# Copyright 2023 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 warnings from typing import Callable, Optional, Union import torch import torch.nn.functional as F from torch import nn from ..utils import deprecate, logging, maybe_allow_in_graph from ..utils.import_utils import is_xformers_available logger = logging.get_logger(__name__) # pylint: disable=invalid-name if is_xformers_available(): import xformers import xformers.ops else: xformers = None @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. """ def __init__( self, query_dim: int, cross_attention_dim: Optional[int] = None, heads: int = 8, dim_head: int = 64, dropout: float = 0.0, bias=False, upcast_attention: bool = False, upcast_softmax: bool = False, cross_attention_norm: Optional[str] = None, cross_attention_norm_num_groups: int = 32, added_kv_proj_dim: Optional[int] = None, norm_num_groups: 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=False, processor: Optional["AttnProcessor"] = None, ): super().__init__() inner_dim = dim_head * heads 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 # 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 = 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 cross_attention_norm is None: self.norm_cross = None elif cross_attention_norm == "layer_norm": self.norm_cross = nn.LayerNorm(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 = 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, inner_dim, bias=bias) if not self.only_cross_attention: # only relevant for the `AddedKVProcessor` classes self.to_k = nn.Linear(cross_attention_dim, inner_dim, bias=bias) self.to_v = nn.Linear(cross_attention_dim, 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, inner_dim) self.add_v_proj = nn.Linear(added_kv_proj_dim, inner_dim) self.to_out = nn.ModuleList([]) self.to_out.append(nn.Linear(inner_dim, query_dim, bias=out_bias)) self.to_out.append(nn.Dropout(dropout)) # 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_memory_efficient_attention_xformers( self, use_memory_efficient_attention_xformers: bool, attention_op: Optional[Callable] = None ): is_lora = hasattr(self, "processor") and isinstance( self.processor, (LoRAAttnProcessor, LoRAXFormersAttnProcessor) ) is_custom_diffusion = hasattr(self, "processor") and isinstance( self.processor, (CustomDiffusionAttnProcessor, CustomDiffusionXFormersAttnProcessor) ) if use_memory_efficient_attention_xformers: if self.added_kv_proj_dim is not None: # TODO(Anton, 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 raise NotImplementedError( "Memory efficient attention with `xformers` is currently not supported when" " `self.added_kv_proj_dim` is defined." ) elif 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 " ) elif hasattr(F, "scaled_dot_product_attention") and self.scale_qk: warnings.warn( "You have specified using flash attention using xFormers but you have PyTorch 2.0 already installed. " "We will default to PyTorch's native efficient flash attention implementation (`F.scaled_dot_product_attention`) " "introduced in PyTorch 2.0. In case you are using LoRA or Custom Diffusion, we will fall " "back to their respective attention processors i.e., we will NOT use the PyTorch 2.0 " "native efficient flash attention." ) 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: 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) print( f"is_lora is set to {is_lora}, type: LoRAXFormersAttnProcessor: {isinstance(processor, LoRAXFormersAttnProcessor)}" ) 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) else: processor = XFormersAttnProcessor(attention_op=attention_op) else: if is_lora: processor = LoRAAttnProcessor( 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: processor = CustomDiffusionAttnProcessor( 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 print("Still defaulting to: AttnProcessor2_0 :O") 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): 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"): # 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 forward(self, hidden_states, encoder_hidden_states=None, attention_mask=None, **cross_attention_kwargs): # 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 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): 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, out_dim=3): head_size = self.heads batch_size, seq_len, dim = tensor.shape tensor = tensor.reshape(batch_size, seq_len, 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, dim // head_size) return tensor def get_attention_scores(self, query, key, attention_mask=None): 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, target_length, batch_size=None, out_dim=3): if batch_size is None: deprecate( "batch_size=None", "0.0.15", ( "Not passing the `batch_size` parameter to `prepare_attention_mask` can lead to incorrect" " attention mask preparation and is deprecated behavior. Please make sure to pass `batch_size` to" " `prepare_attention_mask` when preparing the attention_mask." ), ) batch_size = 1 head_size = self.heads if attention_mask is None: return attention_mask if attention_mask.shape[-1] != 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: 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): 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 class AttnProcessor: def __call__( self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None, ): 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 ) attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) 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) query = attn.head_to_batch_dim(query) key = attn.head_to_batch_dim(key) value = attn.head_to_batch_dim(value) attention_probs = attn.get_attention_scores(query, key, attention_mask) hidden_states = torch.bmm(attention_probs, value) hidden_states = attn.batch_to_head_dim(hidden_states) # 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 LoRALinearLayer(nn.Module): def __init__(self, in_features, out_features, rank=4): super().__init__() if rank > min(in_features, out_features): raise ValueError(f"LoRA rank {rank} must be less or equal than {min(in_features, out_features)}") self.down = nn.Linear(in_features, rank, bias=False) self.up = nn.Linear(rank, out_features, bias=False) nn.init.normal_(self.down.weight, std=1 / rank) nn.init.zeros_(self.up.weight) def forward(self, hidden_states): orig_dtype = hidden_states.dtype dtype = self.down.weight.dtype down_hidden_states = self.down(hidden_states.to(dtype)) up_hidden_states = self.up(down_hidden_states) return up_hidden_states.to(orig_dtype) class LoRAAttnProcessor(nn.Module): def __init__(self, hidden_size, cross_attention_dim=None, rank=4): super().__init__() self.hidden_size = hidden_size self.cross_attention_dim = cross_attention_dim self.rank = rank self.to_q_lora = LoRALinearLayer(hidden_size, hidden_size, rank) self.to_k_lora = LoRALinearLayer(cross_attention_dim or hidden_size, hidden_size, rank) self.to_v_lora = LoRALinearLayer(cross_attention_dim or hidden_size, hidden_size, rank) self.to_out_lora = LoRALinearLayer(hidden_size, hidden_size, rank) def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None, scale=1.0): 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 ) attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) 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) + scale * self.to_q_lora(hidden_states) query = attn.head_to_batch_dim(query) 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) + scale * self.to_k_lora(encoder_hidden_states) value = attn.to_v(encoder_hidden_states) + scale * self.to_v_lora(encoder_hidden_states) key = attn.head_to_batch_dim(key) value = attn.head_to_batch_dim(value) attention_probs = attn.get_attention_scores(query, key, attention_mask) hidden_states = torch.bmm(attention_probs, value) hidden_states = attn.batch_to_head_dim(hidden_states) # linear proj hidden_states = attn.to_out[0](hidden_states) + scale * self.to_out_lora(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 CustomDiffusionAttnProcessor(nn.Module): def __init__( self, train_kv=True, train_q_out=True, hidden_size=None, cross_attention_dim=None, out_bias=True, dropout=0.0, ): super().__init__() self.train_kv = train_kv self.train_q_out = train_q_out self.hidden_size = hidden_size self.cross_attention_dim = cross_attention_dim # `_custom_diffusion` id for easy serialization and loading. if self.train_kv: self.to_k_custom_diffusion = nn.Linear(cross_attention_dim or hidden_size, hidden_size, bias=False) self.to_v_custom_diffusion = nn.Linear(cross_attention_dim or hidden_size, hidden_size, bias=False) if self.train_q_out: self.to_q_custom_diffusion = nn.Linear(hidden_size, hidden_size, bias=False) self.to_out_custom_diffusion = nn.ModuleList([]) self.to_out_custom_diffusion.append(nn.Linear(hidden_size, hidden_size, bias=out_bias)) self.to_out_custom_diffusion.append(nn.Dropout(dropout)) def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None): batch_size, sequence_length, _ = hidden_states.shape attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) if self.train_q_out: query = self.to_q_custom_diffusion(hidden_states) else: query = attn.to_q(hidden_states) if encoder_hidden_states is None: crossattn = False encoder_hidden_states = hidden_states else: crossattn = True if attn.norm_cross: encoder_hidden_states = attn.norm_encoder_hidden_states(encoder_hidden_states) if self.train_kv: key = self.to_k_custom_diffusion(encoder_hidden_states) value = self.to_v_custom_diffusion(encoder_hidden_states) else: key = attn.to_k(encoder_hidden_states) value = attn.to_v(encoder_hidden_states) if crossattn: detach = torch.ones_like(key) detach[:, :1, :] = detach[:, :1, :] * 0.0 key = detach * key + (1 - detach) * key.detach() value = detach * value + (1 - detach) * value.detach() query = attn.head_to_batch_dim(query) key = attn.head_to_batch_dim(key) value = attn.head_to_batch_dim(value) attention_probs = attn.get_attention_scores(query, key, attention_mask) hidden_states = torch.bmm(attention_probs, value) hidden_states = attn.batch_to_head_dim(hidden_states) if self.train_q_out: # linear proj hidden_states = self.to_out_custom_diffusion[0](hidden_states) # dropout hidden_states = self.to_out_custom_diffusion[1](hidden_states) else: # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) return hidden_states class AttnAddedKVProcessor: def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None): residual = hidden_states hidden_states = hidden_states.view(hidden_states.shape[0], hidden_states.shape[1], -1).transpose(1, 2) batch_size, sequence_length, _ = hidden_states.shape attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) 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) hidden_states = attn.group_norm(hidden_states.transpose(1, 2)).transpose(1, 2) query = attn.to_q(hidden_states) query = attn.head_to_batch_dim(query) 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_key_proj = attn.head_to_batch_dim(encoder_hidden_states_key_proj) encoder_hidden_states_value_proj = attn.head_to_batch_dim(encoder_hidden_states_value_proj) if not attn.only_cross_attention: key = attn.to_k(hidden_states) value = attn.to_v(hidden_states) key = attn.head_to_batch_dim(key) value = attn.head_to_batch_dim(value) key = torch.cat([encoder_hidden_states_key_proj, key], dim=1) value = torch.cat([encoder_hidden_states_value_proj, value], dim=1) else: key = encoder_hidden_states_key_proj value = encoder_hidden_states_value_proj attention_probs = attn.get_attention_scores(query, key, attention_mask) hidden_states = torch.bmm(attention_probs, value) hidden_states = attn.batch_to_head_dim(hidden_states) # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) hidden_states = hidden_states.transpose(-1, -2).reshape(residual.shape) hidden_states = hidden_states + residual return hidden_states class AttnAddedKVProcessor2_0: def __init__(self): if not hasattr(F, "scaled_dot_product_attention"): raise ImportError( "AttnAddedKVProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0." ) def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None): residual = hidden_states hidden_states = hidden_states.view(hidden_states.shape[0], hidden_states.shape[1], -1).transpose(1, 2) batch_size, sequence_length, _ = hidden_states.shape attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size, out_dim=4) 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) hidden_states = attn.group_norm(hidden_states.transpose(1, 2)).transpose(1, 2) query = attn.to_q(hidden_states) query = attn.head_to_batch_dim(query, out_dim=4) 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_key_proj = attn.head_to_batch_dim(encoder_hidden_states_key_proj, out_dim=4) encoder_hidden_states_value_proj = attn.head_to_batch_dim(encoder_hidden_states_value_proj, out_dim=4) if not attn.only_cross_attention: key = attn.to_k(hidden_states) value = attn.to_v(hidden_states) key = attn.head_to_batch_dim(key, out_dim=4) value = attn.head_to_batch_dim(value, out_dim=4) key = torch.cat([encoder_hidden_states_key_proj, key], dim=2) value = torch.cat([encoder_hidden_states_value_proj, value], dim=2) else: key = encoder_hidden_states_key_proj value = encoder_hidden_states_value_proj # 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, residual.shape[1]) # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) hidden_states = hidden_states.transpose(-1, -2).reshape(residual.shape) hidden_states = hidden_states + residual return hidden_states class LoRAAttnAddedKVProcessor(nn.Module): def __init__(self, hidden_size, cross_attention_dim=None, rank=4): super().__init__() self.hidden_size = hidden_size self.cross_attention_dim = cross_attention_dim self.rank = rank self.to_q_lora = LoRALinearLayer(hidden_size, hidden_size, rank) self.add_k_proj_lora = LoRALinearLayer(cross_attention_dim or hidden_size, hidden_size, rank) self.add_v_proj_lora = LoRALinearLayer(cross_attention_dim or hidden_size, hidden_size, rank) self.to_k_lora = LoRALinearLayer(hidden_size, hidden_size, rank) self.to_v_lora = LoRALinearLayer(hidden_size, hidden_size, rank) self.to_out_lora = LoRALinearLayer(hidden_size, hidden_size, rank) def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None, scale=1.0): residual = hidden_states hidden_states = hidden_states.view(hidden_states.shape[0], hidden_states.shape[1], -1).transpose(1, 2) batch_size, sequence_length, _ = hidden_states.shape attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) 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) hidden_states = attn.group_norm(hidden_states.transpose(1, 2)).transpose(1, 2) query = attn.to_q(hidden_states) + scale * self.to_q_lora(hidden_states) query = attn.head_to_batch_dim(query) encoder_hidden_states_key_proj = attn.add_k_proj(encoder_hidden_states) + scale * self.add_k_proj_lora( encoder_hidden_states ) encoder_hidden_states_value_proj = attn.add_v_proj(encoder_hidden_states) + scale * self.add_v_proj_lora( encoder_hidden_states ) encoder_hidden_states_key_proj = attn.head_to_batch_dim(encoder_hidden_states_key_proj) encoder_hidden_states_value_proj = attn.head_to_batch_dim(encoder_hidden_states_value_proj) if not attn.only_cross_attention: key = attn.to_k(hidden_states) + scale * self.to_k_lora(hidden_states) value = attn.to_v(hidden_states) + scale * self.to_v_lora(hidden_states) key = attn.head_to_batch_dim(key) value = attn.head_to_batch_dim(value) key = torch.cat([encoder_hidden_states_key_proj, key], dim=1) value = torch.cat([encoder_hidden_states_value_proj, value], dim=1) else: key = encoder_hidden_states_key_proj value = encoder_hidden_states_value_proj attention_probs = attn.get_attention_scores(query, key, attention_mask) hidden_states = torch.bmm(attention_probs, value) hidden_states = attn.batch_to_head_dim(hidden_states) # linear proj hidden_states = attn.to_out[0](hidden_states) + scale * self.to_out_lora(hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) hidden_states = hidden_states.transpose(-1, -2).reshape(residual.shape) hidden_states = hidden_states + residual return hidden_states class XFormersAttnProcessor: def __init__(self, attention_op: Optional[Callable] = None): self.attention_op = attention_op def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None): 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 ) attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) 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) query = attn.head_to_batch_dim(query).contiguous() key = attn.head_to_batch_dim(key).contiguous() value = attn.head_to_batch_dim(value).contiguous() hidden_states = xformers.ops.memory_efficient_attention( query, key, value, attn_bias=attention_mask, op=self.attention_op, scale=attn.scale ) hidden_states = hidden_states.to(query.dtype) hidden_states = attn.batch_to_head_dim(hidden_states) # 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 AttnProcessor2_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 __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None): 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 ) inner_dim = hidden_states.shape[-1] if 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]) 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) 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) # 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 LoRAXFormersAttnProcessor(nn.Module): def __init__(self, hidden_size, cross_attention_dim, rank=4, attention_op: Optional[Callable] = None): super().__init__() self.hidden_size = hidden_size self.cross_attention_dim = cross_attention_dim self.rank = rank self.attention_op = attention_op self.to_q_lora = LoRALinearLayer(hidden_size, hidden_size, rank) self.to_k_lora = LoRALinearLayer(cross_attention_dim or hidden_size, hidden_size, rank) self.to_v_lora = LoRALinearLayer(cross_attention_dim or hidden_size, hidden_size, rank) self.to_out_lora = LoRALinearLayer(hidden_size, hidden_size, rank) def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None, scale=1.0): 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 ) attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) 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) + scale * self.to_q_lora(hidden_states) query = attn.head_to_batch_dim(query).contiguous() 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) + scale * self.to_k_lora(encoder_hidden_states) value = attn.to_v(encoder_hidden_states) + scale * self.to_v_lora(encoder_hidden_states) key = attn.head_to_batch_dim(key).contiguous() value = attn.head_to_batch_dim(value).contiguous() hidden_states = xformers.ops.memory_efficient_attention( query, key, value, attn_bias=attention_mask, op=self.attention_op, scale=attn.scale ) hidden_states = attn.batch_to_head_dim(hidden_states) # linear proj hidden_states = attn.to_out[0](hidden_states) + scale * self.to_out_lora(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 CustomDiffusionXFormersAttnProcessor(nn.Module): def __init__( self, train_kv=True, train_q_out=False, hidden_size=None, cross_attention_dim=None, out_bias=True, dropout=0.0, attention_op: Optional[Callable] = None, ): super().__init__() self.train_kv = train_kv self.train_q_out = train_q_out self.hidden_size = hidden_size self.cross_attention_dim = cross_attention_dim self.attention_op = attention_op # `_custom_diffusion` id for easy serialization and loading. if self.train_kv: self.to_k_custom_diffusion = nn.Linear(cross_attention_dim or hidden_size, hidden_size, bias=False) self.to_v_custom_diffusion = nn.Linear(cross_attention_dim or hidden_size, hidden_size, bias=False) if self.train_q_out: self.to_q_custom_diffusion = nn.Linear(hidden_size, hidden_size, bias=False) self.to_out_custom_diffusion = nn.ModuleList([]) self.to_out_custom_diffusion.append(nn.Linear(hidden_size, hidden_size, bias=out_bias)) self.to_out_custom_diffusion.append(nn.Dropout(dropout)) def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None): batch_size, sequence_length, _ = ( hidden_states.shape if encoder_hidden_states is None else encoder_hidden_states.shape ) attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) if self.train_q_out: query = self.to_q_custom_diffusion(hidden_states) else: query = attn.to_q(hidden_states) if encoder_hidden_states is None: crossattn = False encoder_hidden_states = hidden_states else: crossattn = True if attn.norm_cross: encoder_hidden_states = attn.norm_encoder_hidden_states(encoder_hidden_states) if self.train_kv: key = self.to_k_custom_diffusion(encoder_hidden_states) value = self.to_v_custom_diffusion(encoder_hidden_states) else: key = attn.to_k(encoder_hidden_states) value = attn.to_v(encoder_hidden_states) if crossattn: detach = torch.ones_like(key) detach[:, :1, :] = detach[:, :1, :] * 0.0 key = detach * key + (1 - detach) * key.detach() value = detach * value + (1 - detach) * value.detach() query = attn.head_to_batch_dim(query).contiguous() key = attn.head_to_batch_dim(key).contiguous() value = attn.head_to_batch_dim(value).contiguous() hidden_states = xformers.ops.memory_efficient_attention( query, key, value, attn_bias=attention_mask, op=self.attention_op, scale=attn.scale ) hidden_states = hidden_states.to(query.dtype) hidden_states = attn.batch_to_head_dim(hidden_states) if self.train_q_out: # linear proj hidden_states = self.to_out_custom_diffusion[0](hidden_states) # dropout hidden_states = self.to_out_custom_diffusion[1](hidden_states) else: # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) return hidden_states class SlicedAttnProcessor: def __init__(self, slice_size): self.slice_size = slice_size def __call__(self, attn: Attention, hidden_states, encoder_hidden_states=None, attention_mask=None): 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 ) attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) 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) dim = query.shape[-1] query = attn.head_to_batch_dim(query) 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) key = attn.head_to_batch_dim(key) value = attn.head_to_batch_dim(value) batch_size_attention, query_tokens, _ = query.shape hidden_states = torch.zeros( (batch_size_attention, query_tokens, dim // attn.heads), device=query.device, dtype=query.dtype ) for i in range(batch_size_attention // self.slice_size): start_idx = i * self.slice_size end_idx = (i + 1) * self.slice_size query_slice = query[start_idx:end_idx] key_slice = key[start_idx:end_idx] attn_mask_slice = attention_mask[start_idx:end_idx] if attention_mask is not None else None attn_slice = attn.get_attention_scores(query_slice, key_slice, attn_mask_slice) attn_slice = torch.bmm(attn_slice, value[start_idx:end_idx]) hidden_states[start_idx:end_idx] = attn_slice hidden_states = attn.batch_to_head_dim(hidden_states) # 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 SlicedAttnAddedKVProcessor: def __init__(self, slice_size): self.slice_size = slice_size def __call__(self, attn: "Attention", hidden_states, encoder_hidden_states=None, attention_mask=None): residual = hidden_states hidden_states = hidden_states.view(hidden_states.shape[0], hidden_states.shape[1], -1).transpose(1, 2) batch_size, sequence_length, _ = hidden_states.shape attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) 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) hidden_states = attn.group_norm(hidden_states.transpose(1, 2)).transpose(1, 2) query = attn.to_q(hidden_states) dim = query.shape[-1] query = attn.head_to_batch_dim(query) 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_key_proj = attn.head_to_batch_dim(encoder_hidden_states_key_proj) encoder_hidden_states_value_proj = attn.head_to_batch_dim(encoder_hidden_states_value_proj) if not attn.only_cross_attention: key = attn.to_k(hidden_states) value = attn.to_v(hidden_states) key = attn.head_to_batch_dim(key) value = attn.head_to_batch_dim(value) key = torch.cat([encoder_hidden_states_key_proj, key], dim=1) value = torch.cat([encoder_hidden_states_value_proj, value], dim=1) else: key = encoder_hidden_states_key_proj value = encoder_hidden_states_value_proj batch_size_attention, query_tokens, _ = query.shape hidden_states = torch.zeros( (batch_size_attention, query_tokens, dim // attn.heads), device=query.device, dtype=query.dtype ) for i in range(batch_size_attention // self.slice_size): start_idx = i * self.slice_size end_idx = (i + 1) * self.slice_size query_slice = query[start_idx:end_idx] key_slice = key[start_idx:end_idx] attn_mask_slice = attention_mask[start_idx:end_idx] if attention_mask is not None else None attn_slice = attn.get_attention_scores(query_slice, key_slice, attn_mask_slice) attn_slice = torch.bmm(attn_slice, value[start_idx:end_idx]) hidden_states[start_idx:end_idx] = attn_slice hidden_states = attn.batch_to_head_dim(hidden_states) # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) hidden_states = hidden_states.transpose(-1, -2).reshape(residual.shape) hidden_states = hidden_states + residual return hidden_states AttentionProcessor = Union[ AttnProcessor, AttnProcessor2_0, XFormersAttnProcessor, SlicedAttnProcessor, AttnAddedKVProcessor, SlicedAttnAddedKVProcessor, AttnAddedKVProcessor2_0, LoRAAttnProcessor, LoRAXFormersAttnProcessor, LoRAAttnAddedKVProcessor, CustomDiffusionAttnProcessor, CustomDiffusionXFormersAttnProcessor, ]