[PATCH net-next v6 07/11] net/smc: register loopback-ism into SMC-D device list

Wen Gu
2024-04-14T04:03:30Z

After the loopback-ism device is ready, add it to the SMC-D device list
as an ISMv2 device, and always keep it at the beginning to ensure it is
preferred for providing a shortcut for data transfer within the same
kernel.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
net/smc/smc_ism.c | 30 +++++++++++++++++++++---------
net/smc/smc_ism.h | 1 +
net/smc/smc_loopback.c | 20 +++++++++++++-------
3 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 188fd28423c2..6bed0a61b746 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -91,6 +91,11 @@ bool smc_ism_is_v2_capable(void)
return smc_ism_v2_capable;
}

+void smc_ism_set_v2_capable(void)
+{
+ smc_ism_v2_capable = true;
+}
+
/* Set a connection using this DMBE. */
void smc_ism_set_conn(struct smc_connection *conn)
{
@@ -439,7 +444,7 @@ static struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
static void smcd_register_dev(struct ism_dev *ism)
{
const struct smcd_ops *ops = ism_get_smcd_ops();
- struct smcd_dev *smcd;
+ struct smcd_dev *smcd, *fentry;

if (!ops)
return;
@@ -454,16 +459,23 @@ static void smcd_register_dev(struct ism_dev *ism)
if (smc_pnetid_by_dev_port(&ism->pdev->dev, 0, smcd->pnetid))
smc_pnetid_by_table_smcd(smcd);

+ if (smcd->ops->supports_v2())
+ smc_ism_set_v2_capable();
mutex_lock(&smcd_dev_list.mutex);
- if (list_empty(&smcd_dev_list.list)) {
- if (smcd->ops->supports_v2())
- smc_ism_v2_capable = true;
- }
- /* sort list: devices without pnetid before devices with pnetid */
- if (smcd->pnetid[0])
+ /* sort list:
+ * - devices without pnetid before devices with pnetid;
+ * - loopback-ism always at the very beginning;
+ */
+ if (!smcd->pnetid[0]) {
+ fentry = list_first_entry_or_null(&smcd_dev_list.list,
+ struct smcd_dev, list);
+ if (fentry && smc_ism_is_loopback(fentry))
+ list_add(&smcd->list, &fentry->list);
+ else
+ list_add(&smcd->list, &smcd_dev_list.list);
+ } else {
list_add_tail(&smcd->list, &smcd_dev_list.list);
- else
- list_add(&smcd->list, &smcd_dev_list.list);
+ }
mutex_unlock(&smcd_dev_list.mutex);

pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h
index 322973527c61..e6f57e5e1ef9 100644
--- a/net/smc/smc_ism.h
+++ b/net/smc/smc_ism.h
@@ -52,6 +52,7 @@ int smc_ism_signal_shutdown(struct smc_link_group *lgr);
void smc_ism_get_system_eid(u8 **eid);
u16 smc_ism_get_chid(struct smcd_dev *dev);
bool smc_ism_is_v2_capable(void);
+void smc_ism_set_v2_capable(void);
int smc_ism_init(void);
void smc_ism_exit(void);
int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb);
diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
index d75852549b00..94a57f4ee3f9 100644
--- a/net/smc/smc_loopback.c
+++ b/net/smc/smc_loopback.c
@@ -246,10 +246,12 @@ static int smcd_lo_register_dev(struct smc_lo_dev *ldev)
return -ENOMEM;
ldev->smcd = smcd;
smcd->priv = ldev;
-
- /* TODO:
- * register loopback-ism to smcd_dev list.
- */
+ smc_ism_set_v2_capable();
+ mutex_lock(&smcd_dev_list.mutex);
+ list_add(&smcd->list, &smcd_dev_list.list);
+ mutex_unlock(&smcd_dev_list.mutex);
+ pr_warn_ratelimited("smc: adding smcd device %s\n",
+ dev_name(&ldev->dev));
return 0;
}

@@ -257,9 +259,13 @@ static void smcd_lo_unregister_dev(struct smc_lo_dev *ldev)
{
struct smcd_dev *smcd = ldev->smcd;

- /* TODO:
- * unregister loopback-ism from smcd_dev list.
- */
+ pr_warn_ratelimited("smc: removing smcd device %s\n",
+ dev_name(&ldev->dev));
+ smcd->going_away = 1;
+ smc_smcd_terminate_all(smcd);
+ mutex_lock(&smcd_dev_list.mutex);
+ list_del_init(&smcd->list);
+ mutex_unlock(&smcd_dev_list.mutex);
kfree(smcd->conn);
kfree(smcd);
}
--
2.32.0.3.g01195cf9f