[PATCH net-next 11/14] net/dibs: Move vlan support to dibs_dev_ops

Alexandra Winter
2025-09-05T14:54:45Z

It can be debated how much benefit definition of vlan ids for dibs devices
brings, as the dmbs are accessible only by a single peer anyhow. But ism
provides vlan support and smcd exploits it, so move it to dibs layer as an
optional feature.

smcd_loopback simply ignores all vlan settings, do the same in
dibs_loopback.

SMC-D and ISM have a method to use the invalid VLAN ID 1FFF
(ISM_RESERVED_VLANID), to indicate that both communication peers support
routable SMC-Dv2. Tolerate it in dibs, but move it to SMC only.

Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
---
drivers/s390/net/ism_drv.c | 47 +++++---------------------------------
include/linux/dibs.h | 19 +++++++++++++++
include/net/smc.h | 5 ----
net/smc/smc_ism.c | 14 ++++++++----
net/smc/smc_loopback.c | 5 ----
5 files changed, 34 insertions(+), 56 deletions(-)

diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c
index e58c55fb03c2..ed4c28ca355b 100644
--- a/drivers/s390/net/ism_drv.c
+++ b/drivers/s390/net/ism_drv.c
@@ -36,7 +36,6 @@ static struct ism_client *clients[MAX_CLIENTS]; /* use an array rather than */
/* a list for fast mapping */
static u8 max_client;
static DEFINE_MUTEX(clients_lock);
-static bool ism_v2_capable;
struct ism_dev_list {
struct list_head list;
struct mutex mutex; /* protects ism device list */
@@ -409,8 +408,9 @@ int ism_unregister_dmb(struct ism_dev *ism, struct ism_dmb *dmb)
}
EXPORT_SYMBOL_GPL(ism_unregister_dmb);

-static int ism_add_vlan_id(struct ism_dev *ism, u64 vlan_id)
+static int ism_add_vlan_id(struct dibs_dev *dibs, u64 vlan_id)
{
+ struct ism_dev *ism = dibs->drv_priv;
union ism_set_vlan_id cmd;

memset(&cmd, 0, sizeof(cmd));
@@ -422,8 +422,9 @@ static int ism_add_vlan_id(struct ism_dev *ism, u64 vlan_id)
return ism_cmd(ism, &cmd);
}

-static int ism_del_vlan_id(struct ism_dev *ism, u64 vlan_id)
+static int ism_del_vlan_id(struct dibs_dev *dibs, u64 vlan_id)
{
+ struct ism_dev *ism = dibs->drv_priv;
union ism_set_vlan_id cmd;

memset(&cmd, 0, sizeof(cmd));
@@ -536,6 +537,8 @@ static irqreturn_t ism_handle_irq(int irq, void *data)

static const struct dibs_dev_ops ism_ops = {
.get_fabric_id = ism_get_chid,
+ .add_vlan_id = ism_add_vlan_id,
+ .del_vlan_id = ism_del_vlan_id,
};

static int ism_dev_init(struct ism_dev *ism)
@@ -565,12 +568,6 @@ static int ism_dev_init(struct ism_dev *ism)
if (ret)
goto unreg_sba;

- if (!ism_add_vlan_id(ism, ISM_RESERVED_VLANID))
- /* hardware is V2 capable */
- ism_v2_capable = true;
- else
- ism_v2_capable = false;
-
mutex_lock(&ism_dev_list.mutex);
mutex_lock(&clients_lock);
for (i = 0; i < max_client; ++i) {
@@ -611,8 +608,6 @@ static void ism_dev_exit(struct ism_dev *ism)

mutex_lock(&ism_dev_list.mutex);

- if (ism_v2_capable)
- ism_del_vlan_id(ism, ISM_RESERVED_VLANID);
unregister_ieq(ism);
unregister_sba(ism);
free_irq(pci_irq_vector(pdev, 0), ism);
@@ -786,26 +781,6 @@ static int smcd_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
return ism_unregister_dmb(smcd->priv, (struct ism_dmb *)dmb);
}

-static int smcd_add_vlan_id(struct smcd_dev *smcd, u64 vlan_id)
-{
- return ism_add_vlan_id(smcd->priv, vlan_id);
-}
-
-static int smcd_del_vlan_id(struct smcd_dev *smcd, u64 vlan_id)
-{
- return ism_del_vlan_id(smcd->priv, vlan_id);
-}
-
-static int smcd_set_vlan_required(struct smcd_dev *smcd)
-{
- return ism_cmd_simple(smcd->priv, ISM_SET_VLAN);
-}
-
-static int smcd_reset_vlan_required(struct smcd_dev *smcd)
-{
- return ism_cmd_simple(smcd->priv, ISM_RESET_VLAN);
-}
-
static int ism_signal_ieq(struct ism_dev *ism, u64 rgid, u32 trigger_irq,
u32 event_code, u64 info)
{
@@ -837,22 +812,12 @@ static int smcd_move(struct smcd_dev *smcd, u64 dmb_tok, unsigned int idx,
return ism_move(smcd->priv, dmb_tok, idx, sf, offset, data, size);
}

-static int smcd_supports_v2(void)
-{
- return ism_v2_capable;
-}
-
static const struct smcd_ops ism_smcd_ops = {
.query_remote_gid = smcd_query_rgid,
.register_dmb = smcd_register_dmb,
.unregister_dmb = smcd_unregister_dmb,
- .add_vlan_id = smcd_add_vlan_id,
- .del_vlan_id = smcd_del_vlan_id,
- .set_vlan_required = smcd_set_vlan_required,
- .reset_vlan_required = smcd_reset_vlan_required,
.signal_event = smcd_signal_ieq,
.move_data = smcd_move,
- .supports_v2 = smcd_supports_v2,
};

const struct smcd_ops *ism_get_smcd_ops(void)
diff --git a/include/linux/dibs.h b/include/linux/dibs.h
index 904f37505c27..166148fb8d76 100644
--- a/include/linux/dibs.h
+++ b/include/linux/dibs.h
@@ -133,6 +133,25 @@ struct dibs_dev_ops {
* Return: 2 byte dibs fabric id
*/
u16 (*get_fabric_id)(struct dibs_dev *dev);
+ /**
+ * add_vlan_id() - add dibs device to vlan (optional, deprecated)
+ * @dev: dibs device
+ * @vlan_id: vlan id
+ *
+ * In order to write into a vlan-tagged dmb, the remote device needs
+ * to belong to the this vlan. A device can belong to more than 1 vlan.
+ * Any device can access an untagged dmb.
+ * Deprecated, only supported for backwards compatibility.
+ * Return: zero on success
+ */
+ int (*add_vlan_id)(struct dibs_dev *dev, u64 vlan_id);
+ /**
+ * del_vlan_id() - remove dibs device from vlan (optional, deprecated)
+ * @dev: dibs device
+ * @vlan_id: vlan id
+ * Return: zero on success
+ */
+ int (*del_vlan_id)(struct dibs_dev *dev, u64 vlan_id);
};

struct dibs_dev {
diff --git a/include/net/smc.h b/include/net/smc.h
index 9cb8385bbc6e..51b4aefc106a 100644
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -61,13 +61,8 @@ struct smcd_ops {
int (*move_data)(struct smcd_dev *dev, u64 dmb_tok, unsigned int idx,
bool sf, unsigned int offset, void *data,
unsigned int size);
- int (*supports_v2)(void);

/* optional operations */
- int (*add_vlan_id)(struct smcd_dev *dev, u64 vlan_id);
- int (*del_vlan_id)(struct smcd_dev *dev, u64 vlan_id);
- int (*set_vlan_required)(struct smcd_dev *dev);
- int (*reset_vlan_required)(struct smcd_dev *dev);
int (*signal_event)(struct smcd_dev *dev, struct smcd_gid *rgid,
u32 trigger_irq, u32 event_code, u64 info);
int (*support_dmb_nocopy)(struct smcd_dev *dev);
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 00868583b115..435e28364885 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -140,7 +140,7 @@ int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)

if (!vlanid) /* No valid vlan id */
return -EINVAL;
- if (!smcd->ops->add_vlan_id)
+ if (!smcd->dibs->ops->add_vlan_id)
return -EOPNOTSUPP;

/* create new vlan entry, in case we need it */
@@ -163,7 +163,7 @@ int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
/* no existing entry found.
* add new entry to device; might fail, e.g., if HW limit reached
*/
- if (smcd->ops->add_vlan_id(smcd, vlanid)) {
+ if (smcd->dibs->ops->add_vlan_id(smcd->dibs, vlanid)) {
kfree(new_vlan);
rc = -EIO;
goto out;
@@ -187,7 +187,7 @@ int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)

if (!vlanid) /* No valid vlan id */
return -EINVAL;
- if (!smcd->ops->del_vlan_id)
+ if (!smcd->dibs->ops->del_vlan_id)
return -EOPNOTSUPP;

spin_lock_irqsave(&smcd->lock, flags);
@@ -205,7 +205,7 @@ int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
}

/* Found and the last reference just gone */
- if (smcd->ops->del_vlan_id(smcd, vlanid))
+ if (smcd->dibs->ops->del_vlan_id(smcd->dibs, vlanid))
rc = -EIO;
list_del(&vlan->list);
kfree(vlan);
@@ -537,8 +537,12 @@ static void smcd_register_dev(struct dibs_dev *dibs)
if (smc_pnetid_by_dev_port(dibs->dev.parent, 0, smcd->pnetid))
smc_pnetid_by_table_smcd(smcd);

- if (smcd->ops->supports_v2())
+ if (smc_ism_is_loopback(dibs) ||
+ (dibs->ops->add_vlan_id &&
+ !dibs->ops->add_vlan_id(dibs, ISM_RESERVED_VLANID))) {
smc_ism_set_v2_capable();
+ }
+
mutex_lock(&smcd_dev_list.mutex);
/* sort list:
* - devices without pnetid before devices with pnetid;
diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
index 454d9d6a6e8f..982a19430313 100644
--- a/net/smc/smc_loopback.c
+++ b/net/smc/smc_loopback.c
@@ -20,7 +20,6 @@
#include "smc_ism.h"
#include "smc_loopback.h"

-#define SMC_LO_V2_CAPABLE 0x1 /* loopback-ism acts as ISMv2 */
#define SMC_LO_SUPPORT_NOCOPY 0x1
#define SMC_DMA_ADDR_INVALID (~(dma_addr_t)0)

@@ -242,10 +241,6 @@ static const struct smcd_ops lo_ops = {
.support_dmb_nocopy = smc_lo_support_dmb_nocopy,
.attach_dmb = smc_lo_attach_dmb,
.detach_dmb = smc_lo_detach_dmb,
- .add_vlan_id = NULL,
- .del_vlan_id = NULL,
- .set_vlan_required = NULL,
- .reset_vlan_required = NULL,
.signal_event = NULL,
.move_data = smc_lo_move_data,
};
--
2.48.1