linux/net/smc/smc_ib.c
Ursula Braun a4cf0443c4 smc: introduce SMC as an IB-client
* create a list of SMC IB-devices

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09 16:07:38 -05:00

144 lines
3.9 KiB
C

/*
* 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 <rdma/ib_verbs.h>
#include "smc_ib.h"
#include "smc.h"
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_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;
}
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;
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);
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);
}