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-rw-r--r--net/smc/smc_ib.c466
1 files changed, 466 insertions, 0 deletions
diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
new file mode 100644
index 000000000000..e6743c008ac5
--- /dev/null
+++ b/net/smc/smc_ib.c
@@ -0,0 +1,466 @@
+/*
+ * 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);
+}