[ET-VK] Replace Uniform buffers with push constants for permute op

Pull Request resolved: #7231

This diff replaces uniform buffers with push constants for permute op in the Vulkan backend of Executorch. The changes include updating the GLSL code to use push constants instead of uniform buffers and updating the C++ code to pass the sizes as push constants to the shader.
ghstack-source-id: 258464051
@exported-using-ghexport

Differential Revision: [D66890825](https://our.internmc.facebook.com/intern/diff/D66890825/)

Author: trivedivivek

backends/vulkan/runtime/graph/ops/glsl/permute.glsl

@@ -19,15 +19,9 @@ layout(std430) buffer;
 layout(set = 0, binding = 0, ${IMAGE_FORMAT[DTYPE]}) uniform PRECISION restrict writeonly ${IMAGE_T[NDIM][DTYPE]} image_out;
 layout(set = 0, binding = 1) uniform PRECISION ${SAMPLER_T[NDIM][DTYPE]} image_in;
 
-layout(set = 0, binding = 2) uniform PRECISION restrict OutLimits {
-  ivec3 out_limits;
-};
-
-layout(set = 0, binding = 3) uniform PRECISION restrict Sizes {
+layout(push_constant) uniform PRECISION restrict Block {
+  ivec4 out_limits;
   ivec4 sizes;
-};
-
-layout(set = 0, binding = 4) uniform PRECISION restrict Block {
   // output dims
   ivec4 out_ndims;
   // x = output channels aligned to 4, y = input channels aligned to 4
@@ -41,7 +35,7 @@ layout(local_size_x_id = 0, local_size_y_id = 1, local_size_z_id = 2) in;
 void main() {
   const u16vec3 pos = u16vec3(gl_GlobalInvocationID);
 
-  if (any(greaterThanEqual(pos, out_limits))) {
+  if (any(greaterThanEqual(pos, out_limits.xyz))) {
     return;
   }
 

backends/vulkan/runtime/graph/ops/impl/Permute.cpp

@@ -75,13 +75,7 @@ void add_permute_node(
   int32_t out_c_aligned = utils::align_up_4(out_channels);
   int32_t in_c_aligned = utils::align_up_4(in_channels);
 
-  const struct Block final {
-    ivec4 out_ndims;
-    ivec2 ch_info;
-  } params{
-      out_dims,
-      {out_c_aligned, in_c_aligned},
-  };
+  const ivec2 ch_info = {out_c_aligned, in_c_aligned};
 
   graph.execute_nodes().emplace_back(new DispatchNode(
       graph,
@@ -90,14 +84,16 @@ void add_permute_node(
       graph.create_local_wg_size(out),
       {{out, vkapi::MemoryAccessType::WRITE},
        {in, vkapi::MemoryAccessType::READ}},
-      {t_out->logical_limits_ubo(),
-       t_out->sizes_ubo(),
-       graph.create_params_buffer(params)},
+      {},
       // Specialization Constants
       {},
       // Resizing Logic
       nullptr,
-      {}));
+      {},
+      {{graph.logical_limits_pc_of(out),
+        graph.sizes_pc_of(out),
+        PushConstantDataInfo(&out_dims, sizeof(out_dims)),
+        PushConstantDataInfo(&ch_info, sizeof(ch_info))}}));
 }
 
 void add_permute_node(