// SPDX-FileCopyrightText: © 2026 Tenstorrent Inc. // SPDX-License-Identifier: Apache-2.0 // cmm GELU helper (round 8), NCRISC: the pre-GELU fc1-output pages assigned to this helper core -> CB 20. // Round 11 (HELP_RD_ALL, default): every read is issued up front, tagged with a transaction id (1 + i % 15), and page i // is pushed after the trid-i read barrier (the library DRAM-sharded reader pattern; the plain-counter early signal of // round 10 was the unsafe one), instead of one read + full barrier per page (~0.5 us of latency per page). // compile-time: TensorAccessorArgs(pre). runtime: pre_addr, n, then n page indices (fixed length CMM_HELP_MAXT). #include #include "api/dataflow/dataflow_api.h" void kernel_main() { const uint32_t pre_addr = get_arg_val(0); const uint32_t n = get_arg_val(1); constexpr auto pre_args = TensorAccessorArgs<0>(); constexpr uint32_t cb = 20; const uint32_t page = get_local_cb_interface(cb).fifo_page_size; const auto pre = TensorAccessor(pre_args, pre_addr, page); #ifdef HELP_RD_ALL // CB 20 holds CMM_HELP_MAXT >= n pages: reserve all, issue all cb_reserve_back(cb, n); uint32_t dst = get_write_ptr(cb); for (uint32_t i = 0; i < n; ++i) { noc_async_read_set_trid(1 + i % 15); noc_async_read(pre.get_noc_addr(get_arg_val(2 + i)), dst, page); dst += page; } for (uint32_t i = 0; i < n; ++i) { noc_async_read_barrier_with_trid(1 + i % 15); cb_push_back(cb, 1); } noc_async_read_set_trid(0); noc_async_read_barrier(); #elif defined(HELP_RD_WIN) // a window of HELP_RD_WIN reads in flight (trid 1 + i % W): page i is pushed after its trid barrier constexpr uint32_t W = HELP_RD_WIN; cb_reserve_back(cb, n); const uint32_t base = get_write_ptr(cb); uint32_t issued = 0; for (uint32_t i = 0; i < n; ++i) { while (issued < n && issued < i + W) { noc_async_read_set_trid(1 + issued % W); noc_async_read(pre.get_noc_addr(get_arg_val(2 + issued)), base + issued * page, page); ++issued; } noc_async_read_barrier_with_trid(1 + i % W); cb_push_back(cb, 1); } noc_async_read_set_trid(0); noc_async_read_barrier(); #else for (uint32_t i = 0; i < n; ++i) { cb_reserve_back(cb, 1); noc_async_read(pre.get_noc_addr(get_arg_val(2 + i)), get_write_ptr(cb), page); noc_async_read_barrier(); cb_push_back(cb, 1); } #endif #ifdef HELP_PF // round 11: after its GELU inputs, this core reads the first K blocks of a LATER xmm's packed weight (its own // N-group: it is that xmm's weight sender) from DRAM into its persistent L1 prefetch buffer (tt_kernels.XmmPrefetch). // runtime args 2 + HELP_MAXT ..: npf, w_addr, npf x (bank, bank offset, local dst, bytes) constexpr uint32_t P = 2 + HELP_MAXT; const uint32_t npf = get_arg_val(P); if (npf) { const uint32_t w_addr = get_arg_val(P + 1); for (uint32_t i = 0; i < npf; ++i) { const uint32_t bank = get_arg_val(P + 2 + 4 * i), off = get_arg_val(P + 3 + 4 * i); const uint32_t ldst = get_arg_val(P + 4 + 4 * i), bytes = get_arg_val(P + 5 + 4 * i); noc_async_read(get_noc_addr_from_bank_id(bank, w_addr + off), ldst, bytes); } noc_async_read_barrier(); } #endif }