[Kandinsky 3.0] Follow-up TODOs (huggingface#5944)

clean-up kendinsky 3.0

src/diffusers/models/__init__.py

@@ -42,7 +42,7 @@
     _import_structure["unet_2d"] = ["UNet2DModel"]
     _import_structure["unet_2d_condition"] = ["UNet2DConditionModel"]
     _import_structure["unet_3d_condition"] = ["UNet3DConditionModel"]
-    _import_structure["unet_kandi3"] = ["Kandinsky3UNet"]
+    _import_structure["unet_kandinsky3"] = ["Kandinsky3UNet"]
     _import_structure["unet_motion_model"] = ["MotionAdapter", "UNetMotionModel"]
     _import_structure["unet_spatio_temporal_condition"] = ["UNetSpatioTemporalConditionModel"]
     _import_structure["vq_model"] = ["VQModel"]
@@ -72,7 +72,7 @@
         from .unet_2d import UNet2DModel
         from .unet_2d_condition import UNet2DConditionModel
         from .unet_3d_condition import UNet3DConditionModel
-        from .unet_kandi3 import Kandinsky3UNet
+        from .unet_kandinsky3 import Kandinsky3UNet
         from .unet_motion_model import MotionAdapter, UNetMotionModel
         from .unet_spatio_temporal_condition import UNetSpatioTemporalConditionModel
         from .vq_model import VQModel

src/diffusers/models/attention_processor.py

@@ -16,7 +16,7 @@
 
 import torch
 import torch.nn.functional as F
-from torch import einsum, nn
+from torch import nn
 
 from ..utils import USE_PEFT_BACKEND, deprecate, logging
 from ..utils.import_utils import is_xformers_available
@@ -109,15 +109,17 @@ def __init__(
         residual_connection: bool = False,
         _from_deprecated_attn_block: bool = False,
         processor: Optional["AttnProcessor"] = None,
+        out_dim: int = None,
     ):
         super().__init__()
-        self.inner_dim = dim_head * heads
+        self.inner_dim = out_dim if out_dim is not None else dim_head * heads
         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.out_dim = out_dim if out_dim is not None else query_dim
 
         # 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
@@ -126,7 +128,7 @@ def __init__(
         self.scale_qk = scale_qk
         self.scale = dim_head**-0.5 if self.scale_qk else 1.0
 
-        self.heads = heads
+        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`
@@ -193,7 +195,7 @@ def __init__(
             self.add_v_proj = linear_cls(added_kv_proj_dim, self.inner_dim)
 
         self.to_out = nn.ModuleList([])
-        self.to_out.append(linear_cls(self.inner_dim, query_dim, bias=out_bias))
+        self.to_out.append(linear_cls(self.inner_dim, self.out_dim, bias=out_bias))
         self.to_out.append(nn.Dropout(dropout))
 
         # set attention processor
@@ -2219,44 +2221,6 @@ def __call__(
         return hidden_states
 
 
-# TODO(Yiyi): This class should not exist, we can replace it with a normal attention processor I believe
-# this way torch.compile and co. will work as well
-class Kandi3AttnProcessor:
-    r"""
-    Default kandinsky3 proccesor for performing attention-related computations.
-    """
-
-    @staticmethod
-    def _reshape(hid_states, h):
-        b, n, f = hid_states.shape
-        d = f // h
-        return hid_states.unsqueeze(-1).reshape(b, n, h, d).permute(0, 2, 1, 3)
-
-    def __call__(
-        self,
-        attn,
-        x,
-        context,
-        context_mask=None,
-    ):
-        query = self._reshape(attn.to_q(x), h=attn.num_heads)
-        key = self._reshape(attn.to_k(context), h=attn.num_heads)
-        value = self._reshape(attn.to_v(context), h=attn.num_heads)
-
-        attention_matrix = einsum("b h i d, b h j d -> b h i j", query, key)
-
-        if context_mask is not None:
-            max_neg_value = -torch.finfo(attention_matrix.dtype).max
-            context_mask = context_mask.unsqueeze(1).unsqueeze(1)
-            attention_matrix = attention_matrix.masked_fill(~(context_mask != 0), max_neg_value)
-        attention_matrix = (attention_matrix * attn.scale).softmax(dim=-1)
-
-        out = einsum("b h i j, b h j d -> b h i d", attention_matrix, value)
-        out = out.permute(0, 2, 1, 3).reshape(out.shape[0], out.shape[2], -1)
-        out = attn.to_out[0](out)
-        return out
-
-
 LORA_ATTENTION_PROCESSORS = (
     LoRAAttnProcessor,
     LoRAAttnProcessor2_0,
@@ -2282,7 +2246,6 @@ def __call__(
     LoRAXFormersAttnProcessor,
     IPAdapterAttnProcessor,
     IPAdapterAttnProcessor2_0,
-    Kandi3AttnProcessor,
 )
 
 AttentionProcessor = Union[