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Mojo struct

KVCacheMHAOperand

struct KVCacheMHAOperand[cache_t: KVCacheT]

An implementation for mo.opaque KVCacheT arguments to MHA kernels.

We can eventually remove this trait and just add it as a sub-trait in the KVCacheT type, but we need to solve some cyclic dependencies first.

Fields

  • cache (cache_t):

Implemented traits

AnyType, Copyable, DevicePassable, ImplicitlyCopyable, ImplicitlyDestructible, MHAOperand, Movable, RegisterPassable, TrivialRegisterPassable

comptime members

device_type

comptime device_type = KVCacheMHAOperand[cache_t]

dtype

comptime dtype = cache_t.dtype

page_size

comptime page_size = cache_t.page_size_

quantization_enabled

comptime quantization_enabled = cache_t.quantization_enabled

quantization_granularity

comptime quantization_granularity = cache_t.quantization_granularity

scale_dtype

comptime scale_dtype = cache_t.scale_dtype

Methods

__init__

__init__(cache: cache_t) -> Self

get_type_name

static get_type_name() -> String

Returns:

String

block_paged_ptr

block_paged_ptr[tile_size: Int](self, batch_idx: UInt32, start_tok_idx: UInt32, head_idx: UInt32, head_dim_idx: UInt32 = 0) -> UnsafePointer[Scalar[KVCacheMHAOperand[cache_t].dtype], ImmutAnyOrigin]

Returns:

UnsafePointer

scales_block_paged_ptr

scales_block_paged_ptr(self, batch_idx: Int, start_tok_idx: Int, head_idx: Int, head_dim_idx: Int = 0) -> UnsafePointer[Scalar[KVCacheMHAOperand[cache_t].scale_dtype], ImmutAnyOrigin]

Returns:

UnsafePointer

load_scale

load_scale[width: Int](self, batch_idx: Int, start_tok_idx: Int, head_idx: Int, head_dim_idx: Int) -> SIMD[KVCacheMHAOperand[cache_t].scale_dtype, width]

Returns:

SIMD

cache_length

cache_length(self, batch_idx: Int) -> Int

Returns:

Int

max_context_length

max_context_length(self) -> UInt32

Returns:

UInt32

num_kv_rows

num_kv_rows(self) -> Int

Returns the total number of virtual rows in the KV memory view.

Returns:

Int

row_idx

row_idx(self, batch_idx: UInt32, start_tok_idx: UInt32) -> UInt32

Returns the row idx when viewing the memory as a matrix.

Returns:

UInt32

create_tma_tile

create_tma_tile[swizzle_mode: TensorMapSwizzle, *, BN: Int, depth: Int, BK: Int = padded_depth[KVCacheMHAOperand[cache_t].dtype, swizzle_mode, depth]()](self, ctx: DeviceContext, out tma: TMATensorTile[KVCacheMHAOperand[cache_t].dtype, 3, _padded_shape[3, KVCacheMHAOperand[cache_t].dtype, IndexList(VariadicList(BN, 1, BK), Tuple()), swizzle_mode](), _ragged_shape[3, KVCacheMHAOperand[cache_t].dtype, IndexList(VariadicList(BN, 1, BK), Tuple()), swizzle_mode]()])

Creates a TMA tile for efficient GPU memory transfers.

Returns:

TMATensorTile

create_scale_tma_tile

create_scale_tma_tile[BMN: Int](self, ctx: DeviceContext, out tma: TMATensorTile[KVCacheMHAOperand[cache_t].scale_dtype, 2, Index[Int, Int](VariadicPack(1, BMN))])

Creates a TMA tile for efficient GPU memory transfers. This is useful for m-major MMA operations where we don't need to mask any extra rows.

Returns:

TMATensorTile

create_ragged_tma_tile

create_ragged_tma_tile[swizzle_mode: TensorMapSwizzle, *, BN: Int, depth: Int, BK: Int = padded_depth[KVCacheMHAOperand[cache_t].dtype, swizzle_mode, depth]()](self, ctx: DeviceContext, out tma: RaggedTMA3DTile[KVCacheMHAOperand[cache_t].dtype, swizzle_mode, BN, BK])

Returns:

RaggedTMA3DTile

create_rope_tma_tile

create_rope_tma_tile[swizzle_mode: TensorMapSwizzle, *, BN: Int, BK: Int, padded_depth: Int](self, ctx: DeviceContext, out tma: TMATensorTile[DType.bfloat16, 3, _padded_shape[3, DType.bfloat16, IndexList(VariadicList(BN, 1, BK), Tuple()), swizzle_mode](), _ragged_shape[3, DType.bfloat16, IndexList(VariadicList(BN, 1, BK), Tuple()), swizzle_mode]()])

Delegates to the underlying KVCache to create a BF16 rope TMA tile.

Returns:

TMATensorTile

create_gather4_tma_tile

create_gather4_tma_tile[row_width: Int, swizzle_mode: TensorMapSwizzle = TensorMapSwizzle.SWIZZLE_NONE](self, ctx: DeviceContext, out tma: TMATensorTile[KVCacheMHAOperand[cache_t].dtype, 2, IndexList(VariadicList(4, row_width), Tuple()), IndexList(VariadicList(1, row_width), Tuple())])

Creates a 2D TMA gather4 descriptor for this KV cache operand.

Returns:

TMATensorTile

scales_raw_ptr

scales_raw_ptr(self) -> UnsafePointer[Float32, MutAnyOrigin]

Returns the base pointer to the quantization scales tensor.

Returns:

UnsafePointer

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