[linux-2.6-block.git] / net / smc / smc_ib.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  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 <linux/scatterlist.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_cache.h>

#include "smc_pnet.h"
#include "smc_ib.h"
#include "smc_core.h"
#include "smc_wr.h"
#include "smc.h"

#define SMC_MAX_CQE 32766	/* max. # of completion queue elements */

#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
								 */

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.type = RDMA_AH_ATTR_TYPE_ROCE;
	rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
	rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, lnk->sgid_index, 1, 0);
	rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
	memcpy(&qp_attr.ah_attr.roce.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 = smc_get_lgr(lnk);
	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;
}

static int smc_ib_fill_mac(struct smc_ib_device *smcibdev, u8 ibport)
{
	const struct ib_gid_attr *attr;
	int rc;

	attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, 0);
	if (IS_ERR(attr))
		return -ENODEV;

	rc = rdma_read_gid_l2_fields(attr, NULL, smcibdev->mac[ibport - 1]);
	rdma_put_gid_attr(attr);
	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;
}

/* determine the gid for an ib-device port and vlan id */
int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
			 unsigned short vlan_id, u8 gid[], u8 *sgid_index)
{
	const struct ib_gid_attr *attr;
	const struct net_device *ndev;
	int i;

	for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
		attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
		if (IS_ERR(attr))
			continue;

		rcu_read_lock();
		ndev = rdma_read_gid_attr_ndev_rcu(attr);
		if (!IS_ERR(ndev) &&
		    ((!vlan_id && !is_vlan_dev(attr->ndev)) ||
		     (vlan_id && is_vlan_dev(attr->ndev) &&
		      vlan_dev_vlan_id(attr->ndev) == vlan_id)) &&
		    attr->gid_type == IB_GID_TYPE_ROCE) {
			rcu_read_unlock();
			if (gid)
				memcpy(gid, &attr->gid, SMC_GID_SIZE);
			if (sgid_index)
				*sgid_index = attr->index;
			rdma_put_gid_attr(attr);
			return 0;
		}
		rcu_read_unlock();
		rdma_put_gid_attr(attr);
	}
	return -ENODEV;
}

static 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;
	/* the SMC protocol requires specification of the RoCE MAC address */
	rc = smc_ib_fill_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;
}

/* 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);
		if (!smc_ib_port_active(smcibdev, port_idx + 1))
			smc_port_terminate(smcibdev, port_idx + 1);
	}
}

/* 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);

	switch (ibevent->event) {
	case IB_EVENT_DEVICE_FATAL:
		/* terminate all ports on device */
		for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++)
			set_bit(port_idx, &smcibdev->port_event_mask);
		schedule_work(&smcibdev->port_event_work);
		break;
	case IB_EVENT_PORT_ERR:
	case IB_EVENT_PORT_ACTIVE:
	case IB_EVENT_GID_CHANGE:
		port_idx = ibevent->element.port_num - 1;
		if (port_idx < SMC_MAX_PORTS) {
			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)
{
	if (lnk->roce_pd)
		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)
{
	struct smc_link *lnk = (struct smc_link *)priv;
	struct smc_ib_device *smcibdev = lnk->smcibdev;
	u8 port_idx;

	switch (ibevent->event) {
	case IB_EVENT_QP_FATAL:
	case IB_EVENT_QP_ACCESS_ERR:
		port_idx = ibevent->element.qp->port - 1;
		if (port_idx < SMC_MAX_PORTS) {
			set_bit(port_idx, &smcibdev->port_event_mask);
			schedule_work(&smcibdev->port_event_work);
		}
		break;
	default:
		break;
	}
}

void smc_ib_destroy_queue_pair(struct smc_link *lnk)
{
	if (lnk->roce_qp)
		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 = {
				/* include unsolicited rdma_writes as well,
				 * there are max. 2 RDMA_WRITE per 1 WR_SEND
				 */
			.max_send_wr = SMC_WR_BUF_CNT * 3,
			.max_recv_wr = SMC_WR_BUF_CNT * 3,
			.max_send_sge = SMC_IB_MAX_SEND_SGE,
			.max_recv_sge = 1,
		},
		.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;
}

void smc_ib_put_memory_region(struct ib_mr *mr)
{
	ib_dereg_mr(mr);
}

static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
{
	unsigned int offset = 0;
	int sg_num;

	/* map the largest prefix of a dma mapped SG list */
	sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
			      buf_slot->sgt[SMC_SINGLE_LINK].sgl,
			      buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
			      &offset, PAGE_SIZE);

	return sg_num;
}

/* Allocate a memory region and map the dma mapped SG list of buf_slot */
int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
			     struct smc_buf_desc *buf_slot)
{
	if (buf_slot->mr_rx[SMC_SINGLE_LINK])
		return 0; /* already done */

	buf_slot->mr_rx[SMC_SINGLE_LINK] =
		ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
	if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
		int rc;

		rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
		buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
		return rc;
	}

	if (smc_ib_map_mr_sg(buf_slot) != 1)
		return -EINVAL;

	return 0;
}

/* synchronize buffer usage for cpu access */
void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
			    struct smc_buf_desc *buf_slot,
			    enum dma_data_direction data_direction)
{
	struct scatterlist *sg;
	unsigned int i;

	/* for now there is just one DMA address */
	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
		    buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
		if (!sg_dma_len(sg))
			break;
		ib_dma_sync_single_for_cpu(smcibdev->ibdev,
					   sg_dma_address(sg),
					   sg_dma_len(sg),
					   data_direction);
	}
}

/* synchronize buffer usage for device access */
void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
			       struct smc_buf_desc *buf_slot,
			       enum dma_data_direction data_direction)
{
	struct scatterlist *sg;
	unsigned int i;

	/* for now there is just one DMA address */
	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
		    buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
		if (!sg_dma_len(sg))
			break;
		ib_dma_sync_single_for_device(smcibdev->ibdev,
					      sg_dma_address(sg),
					      sg_dma_len(sg),
					      data_direction);
	}
}

/* Map a new TX or RX buffer SG-table to DMA */
int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
		      struct smc_buf_desc *buf_slot,
		      enum dma_data_direction data_direction)
{
	int mapped_nents;

	mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
				     buf_slot->sgt[SMC_SINGLE_LINK].sgl,
				     buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
				     data_direction);
	if (!mapped_nents)
		return -ENOMEM;

	return mapped_nents;
}

void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
			 struct smc_buf_desc *buf_slot,
			 enum dma_data_direction data_direction)
{
	if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
		return; /* already unmapped */

	ib_dma_unmap_sg(smcibdev->ibdev,
			buf_slot->sgt[SMC_SINGLE_LINK].sgl,
			buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
			data_direction);
	buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
}

long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
{
	struct ib_cq_init_attr cqattr =	{
		.cqe = SMC_MAX_CQE, .comp_vector = 0 };
	int cqe_size_order, smc_order;
	long rc;

	/* the calculated number of cq entries fits to mlx5 cq allocation */
	cqe_size_order = cache_line_size() == 128 ? 7 : 6;
	smc_order = MAX_ORDER - cqe_size_order - 1;
	if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
		cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
	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;
	}
	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;
	smcibdev->initialized = 0;
	smc_wr_remove_dev(smcibdev);
	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;
	u8 port_cnt;
	int i;

	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);
	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
			      smc_ib_global_event_handler);
	ib_register_event_handler(&smcibdev->event_handler);

	/* trigger reading of the port attributes */
	port_cnt = smcibdev->ibdev->phys_port_cnt;
	for (i = 0;
	     i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
	     i++) {
		set_bit(i, &smcibdev->port_event_mask);
		/* determine pnetids of the port */
		smc_pnetid_by_dev_port(ibdev->dev.parent, i,
				       smcibdev->pnetid[i]);
	}
	schedule_work(&smcibdev->port_event_work);
}

/* 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_ib_cleanup_per_ibdev(smcibdev);
	ib_unregister_event_handler(&smcibdev->event_handler);
	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);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
a4cf0443 UB	2	/*
	3	* Shared Memory Communications over RDMA (SMC-R) and RoCE
	4	*
	5	* IB infrastructure:
	6	* Establish SMC-R as an Infiniband Client to be notified about added and
	7	* removed IB devices of type RDMA.
	8	* Determine device and port characteristics for these IB devices.
	9	*
	10	* Copyright IBM Corp. 2016
	11	*
	12	* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
	13	*/
	14
	15	#include <linux/random.h>
bd4ad577	16	#include <linux/workqueue.h>
10428dd8	17	#include <linux/scatterlist.h>
a4cf0443	18	#include <rdma/ib_verbs.h>
ddb457c6	19	#include <rdma/ib_cache.h>
a4cf0443	20
6812baab	21	#include "smc_pnet.h"
a4cf0443	22	#include "smc_ib.h"
cd6851f3	23	#include "smc_core.h"
f38ba179	24	#include "smc_wr.h"
a4cf0443 UB	25	#include "smc.h"
a4cf0443 UB	26
c9f4c6cf UB	27	#define SMC_MAX_CQE 32766 /* max. # of completion queue elements */
c9f4c6cf UB	28
bd4ad577 UB	29	#define SMC_QP_MIN_RNR_TIMER 5
	30	#define SMC_QP_TIMEOUT 15 /* 4096 * 2 ** timeout usec */
	31	#define SMC_QP_RETRY_CNT 7 /* 7: infinite */
	32	#define SMC_QP_RNR_RETRY 7 /* 7: infinite */
	33
a4cf0443 UB	34	struct smc_ib_devices smc_ib_devices = { /* smc-registered ib devices */
	35	.lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
	36	.list = LIST_HEAD_INIT(smc_ib_devices.list),
	37	};
	38
	39	#define SMC_LOCAL_SYSTEMID_RESET "%%%%%%%"
	40
	41	u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET; /* unique system
	42	* identifier
	43	*/
	44
bd4ad577 UB	45	static int smc_ib_modify_qp_init(struct smc_link *lnk)
	46	{
	47	struct ib_qp_attr qp_attr;
	48
	49	memset(&qp_attr, 0, sizeof(qp_attr));
	50	qp_attr.qp_state = IB_QPS_INIT;
	51	qp_attr.pkey_index = 0;
	52	qp_attr.port_num = lnk->ibport;
	53	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
	54	\| IB_ACCESS_REMOTE_WRITE;
	55	return ib_modify_qp(lnk->roce_qp, &qp_attr,
	56	IB_QP_STATE \| IB_QP_PKEY_INDEX \|
	57	IB_QP_ACCESS_FLAGS \| IB_QP_PORT);
	58	}
	59
	60	static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
	61	{
	62	enum ib_qp_attr_mask qp_attr_mask =
	63	IB_QP_STATE \| IB_QP_AV \| IB_QP_PATH_MTU \| IB_QP_DEST_QPN \|
	64	IB_QP_RQ_PSN \| IB_QP_MAX_DEST_RD_ATOMIC \| IB_QP_MIN_RNR_TIMER;
	65	struct ib_qp_attr qp_attr;
	66
	67	memset(&qp_attr, 0, sizeof(qp_attr));
	68	qp_attr.qp_state = IB_QPS_RTR;
	69	qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
44c58487	70	qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
d8966fcd	71	rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
7005ada6	72	rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, lnk->sgid_index, 1, 0);
d8966fcd	73	rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
44c58487	74	memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
bd4ad577 UB	75	sizeof(lnk->peer_mac));
	76	qp_attr.dest_qp_num = lnk->peer_qpn;
	77	qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
	78	qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
	79	* requests
	80	*/
	81	qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
	82
	83	return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
	84	}
	85
	86	int smc_ib_modify_qp_rts(struct smc_link *lnk)
	87	{
	88	struct ib_qp_attr qp_attr;
	89
	90	memset(&qp_attr, 0, sizeof(qp_attr));
	91	qp_attr.qp_state = IB_QPS_RTS;
	92	qp_attr.timeout = SMC_QP_TIMEOUT; /* local ack timeout */
	93	qp_attr.retry_cnt = SMC_QP_RETRY_CNT; /* retry count */
	94	qp_attr.rnr_retry = SMC_QP_RNR_RETRY; /* RNR retries, 7=infinite */
	95	qp_attr.sq_psn = lnk->psn_initial; /* starting send packet seq # */
	96	qp_attr.max_rd_atomic = 1; /* # of outstanding RDMA reads and
	97	* atomic ops allowed
	98	*/
	99	return ib_modify_qp(lnk->roce_qp, &qp_attr,
	100	IB_QP_STATE \| IB_QP_TIMEOUT \| IB_QP_RETRY_CNT \|
	101	IB_QP_SQ_PSN \| IB_QP_RNR_RETRY \|
	102	IB_QP_MAX_QP_RD_ATOMIC);
	103	}
	104
	105	int smc_ib_modify_qp_reset(struct smc_link *lnk)
	106	{
	107	struct ib_qp_attr qp_attr;
	108
	109	memset(&qp_attr, 0, sizeof(qp_attr));
	110	qp_attr.qp_state = IB_QPS_RESET;
	111	return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
	112	}
	113
	114	int smc_ib_ready_link(struct smc_link *lnk)
	115	{
00e5fb26	116	struct smc_link_group *lgr = smc_get_lgr(lnk);
bd4ad577 UB	117	int rc = 0;
	118
	119	rc = smc_ib_modify_qp_init(lnk);
	120	if (rc)
	121	goto out;
	122
	123	rc = smc_ib_modify_qp_rtr(lnk);
	124	if (rc)
	125	goto out;
	126	smc_wr_remember_qp_attr(lnk);
	127	rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
	128	IB_CQ_SOLICITED_MASK);
	129	if (rc)
	130	goto out;
	131	rc = smc_wr_rx_post_init(lnk);
	132	if (rc)
	133	goto out;
	134	smc_wr_remember_qp_attr(lnk);
	135
	136	if (lgr->role == SMC_SERV) {
	137	rc = smc_ib_modify_qp_rts(lnk);
	138	if (rc)
	139	goto out;
	140	smc_wr_remember_qp_attr(lnk);
	141	}
	142	out:
	143	return rc;
	144	}
	145
7005ada6	146	static int smc_ib_fill_mac(struct smc_ib_device *smcibdev, u8 ibport)
be6a3f38	147	{
b4c296f9	148	const struct ib_gid_attr *attr;
5102eca9	149	int rc;
be6a3f38	150
b4c296f9 JG	151	attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, 0);
b4c296f9 JG	152	if (IS_ERR(attr))
be6a3f38 UB	153	return -ENODEV;
be6a3f38 UB	154
5102eca9	155	rc = rdma_read_gid_l2_fields(attr, NULL, smcibdev->mac[ibport - 1]);
b4c296f9 JG	156	rdma_put_gid_attr(attr);
b4c296f9 JG	157	return rc;
be6a3f38 UB	158	}
	159
	160	/* Create an identifier unique for this instance of SMC-R.
	161	* The MAC-address of the first active registered IB device
	162	* plus a random 2-byte number is used to create this identifier.
	163	* This name is delivered to the peer during connection initialization.
	164	*/
	165	static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
	166	u8 ibport)
	167	{
	168	memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
	169	sizeof(smcibdev->mac[ibport - 1]));
	170	get_random_bytes(&local_systemid[0], 2);
	171	}
	172
	173	bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
	174	{
	175	return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
	176	}
	177
7005ada6 UB	178	/* determine the gid for an ib-device port and vlan id */
	179	int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
	180	unsigned short vlan_id, u8 gid[], u8 *sgid_index)
	181	{
b4c296f9	182	const struct ib_gid_attr *attr;
5102eca9	183	const struct net_device *ndev;
7005ada6 UB	184	int i;
	185
	186	for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
b4c296f9 JG	187	attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
b4c296f9 JG	188	if (IS_ERR(attr))
7005ada6	189	continue;
b4c296f9	190
5102eca9 PP	191	rcu_read_lock();
	192	ndev = rdma_read_gid_attr_ndev_rcu(attr);
	193	if (!IS_ERR(ndev) &&
b4c296f9 JG	194	((!vlan_id && !is_vlan_dev(attr->ndev)) \|\|
	195	(vlan_id && is_vlan_dev(attr->ndev) &&
	196	vlan_dev_vlan_id(attr->ndev) == vlan_id)) &&
	197	attr->gid_type == IB_GID_TYPE_ROCE) {
5102eca9	198	rcu_read_unlock();
7005ada6	199	if (gid)
b4c296f9	200	memcpy(gid, &attr->gid, SMC_GID_SIZE);
7005ada6	201	if (sgid_index)
b4c296f9 JG	202	*sgid_index = attr->index;
b4c296f9 JG	203	rdma_put_gid_attr(attr);
7005ada6 UB	204	return 0;
7005ada6 UB	205	}
5102eca9	206	rcu_read_unlock();
b4c296f9	207	rdma_put_gid_attr(attr);
7005ada6 UB	208	}
	209	return -ENODEV;
	210	}
	211
be6a3f38 UB	212	static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
	213	{
	214	int rc;
	215
	216	memset(&smcibdev->pattr[ibport - 1], 0,
	217	sizeof(smcibdev->pattr[ibport - 1]));
	218	rc = ib_query_port(smcibdev->ibdev, ibport,
	219	&smcibdev->pattr[ibport - 1]);
	220	if (rc)
	221	goto out;
	222	/* the SMC protocol requires specification of the RoCE MAC address */
7005ada6	223	rc = smc_ib_fill_mac(smcibdev, ibport);
be6a3f38 UB	224	if (rc)
	225	goto out;
	226	if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
	227	sizeof(local_systemid)) &&
	228	smc_ib_port_active(smcibdev, ibport))
	229	/* create unique system identifier */
	230	smc_ib_define_local_systemid(smcibdev, ibport);
	231	out:
	232	return rc;
	233	}
	234
bd4ad577 UB	235	/* process context wrapper for might_sleep smc_ib_remember_port_attr */
	236	static void smc_ib_port_event_work(struct work_struct *work)
	237	{
	238	struct smc_ib_device *smcibdev = container_of(
	239	work, struct smc_ib_device, port_event_work);
	240	u8 port_idx;
	241
	242	for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
	243	smc_ib_remember_port_attr(smcibdev, port_idx + 1);
	244	clear_bit(port_idx, &smcibdev->port_event_mask);
da05bf29	245	if (!smc_ib_port_active(smcibdev, port_idx + 1))
9fda3510	246	smc_port_terminate(smcibdev, port_idx + 1);
bd4ad577 UB	247	}
	248	}
	249
	250	/* can be called in IRQ context */
	251	static void smc_ib_global_event_handler(struct ib_event_handler *handler,
	252	struct ib_event *ibevent)
	253	{
	254	struct smc_ib_device *smcibdev;
	255	u8 port_idx;
	256
	257	smcibdev = container_of(handler, struct smc_ib_device, event_handler);
bd4ad577 UB	258
bd4ad577 UB	259	switch (ibevent->event) {
bd4ad577	260	case IB_EVENT_DEVICE_FATAL:
81cf6430 KG	261	/* terminate all ports on device */
	262	for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++)
	263	set_bit(port_idx, &smcibdev->port_event_mask);
	264	schedule_work(&smcibdev->port_event_work);
	265	break;
	266	case IB_EVENT_PORT_ERR:
bd4ad577	267	case IB_EVENT_PORT_ACTIVE:
81cf6430	268	case IB_EVENT_GID_CHANGE:
bd4ad577	269	port_idx = ibevent->element.port_num - 1;
81cf6430 KG	270	if (port_idx < SMC_MAX_PORTS) {
	271	set_bit(port_idx, &smcibdev->port_event_mask);
	272	schedule_work(&smcibdev->port_event_work);
	273	}
bd4ad577 UB	274	break;
	275	default:
	276	break;
	277	}
	278	}
	279
f38ba179 UB	280	void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
f38ba179 UB	281	{
da05bf29 UB	282	if (lnk->roce_pd)
da05bf29 UB	283	ib_dealloc_pd(lnk->roce_pd);
f38ba179 UB	284	lnk->roce_pd = NULL;
	285	}
	286
	287	int smc_ib_create_protection_domain(struct smc_link *lnk)
	288	{
	289	int rc;
	290
897e1c24	291	lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
f38ba179 UB	292	rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
	293	if (IS_ERR(lnk->roce_pd))
	294	lnk->roce_pd = NULL;
	295	return rc;
	296	}
	297
	298	static void smc_ib_qp_event_handler(struct ib_event ibevent, void priv)
	299	{
e5f3aa04 KG	300	struct smc_link lnk = (struct smc_link )priv;
e5f3aa04 KG	301	struct smc_ib_device *smcibdev = lnk->smcibdev;
da05bf29 UB	302	u8 port_idx;
da05bf29 UB	303
f38ba179	304	switch (ibevent->event) {
81cf6430	305	case IB_EVENT_QP_FATAL:
f38ba179	306	case IB_EVENT_QP_ACCESS_ERR:
e5f3aa04	307	port_idx = ibevent->element.qp->port - 1;
81cf6430 KG	308	if (port_idx < SMC_MAX_PORTS) {
	309	set_bit(port_idx, &smcibdev->port_event_mask);
	310	schedule_work(&smcibdev->port_event_work);
	311	}
f38ba179 UB	312	break;
	313	default:
	314	break;
	315	}
	316	}
	317
	318	void smc_ib_destroy_queue_pair(struct smc_link *lnk)
	319	{
da05bf29 UB	320	if (lnk->roce_qp)
da05bf29 UB	321	ib_destroy_qp(lnk->roce_qp);
f38ba179 UB	322	lnk->roce_qp = NULL;
	323	}
	324
	325	/* create a queue pair within the protection domain for a link */
	326	int smc_ib_create_queue_pair(struct smc_link *lnk)
	327	{
	328	struct ib_qp_init_attr qp_attr = {
	329	.event_handler = smc_ib_qp_event_handler,
	330	.qp_context = lnk,
	331	.send_cq = lnk->smcibdev->roce_cq_send,
	332	.recv_cq = lnk->smcibdev->roce_cq_recv,
	333	.srq = NULL,
	334	.cap = {
f38ba179 UB	335	/* include unsolicited rdma_writes as well,
	336	* there are max. 2 RDMA_WRITE per 1 WR_SEND
	337	*/
652a1e41	338	.max_send_wr = SMC_WR_BUF_CNT * 3,
f38ba179 UB	339	.max_recv_wr = SMC_WR_BUF_CNT * 3,
	340	.max_send_sge = SMC_IB_MAX_SEND_SGE,
	341	.max_recv_sge = 1,
f38ba179 UB	342	},
	343	.sq_sig_type = IB_SIGNAL_REQ_WR,
	344	.qp_type = IB_QPT_RC,
	345	};
	346	int rc;
	347
	348	lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
	349	rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
	350	if (IS_ERR(lnk->roce_qp))
	351	lnk->roce_qp = NULL;
	352	else
	353	smc_wr_remember_qp_attr(lnk);
	354	return rc;
	355	}
	356
897e1c24 UB	357	void smc_ib_put_memory_region(struct ib_mr *mr)
	358	{
	359	ib_dereg_mr(mr);
	360	}
	361
	362	static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
	363	{
	364	unsigned int offset = 0;
	365	int sg_num;
	366
	367	/* map the largest prefix of a dma mapped SG list */
	368	sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
	369	buf_slot->sgt[SMC_SINGLE_LINK].sgl,
	370	buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
	371	&offset, PAGE_SIZE);
	372
	373	return sg_num;
	374	}
	375
	376	/* Allocate a memory region and map the dma mapped SG list of buf_slot */
	377	int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
	378	struct smc_buf_desc *buf_slot)
	379	{
	380	if (buf_slot->mr_rx[SMC_SINGLE_LINK])
	381	return 0; /* already done */
	382
	383	buf_slot->mr_rx[SMC_SINGLE_LINK] =
	384	ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
	385	if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
	386	int rc;
	387
	388	rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
	389	buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
	390	return rc;
	391	}
	392
	393	if (smc_ib_map_mr_sg(buf_slot) != 1)
	394	return -EINVAL;
	395
	396	return 0;
	397	}
	398
10428dd8 UB	399	/* synchronize buffer usage for cpu access */
	400	void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
	401	struct smc_buf_desc *buf_slot,
	402	enum dma_data_direction data_direction)
	403	{
	404	struct scatterlist *sg;
	405	unsigned int i;
	406
	407	/* for now there is just one DMA address */
	408	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
	409	buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
	410	if (!sg_dma_len(sg))
	411	break;
	412	ib_dma_sync_single_for_cpu(smcibdev->ibdev,
	413	sg_dma_address(sg),
	414	sg_dma_len(sg),
	415	data_direction);
	416	}
	417	}
	418
	419	/* synchronize buffer usage for device access */
	420	void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
	421	struct smc_buf_desc *buf_slot,
	422	enum dma_data_direction data_direction)
	423	{
	424	struct scatterlist *sg;
	425	unsigned int i;
	426
	427	/* for now there is just one DMA address */
	428	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
	429	buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
	430	if (!sg_dma_len(sg))
	431	break;
	432	ib_dma_sync_single_for_device(smcibdev->ibdev,
	433	sg_dma_address(sg),
	434	sg_dma_len(sg),
	435	data_direction);
	436	}
	437	}
	438
a3fe3d01 UB	439	/* Map a new TX or RX buffer SG-table to DMA */
	440	int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
	441	struct smc_buf_desc *buf_slot,
	442	enum dma_data_direction data_direction)
	443	{
	444	int mapped_nents;
	445
	446	mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
	447	buf_slot->sgt[SMC_SINGLE_LINK].sgl,
	448	buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
	449	data_direction);
	450	if (!mapped_nents)
	451	return -ENOMEM;
	452
	453	return mapped_nents;
	454	}
	455
	456	void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
	457	struct smc_buf_desc *buf_slot,
	458	enum dma_data_direction data_direction)
	459	{
	460	if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
	461	return; /* already unmapped */
	462
	463	ib_dma_unmap_sg(smcibdev->ibdev,
	464	buf_slot->sgt[SMC_SINGLE_LINK].sgl,
	465	buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
	466	data_direction);
	467	buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
	468	}
	469
bd4ad577 UB	470	long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
	471	{
	472	struct ib_cq_init_attr cqattr = {
c9f4c6cf UB	473	.cqe = SMC_MAX_CQE, .comp_vector = 0 };
c9f4c6cf UB	474	int cqe_size_order, smc_order;
bd4ad577 UB	475	long rc;
bd4ad577 UB	476
c9f4c6cf UB	477	/* the calculated number of cq entries fits to mlx5 cq allocation */
	478	cqe_size_order = cache_line_size() == 128 ? 7 : 6;
	479	smc_order = MAX_ORDER - cqe_size_order - 1;
	480	if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
	481	cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
bd4ad577 UB	482	smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
	483	smc_wr_tx_cq_handler, NULL,
	484	smcibdev, &cqattr);
	485	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
	486	if (IS_ERR(smcibdev->roce_cq_send)) {
	487	smcibdev->roce_cq_send = NULL;
	488	return rc;
	489	}
	490	smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
	491	smc_wr_rx_cq_handler, NULL,
	492	smcibdev, &cqattr);
	493	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
	494	if (IS_ERR(smcibdev->roce_cq_recv)) {
	495	smcibdev->roce_cq_recv = NULL;
	496	goto err;
	497	}
bd4ad577 UB	498	smc_wr_add_dev(smcibdev);
	499	smcibdev->initialized = 1;
	500	return rc;
	501
	502	err:
	503	ib_destroy_cq(smcibdev->roce_cq_send);
	504	return rc;
	505	}
	506
	507	static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
	508	{
	509	if (!smcibdev->initialized)
	510	return;
da05bf29	511	smcibdev->initialized = 0;
bd4ad577	512	smc_wr_remove_dev(smcibdev);
bd4ad577 UB	513	ib_destroy_cq(smcibdev->roce_cq_recv);
	514	ib_destroy_cq(smcibdev->roce_cq_send);
	515	}
	516
a4cf0443 UB	517	static struct ib_client smc_ib_client;
	518
	519	/* callback function for ib_register_client() */
	520	static void smc_ib_add_dev(struct ib_device *ibdev)
	521	{
	522	struct smc_ib_device *smcibdev;
be6a3f38 UB	523	u8 port_cnt;
be6a3f38 UB	524	int i;
a4cf0443 UB	525
	526	if (ibdev->node_type != RDMA_NODE_IB_CA)
	527	return;
	528
	529	smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
	530	if (!smcibdev)
	531	return;
	532
	533	smcibdev->ibdev = ibdev;
bd4ad577	534	INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
a4cf0443 UB	535
	536	spin_lock(&smc_ib_devices.lock);
	537	list_add_tail(&smcibdev->list, &smc_ib_devices.list);
	538	spin_unlock(&smc_ib_devices.lock);
	539	ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
be6a3f38 UB	540	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
	541	smc_ib_global_event_handler);
	542	ib_register_event_handler(&smcibdev->event_handler);
	543
	544	/* trigger reading of the port attributes */
	545	port_cnt = smcibdev->ibdev->phys_port_cnt;
	546	for (i = 0;
	547	i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
0afff91c	548	i++) {
be6a3f38	549	set_bit(i, &smcibdev->port_event_mask);
0afff91c UB	550	/* determine pnetids of the port */
	551	smc_pnetid_by_dev_port(ibdev->dev.parent, i,
	552	smcibdev->pnetid[i]);
	553	}
be6a3f38	554	schedule_work(&smcibdev->port_event_work);
a4cf0443 UB	555	}
	556
	557	/* callback function for ib_register_client() */
	558	static void smc_ib_remove_dev(struct ib_device ibdev, void client_data)
	559	{
	560	struct smc_ib_device *smcibdev;
	561
	562	smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
	563	ib_set_client_data(ibdev, &smc_ib_client, NULL);
	564	spin_lock(&smc_ib_devices.lock);
	565	list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
	566	spin_unlock(&smc_ib_devices.lock);
bd4ad577	567	smc_ib_cleanup_per_ibdev(smcibdev);
be6a3f38	568	ib_unregister_event_handler(&smcibdev->event_handler);
a4cf0443 UB	569	kfree(smcibdev);
	570	}
	571
	572	static struct ib_client smc_ib_client = {
	573	.name = "smc_ib",
	574	.add = smc_ib_add_dev,
	575	.remove = smc_ib_remove_dev,
	576	};
	577
	578	int __init smc_ib_register_client(void)
	579	{
	580	return ib_register_client(&smc_ib_client);
	581	}
	582
	583	void smc_ib_unregister_client(void)
	584	{
	585	ib_unregister_client(&smc_ib_client);
	586	}