dibs: Local gid for dibs devices

Define a uuid_t GID attribute to identify a dibs device.

SMC uses 64 Bit and 128 Bit Global Identifiers (GIDs) per device, that
need to be sent via the SMC protocol. Because the smc code uses integers,
network endianness and host endianness need to be considered. Avoid this
in the dibs layer by using uuid_t byte arrays. Future patches could change
SMC to use uuid_t. For now conversion helper functions are introduced.

ISM devices provide 64 Bit GIDs. Map them to dibs uuid_t GIDs like this:
 _________________________________________
| 64 Bit ISM-vPCI GID | 00000000_00000000 |
 -----------------------------------------
If interpreted as UUID [1], this would be interpreted as the UIID variant,
that is reserved for NCS backward compatibility. So it will not collide
with UUIDs that were generated according to the standard.

smc_loopback already uses version 4 UUIDs as 128 Bit GIDs, move that to
dibs loopback. A temporary change to smc_lo_query_rgid() is required,
that will be moved to dibs_loopback with a follow-on patch.

Provide gid of a dibs device as sysfs read-only attribute.

Link: https://datatracker.ietf.org/doc/html/rfc4122
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Julian Ruess <julianr@linux.ibm.com>
Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Link: https://patch.msgid.link/20250918110500.1731261-11-wintera@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/dibs/dibs_loopback.c b/drivers/dibs/dibs_loopback.c
index 76e479d5724b6f51df1af6a4083f273a6bf57035..d7e6fa5e90f3b2dcebc33b2808148c4790535650 100644 (file)
--- a/drivers/dibs/dibs_loopback.c
+++ b/drivers/dibs/dibs_loopback.c
@@ -46,6 +46,7 @@ static int dibs_lo_dev_probe(void)
 
        ldev->dibs = dibs;
        dibs->drv_priv = ldev;
+       uuid_gen(&dibs->gid);
        dibs->ops = &dibs_lo_ops;
 
        dibs->dev.parent = NULL;

diff --git a/drivers/dibs/dibs_main.c b/drivers/dibs/dibs_main.c
index b3f21805aa59a9f6f829a0f70a433b8466c5d446..f20ed0594a511ebe545020b70d39252fc124226e 100644 (file)
--- a/drivers/dibs/dibs_main.c
+++ b/drivers/dibs/dibs_main.c
@@ -114,6 +114,17 @@ struct dibs_dev *dibs_dev_alloc(void)
 }
 EXPORT_SYMBOL_GPL(dibs_dev_alloc);
 
+static ssize_t gid_show(struct device *dev, struct device_attribute *attr,
+                       char *buf)
+{
+       struct dibs_dev *dibs;
+
+       dibs = container_of(dev, struct dibs_dev, dev);
+
+       return sysfs_emit(buf, "%pUb\n", &dibs->gid);
+}
+static DEVICE_ATTR_RO(gid);
+
 static ssize_t fabric_id_show(struct device *dev, struct device_attribute *attr,
                              char *buf)
 {
@@ -128,6 +139,7 @@ static ssize_t fabric_id_show(struct device *dev, struct device_attribute *attr,
 static DEVICE_ATTR_RO(fabric_id);
 
 static struct attribute *dibs_dev_attrs[] = {
+       &dev_attr_gid.attr,
        &dev_attr_fabric_id.attr,
        NULL,
 };

diff --git a/drivers/s390/net/ism.h b/drivers/s390/net/ism.h
index 3078779fa71e359580068b1d61eb0253f76c75ea..1b9fa14da20c8a160c65e66ba911b6d7b9d9ced8 100644 (file)
--- a/drivers/s390/net/ism.h
+++ b/drivers/s390/net/ism.h
@@ -67,6 +67,15 @@ union ism_reg_ieq {
        } response;
 } __aligned(16);
 
+/* ISM-vPCI devices provide 64 Bit GIDs
+ * Map them to ISM UUID GIDs like this:
+ *  _________________________________________
+ * | 64 Bit ISM-vPCI GID | 00000000_00000000 |
+ *  -----------------------------------------
+ * This will be interpreted as a UIID variant, that is reserved
+ * for NCS backward compatibility. So it will not collide with
+ * proper UUIDs.
+ */
 union ism_read_gid {
        struct {
                struct ism_req_hdr hdr;

diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c
index ab1d61eb3e3bf28e1ab7b09a7bf031a07a44b973..e58c55fb03c25e0a67737944e6b5dbf752334eb8 100644 (file)
--- a/drivers/s390/net/ism_drv.c
+++ b/drivers/s390/net/ism_drv.c
@@ -272,8 +272,9 @@ static int unregister_ieq(struct ism_dev *ism)
        return 0;
 }
 
-static int ism_read_local_gid(struct ism_dev *ism)
+static int ism_read_local_gid(struct dibs_dev *dibs)
 {
+       struct ism_dev *ism = dibs->drv_priv;
        union ism_read_gid cmd;
        int ret;
 
@@ -285,7 +286,8 @@ static int ism_read_local_gid(struct ism_dev *ism)
        if (ret)
                goto out;
 
-       ism->local_gid = cmd.response.gid;
+       memset(&dibs->gid, 0, sizeof(dibs->gid));
+       memcpy(&dibs->gid, &cmd.response.gid, sizeof(cmd.response.gid));
 out:
        return ret;
 }
@@ -563,10 +565,6 @@ static int ism_dev_init(struct ism_dev *ism)
        if (ret)
                goto unreg_sba;
 
-       ret = ism_read_local_gid(ism);
-       if (ret)
-               goto unreg_ieq;
-
        if (!ism_add_vlan_id(ism, ISM_RESERVED_VLANID))
                /* hardware is V2 capable */
                ism_v2_capable = true;
@@ -588,8 +586,6 @@ static int ism_dev_init(struct ism_dev *ism)
        query_info(ism);
        return 0;
 
-unreg_ieq:
-       unregister_ieq(ism);
 unreg_sba:
        unregister_sba(ism);
 free_irq:
@@ -672,6 +668,11 @@ static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        if (ret)
                goto err_dibs;
 
+       /* after ism_dev_init() we can call ism function to set gid */
+       ret = ism_read_local_gid(dibs);
+       if (ret)
+               goto err_ism;
+
        dibs->dev.parent = &pdev->dev;
 
        zdev = to_zpci(pdev);
@@ -841,18 +842,6 @@ static int smcd_supports_v2(void)
        return ism_v2_capable;
 }
 
-static u64 ism_get_local_gid(struct ism_dev *ism)
-{
-       return ism->local_gid;
-}
-
-static void smcd_get_local_gid(struct smcd_dev *smcd,
-                              struct smcd_gid *smcd_gid)
-{
-       smcd_gid->gid = ism_get_local_gid(smcd->priv);
-       smcd_gid->gid_ext = 0;
-}
-
 static const struct smcd_ops ism_smcd_ops = {
        .query_remote_gid = smcd_query_rgid,
        .register_dmb = smcd_register_dmb,
@@ -864,7 +853,6 @@ static const struct smcd_ops ism_smcd_ops = {
        .signal_event = smcd_signal_ieq,
        .move_data = smcd_move,
        .supports_v2 = smcd_supports_v2,
-       .get_local_gid = smcd_get_local_gid,
 };
 
 const struct smcd_ops *ism_get_smcd_ops(void)

diff --git a/include/linux/dibs.h b/include/linux/dibs.h
index 793c6e1ece0fbde557aacaef2624c26d31b49645..904f37505c279ac1a5d5cb69b98bfc2f4e499272 100644 (file)
--- a/include/linux/dibs.h
+++ b/include/linux/dibs.h
@@ -10,6 +10,8 @@
 #define _DIBS_H
 
 #include <linux/device.h>
+#include <linux/uuid.h>
+
 /* DIBS - Direct Internal Buffer Sharing - concept
  * -----------------------------------------------
  * In the case of multiple system sharing the same hardware, dibs fabrics can
@@ -138,6 +140,7 @@ struct dibs_dev {
        struct device dev;
        /* To be filled by device driver, before calling dibs_dev_add(): */
        const struct dibs_dev_ops *ops;
+       uuid_t gid;
        /* priv pointer for device driver */
        void *drv_priv;
 

diff --git a/include/linux/ism.h b/include/linux/ism.h
index 84f1afb3dded37e2a75233e9d0783cd2c27730eb..a926dd61b5a1598680463c81c5cc58f6fe0f2101 100644 (file)
--- a/include/linux/ism.h
+++ b/include/linux/ism.h
@@ -42,7 +42,6 @@ struct ism_dev {
        struct ism_eq *ieq;
        dma_addr_t ieq_dma_addr;
 
-       u64 local_gid;
        int ieq_idx;
 
        struct ism_client *subs[MAX_CLIENTS];

diff --git a/include/net/smc.h b/include/net/smc.h
index 05faac83371eb99df52d9ea8ede2ff8346f584c9..9cb8385bbc6ec4f6eaa16579aa61404b1de433ec 100644 (file)
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -62,7 +62,6 @@ struct smcd_ops {
                         bool sf, unsigned int offset, void *data,
                         unsigned int size);
        int (*supports_v2)(void);
-       void (*get_local_gid)(struct smcd_dev *dev, struct smcd_gid *gid);
 
        /* optional operations */
        int (*add_vlan_id)(struct smcd_dev *dev, u64 vlan_id);

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 09745baa10170077ca143feccdcff9d521448e5d..157aace169d496e067cc4792a1064724b77a7a52 100644 (file)
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -916,7 +916,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
                /* add SMC-D specifics */
                if (ini->ism_dev[0]) {
                        smcd = ini->ism_dev[0];
-                       smcd->ops->get_local_gid(smcd, &smcd_gid);
+                       copy_to_smcdgid(&smcd_gid, &smcd->dibs->gid);
                        pclc_smcd->ism.gid = htonll(smcd_gid.gid);
                        pclc_smcd->ism.chid =
                                htons(smc_ism_get_chid(ini->ism_dev[0]));
@@ -966,7 +966,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
                if (ini->ism_offered_cnt) {
                        for (i = 1; i <= ini->ism_offered_cnt; i++) {
                                smcd = ini->ism_dev[i];
-                               smcd->ops->get_local_gid(smcd, &smcd_gid);
+                               copy_to_smcdgid(&smcd_gid, &smcd->dibs->gid);
                                gidchids[entry].chid =
                                        htons(smc_ism_get_chid(ini->ism_dev[i]));
                                gidchids[entry].gid = htonll(smcd_gid.gid);
@@ -1059,7 +1059,7 @@ smcd_clc_prep_confirm_accept(struct smc_connection *conn,
        /* SMC-D specific settings */
        memcpy(clc->hdr.eyecatcher, SMCD_EYECATCHER,
               sizeof(SMCD_EYECATCHER));
-       smcd->ops->get_local_gid(smcd, &smcd_gid);
+       copy_to_smcdgid(&smcd_gid, &smcd->dibs->gid);
        clc->hdr.typev1 = SMC_TYPE_D;
        clc->d0.gid = htonll(smcd_gid.gid);
        clc->d0.token = htonll(conn->rmb_desc->token);

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 42ab0795d563d76c27a6bfc7671b3bd85b795ee0..be0c2da83d2bf8cb6c95df1e10b66d78526cd208 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -555,7 +555,7 @@ static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr,
 
        if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
                goto errattr;
-       smcd->ops->get_local_gid(smcd, &smcd_gid);
+       copy_to_smcdgid(&smcd_gid, &smcd->dibs->gid);
        if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID,
                              smcd_gid.gid, SMC_NLA_LGR_D_PAD))
                goto errattr;

diff --git a/net/smc/smc_diag.c b/net/smc/smc_diag.c
index 8ed2f6689b017098ff8e8a3c15b8104d69643437..bf0beaa23bdb63edfe0c37515aa17a04bb648c08 100644 (file)
--- a/net/smc/smc_diag.c
+++ b/net/smc/smc_diag.c
@@ -175,7 +175,7 @@ static int __smc_diag_dump(struct sock *sk, struct sk_buff *skb,
                dinfo.linkid = *((u32 *)conn->lgr->id);
                dinfo.peer_gid = conn->lgr->peer_gid.gid;
                dinfo.peer_gid_ext = conn->lgr->peer_gid.gid_ext;
-               smcd->ops->get_local_gid(smcd, &smcd_gid);
+               copy_to_smcdgid(&smcd_gid, &smcd->dibs->gid);
                dinfo.my_gid = smcd_gid.gid;
                dinfo.my_gid_ext = smcd_gid.gid_ext;
                dinfo.token = conn->rmb_desc->token;

diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h
index 04699951d03f282822ef97a1b3f9dd817c3dd921..139e99da2c9fd3229e44b084ad2185bba65e1072 100644 (file)
--- a/net/smc/smc_ism.h
+++ b/net/smc/smc_ism.h
@@ -96,4 +96,26 @@ static inline bool smc_ism_is_loopback(struct dibs_dev *dibs)
        return (dibs->ops->get_fabric_id(dibs) == DIBS_LOOPBACK_FABRIC);
 }
 
+static inline void copy_to_smcdgid(struct smcd_gid *sgid, uuid_t *dibs_gid)
+{
+       __be64 temp;
+
+       memcpy(&temp, dibs_gid, sizeof(sgid->gid));
+       sgid->gid = ntohll(temp);
+       memcpy(&temp, (uint8_t *)dibs_gid + sizeof(sgid->gid),
+              sizeof(sgid->gid_ext));
+       sgid->gid_ext = ntohll(temp);
+}
+
+static inline void copy_to_dibsgid(uuid_t *dibs_gid, struct smcd_gid *sgid)
+{
+       __be64 temp;
+
+       temp = htonll(sgid->gid);
+       memcpy(dibs_gid, &temp, sizeof(sgid->gid));
+       temp = htonll(sgid->gid_ext);
+       memcpy((uint8_t *)dibs_gid + sizeof(sgid->gid), &temp,
+              sizeof(sgid->gid_ext));
+}
+
 #endif

diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
index 262d0d0df4d015d233c5a9b2b8eebd4bdc8946c4..454d9d6a6e8f1a5230c52613a9d1f11036b41863 100644 (file)
--- a/net/smc/smc_loopback.c
+++ b/net/smc/smc_loopback.c
@@ -13,6 +13,7 @@
 
 #include <linux/device.h>
 #include <linux/types.h>
+#include <linux/dibs.h>
 #include <net/smc.h>
 
 #include "smc_cdc.h"
@@ -25,25 +26,14 @@
 
 static struct smc_lo_dev *lo_dev;
 
-static void smc_lo_generate_ids(struct smc_lo_dev *ldev)
-{
-       struct smcd_gid *lgid = &ldev->local_gid;
-       uuid_t uuid;
-
-       uuid_gen(&uuid);
-       memcpy(&lgid->gid, &uuid, sizeof(lgid->gid));
-       memcpy(&lgid->gid_ext, (u8 *)&uuid + sizeof(lgid->gid),
-              sizeof(lgid->gid_ext));
-}
-
 static int smc_lo_query_rgid(struct smcd_dev *smcd, struct smcd_gid *rgid,
                             u32 vid_valid, u32 vid)
 {
-       struct smc_lo_dev *ldev = smcd->priv;
+       uuid_t temp;
 
+       copy_to_dibsgid(&temp, rgid);
        /* rgid should be the same as lgid */
-       if (!ldev || rgid->gid != ldev->local_gid.gid ||
-           rgid->gid_ext != ldev->local_gid.gid_ext)
+       if (!uuid_equal(&temp, &smcd->dibs->gid))
                return -ENETUNREACH;
        return 0;
 }
@@ -245,15 +235,6 @@ static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok,
        return 0;
 }
 
-static void smc_lo_get_local_gid(struct smcd_dev *smcd,
-                                struct smcd_gid *smcd_gid)
-{
-       struct smc_lo_dev *ldev = smcd->priv;
-
-       smcd_gid->gid = ldev->local_gid.gid;
-       smcd_gid->gid_ext = ldev->local_gid.gid_ext;
-}
-
 static const struct smcd_ops lo_ops = {
        .query_remote_gid = smc_lo_query_rgid,
        .register_dmb = smc_lo_register_dmb,
@@ -267,7 +248,6 @@ static const struct smcd_ops lo_ops = {
        .reset_vlan_required    = NULL,
        .signal_event           = NULL,
        .move_data = smc_lo_move_data,
-       .get_local_gid = smc_lo_get_local_gid,
 };
 
 const struct smcd_ops *smc_lo_get_smcd_ops(void)
@@ -277,7 +257,6 @@ const struct smcd_ops *smc_lo_get_smcd_ops(void)
 
 static void smc_lo_dev_init(struct smc_lo_dev *ldev)
 {
-       smc_lo_generate_ids(ldev);
        rwlock_init(&ldev->dmb_ht_lock);
        hash_init(ldev->dmb_ht);
        atomic_set(&ldev->dmb_cnt, 0);

diff --git a/net/smc/smc_loopback.h b/net/smc/smc_loopback.h
index a033bf10890a6af3a5cda6d3e550a7988a4d1b9e..33bb96ec8b77de44210616bcd8d7b7be27f2ef2c 100644 (file)
--- a/net/smc/smc_loopback.h
+++ b/net/smc/smc_loopback.h
@@ -32,7 +32,6 @@ struct smc_lo_dmb_node {
 
 struct smc_lo_dev {
        struct smcd_dev *smcd;
-       struct smcd_gid local_gid;
        atomic_t dmb_cnt;
        rwlock_t dmb_ht_lock;
        DECLARE_BITMAP(sba_idx_mask, SMC_LO_MAX_DMBS);