Function prefill_attention_paged_turbo_64 

pub fn prefill_attention_paged_turbo_64(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    q: DevicePtr,
    k_cache: DevicePtr,
    v_cache: DevicePtr,
    output: DevicePtr,
    block_table: DevicePtr,
    q_len: u32,
    kv_len: u32,
    q_offset: u32,
    num_q_heads: u32,
    num_kv_heads: u32,
    head_dim: u32,
    cache_block_size: u32,
    sliding_window: u32,
    inv_sqrt_d: f32,
    block_stride_bytes: u64,
    data_section_bytes: u64,
    stream: u64,
) -> Result<()>

Paged prefill Flash Attention — symmetric TurboQuant KV cache, BR=64. Shared launch wrapper for the turbo8 / turbo4 / turbo3 _64 kernel entries: identical ABI, the caller selects the dtype via kernel and passes that pool’s block stride + data-section offset.