import inspect import math from typing import Callable, List, Optional, Tuple, Union import torch import torch.nn.functional as F from torch import nn from diffusers.utils import deprecate, logging from diffusers.utils.import_utils import is_torch_npu_available, is_xformers_available from diffusers.utils.torch_utils import is_torch_version, maybe_allow_in_graph logger = logging.get_logger(__name__) # pylint: disable=invalid-name if is_torch_npu_available(): import torch_npu 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. kv_heads (`int`, *optional*, defaults to `None`): The number of key and value heads to use for multi-head attention. Defaults to `heads`. If `kv_heads=heads`, the model will use Multi Head Attention (MHA), if `kv_heads=1` the model will use Multi Query Attention (MQA) otherwise GQA is used. 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, kv_heads: Optional[int] = None, 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, added_kv_proj_dim: Optional[int] = None, added_proj_bias: Optional[bool] = True, 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, out_context_dim: int = None, context_pre_only=None, pre_only=False, elementwise_affine: bool = True, is_causal: bool = False, ): super().__init__() # To prevent circular import. from .normalization import FP32LayerNorm, LpNorm, RMSNorm self.inner_dim = out_dim if out_dim is not None else dim_head * heads self.inner_kv_dim = self.inner_dim if kv_heads is None else dim_head * kv_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.out_context_dim = out_context_dim if out_context_dim is not None else query_dim self.context_pre_only = context_pre_only self.pre_only = pre_only self.is_causal = is_causal # 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, elementwise_affine=elementwise_affine) self.norm_k = nn.LayerNorm(dim_head, eps=eps, elementwise_affine=elementwise_affine) elif qk_norm == "fp32_layer_norm": self.norm_q = FP32LayerNorm(dim_head, elementwise_affine=False, bias=False, eps=eps) self.norm_k = FP32LayerNorm(dim_head, elementwise_affine=False, bias=False, eps=eps) elif qk_norm == "layer_norm_across_heads": # Lumina applys qk norm across all heads self.norm_q = nn.LayerNorm(dim_head * heads, eps=eps) self.norm_k = nn.LayerNorm(dim_head * kv_heads, eps=eps) elif qk_norm == "rms_norm": self.norm_q = RMSNorm(dim_head, eps=eps) self.norm_k = RMSNorm(dim_head, eps=eps) elif qk_norm == "l2": self.norm_q = LpNorm(p=2, dim=-1, eps=eps) self.norm_k = LpNorm(p=2, dim=-1, eps=eps) else: raise ValueError(f"unknown qk_norm: {qk_norm}. Should be None,'layer_norm','fp32_layer_norm','rms_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_kv_dim, bias=bias) self.to_v = nn.Linear(self.cross_attention_dim, self.inner_kv_dim, bias=bias) else: self.to_k = None self.to_v = None self.added_proj_bias = added_proj_bias if self.added_kv_proj_dim is not None: self.add_k_proj = nn.Linear(added_kv_proj_dim, self.inner_kv_dim, bias=added_proj_bias) self.add_v_proj = nn.Linear(added_kv_proj_dim, self.inner_kv_dim, bias=added_proj_bias) if self.context_pre_only is not None: self.add_q_proj = nn.Linear(added_kv_proj_dim, self.inner_dim, bias=added_proj_bias) if not self.pre_only: 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: self.to_add_out = nn.Linear(self.inner_dim, self.out_context_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_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, ), ) is_ip_adapter = hasattr(self, "processor") and isinstance( self.processor, (IPAdapterAttnProcessor, IPAdapterAttnProcessor2_0, IPAdapterXFormersAttnProcessor), ) if use_memory_efficient_attention_xformers: if is_added_kv_processor and is_custom_diffusion: raise NotImplementedError( f"Memory efficient attention is currently not supported for 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_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) elif is_ip_adapter: processor = IPAdapterXFormersAttnProcessor( hidden_size=self.processor.hidden_size, cross_attention_dim=self.processor.cross_attention_dim, num_tokens=self.processor.num_tokens, scale=self.processor.scale, attention_op=attention_op, ) processor.load_state_dict(self.processor.state_dict()) if hasattr(self.processor, "to_k_ip"): processor.to( device=self.processor.to_k_ip[0].weight.device, dtype=self.processor.to_k_ip[0].weight.dtype ) else: processor = XFormersAttnProcessor(attention_op=attention_op) else: if 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) elif is_ip_adapter: processor = IPAdapterAttnProcessor2_0( hidden_size=self.processor.hidden_size, cross_attention_dim=self.processor.cross_attention_dim, num_tokens=self.processor.num_tokens, scale=self.processor.scale, ) processor.load_state_dict(self.processor.state_dict()) if hasattr(self.processor, "to_k_ip"): processor.to( device=self.processor.to_k_ip[0].weight.device, dtype=self.processor.to_k_ip[0].weight.dtype ) 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 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: Optional[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) # handle added projections for SD3 and others. if hasattr(self, "add_q_proj") and hasattr(self, "add_k_proj") and hasattr(self, "add_v_proj"): concatenated_weights = torch.cat( [self.add_q_proj.weight.data, self.add_k_proj.weight.data, self.add_v_proj.weight.data] ) in_features = concatenated_weights.shape[1] out_features = concatenated_weights.shape[0] self.to_added_qkv = nn.Linear( in_features, out_features, bias=self.added_proj_bias, device=device, dtype=dtype ) self.to_added_qkv.weight.copy_(concatenated_weights) if self.added_proj_bias: concatenated_bias = torch.cat( [self.add_q_proj.bias.data, self.add_k_proj.bias.data, self.add_v_proj.bias.data] ) self.to_added_qkv.bias.copy_(concatenated_bias) self.fused_projections = fuse class MochiAttnProcessor2_0: """Attention processor used in Mochi.""" def __init__(self): if not hasattr(F, "scaled_dot_product_attention"): raise ImportError("MochiAttnProcessor2_0 requires PyTorch 2.0. To use it, please upgrade PyTorch to 2.0.") def __call__( self, attn: Attention, hidden_states: torch.Tensor, encoder_hidden_states: torch.Tensor, attention_mask: Optional[torch.Tensor] = None, image_rotary_emb: Optional[torch.Tensor] = None, ) -> torch.Tensor: query = attn.to_q(hidden_states) key = attn.to_k(hidden_states) value = attn.to_v(hidden_states) query = query.unflatten(2, (attn.heads, -1)) key = key.unflatten(2, (attn.heads, -1)) value = value.unflatten(2, (attn.heads, -1)) if attn.norm_q is not None: query = attn.norm_q(query) if attn.norm_k is not None: key = attn.norm_k(key) encoder_query = attn.add_q_proj(encoder_hidden_states) encoder_key = attn.add_k_proj(encoder_hidden_states) encoder_value = attn.add_v_proj(encoder_hidden_states) encoder_query = encoder_query.unflatten(2, (attn.heads, -1)) encoder_key = encoder_key.unflatten(2, (attn.heads, -1)) encoder_value = encoder_value.unflatten(2, (attn.heads, -1)) if attn.norm_added_q is not None: encoder_query = attn.norm_added_q(encoder_query) if attn.norm_added_k is not None: encoder_key = attn.norm_added_k(encoder_key) if image_rotary_emb is not None: def apply_rotary_emb(x, freqs_cos, freqs_sin): x_even = x[..., 0::2].float() x_odd = x[..., 1::2].float() cos = (x_even * freqs_cos - x_odd * freqs_sin).to(x.dtype) sin = (x_even * freqs_sin + x_odd * freqs_cos).to(x.dtype) return torch.stack([cos, sin], dim=-1).flatten(-2) query = apply_rotary_emb(query, *image_rotary_emb) key = apply_rotary_emb(key, *image_rotary_emb) query, key, value = query.transpose(1, 2), key.transpose(1, 2), value.transpose(1, 2) encoder_query, encoder_key, encoder_value = ( encoder_query.transpose(1, 2), encoder_key.transpose(1, 2), encoder_value.transpose(1, 2), ) sequence_length = query.size(2) encoder_sequence_length = encoder_query.size(2) query = torch.cat([query, encoder_query], dim=2) key = torch.cat([key, encoder_key], dim=2) value = torch.cat([value, encoder_value], dim=2) hidden_states = F.scaled_dot_product_attention(query, key, value, dropout_p=0.0, is_causal=False) hidden_states = hidden_states.transpose(1, 2).flatten(2, 3) hidden_states = hidden_states.to(query.dtype) hidden_states, encoder_hidden_states = hidden_states.split_with_sizes( (sequence_length, encoder_sequence_length), dim=1 ) # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) if hasattr(attn, "to_add_out"): encoder_hidden_states = attn.to_add_out(encoder_hidden_states) return hidden_states, encoder_hidden_states class CogVideoXAttnProcessor2_0: r""" Processor for implementing scaled dot-product attention for the CogVideoX model. It applies a rotary embedding on query and key vectors, but does not include spatial normalization. """ def __init__(self): if not hasattr(F, "scaled_dot_product_attention"): raise ImportError("CogVideoXAttnProcessor requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0.") def __call__( self, attn: Attention, hidden_states: torch.Tensor, encoder_hidden_states: torch.Tensor, attention_mask: Optional[torch.Tensor] = None, image_rotary_emb: Optional[torch.Tensor] = None, ) -> torch.Tensor: text_seq_length = encoder_hidden_states.size(1) hidden_states = torch.cat([encoder_hidden_states, hidden_states], dim=1) batch_size, sequence_length, _ = ( hidden_states.shape if encoder_hidden_states is None else encoder_hidden_states.shape ) if attention_mask is not None: attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) attention_mask = attention_mask.view(batch_size, attn.heads, -1, attention_mask.shape[-1]) 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) # Apply RoPE if needed if image_rotary_emb is not None: from .embeddings import apply_rotary_emb query[:, :, text_seq_length:] = apply_rotary_emb(query[:, :, text_seq_length:], image_rotary_emb) if not attn.is_cross_attention: key[:, :, text_seq_length:] = apply_rotary_emb(key[:, :, text_seq_length:], 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) # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) encoder_hidden_states, hidden_states = hidden_states.split( [text_seq_length, hidden_states.size(1) - text_seq_length], dim=1 ) return hidden_states, encoder_hidden_states class FusedCogVideoXAttnProcessor2_0: r""" Processor for implementing scaled dot-product attention for the CogVideoX model. It applies a rotary embedding on query and key vectors, but does not include spatial normalization. """ def __init__(self): if not hasattr(F, "scaled_dot_product_attention"): raise ImportError("CogVideoXAttnProcessor requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0.") def __call__( self, attn: Attention, hidden_states: torch.Tensor, encoder_hidden_states: torch.Tensor, attention_mask: Optional[torch.Tensor] = None, image_rotary_emb: Optional[torch.Tensor] = None, ) -> torch.Tensor: text_seq_length = encoder_hidden_states.size(1) hidden_states = torch.cat([encoder_hidden_states, hidden_states], dim=1) batch_size, sequence_length, _ = ( hidden_states.shape if encoder_hidden_states is None else encoder_hidden_states.shape ) if attention_mask is not None: attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size) attention_mask = attention_mask.view(batch_size, attn.heads, -1, attention_mask.shape[-1]) qkv = attn.to_qkv(hidden_states) split_size = qkv.shape[-1] // 3 query, key, value = torch.split(qkv, split_size, dim=-1) 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 image_rotary_emb is not None: from .embeddings import apply_rotary_emb query[:, :, text_seq_length:] = apply_rotary_emb(query[:, :, text_seq_length:], image_rotary_emb) if not attn.is_cross_attention: key[:, :, text_seq_length:] = apply_rotary_emb(key[:, :, text_seq_length:], 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) # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) encoder_hidden_states, hidden_states = hidden_states.split( [text_seq_length, hidden_states.size(1) - text_seq_length], dim=1 ) return hidden_states, encoder_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 __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: from .embeddings import apply_rotary_emb query = apply_rotary_emb(query, image_rotary_emb) key = apply_rotary_emb(key, image_rotary_emb) 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) 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 FusedFluxAttnProcessor2_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( "FusedFluxAttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0." ) 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. qkv = attn.to_qkv(hidden_states) split_size = qkv.shape[-1] // 3 query, key, value = torch.split(qkv, split_size, dim=-1) 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` # `context` projections. if encoder_hidden_states is not None: encoder_qkv = attn.to_added_qkv(encoder_hidden_states) split_size = encoder_qkv.shape[-1] // 3 ( encoder_hidden_states_query_proj, encoder_hidden_states_key_proj, encoder_hidden_states_value_proj, ) = torch.split(encoder_qkv, split_size, dim=-1) 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: from .embeddings import apply_rotary_emb query = apply_rotary_emb(query, image_rotary_emb) key = apply_rotary_emb(key, image_rotary_emb) 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) 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 MochiVaeAttnProcessor2_0: r""" Attention processor used in Mochi VAE. """ 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: torch.Tensor, encoder_hidden_states: Optional[torch.Tensor] = None, attention_mask: Optional[torch.Tensor] = None, ) -> torch.Tensor: residual = hidden_states is_single_frame = hidden_states.shape[1] == 1 batch_size, sequence_length, _ = ( hidden_states.shape if encoder_hidden_states is None else encoder_hidden_states.shape ) 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 is_single_frame: hidden_states = attn.to_v(hidden_states) # linear proj hidden_states = attn.to_out[0](hidden_states) # dropout hidden_states = attn.to_out[1](hidden_states) if attn.residual_connection: hidden_states = hidden_states + residual hidden_states = hidden_states / attn.rescale_output_factor return hidden_states query = attn.to_q(hidden_states) if encoder_hidden_states is None: encoder_hidden_states = 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) # 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=attn.is_causal ) 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 attn.residual_connection: hidden_states = hidden_states + residual hidden_states = hidden_states / attn.rescale_output_factor return hidden_states