/* * Shared Memory Communications over RDMA (SMC-R) and RoCE * * IB infrastructure: * Establish SMC-R as an Infiniband Client to be notified about added and * removed IB devices of type RDMA. * Determine device and port characteristics for these IB devices. * * Copyright IBM Corp. 2016 * * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> */ #include <linux/random.h> #include <linux/workqueue.h> #include <rdma/ib_verbs.h> #include "smc_pnet.h" #include "smc_ib.h" #include "smc_core.h" #include "smc_wr.h" #include "smc.h" #define SMC_QP_MIN_RNR_TIMER 5 #define SMC_QP_TIMEOUT 15 /* 4096 * 2 ** timeout usec */ #define SMC_QP_RETRY_CNT 7 /* 7: infinite */ #define SMC_QP_RNR_RETRY 7 /* 7: infinite */ struct smc_ib_devices smc_ib_devices = { /* smc-registered ib devices */ .lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock), .list = LIST_HEAD_INIT(smc_ib_devices.list), }; #define SMC_LOCAL_SYSTEMID_RESET "%%%%%%%" u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET; /* unique system * identifier */ int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags, struct ib_mr **mr) { int rc; if (*mr) return 0; /* already done */ /* obtain unique key - * next invocation of get_dma_mr returns a different key! */ *mr = pd->device->get_dma_mr(pd, access_flags); rc = PTR_ERR_OR_ZERO(*mr); if (IS_ERR(*mr)) *mr = NULL; return rc; } static int smc_ib_modify_qp_init(struct smc_link *lnk) { struct ib_qp_attr qp_attr; memset(&qp_attr, 0, sizeof(qp_attr)); qp_attr.qp_state = IB_QPS_INIT; qp_attr.pkey_index = 0; qp_attr.port_num = lnk->ibport; qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE; return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE | IB_QP_PKEY_INDEX | IB_QP_ACCESS_FLAGS | IB_QP_PORT); } static int smc_ib_modify_qp_rtr(struct smc_link *lnk) { enum ib_qp_attr_mask qp_attr_mask = IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN | IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER; struct ib_qp_attr qp_attr; memset(&qp_attr, 0, sizeof(qp_attr)); qp_attr.qp_state = IB_QPS_RTR; qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu); qp_attr.ah_attr.port_num = lnk->ibport; qp_attr.ah_attr.ah_flags = IB_AH_GRH; qp_attr.ah_attr.grh.hop_limit = 1; memcpy(&qp_attr.ah_attr.grh.dgid, lnk->peer_gid, sizeof(lnk->peer_gid)); memcpy(&qp_attr.ah_attr.dmac, lnk->peer_mac, sizeof(lnk->peer_mac)); qp_attr.dest_qp_num = lnk->peer_qpn; qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */ qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming * requests */ qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER; return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask); } int smc_ib_modify_qp_rts(struct smc_link *lnk) { struct ib_qp_attr qp_attr; memset(&qp_attr, 0, sizeof(qp_attr)); qp_attr.qp_state = IB_QPS_RTS; qp_attr.timeout = SMC_QP_TIMEOUT; /* local ack timeout */ qp_attr.retry_cnt = SMC_QP_RETRY_CNT; /* retry count */ qp_attr.rnr_retry = SMC_QP_RNR_RETRY; /* RNR retries, 7=infinite */ qp_attr.sq_psn = lnk->psn_initial; /* starting send packet seq # */ qp_attr.max_rd_atomic = 1; /* # of outstanding RDMA reads and * atomic ops allowed */ return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT | IB_QP_SQ_PSN | IB_QP_RNR_RETRY | IB_QP_MAX_QP_RD_ATOMIC); } int smc_ib_modify_qp_reset(struct smc_link *lnk) { struct ib_qp_attr qp_attr; memset(&qp_attr, 0, sizeof(qp_attr)); qp_attr.qp_state = IB_QPS_RESET; return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE); } int smc_ib_ready_link(struct smc_link *lnk) { struct smc_link_group *lgr = container_of(lnk, struct smc_link_group, lnk[0]); int rc = 0; rc = smc_ib_modify_qp_init(lnk); if (rc) goto out; rc = smc_ib_modify_qp_rtr(lnk); if (rc) goto out; smc_wr_remember_qp_attr(lnk); rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv, IB_CQ_SOLICITED_MASK); if (rc) goto out; rc = smc_wr_rx_post_init(lnk); if (rc) goto out; smc_wr_remember_qp_attr(lnk); if (lgr->role == SMC_SERV) { rc = smc_ib_modify_qp_rts(lnk); if (rc) goto out; smc_wr_remember_qp_attr(lnk); } out: return rc; } /* process context wrapper for might_sleep smc_ib_remember_port_attr */ static void smc_ib_port_event_work(struct work_struct *work) { struct smc_ib_device *smcibdev = container_of( work, struct smc_ib_device, port_event_work); u8 port_idx; for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) { smc_ib_remember_port_attr(smcibdev, port_idx + 1); clear_bit(port_idx, &smcibdev->port_event_mask); } } /* can be called in IRQ context */ static void smc_ib_global_event_handler(struct ib_event_handler *handler, struct ib_event *ibevent) { struct smc_ib_device *smcibdev; u8 port_idx; smcibdev = container_of(handler, struct smc_ib_device, event_handler); if (!smc_pnet_find_ib(smcibdev->ibdev->name)) return; switch (ibevent->event) { case IB_EVENT_PORT_ERR: port_idx = ibevent->element.port_num - 1; set_bit(port_idx, &smcibdev->port_event_mask); schedule_work(&smcibdev->port_event_work); /* fall through */ case IB_EVENT_DEVICE_FATAL: /* tbd in follow-on patch: * abnormal close of corresponding connections */ break; case IB_EVENT_PORT_ACTIVE: port_idx = ibevent->element.port_num - 1; set_bit(port_idx, &smcibdev->port_event_mask); schedule_work(&smcibdev->port_event_work); break; default: break; } } void smc_ib_dealloc_protection_domain(struct smc_link *lnk) { ib_dealloc_pd(lnk->roce_pd); lnk->roce_pd = NULL; } int smc_ib_create_protection_domain(struct smc_link *lnk) { int rc; lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0); rc = PTR_ERR_OR_ZERO(lnk->roce_pd); if (IS_ERR(lnk->roce_pd)) lnk->roce_pd = NULL; return rc; } static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv) { switch (ibevent->event) { case IB_EVENT_DEVICE_FATAL: case IB_EVENT_GID_CHANGE: case IB_EVENT_PORT_ERR: case IB_EVENT_QP_ACCESS_ERR: /* tbd in follow-on patch: * abnormal close of corresponding connections */ break; default: break; } } void smc_ib_destroy_queue_pair(struct smc_link *lnk) { ib_destroy_qp(lnk->roce_qp); lnk->roce_qp = NULL; } /* create a queue pair within the protection domain for a link */ int smc_ib_create_queue_pair(struct smc_link *lnk) { struct ib_qp_init_attr qp_attr = { .event_handler = smc_ib_qp_event_handler, .qp_context = lnk, .send_cq = lnk->smcibdev->roce_cq_send, .recv_cq = lnk->smcibdev->roce_cq_recv, .srq = NULL, .cap = { .max_send_wr = SMC_WR_BUF_CNT, /* include unsolicited rdma_writes as well, * there are max. 2 RDMA_WRITE per 1 WR_SEND */ .max_recv_wr = SMC_WR_BUF_CNT * 3, .max_send_sge = SMC_IB_MAX_SEND_SGE, .max_recv_sge = 1, .max_inline_data = SMC_WR_TX_SIZE, }, .sq_sig_type = IB_SIGNAL_REQ_WR, .qp_type = IB_QPT_RC, }; int rc; lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr); rc = PTR_ERR_OR_ZERO(lnk->roce_qp); if (IS_ERR(lnk->roce_qp)) lnk->roce_qp = NULL; else smc_wr_remember_qp_attr(lnk); return rc; } /* map a new TX or RX buffer to DMA */ int smc_ib_buf_map(struct smc_ib_device *smcibdev, int buf_size, struct smc_buf_desc *buf_slot, enum dma_data_direction data_direction) { int rc = 0; if (buf_slot->dma_addr[SMC_SINGLE_LINK]) return rc; /* already mapped */ buf_slot->dma_addr[SMC_SINGLE_LINK] = ib_dma_map_single(smcibdev->ibdev, buf_slot->cpu_addr, buf_size, data_direction); if (ib_dma_mapping_error(smcibdev->ibdev, buf_slot->dma_addr[SMC_SINGLE_LINK])) rc = -EIO; return rc; } void smc_ib_buf_unmap(struct smc_ib_device *smcibdev, int buf_size, struct smc_buf_desc *buf_slot, enum dma_data_direction data_direction) { if (!buf_slot->dma_addr[SMC_SINGLE_LINK]) return; /* already unmapped */ ib_dma_unmap_single(smcibdev->ibdev, *buf_slot->dma_addr, buf_size, data_direction); buf_slot->dma_addr[SMC_SINGLE_LINK] = 0; } static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport) { struct net_device *ndev; int rc; rc = ib_query_gid(smcibdev->ibdev, ibport, 0, &smcibdev->gid[ibport - 1], NULL); /* the SMC protocol requires specification of the roce MAC address; * if net_device cannot be determined, it can be derived from gid 0 */ ndev = smcibdev->ibdev->get_netdev(smcibdev->ibdev, ibport); if (ndev) { memcpy(&smcibdev->mac, ndev->dev_addr, ETH_ALEN); } else if (!rc) { memcpy(&smcibdev->mac[ibport - 1][0], &smcibdev->gid[ibport - 1].raw[8], 3); memcpy(&smcibdev->mac[ibport - 1][3], &smcibdev->gid[ibport - 1].raw[13], 3); smcibdev->mac[ibport - 1][0] &= ~0x02; } return rc; } /* Create an identifier unique for this instance of SMC-R. * The MAC-address of the first active registered IB device * plus a random 2-byte number is used to create this identifier. * This name is delivered to the peer during connection initialization. */ static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev, u8 ibport) { memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1], sizeof(smcibdev->mac[ibport - 1])); get_random_bytes(&local_systemid[0], 2); } bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport) { return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE; } int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport) { int rc; memset(&smcibdev->pattr[ibport - 1], 0, sizeof(smcibdev->pattr[ibport - 1])); rc = ib_query_port(smcibdev->ibdev, ibport, &smcibdev->pattr[ibport - 1]); if (rc) goto out; rc = smc_ib_fill_gid_and_mac(smcibdev, ibport); if (rc) goto out; if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET, sizeof(local_systemid)) && smc_ib_port_active(smcibdev, ibport)) /* create unique system identifier */ smc_ib_define_local_systemid(smcibdev, ibport); out: return rc; } long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev) { struct ib_cq_init_attr cqattr = { .cqe = SMC_WR_MAX_CQE, .comp_vector = 0 }; long rc; smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev, smc_wr_tx_cq_handler, NULL, smcibdev, &cqattr); rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send); if (IS_ERR(smcibdev->roce_cq_send)) { smcibdev->roce_cq_send = NULL; return rc; } smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev, smc_wr_rx_cq_handler, NULL, smcibdev, &cqattr); rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv); if (IS_ERR(smcibdev->roce_cq_recv)) { smcibdev->roce_cq_recv = NULL; goto err; } INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev, smc_ib_global_event_handler); ib_register_event_handler(&smcibdev->event_handler); smc_wr_add_dev(smcibdev); smcibdev->initialized = 1; return rc; err: ib_destroy_cq(smcibdev->roce_cq_send); return rc; } static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev) { if (!smcibdev->initialized) return; smc_wr_remove_dev(smcibdev); ib_unregister_event_handler(&smcibdev->event_handler); ib_destroy_cq(smcibdev->roce_cq_recv); ib_destroy_cq(smcibdev->roce_cq_send); } static struct ib_client smc_ib_client; /* callback function for ib_register_client() */ static void smc_ib_add_dev(struct ib_device *ibdev) { struct smc_ib_device *smcibdev; if (ibdev->node_type != RDMA_NODE_IB_CA) return; smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL); if (!smcibdev) return; smcibdev->ibdev = ibdev; INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work); spin_lock(&smc_ib_devices.lock); list_add_tail(&smcibdev->list, &smc_ib_devices.list); spin_unlock(&smc_ib_devices.lock); ib_set_client_data(ibdev, &smc_ib_client, smcibdev); } /* callback function for ib_register_client() */ static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data) { struct smc_ib_device *smcibdev; smcibdev = ib_get_client_data(ibdev, &smc_ib_client); ib_set_client_data(ibdev, &smc_ib_client, NULL); spin_lock(&smc_ib_devices.lock); list_del_init(&smcibdev->list); /* remove from smc_ib_devices */ spin_unlock(&smc_ib_devices.lock); smc_pnet_remove_by_ibdev(smcibdev); smc_ib_cleanup_per_ibdev(smcibdev); kfree(smcibdev); } static struct ib_client smc_ib_client = { .name = "smc_ib", .add = smc_ib_add_dev, .remove = smc_ib_remove_dev, }; int __init smc_ib_register_client(void) { return ib_register_client(&smc_ib_client); } void smc_ib_unregister_client(void) { ib_unregister_client(&smc_ib_client); }