From 77522be0a56d6fb8db7de2190f7c513e227679cf Mon Sep 17 00:00:00 2001 From: Viacheslav Ovsiienko Date: Thu, 16 Jul 2020 08:23:12 +0000 Subject: [PATCH] net/mlx5: introduce clock queue service routine Service routine is invoked periodically on Rearm Queue completion interrupts, typically once per some milliseconds (1-16) to track clock jitter and wander in robust fashion. It performs the following: - fetches the completed CQEs for Rearm Queue - restarts Rearm Queue on errors - pushes new requests to Rearm Queue to make it continuously running and pushing cross-channel requests to Clock Queue - reads and caches the Clock Queue CQE to be used in datapath - gathers statistics to estimate clock jitter and wander - gathers Clock Queue errors statistics Signed-off-by: Viacheslav Ovsiienko Acked-by: Matan Azrad --- drivers/net/mlx5/mlx5.h | 16 ++ drivers/net/mlx5/mlx5_defs.h | 1 + drivers/net/mlx5/mlx5_rxtx.h | 20 +++ drivers/net/mlx5/mlx5_txpp.c | 338 +++++++++++++++++++++++++++++++++++ 4 files changed, 375 insertions(+) diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h index e8a7b10111..bb2c096b4f 100644 --- a/drivers/net/mlx5/mlx5.h +++ b/drivers/net/mlx5/mlx5.h @@ -555,6 +555,12 @@ struct mlx5_txpp_wq { volatile uint32_t *sq_dbrec; }; +/* Tx packet pacing internal timestamp. */ +struct mlx5_txpp_ts { + rte_atomic64_t ci_ts; + rte_atomic64_t ts; +}; + /* Tx packet pacing structure. */ struct mlx5_dev_txpp { pthread_mutex_t mutex; /* Pacing create/destroy mutex. */ @@ -570,6 +576,15 @@ struct mlx5_dev_txpp { struct mlx5_txpp_wq rearm_queue; /* Clock Queue. */ struct mlx5dv_pp *pp; /* Packet pacing context. */ uint16_t pp_id; /* Packet pacing context index. */ + uint16_t ts_n; /* Number of captured timestamps. */ + uint16_t ts_p; /* Pointer to statisticks timestamp. */ + struct mlx5_txpp_ts *tsa; /* Timestamps sliding window stats. */ + struct mlx5_txpp_ts ts; /* Cached completion id/timestamp. */ + uint32_t sync_lost:1; /* ci/timestamp synchronization lost. */ + /* Statistics counters. */ + rte_atomic32_t err_miss_int; /* Missed service interrupt. */ + rte_atomic32_t err_rearm_queue; /* Rearm Queue errors. */ + rte_atomic32_t err_clock_queue; /* Clock Queue errors. */ }; /* @@ -993,5 +1008,6 @@ void mlx5_os_set_reg_mr_cb(mlx5_reg_mr_t *reg_mr_cb, int mlx5_txpp_start(struct rte_eth_dev *dev); void mlx5_txpp_stop(struct rte_eth_dev *dev); +void mlx5_txpp_interrupt_handler(void *cb_arg); #endif /* RTE_PMD_MLX5_H_ */ diff --git a/drivers/net/mlx5/mlx5_defs.h b/drivers/net/mlx5/mlx5_defs.h index a8626a4acd..7ed3e886bf 100644 --- a/drivers/net/mlx5/mlx5_defs.h +++ b/drivers/net/mlx5/mlx5_defs.h @@ -172,6 +172,7 @@ #define MLX5_TXDB_HEURISTIC 2 /* Tx accurate scheduling on timestamps parameters. */ +#define MLX5_TXPP_WAIT_INIT_TS 1000ul /* How long to wait timestamp. */ #define MLX5_TXPP_CLKQ_SIZE 1 #define MLX5_TXPP_REARM ((1UL << MLX5_WQ_INDEX_WIDTH) / 4) #define MLX5_TXPP_REARM_SQ_SIZE (((1UL << MLX5_CQ_INDEX_WIDTH) / \ diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h index 1b797da820..8a8d2b51a3 100644 --- a/drivers/net/mlx5/mlx5_rxtx.h +++ b/drivers/net/mlx5/mlx5_rxtx.h @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -695,4 +696,23 @@ mlx5_tx_dbrec(struct mlx5_txq_data *txq, volatile struct mlx5_wqe *wqe) mlx5_tx_dbrec_cond_wmb(txq, wqe, 1); } +/** + * Convert timestamp from HW format to linear counter + * from Packet Pacing Clock Queue CQE timestamp format. + * + * @param sh + * Pointer to the device shared context. Might be needed + * to convert according current device configuration. + * @param ts + * Timestamp from CQE to convert. + * @return + * UTC in nanoseconds + */ +static __rte_always_inline uint64_t +mlx5_txpp_convert_rx_ts(struct mlx5_dev_ctx_shared *sh, uint64_t ts) +{ + RTE_SET_USED(sh); + return (ts & UINT32_MAX) + (ts >> 32) * NS_PER_S; +} + #endif /* RTE_PMD_MLX5_RXTX_H_ */ diff --git a/drivers/net/mlx5/mlx5_txpp.c b/drivers/net/mlx5/mlx5_txpp.c index a0ee8720f8..8f7284b935 100644 --- a/drivers/net/mlx5/mlx5_txpp.c +++ b/drivers/net/mlx5/mlx5_txpp.c @@ -1,6 +1,9 @@ /* SPDX-License-Identifier: BSD-3-Clause * Copyright 2020 Mellanox Technologies, Ltd */ +#include +#include + #include #include #include @@ -144,6 +147,33 @@ mlx5_txpp_destroy_clock_queue(struct mlx5_dev_ctx_shared *sh) struct mlx5_txpp_wq *wq = &sh->txpp.clock_queue; mlx5_txpp_destroy_send_queue(wq); + if (sh->txpp.tsa) { + rte_free(sh->txpp.tsa); + sh->txpp.tsa = NULL; + } +} + +static void +mlx5_txpp_doorbell_rearm_queue(struct mlx5_dev_ctx_shared *sh, uint16_t ci) +{ + struct mlx5_txpp_wq *wq = &sh->txpp.rearm_queue; + union { + uint32_t w32[2]; + uint64_t w64; + } cs; + + wq->sq_ci = ci + 1; + cs.w32[0] = rte_cpu_to_be_32(rte_be_to_cpu_32 + (wq->wqes[ci & (wq->sq_size - 1)].ctrl[0]) | (ci - 1) << 8); + cs.w32[1] = wq->wqes[ci & (wq->sq_size - 1)].ctrl[1]; + /* Update SQ doorbell record with new SQ ci. */ + rte_compiler_barrier(); + *wq->sq_dbrec = rte_cpu_to_be_32(wq->sq_ci); + /* Make sure the doorbell record is updated. */ + rte_wmb(); + /* Write to doorbel register to start processing. */ + __mlx5_uar_write64_relaxed(cs.w64, sh->tx_uar->reg_addr, NULL); + rte_wmb(); } static void @@ -433,6 +463,16 @@ mlx5_txpp_create_clock_queue(struct mlx5_dev_ctx_shared *sh) uint32_t umem_size, umem_dbrec; int ret; + sh->txpp.tsa = rte_zmalloc_socket(__func__, + MLX5_TXPP_REARM_SQ_SIZE * + sizeof(struct mlx5_txpp_ts), + 0, sh->numa_node); + if (!sh->txpp.tsa) { + DRV_LOG(ERR, "Failed to allocate memory for CQ stats."); + return -ENOMEM; + } + sh->txpp.ts_p = 0; + sh->txpp.ts_n = 0; /* Allocate memory buffer for CQEs and doorbell record. */ umem_size = sizeof(struct mlx5_cqe) * MLX5_TXPP_CLKQ_SIZE; umem_dbrec = RTE_ALIGN(umem_size, MLX5_DBR_SIZE); @@ -562,6 +602,299 @@ error: return ret; } +/* Enable notification from the Rearm Queue CQ. */ +static inline void +mlx5_txpp_cq_arm(struct mlx5_dev_ctx_shared *sh) +{ + struct mlx5_txpp_wq *aq = &sh->txpp.rearm_queue; + uint32_t arm_sn = aq->arm_sn << MLX5_CQ_SQN_OFFSET; + uint32_t db_hi = arm_sn | MLX5_CQ_DBR_CMD_ALL | aq->cq_ci; + uint64_t db_be = rte_cpu_to_be_64(((uint64_t)db_hi << 32) | aq->cq->id); + uint32_t *addr = RTE_PTR_ADD(sh->tx_uar->base_addr, MLX5_CQ_DOORBELL); + + rte_compiler_barrier(); + aq->cq_dbrec[MLX5_CQ_ARM_DB] = rte_cpu_to_be_32(db_hi); + rte_wmb(); +#ifdef RTE_ARCH_64 + *(uint64_t *)addr = db_be; +#else + *(uint32_t *)addr = db_be; + rte_io_wmb(); + *((uint32_t *)addr + 1) = db_be >> 32; +#endif + aq->arm_sn++; +} + +static inline void +mlx5_atomic_read_cqe(rte_int128_t *from, rte_int128_t *ts) +{ + /* + * The only CQE of Clock Queue is being continuously + * update by hardware with soecified rate. We have to + * read timestump and WQE completion index atomically. + */ +#if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_ARM64) + rte_int128_t src; + + memset(&src, 0, sizeof(src)); + *ts = src; + /* if (*from == *ts) *from = *src else *ts = *from; */ + rte_atomic128_cmp_exchange(from, ts, &src, 0, + __ATOMIC_RELAXED, __ATOMIC_RELAXED); +#else + rte_atomic64_t *cqe = (rte_atomic64_t *)from; + + /* Power architecture does not support 16B compare-and-swap. */ + for (;;) { + int64_t tm, op; + int64_t *ps; + + rte_compiler_barrier(); + tm = rte_atomic64_read(cqe + 0); + op = rte_atomic64_read(cqe + 1); + rte_compiler_barrier(); + if (tm != rte_atomic64_read(cqe + 0)) + continue; + if (op != rte_atomic64_read(cqe + 1)) + continue; + ps = (int64_t *)ts; + ps[0] = tm; + ps[1] = op; + return; + } +#endif +} + +/* Stores timestamp in the cache structure to share data with datapath. */ +static inline void +mlx5_txpp_cache_timestamp(struct mlx5_dev_ctx_shared *sh, + uint64_t ts, uint64_t ci) +{ + ci = ci << (64 - MLX5_CQ_INDEX_WIDTH); + ci |= (ts << MLX5_CQ_INDEX_WIDTH) >> MLX5_CQ_INDEX_WIDTH; + rte_compiler_barrier(); + rte_atomic64_set(&sh->txpp.ts.ts, ts); + rte_atomic64_set(&sh->txpp.ts.ci_ts, ci); + rte_wmb(); +} + +/* Reads timestamp from Clock Queue CQE and stores in the cache. */ +static inline void +mlx5_txpp_update_timestamp(struct mlx5_dev_ctx_shared *sh) +{ + struct mlx5_txpp_wq *wq = &sh->txpp.clock_queue; + struct mlx5_cqe *cqe = (struct mlx5_cqe *)(uintptr_t)wq->cqes; + union { + rte_int128_t u128; + struct mlx5_cqe_ts cts; + } to; + uint64_t ts; + uint16_t ci; + + static_assert(sizeof(struct mlx5_cqe_ts) == sizeof(rte_int128_t), + "Wrong timestamp CQE part size"); + mlx5_atomic_read_cqe((rte_int128_t *)&cqe->timestamp, &to.u128); + if (to.cts.op_own >> 4) { + DRV_LOG(DEBUG, "Clock Queue error sync lost."); + rte_atomic32_inc(&sh->txpp.err_clock_queue); + sh->txpp.sync_lost = 1; + return; + } + ci = rte_be_to_cpu_16(to.cts.wqe_counter); + ts = rte_be_to_cpu_64(to.cts.timestamp); + ts = mlx5_txpp_convert_rx_ts(sh, ts); + wq->cq_ci += (ci - wq->sq_ci) & UINT16_MAX; + wq->sq_ci = ci; + mlx5_txpp_cache_timestamp(sh, ts, wq->cq_ci); +} + +/* Waits for the first completion on Clock Queue to init timestamp. */ +static inline void +mlx5_txpp_init_timestamp(struct mlx5_dev_ctx_shared *sh) +{ + struct mlx5_txpp_wq *wq = &sh->txpp.clock_queue; + uint32_t wait; + + sh->txpp.ts_p = 0; + sh->txpp.ts_n = 0; + for (wait = 0; wait < MLX5_TXPP_WAIT_INIT_TS; wait++) { + struct timespec onems; + + mlx5_txpp_update_timestamp(sh); + if (wq->sq_ci) + return; + /* Wait one millisecond and try again. */ + onems.tv_sec = 0; + onems.tv_nsec = NS_PER_S / MS_PER_S; + nanosleep(&onems, 0); + } + DRV_LOG(ERR, "Unable to initialize timestamp."); + sh->txpp.sync_lost = 1; +} + +#ifdef HAVE_IBV_DEVX_EVENT +/* Gather statistics for timestamp from Clock Queue CQE. */ +static inline void +mlx5_txpp_gather_timestamp(struct mlx5_dev_ctx_shared *sh) +{ + /* Check whether we have a valid timestamp. */ + if (!sh->txpp.clock_queue.sq_ci && !sh->txpp.ts_n) + return; + MLX5_ASSERT(sh->txpp.ts_p < MLX5_TXPP_REARM_SQ_SIZE); + sh->txpp.tsa[sh->txpp.ts_p] = sh->txpp.ts; + if (++sh->txpp.ts_p >= MLX5_TXPP_REARM_SQ_SIZE) + sh->txpp.ts_p = 0; + if (sh->txpp.ts_n < MLX5_TXPP_REARM_SQ_SIZE) + ++sh->txpp.ts_n; +} + +/* Handles Rearm Queue completions in periodic service. */ +static __rte_always_inline void +mlx5_txpp_handle_rearm_queue(struct mlx5_dev_ctx_shared *sh) +{ + struct mlx5_txpp_wq *wq = &sh->txpp.rearm_queue; + uint32_t cq_ci = wq->cq_ci; + bool error = false; + int ret; + + do { + volatile struct mlx5_cqe *cqe; + + cqe = &wq->cqes[cq_ci & (MLX5_TXPP_REARM_CQ_SIZE - 1)]; + ret = check_cqe(cqe, MLX5_TXPP_REARM_CQ_SIZE, cq_ci); + switch (ret) { + case MLX5_CQE_STATUS_ERR: + error = true; + ++cq_ci; + break; + case MLX5_CQE_STATUS_SW_OWN: + wq->sq_ci += 2; + ++cq_ci; + break; + case MLX5_CQE_STATUS_HW_OWN: + break; + default: + MLX5_ASSERT(false); + break; + } + } while (ret != MLX5_CQE_STATUS_HW_OWN); + if (likely(cq_ci != wq->cq_ci)) { + /* Check whether we have missed interrupts. */ + if (cq_ci - wq->cq_ci != 1) { + DRV_LOG(DEBUG, "Rearm Queue missed interrupt."); + rte_atomic32_inc(&sh->txpp.err_miss_int); + /* Check sync lost on wqe index. */ + if (cq_ci - wq->cq_ci >= + (((1UL << MLX5_WQ_INDEX_WIDTH) / + MLX5_TXPP_REARM) - 1)) + error = 1; + } + /* Update doorbell record to notify hardware. */ + rte_compiler_barrier(); + *wq->cq_dbrec = rte_cpu_to_be_32(cq_ci); + rte_wmb(); + wq->cq_ci = cq_ci; + /* Fire new requests to Rearm Queue. */ + if (error) { + DRV_LOG(DEBUG, "Rearm Queue error sync lost."); + rte_atomic32_inc(&sh->txpp.err_rearm_queue); + sh->txpp.sync_lost = 1; + } + } +} + +/* Handles Clock Queue completions in periodic service. */ +static __rte_always_inline void +mlx5_txpp_handle_clock_queue(struct mlx5_dev_ctx_shared *sh) +{ + mlx5_txpp_update_timestamp(sh); + mlx5_txpp_gather_timestamp(sh); +} +#endif + +/* Invoked periodically on Rearm Queue completions. */ +void +mlx5_txpp_interrupt_handler(void *cb_arg) +{ +#ifndef HAVE_IBV_DEVX_EVENT + RTE_SET_USED(cb_arg); + return; +#else + struct mlx5_dev_ctx_shared *sh = cb_arg; + union { + struct mlx5dv_devx_async_event_hdr event_resp; + uint8_t buf[sizeof(struct mlx5dv_devx_async_event_hdr) + 128]; + } out; + + MLX5_ASSERT(rte_eal_process_type() == RTE_PROC_PRIMARY); + /* Process events in the loop. Only rearm completions are expected. */ + while (mlx5_glue->devx_get_event + (sh->txpp.echan, + &out.event_resp, + sizeof(out.buf)) >= + (ssize_t)sizeof(out.event_resp.cookie)) { + mlx5_txpp_handle_rearm_queue(sh); + mlx5_txpp_handle_clock_queue(sh); + mlx5_txpp_cq_arm(sh); + mlx5_txpp_doorbell_rearm_queue + (sh, sh->txpp.rearm_queue.sq_ci - 1); + } +#endif /* HAVE_IBV_DEVX_ASYNC */ +} + +static void +mlx5_txpp_stop_service(struct mlx5_dev_ctx_shared *sh) +{ + if (!sh->txpp.intr_handle.fd) + return; + mlx5_intr_callback_unregister(&sh->txpp.intr_handle, + mlx5_txpp_interrupt_handler, sh); + sh->txpp.intr_handle.fd = 0; +} + +/* Attach interrupt handler and fires first request to Rearm Queue. */ +static int +mlx5_txpp_start_service(struct mlx5_dev_ctx_shared *sh) +{ + uint16_t event_nums[1] = {0}; + int flags; + int ret; + + /* Attach interrupt handler to process Rearm Queue completions. */ + flags = fcntl(sh->txpp.echan->fd, F_GETFL); + ret = fcntl(sh->txpp.echan->fd, F_SETFL, flags | O_NONBLOCK); + if (ret) { + DRV_LOG(ERR, "Failed to change event channel FD."); + rte_errno = errno; + return -rte_errno; + } + memset(&sh->txpp.intr_handle, 0, sizeof(sh->txpp.intr_handle)); + sh->txpp.intr_handle.fd = sh->txpp.echan->fd; + sh->txpp.intr_handle.type = RTE_INTR_HANDLE_EXT; + if (rte_intr_callback_register(&sh->txpp.intr_handle, + mlx5_txpp_interrupt_handler, sh)) { + sh->txpp.intr_handle.fd = 0; + DRV_LOG(ERR, "Failed to register CQE interrupt %d.", rte_errno); + return -rte_errno; + } + /* Subscribe CQ event to the event channel controlled by the driver. */ + ret = mlx5_glue->devx_subscribe_devx_event(sh->txpp.echan, + sh->txpp.rearm_queue.cq->obj, + sizeof(event_nums), + event_nums, 0); + if (ret) { + DRV_LOG(ERR, "Failed to subscribe CQE event."); + rte_errno = errno; + return -errno; + } + /* Enable interrupts in the CQ. */ + mlx5_txpp_cq_arm(sh); + /* Fire the first request on Rearm Queue. */ + mlx5_txpp_doorbell_rearm_queue(sh, sh->txpp.rearm_queue.sq_size - 1); + mlx5_txpp_init_timestamp(sh); + return 0; +} + /* * The routine initializes the packet pacing infrastructure: * - allocates PP context @@ -595,8 +928,12 @@ mlx5_txpp_create(struct mlx5_dev_ctx_shared *sh, struct mlx5_priv *priv) ret = mlx5_txpp_create_rearm_queue(sh); if (ret) goto exit; + ret = mlx5_txpp_start_service(sh); + if (ret) + goto exit; exit: if (ret) { + mlx5_txpp_stop_service(sh); mlx5_txpp_destroy_rearm_queue(sh); mlx5_txpp_destroy_clock_queue(sh); mlx5_txpp_free_pp_index(sh); @@ -618,6 +955,7 @@ exit: static void mlx5_txpp_destroy(struct mlx5_dev_ctx_shared *sh) { + mlx5_txpp_stop_service(sh); mlx5_txpp_destroy_rearm_queue(sh); mlx5_txpp_destroy_clock_queue(sh); mlx5_txpp_free_pp_index(sh); -- 2.20.1