim (`int`, *optional*, defaults to `3`): The output dimension of the tensor. If `3`, the tensor is
reshaped to `[batch_size * heads, seq_len, dim // heads]`.
Returns:
`torch.Tensor`: The reshaped tensor.
"""
head_size = self.heads
if tensor.ndim == 3:
batch_size, seq_len, dim = tensor.shape
extra_dim = 1
else:
batch_size, extra_dim, seq_len, dim = tensor.shape
tensor = tensor.reshape(batch_size, seq_len * extra_dim, head_size, dim // head_size)
tensor = tensor.permute(0, 2, 1, 3)
if out_dim == 3:
tensor = tensor.reshape(batch_size * head_size, seq_len * extra_dim, dim // head_size)
return tensor
def get_attention_scores(
self, query: torch.Tensor, key: torch.Tensor, attention_mask: torch.Tensor = None
) -> torch.Tensor:
r"""
Compute the attention scores.
Args:
query (`torch.Tensor`): The query tensor.
key (`torch.Tensor`): The key tensor.
attention_mask (`torch.Tensor`, *optional*): The attention mask to use. If `None`, no mask is applied.
Returns:
`torch.Tensor`: The attention probabilities/scores.
"""
dtype = query.dtype
if self.upcast_attention:
query = query.float()
key = key.float()
if attention_mask is None:
baddbmm_input = torch.empty(
query.shape[0], query.shape[1], key.shape[1], dtype=query.dtype, device=query.device
)
beta = 0
else:
baddbmm_input = attention_mask
beta = 1
attention_scores = torch.baddbmm(
baddbmm_input,
query,
key.transpose(-1, -2),
beta=beta,
alpha=self.scale,
)
del baddbmm_input
if self.upcast_softmax:
attention_scores = attention_scores.float()
attention_probs = attention_scores.softmax(dim=-1)
del attention_scores
attention_probs = attention_probs.to(dtype)
return attention_probs
def prepare_attention_mask(
self, attention_mask: torch.Tensor, target_length: int, batch_size: int, out_dim: int = 3
) -> torch.Tensor:
r"""
Prepare the attention mask for the attention computation.
Args:
attention_mask (`torch.Tensor`):
The attention mask to prepare.
target_length (`int`):
The target length of the attention mask. This is the length of the attention mask after padding.
batch_size (`int`):
The batch size, which is used to repeat the attention mask.
out_dim (`int`, *optional*, defaults to `3`):
The output dimension of the attention mask. Can be either `3` or `4`.
Returns:
`torch.Tensor`: The prepared attention mask.
"""
head_size = self.heads
if attention_mask is None:
return attention_mask
current_length: int = attention_mask.shape[-1]
if current_length != target_length:
if attention_mask.device.type == "mps":
# HACK: MPS: Does not support padding by greater than dimension of input tensor.
# Instead, we can manually construct the padding tensor.
padding_shape = (attention_mask.shape[0], attention_mask.shape[1], target_length)
padding = torch.zeros(padding_shape, dtype=attention_mask.dtype, device=attention_mask.device)
attention_mask = torch.cat([attention_mask, padding], dim=2)
else:
# TODO: for pipelines such as stable-diffusion, padding cross-attn mask:
# we want to instead pad by (0, remaining_length), where remaining_length is:
# remaining_length: int = target_length - current_length
# TODO: re-enable tests/models/test_models_unet_2d_condition.py#test_model_xattn_padding
attention_mask = F.pad(attention_mask, (0, target_length), value=0.0)
if out_dim == 3:
if attention_mask.shape[0] < batch_size * head_size:
attention_mask = attention_mask.repeat_interleave(head_size, dim=0)
elif out_dim == 4:
attention_mask = attention_mask.unsqueeze(1)
attention_mask = attention_mask.repeat_interleave(head_size, dim=1)
return attention_mask
def norm_encoder_hidden_states(self, encoder_hidden_states: torch.Tensor) -> torch.Tensor:
r"""
Normalize the encoder hidden states. Requires `self.norm_cross` to be specified when constructing the
`Attention` class.
Args:
encoder_hidden_states (`torch.Tensor`): Hidden states of the encoder.
Returns:
`torch.Tensor`: The normalized encoder hidden states.
"""
assert self.norm_cross is not None, "self.norm_cross must be defined to call self.norm_encoder_hidden_states"
if isinstance(self.norm_cross, nn.LayerNorm):
encoder_hidden_states = self.norm_cross(encoder_hidden_states)
elif isinstance(self.norm_cross, nn.GroupNorm):
# Group norm norms along the channels dimension and expects
# input to be in the shape of (N, C, *). In this case, we want
# to norm along the hidden dimension, so we need to move
# (batch_size, sequence_length, hidden_size) ->
# (batch_size, hidden_size, sequence_length)
encoder_hidden_states = encoder_hidden_states.transpose(1, 2)
encoder_hidden_states = self.norm_cross(encoder_hidden_states)
encoder_hidden_states = encoder_hidden_states.transpose(1, 2)
else:
assert False
return encoder_hidden_states
@torch.no_grad()
def fuse_projections(self, fuse=True):
device = self.to_q.weight.data.device
dtype = self.to_q.weight.data.dtype
if not self.is_cross_attention:
# fetch weight matrices.
concatenated_weights = torch.cat([self.to_q.weight.data, self.to_k.weight.data, self.to_v.weight.data])
in_features = concatenated_weights.shape[1]
out_features = concatenated_weights.shape[0]
# create a new single projection layer and copy over the weights.
self.to_qkv = nn.Linear(in_features, out_features, bias=self.use_bias, device=device, dtype=dtype)
self.to_qkv.weight.copy_(concatenated_weights)
if self.use_bias:
concatenated_bias = torch.cat([self.to_q.bias.data, self.to_k.bias.data, self.to_v.bias.data])
self.to_qkv.bias.copy_(concatenated_bias)
else:
concatenated_weights = torch.cat([self.to_k.weight.data, self.to_v.weight.data])
in_features = concatenated_weights.shape[1]
out_features = concatenated_weights.shape[0]
self.to_kv = nn.Linear(in_features, out_features, bias=self.use_bias, device=device, dtype=dtype)
self.to_kv.weight.copy_(concatenated_weights)
if self.use_bias:
concatenated_bias = torch.cat([self.to_k.bias.data, self.to_v.bias.data])
self.to_kv.bias.copy_(concatenated_bias)
self.fused_projections = fuse
class CustomJointAttnProcessor2_0:
"""Attention processor used typically in processing the SD3-like self-attention projections. add rms norm for query and key and apply RoPE"""
def __init__(self):
if not hasattr(F, "scaled_dot_product_attention"):
raise ImportError("AttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0.")
def apply_rotary_emb(
self,
x: torch.Tensor,
freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]],
) -> Tuple[torch.Tensor, torch.Tensor]:
"""
Apply rotary embeddings to input tensors using the given frequency tensor. This function applies rotary embeddings
to the given query or key 'x' tensors using the provided frequency tensor 'freqs_cis'. The input tensors are
reshaped as complex numbers, and the frequency tensor is reshaped for broadcasting compatibility. The resulting
tensors contain rotary embeddings and are returned as real tensors.
Args:
x (`torch.Tensor`):
Query or key tensor to apply rotary embeddings. [B, H, S, D] xk (torch.Tensor): Key tensor to apply
freqs_cis (`Tuple[torch.Tensor]`): Precomputed frequency tensor for complex exponentials. ([S, D], [S, D],)
Returns:
Tuple[torch.Tensor, torch.Tensor]: Tuple of modified query tensor and key tensor with rotary embeddings.
"""
cos, sin = freqs_cis # [S, D]
cos = cos[None, None]
sin = sin[None, None]
cos, sin = cos.to(x.device), sin.to(x.device)
x_real, x_imag = x.reshape(*x.shape[:-1], -1, 2).unbind(-1) # [B, S, H, D//2]
x_rotated = torch.stack([-x_imag, x_real], dim=-1).flatten(3)
out = (x.float() * cos + x_rotated.float() * sin).to(x.dtype)
return out
def __call__(
self,
attn: Attention,
hidden_states: torch.FloatTensor,
encoder_hidden_states: torch.FloatTensor = None,
attention_mask: Optional[torch.FloatTensor] = None,
rotary_freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]] = None,
rotary_freqs_cis_cross: Union[torch.Tensor, Tuple[torch.Tensor]] = None,
*args,
**kwargs,
) -> torch.FloatTensor:
hidden_states_len = hidden_states.shape[1]
input_ndim = hidden_states.ndim
if input_ndim == 4:
batch_size, channel, height, width = hidden_states.shape
hidden_states = hidden_states.view(batch_size, channel, height * width).transpose(1, 2)
if encoder_hidden_states is not None:
context_input_ndim = encoder_hidden_states.ndim
if context_input_ndim == 4:
batch_size, channel, height, width = encoder_hidden_states.shape
encoder_hidden_states = encoder_hidden_states.view(batch_size, channel, height * width).transpose(1, 2)
batch_size = hidden_states.shape[0]
# `sample` projections.
query = attn.to_q(hidden_states)
key = attn.to_k(hidden_states)
value = attn.to_v(hidden_states)
# `context` projections.
if encoder_hidden_states is not None:
encoder_hidden_states_query_proj = attn.add_q_proj(encoder_hidden_states)
encoder_hidden_states_key_proj = attn.add_k_proj(encoder_hidden_states)
encoder_hidden_states_value_proj = attn.add_v_proj(encoder_hidden_states)
# attention
if not attn.is_cross_attention:
query = torch.cat([query, encoder_hidden_states_query_proj], dim=1)
key = torch.cat([key, encoder_hidden_states_key_proj], dim=1)
value = torch.cat([value, encoder_hidden_states_value_proj], dim=1)
else:
query = hidden_states
key = encoder_hidden_states
value = encoder_hidden_states
inner_dim = key.shape[-1]
head_dim = inner_dim // attn.heads
query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
# Apply query and key normalization if needed
if attn.norm_q is not None:
query = attn.norm_q(query)
if attn.norm_k is not None:
key = attn.norm_k(key)
# Apply RoPE if needed
if rotary_freqs_cis is not None:
query = self.apply_rotary_emb(query, rotary_freqs_cis)
if not attn.is_cross_attention:
key = self.apply_rotary_emb(key, rotary_freqs_cis)
elif rotary_freqs_cis_cross is not None:
key = self.apply_rotary_emb(key, rotary_freqs_cis_cross)
hidden_states = F.scaled_dot_product_attention(
query, key, value, dropout_p=0.0, is_causal=False
)
hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, attn.heads * head_dim)
hidden_states = hidden_states.to(query.dtype)
# Split the attention outputs.
if encoder_hidden_states is not None and not attn.is_cross_attention:
hidden_states, encoder_hidden_states = (
hidden_states[:, : hidden_states_len],
hidden_states[:, hidden_states_len:],
)
# linear proj
hidden_states = attn.to_out[0](hidden_states)
# dropout
hidden_states = attn.to_out[1](hidden_states)
if encoder_hidden_states is not None and not attn.context_pre_only:
encoder_hidden_states = attn.to_add_out(encoder_hidden_states)
if input_ndim == 4:
hidden_states = hidden_states.transpose(-1, -2).reshape(batch_size, channel, height, width)
if encoder_hidden_states is not None and context_input_ndim == 4:
encoder_hidden_states = encoder_hidden_states.transpose(-1, -2).reshape(batch_size, channel, height, width)
return hidden_states, encoder_hidden_states
class CustomLiteLAProcessor2_0:
"""Attention processor used typically in processing the SD3-like self-attention projections. add rms norm for query and key and apply RoPE"""
def __init__(self):
self.kernel_func = nn.ReLU(inplace=False)
self.eps = 1e-15
self.pad_val = 1.0
def apply_rotary_emb(
self,
x: torch.Tensor,
freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]],
) -> Tuple[torch.Tensor, torch.Tensor]:
"""
Apply rotary embeddings to input tensors using the given frequency tensor. This function applies rotary embeddings
to the given query or key 'x' tensors using the provided frequency tensor 'freqs_cis'. The input tensors are
reshaped as complex numbers, and the frequency tensor is reshaped for broadcasting compatibility. The resulting
tensors contain rotary embeddings and are returned as real tensors.
Args:
x (`torch.Tensor`):
Query or key tensor to apply rotary embeddings. [B, H, S, D] xk (torch.Tensor): Key tensor to apply
freqs_cis (`Tuple[torch.Tensor]`): Precomputed frequency tensor for complex exponentials. ([S, D], [S, D],)
Returns:
Tuple[torch.Tensor, torch.Tensor]: Tuple of modified query tensor and key tensor with rotary embeddings.
"""
cos, sin = freqs_cis # [S, D]
cos = cos[None, None]
sin = sin[None, None]
cos, sin = cos.to(x.device), sin.to(x.device)
x_real, x_imag = x.reshape(*x.shape[:-1], -1, 2).unbind(-1) # [B, S, H, D//2]
x_rotated = torch.stack([-x_imag, x_real], dim=-1).flatten(3)
out = (x.float() * cos + x_rotated.float() * sin).to(x.dtype)
return out
def __call__(
self,
attn: Attention,
hidden_states: torch.FloatTensor,
encoder_hidden_states: torch.FloatTensor = None,
attention_mask: Optional[torch.FloatTensor] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
rotary_freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]] = None,
rotary_freqs_cis_cross: Union[torch.Tensor, Tuple[torch.Tensor]] = None,
*args,
**kwargs,
) -> torch.FloatTensor:
hidden_states_len = hidden_states.shape[1]
input_ndim = hidden_states.ndim
if input_ndim == 4:
batch_size, channel, height, width = hidden_states.shape
hidden_states = hidden_states.view(batch_size, channel, height * width).transpose(1, 2)
if encoder_hidden_states is not None:
context_input_ndim = encoder_hidden_states.ndim
if context_input_ndim == 4:
batch_size, channel, height, width = encoder_hidden_states.shape
encoder_hidden_states = encoder_hidden_states.view(batch_size, channel, height * width).transpose(1, 2)
batch_size = hidden_states.shape[0]
# `sample` projections.
dtype = hidden_states.dtype
query = attn.to_q(hidden_states)
key = attn.to_k(hidden_states)
value = attn.to_v(hidden_states)
# `context` projections.
has_encoder_hidden_state_proj = hasattr(attn, "add_q_proj") and hasattr(attn, "add_k_proj") and hasattr(attn, "add_v_proj")
if encoder_hidden_states is not None and has_encoder_hidden_state_proj:
encoder_hidden_states_query_proj = attn.add_q_proj(encoder_hidden_states)
encoder_hidden_states_key_proj = attn.add_k_proj(encoder_hidden_states)
encoder_hidden_states_value_proj = attn.add_v_proj(encoder_hidden_states)
# attention
if not attn.is_cross_attention:
query = torch.cat([query, encoder_hidden_states_query_proj], dim=1)
key = torch.cat([key, encoder_hidden_states_key_proj], dim=1)
value = torch.cat([value, encoder_hidden_states_value_proj], dim=1)
else:
query = hidden_states
key = encoder_hidden_states
value = encoder_hidden_states
inner_dim = key.shape[-1]
head_dim = inner_dim // attn.heads
query = query.transpose(-1, -2).reshape(batch_size, attn.heads, head_dim, -1)
key = key.transpose(-1, -2).reshape(batch_size, attn.heads, head_dim, -1).transpose(-1, -2)
value = value.transpose(-1, -2).reshape(batch_size, attn.heads, head_dim, -1)
# RoPE需要 [B, H, S, D] 输入
# 此时 query是 [B, H, D, S], 需要转成 [B, H, S, D] 才能应用RoPE
query = query.permute(0, 1, 3, 2) # [B, H, S, D] (从 [B, H, D, S])
# Apply query and key normalization if needed
if attn.norm_q is not None:
query = attn.norm_q(query)
if attn.norm_k is not None:
key = attn.norm_k(key)
# Apply RoPE if needed
if rotary_freqs_cis is not None:
query = self.apply_rotary_emb(query, rotary_freqs_cis)
if not attn.is_cross_attention:
key = self.apply_rotary_emb(key, rotary_freqs_cis)
elif rotary_freqs_cis_cross is not None and has_encoder_hidden_state_proj:
key = self.apply_rotary_emb(key, rotary_freqs_cis_cross)
# 此时 query是 [B, H, S, D],需要还原成 [B, H, D, S]
query = query.permute(0, 1, 3, 2) # [B, H, D, S]
if attention_mask is not None:
# attention_mask: [B, S] -> [B, 1, S, 1]
attention_mask = attention_mask[:, None, :, None].to(key.dtype) # [B, 1, S, 1]
query = query * attention_mask.permute(0, 1, 3, 2) # [B, H, S, D] * [B, 1, S, 1]
if not attn.is_cross_attention:
key = key * attention_mask # key: [B, h, S, D] 与 mask [B, 1, S, 1] 相乘
value = value * attention_mask.permute(0, 1, 3, 2) # 如果 value 是 [B, h, D, S],那么需调整mask以匹配S维度
if attn.is_cross_attention and encoder_attention_mask is not None and has_encoder_hidden_state_proj:
encoder_attention_mask = encoder_attention_mask[:, None, :, None].to(key.dtype) # [B, 1, S_enc, 1]
# 此时 key: [B, h, S_enc, D], value: [B, h, D, S_enc]
key = key * encoder_attention_mask # [B, h, S_enc, D] * [B, 1, S_enc, 1]
value = value * encoder_attention_mask.permute(0, 1, 3, 2) # [B, h, D, S_enc] * [B, 1, 1, S_enc]
query = self.kernel_func(query)
key = self.kernel_func(key)
query, key, value = query.float(), key.float(), value.float()
value = F.pad(value, (0, 0, 0, 1), mode="constant", value=self.pad_val)
vk = torch.matmul(value, key)
hidden_states = torch.matmul(vk, query)
if hidden_states.dtype in [torch.float16, torch.bfloat16]:
hidden_states = hidden_states.float()
hidden_states = hidden_states[:, :, :-1] / (hidden_states[:, :, -1:] + self.eps)
hidden_states = hidden_states.view(batch_size, attn.heads * head_dim, -1).permute(0, 2, 1)
hidden_states = hidden_states.to(dtype)
if encoder_hidden_states is not None:
encoder_hidden_states = encoder_hidden_states.to(dtype)
# Split the attention outputs.
if encoder_hidden_states is not None and not attn.is_cross_attention and has_encoder_hidden_state_proj:
hidden_states, encoder_hidden_states = (
hidden_states[:, : hidden_states_len],
hidden_states[:, hidden_states_len:],
)
# linear proj
hidden_states = attn.to_out[0](hidden_states)
# dropout
hidden_states = attn.to_out[1](hidden_states)
if encoder_hidden_states is not None and not attn.context_pre_only and not attn.is_cross_attention and hasattr(attn, "to_add_out"):
encoder_hidden_states = attn.to_add_out(encoder_hidden_states)
if input_ndim == 4:
hidden_states = hidden_states.transpose(-1, -2).reshape(batch_size, channel, height, width)
if encoder_hidden_states is not None and context_input_ndim == 4:
encoder_hidden_states = encoder_hidden_states.transpose(-1, -2).reshape(batch_size, channel, height, width)
if torch.get_autocast_gpu_dtype() == torch.float16:
hidden_states = hidden_states.clip(-65504, 65504)
if encoder_hidden_states is not None:
encoder_hidden_states = encoder_hidden_states.clip(-65504, 65504)
return hidden_states, encoder_hidden_states
class CustomerAttnProcessor2_0:
r"""
Processor for implementing scaled dot-product attention (enabled by default if you're using PyTorch 2.0).
"""
def __init__(self):
if not hasattr(F, "scaled_dot_product_attention"):
raise ImportError("AttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0.")
def apply_rotary_emb(
self,
x: torch.Tensor,
freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]],
) -> Tuple[torch.Tensor, torch.Tensor]:
"""
Apply rotary embeddings to input tensors using the given frequency tensor. This function applies rotary embeddings
to the given query or key 'x' tensors using the provided frequency tensor 'freqs_cis'. The input tensors are
reshaped as complex numbers, and the frequency tensor is reshaped for broadcasting compatibility. The resulting
tensors contain rotary embeddings and are returned as real tensors.
Args:
x (`torch.Tensor`):
Query or key tensor to apply rotary embeddings. [B, H, S, D] xk (torch.Tensor): Key tensor to apply
freqs_cis (`Tuple[torch.Tensor]`): Precomputed frequency tensor for complex exponentials. ([S, D], [S, D],)
Returns:
Tuple[torch.Tensor, torch.Tensor]: Tuple of modified query tensor and key tensor with rotary embeddings.
"""
cos, sin = freqs_cis # [S, D]
cos = cos[None, None]
sin = sin[None, None]
cos, sin = cos.to(x.device), sin.to(x.device)
x_real, x_imag = x.reshape(*x.shape[:-1], -1, 2).unbind(-1) # [B, S, H, D//2]
x_rotated = torch.stack([-x_imag, x_real], dim=-1).flatten(3)
out = (x.float() * cos + x_rotated.float() * sin).to(x.dtype)
return out
def __call__(
self,
attn: Attention,
hidden_states: torch.FloatTensor,
encoder_hidden_states: torch.FloatTensor = None,
attention_mask: Optional[torch.FloatTensor] = None,
encoder_attention_mask: Optional[torch.FloatTensor] = None,
rotary_freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]] = None,
rotary_freqs_cis_cross: Union[torch.Tensor, Tuple[torch.Tensor]] = None,
*args,
**kwargs,
) -> torch.Tensor:
residual = hidden_states
input_ndim = hidden_states.ndim
if input_ndim == 4:
batch_size, channel, height, width = hidden_states.shape
hidden_states = hidden_states.view(batch_size, channel, height * width).transpose(1, 2)
batch_size, sequence_length, _ = (
hidden_states.shape if encoder_hidden_states is None else encoder_hidden_states.shape
)
has_encoder_hidden_state_proj = hasattr(attn, "add_q_proj") and hasattr(attn, "add_k_proj") and hasattr(attn, "add_v_proj")
if attn.group_norm is not None:
hidden_states = attn.group_norm(hidden_states.transpose(1, 2)).transpose(1, 2)
query = attn.to_q(hidden_states)
if encoder_hidden_states is None:
encoder_hidden_states = hidden_states
elif attn.norm_cross:
encoder_hidden_states = attn.norm_encoder_hidden_states(encoder_hidden_states)
key = attn.to_k(encoder_hidden_states)
value = attn.to_v(encoder_hidden_states)
inner_dim = key.shape[-1]
head_dim = inner_dim // attn.heads
query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
if attn.norm_q is not None:
query = attn.norm_q(query)
if attn.norm_k is not None:
key = attn.norm_k(key)
# Apply RoPE if needed
if rotary_freqs_cis is not None:
query = self.apply_rotary_emb(query, rotary_freqs_cis)
if not attn.is_cross_attention:
key = self.apply_rotary_emb(key, rotary_freqs_cis)
elif rotary_freqs_cis_cross is not None and has_encoder_hidden_state_proj:
key = self.apply_rotary_emb(key, rotary_freqs_cis_cross)
if attn.is_cross_attention and encoder_attention_mask is not None and has_encoder_hidden_state_proj:
# attention_mask: N x S1
# encoder_attention_mask: N x S2
# cross attention 整合attention_mask和encoder_attention_mask
combined_mask = attention_mask[:, :, None] * encoder_attention_mask[:, None, :]
attention_mask = torch.where(combined_mask == 1, 0.0, -torch.inf)
attention_mask = attention_mask[:, None, :, :].expand(-1, attn.heads, -1, -1).to(query.dtype)
elif not attn.is_cross_attention and attention_mask is not None:
attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size)
# scaled_dot_product_attention expects attention_mask shape to be
# (batch, heads, source_length, target_length)
attention_mask = attention_mask.view(batch_size, attn.heads, -1, attention_mask.shape[-1])
# the output of sdp = (batch, num_heads, seq_len, head_dim)
# TODO: add support for attn.scale when we move to Torch 2.1
hidden_states = F.scaled_dot_product_attention(
query, key, value, attn_mask=attention_mask, dropout_p=0.0, is_causal=False
)
hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, attn.heads * head_dim)
hidden_states = hidden_states.to(query.dtype)
# linear proj
hidden_states = attn.to_out[0](hidden_states)
# dropout
hidden_states = attn.to_out[1](hidden_states)
if input_ndim == 4:
hidden_states = hidden_states.transpose(-1, -2).reshape(batch_size, channel, height, width)
if attn.residual_connection:
hidden_states = hidden_states + residual
hidden_states = hidden_states / attn.rescale_output_factor
return hidden_states
class CustomLiteLAMMDiTProcessor2_0:
"""Attention processor used typically in processing the SD3-like self-attention projections. add rms norm for query and key and apply RoPE"""
def __init__(self):
self.kernel_func = nn.ReLU(inplace=False)
self.eps = 1e-15
self.pad_val = 1.0
def apply_linear_attention(self, query, key, value):
key = key.permute(0, 1, 3, 2)
query = self.kernel_func(query)
key = self.kernel_func(key)
query, key, value = query.float(), key.float(), value.float()
value = F.pad(value, (0, 0, 0, 1), mode="constant", value=self.pad_val)
vk = torch.matmul(value, key)
hidden_states = torch.matmul(vk, query)
if hidden_states.dtype in [torch.float16, torch.bfloat16]:
hidden_states = hidden_states.float()
hidden_states = hidden_states[:, :, :-1] / (hidden_states[:, :, -1:] + self.eps)
return hidden_states
def apply_rotary_emb(
self,
x: torch.Tensor,
freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]],
) -> Tuple[torch.Tensor, torch.Tensor]:
"""
Apply rotary embeddings to input tensors using the given frequency tensor. This function applies rotary embeddings
to the given query or key 'x' tensors using the provided frequency tensor 'freqs_cis'. The input tensors are
reshaped as complex numbers, and the frequency tensor is reshaped for broadcasting compatibility. The resulting
tensors contain rotary embeddings and are returned as real tensors.
Args:
x (`torch.Tensor`):
Query or key tensor to apply rotary embeddings. [B, H, S, D] xk (torch.Tensor): Key tensor to apply
freqs_cis (`Tuple[torch.Tensor]`): Precomputed frequency tensor for complex exponentials. ([S, D], [S, D],)
Returns:
Tuple[torch.Tensor, torch.Tensor]: Tuple of modified query tensor and key tensor with rotary embeddings.
"""
cos, sin = freqs_cis # [S, D] or [N, S, D]
if cos.ndim == 2:
cos = cos[None, None]
sin = sin[None, None]
elif cos.ndim == 3:
cos = cos[:, None]
sin = sin[:, None]
cos, sin = cos.to(x.device), sin.to(x.device)
x_real, x_imag = x.reshape(*x.shape[:-1], -1, 2).unbind(-1) # [B, S, H, D//2]
x_rotated = torch.stack([-x_imag, x_real], dim=-1).flatten(3)
out = (x.float() * cos + x_rotated.float() * sin).to(x.dtype)
return out
def __call__(
self,
attn: Attention,
hidden_states: torch.FloatTensor,
encoder_hidden_states: torch.FloatTensor = None,
attention_mask: Optional[torch.FloatTensor] = None,
image_rotary_emb: Optional[torch.Tensor] = None,
) -> torch.FloatTensor:
batch_size, _, _ = hidden_states.shape if encoder_hidden_states is None else encoder_hidden_states.shape
# `sample` projections.
dtype = hidden_states.dtype
query = attn.to_q(hidden_states)
key = attn.to_k(hidden_states)
value = attn.to_v(hidden_states)
inner_dim = key.shape[-1]
head_dim = inner_dim // attn.heads
query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
if attn.norm_q is not None:
query = attn.norm_q(query)
if attn.norm_k is not None:
key = attn.norm_k(key)
# the attention in FluxSingleTransformerBlock does not use `encoder_hidden_states`
if encoder_hidden_states is not None:
# `context` projections.
encoder_hidden_states_query_proj = attn.add_q_proj(encoder_hidden_states)
encoder_hidden_states_key_proj = attn.add_k_proj(encoder_hidden_states)
encoder_hidden_states_value_proj = attn.add_v_proj(encoder_hidden_states)
encoder_hidden_states_query_proj = encoder_hidden_states_query_proj.view(
batch_size, -1, attn.heads, head_dim
).transpose(1, 2)
encoder_hidden_states_key_proj = encoder_hidden_states_key_proj.view(
batch_size, -1, attn.heads, head_dim
).transpose(1, 2)
encoder_hidden_states_value_proj = encoder_hidden_states_value_proj.view(
batch_size, -1, attn.heads, head_dim
).transpose(1, 2)
if attn.norm_added_q is not None:
encoder_hidden_states_query_proj = attn.norm_added_q(encoder_hidden_states_query_proj)
if attn.norm_added_k is not None:
encoder_hidden_states_key_proj = attn.norm_added_k(encoder_hidden_states_key_proj)
# attention
query = torch.cat([encoder_hidden_states_query_proj, query], dim=2)
key = torch.cat([encoder_hidden_states_key_proj, key], dim=2)
value = torch.cat([encoder_hidden_states_value_proj, value], dim=2)
if image_rotary_emb is not None:
query = self.apply_rotary_emb(query, image_rotary_emb)
key = self.apply_rotary_emb(key, image_rotary_emb)
# hidden_states = F.scaled_dot_product_attention(
# query, key, value, attn_mask=attention_mask, dropout_p=0.0, is_causal=False
# )
# apply linear attention
hidden_states = self.apply_linear_attention(query, key, value)
hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, attn.heads * head_dim)
hidden_states = hidden_states.to(dtype)
if encoder_hidden_states is not None:
encoder_hidden_states, hidden_states = (
hidden_states[:, : encoder_hidden_states.shape[1]],
hidden_states[:, encoder_hidden_states.shape[1] :],
)
# linear proj
hidden_states = attn.to_out[0](hidden_states)
# dropout
hidden_states = attn.to_out[1](hidden_states)
encoder_hidden_states = attn.to_add_out(encoder_hidden_states)
return hidden_states, encoder_hidden_states
else:
return hidden_states
class FluxAttnProcessor2_0:
"""Attention processor used typically in processing the SD3-like self-attention projections."""
def __init__(self):
if not hasattr(F, "scaled_dot_product_attention"):
raise ImportError("FluxAttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0.")
def apply_rotary_emb(
self,
x: torch.Tensor,
freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]]
):
cos, sin = freqs_cis # [S, D] or [N, S, D]
if cos.ndim == 2:
cos = cos[None, None]
sin = sin[None, None]
elif cos.ndim == 3:
cos = cos[:, None]
sin = sin[:, None]
cos, sin = cos.to(x.device), sin.to(x.device)
# Used for flux, cogvideox, hunyuan-dit
x_real, x_imag = x.reshape(*x.shape[:-1], -1, 2).unbind(-1) # [B, S, H, D//2]
x_rotated = torch.stack([-x_imag, x_real], dim=-1).flatten(3)
out = (x.float() * cos + x_rotated.float() * sin).to(x.dtype)
return out
def __call__(
self,
attn: Attention,
hidden_states: torch.FloatTensor,
encoder_hidden_states: torch.FloatTensor = None,
attention_mask: Optional[torch.FloatTensor] = None,
image_rotary_emb: Optional[torch.Tensor] = None,
) -> torch.FloatTensor:
batch_size, _, _ = hidden_states.shape if encoder_hidden_states is None else encoder_hidden_states.shape
# `sample` projections.
query = attn.to_q(hidden_states)
key = attn.to_k(hidden_states)
value = attn.to_v(hidden_states)
inner_dim = key.shape[-1]
head_dim = inner_dim // attn.heads
query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
if attn.norm_q is not None:
query = attn.norm_q(query)
if attn.norm_k is not None:
key = attn.norm_k(key)
# the attention in FluxSingleTransformerBlock does not use `encoder_hidden_states`
if encoder_hidden_states is not None:
# `context` projections.
encoder_hidden_states_query_proj = attn.add_q_proj(encoder_hidden_states)
encoder_hidden_states_key_proj = attn.add_k_proj(encoder_hidden_states)
encoder_hidden_states_value_proj = attn.add_v_proj(encoder_hidden_states)
encoder_hidden_states_query_proj = encoder_hidden_states_query_proj.view(
batch_size, -1, attn.heads, head_dim
).transpose(1, 2)
encoder_hidden_states_key_proj = encoder_hidden_states_key_proj.view(
batch_size, -1, attn.heads, head_dim
).transpose(1, 2)
encoder_hidden_states_value_proj = encoder_hidden_states_value_proj.view(
batch_size, -1, attn.heads, head_dim
).transpose(1, 2)
if attn.norm_added_q is not None:
encoder_hidden_states_query_proj = attn.norm_added_q(encoder_hidden_states_query_proj)
if attn.norm_added_k is not None:
encoder_hidden_states_key_proj = attn.norm_added_k(encoder_hidden_states_key_proj)
# attention
query = torch.cat([encoder_hidden_states_query_proj, query], dim=2)
key = torch.cat([encoder_hidden_states_key_proj, key], dim=2)
value = torch.cat([encoder_hidden_states_value_proj, value], dim=2)
if image_rotary_emb is not None:
query = self.apply_rotary_emb(query, image_rotary_emb)
key = self.apply_rotary_emb(key, image_rotary_emb)
hidden_states = F.scaled_dot_product_attention(
query, key, value, attn_mask=attention_mask, dropout_p=0.0, is_causal=False
)
hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, attn.heads * head_dim)
hidden_states = hidden_states.to(query.dtype)
if encoder_hidden_states is not None:
encoder_hidden_states, hidden_states = (
hidden_states[:, : encoder_hidden_states.shape[1]],
hidden_states[:, encoder_hidden_states.shape[1] :],
)
# linear proj
hidden_states = attn.to_out[0](hidden_states)
# dropout
hidden_states = attn.to_out[1](hidden_states)
encoder_hidden_states = attn.to_add_out(encoder_hidden_states)
return hidden_states, encoder_hidden_states
else:
return hidden_states