[PATCH net-next 08/14] net/smc: introduce list of pnetids for Ethernet devices

Karsten Graul
2020-09-26T10:44:56Z

SMCD version 2 allows usage of ISM devices with hardware PNETID
only, if an Ethernet net_device exists with the same hardware PNETID.
This requires to maintain a list of pnetids belonging to
Ethernet net_devices, which is covered by this patch.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
net/smc/smc_netns.h | 1 +
net/smc/smc_pnet.c | 145 +++++++++++++++++++++++++++++++++++++++++---
net/smc/smc_pnet.h | 14 +++++
3 files changed, 153 insertions(+), 7 deletions(-)

diff --git a/net/smc/smc_netns.h b/net/smc/smc_netns.h
index e7a8fc4ae02f..0f4f35aa43ad 100644
--- a/net/smc/smc_netns.h
+++ b/net/smc/smc_netns.h
@@ -16,5 +16,6 @@ extern unsigned int smc_net_id;
/* per-network namespace private data */
struct smc_net {
struct smc_pnettable pnettable;
+ struct smc_pnetids_ndev pnetids_ndev;
};
#endif
diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
index 0b0f2704026f..8a91ca22712f 100644
--- a/net/smc/smc_pnet.c
+++ b/net/smc/smc_pnet.c
@@ -29,6 +29,7 @@
#include "smc_ism.h"
#include "smc_core.h"

+static struct net_device *__pnet_find_base_ndev(struct net_device *ndev);
static struct net_device *pnet_find_base_ndev(struct net_device *ndev);

static const struct nla_policy smc_pnet_policy[SMC_PNETID_MAX + 1] = {
@@ -712,10 +713,115 @@ static struct genl_family smc_pnet_nl_family __ro_after_init = {
.n_ops = ARRAY_SIZE(smc_pnet_ops)
};

+bool smc_pnet_is_ndev_pnetid(struct net *net, u8 *pnetid)
+{
+ struct smc_net *sn = net_generic(net, smc_net_id);
+ struct smc_pnetids_ndev_entry *pe;
+ bool rc = false;
+
+ read_lock(&sn->pnetids_ndev.lock);
+ list_for_each_entry(pe, &sn->pnetids_ndev.list, list) {
+ if (smc_pnet_match(pnetid, pe->pnetid)) {
+ rc = true;
+ goto unlock;
+ }
+ }
+
+unlock:
+ read_unlock(&sn->pnetids_ndev.lock);
+ return rc;
+}
+
+static int smc_pnet_add_pnetid(struct net *net, u8 *pnetid)
+{
+ struct smc_net *sn = net_generic(net, smc_net_id);
+ struct smc_pnetids_ndev_entry *pe, *pi;
+
+ pe = kzalloc(sizeof(*pe), GFP_KERNEL);
+ if (!pe)
+ return -ENOMEM;
+
+ write_lock(&sn->pnetids_ndev.lock);
+ list_for_each_entry(pi, &sn->pnetids_ndev.list, list) {
+ if (smc_pnet_match(pnetid, pe->pnetid)) {
+ refcount_inc(&pi->refcnt);
+ kfree(pe);
+ goto unlock;
+ }
+ }
+ refcount_set(&pe->refcnt, 1);
+ memcpy(pe->pnetid, pnetid, SMC_MAX_PNETID_LEN);
+ list_add_tail(&pe->list, &sn->pnetids_ndev.list);
+
+unlock:
+ write_unlock(&sn->pnetids_ndev.lock);
+ return 0;
+}
+
+static void smc_pnet_remove_pnetid(struct net *net, u8 *pnetid)
+{
+ struct smc_net *sn = net_generic(net, smc_net_id);
+ struct smc_pnetids_ndev_entry *pe, *pe2;
+
+ write_lock(&sn->pnetids_ndev.lock);
+ list_for_each_entry_safe(pe, pe2, &sn->pnetids_ndev.list, list) {
+ if (smc_pnet_match(pnetid, pe->pnetid)) {
+ if (refcount_dec_and_test(&pe->refcnt)) {
+ list_del(&pe->list);
+ kfree(pe);
+ }
+ break;
+ }
+ }
+ write_unlock(&sn->pnetids_ndev.lock);
+}
+
+static void smc_pnet_add_base_pnetid(struct net *net, struct net_device *dev,
+ u8 *ndev_pnetid)
+{
+ struct net_device *base_dev;
+
+ base_dev = __pnet_find_base_ndev(dev);
+ if (base_dev->flags & IFF_UP &&
+ !smc_pnetid_by_dev_port(base_dev->dev.parent, base_dev->dev_port,
+ ndev_pnetid)) {
+ /* add to PNETIDs list */
+ smc_pnet_add_pnetid(net, ndev_pnetid);
+ }
+}
+
+/* create initial list of netdevice pnetids */
+static void smc_pnet_create_pnetids_list(struct net *net)
+{
+ u8 ndev_pnetid[SMC_MAX_PNETID_LEN];
+ struct net_device *dev;
+
+ rtnl_lock();
+ for_each_netdev(net, dev)
+ smc_pnet_add_base_pnetid(net, dev, ndev_pnetid);
+ rtnl_unlock();
+}
+
+/* clean up list of netdevice pnetids */
+static void smc_pnet_destroy_pnetids_list(struct net *net)
+{
+ struct smc_net *sn = net_generic(net, smc_net_id);
+ struct smc_pnetids_ndev_entry *pe, *temp_pe;
+
+ write_lock(&sn->pnetids_ndev.lock);
+ list_for_each_entry_safe(pe, temp_pe, &sn->pnetids_ndev.list, list) {
+ list_del(&pe->list);
+ kfree(pe);
+ }
+ write_unlock(&sn->pnetids_ndev.lock);
+}
+
static int smc_pnet_netdev_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
+ struct net *net = dev_net(event_dev);
+ u8 ndev_pnetid[SMC_MAX_PNETID_LEN];

switch (event) {
case NETDEV_REBOOT:
@@ -725,6 +831,17 @@ static int smc_pnet_netdev_event(struct notifier_block *this,
case NETDEV_REGISTER:
smc_pnet_add_by_ndev(event_dev);
return NOTIFY_OK;
+ case NETDEV_UP:
+ smc_pnet_add_base_pnetid(net, event_dev, ndev_pnetid);
+ return NOTIFY_OK;
+ case NETDEV_DOWN:
+ event_dev = __pnet_find_base_ndev(event_dev);
+ if (!smc_pnetid_by_dev_port(event_dev->dev.parent,
+ event_dev->dev_port, ndev_pnetid)) {
+ /* remove from PNETIDs list */
+ smc_pnet_remove_pnetid(net, ndev_pnetid);
+ }
+ return NOTIFY_OK;
default:
return NOTIFY_DONE;
}
@@ -739,9 +856,14 @@ int smc_pnet_net_init(struct net *net)
{
struct smc_net *sn = net_generic(net, smc_net_id);
struct smc_pnettable *pnettable = &sn->pnettable;
+ struct smc_pnetids_ndev *pnetids_ndev = &sn->pnetids_ndev;

INIT_LIST_HEAD(&pnettable->pnetlist);
rwlock_init(&pnettable->lock);
+ INIT_LIST_HEAD(&pnetids_ndev->list);
+ rwlock_init(&pnetids_ndev->lock);
+
+ smc_pnet_create_pnetids_list(net);

return 0;
}
@@ -756,6 +878,7 @@ int __init smc_pnet_init(void)
rc = register_netdevice_notifier(&smc_netdev_notifier);
if (rc)
genl_unregister_family(&smc_pnet_nl_family);
+
return rc;
}

@@ -764,6 +887,7 @@ void smc_pnet_net_exit(struct net *net)
{
/* flush pnet table */
smc_pnet_remove_by_pnetid(net, NULL);
+ smc_pnet_destroy_pnetids_list(net);
}

void smc_pnet_exit(void)
@@ -772,16 +896,11 @@ void smc_pnet_exit(void)
genl_unregister_family(&smc_pnet_nl_family);
}

-/* Determine one base device for stacked net devices.
- * If the lower device level contains more than one devices
- * (for instance with bonding slaves), just the first device
- * is used to reach a base device.
- */
-static struct net_device *pnet_find_base_ndev(struct net_device *ndev)
+static struct net_device *__pnet_find_base_ndev(struct net_device *ndev)
{
int i, nest_lvl;

- rtnl_lock();
+ ASSERT_RTNL();
nest_lvl = ndev->lower_level;
for (i = 0; i < nest_lvl; i++) {
struct list_head *lower = &ndev->adj_list.lower;
@@ -791,6 +910,18 @@ static struct net_device *pnet_find_base_ndev(struct net_device *ndev)
lower = lower->next;
ndev = netdev_lower_get_next(ndev, &lower);
}
+ return ndev;
+}
+
+/* Determine one base device for stacked net devices.
+ * If the lower device level contains more than one devices
+ * (for instance with bonding slaves), just the first device
+ * is used to reach a base device.
+ */
+static struct net_device *pnet_find_base_ndev(struct net_device *ndev)
+{
+ rtnl_lock();
+ ndev = __pnet_find_base_ndev(ndev);
rtnl_unlock();
return ndev;
}
diff --git a/net/smc/smc_pnet.h b/net/smc/smc_pnet.h
index 811a65986691..677a47ac158e 100644
--- a/net/smc/smc_pnet.h
+++ b/net/smc/smc_pnet.h
@@ -12,6 +12,8 @@
#ifndef _SMC_PNET_H
#define _SMC_PNET_H

+#include <net/smc.h>
+
#if IS_ENABLED(CONFIG_HAVE_PNETID)
#include <asm/pnet.h>
#endif
@@ -31,6 +33,17 @@ struct smc_pnettable {
struct list_head pnetlist;
};

+struct smc_pnetids_ndev { /* list of pnetids for net devices in UP state*/
+ struct list_head list;
+ rwlock_t lock;
+};
+
+struct smc_pnetids_ndev_entry {
+ struct list_head list;
+ u8 pnetid[SMC_MAX_PNETID_LEN];
+ refcount_t refcnt;
+};
+
static inline int smc_pnetid_by_dev_port(struct device *dev,
unsigned short port, u8 *pnetid)
{
@@ -52,4 +65,5 @@ int smc_pnetid_by_table_smcd(struct smcd_dev *smcd);
void smc_pnet_find_alt_roce(struct smc_link_group *lgr,
struct smc_init_info *ini,
struct smc_ib_device *known_dev);
+bool smc_pnet_is_ndev_pnetid(struct net *net, u8 *pnetid);
#endif
--
2.17.1