[PATCH net-next 10/18] net/smc: implement ID-related operations of loopback

Wen Gu
2023-09-19T14:43:14Z

This patch implements GID/CHID/SEID related operations of SMC-D loopback
device. In loopback device, GID is generated by UUIDv4 algorithm, CHID is
reserved 0xFFFF, SEID is generated using the same algorithm as ISM device
under s390 architecture, and is 0 and disabled under non-s390 architecture.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
include/net/smc.h | 6 ++++
net/smc/smc_ism.h | 2 ++
net/smc/smc_loopback.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++----
net/smc/smc_loopback.h | 3 ++
4 files changed, 100 insertions(+), 6 deletions(-)

diff --git a/include/net/smc.h b/include/net/smc.h
index a37fb38..389d26d 100644
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -41,6 +41,12 @@ struct smcd_dmb {
dma_addr_t dma_addr;
};

+struct smcd_seid {
+ u8 seid_string[24];
+ u8 serial_number[4];
+ u8 type[4];
+};
+
#define ISM_EVENT_DMB 0
#define ISM_EVENT_GID 1
#define ISM_EVENT_SWR 2
diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h
index e6ea08c..7ab82dd 100644
--- a/net/smc/smc_ism.h
+++ b/net/smc/smc_ism.h
@@ -15,6 +15,8 @@

#include "smc.h"

+#define S390_ISM_IDENT_MASK 0x00FFFF
+
#define SMC_VIRT_ISM_CHID_MAX 0xFFFF
#define SMC_VIRT_ISM_CHID_MIN 0xFF00

diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
index 7d88856..6b8ff65 100644
--- a/net/smc/smc_loopback.c
+++ b/net/smc/smc_loopback.c
@@ -18,11 +18,92 @@
#include "smc_ism.h"
#include "smc_loopback.h"

+#define SMC_LO_SUPPORTS_V2 0x1 /* SMC-D loopback supports SMC-Dv2 */
+
static const char smc_lo_dev_name[] = "smc_lo";
+static struct smcd_seid SMC_LO_SEID = {
+ .seid_string = "IBM-SYSZ-ISMSEID00000000",
+ .serial_number = "0000",
+ .type = "0000",
+};
+
static struct smc_lo_dev *lo_dev;

+static void smc_lo_create_seid(struct smcd_seid *seid)
+{
+#if IS_ENABLED(CONFIG_S390)
+ struct cpuid id;
+ u16 ident_tail;
+ char tmp[5];
+
+ get_cpu_id(&id);
+ ident_tail = (u16)(id.ident & S390_ISM_IDENT_MASK);
+ snprintf(tmp, 5, "%04X", ident_tail);
+ memcpy(&seid->serial_number, tmp, 4);
+ snprintf(tmp, 5, "%04X", id.machine);
+ memcpy(&seid->type, tmp, 4);
+#else
+ memset(seid, 0, SMC_MAX_EID_LEN);
+#endif
+}
+
+static void smc_lo_generate_id(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));
+
+ ldev->chid = SMC_LO_CHID;
+ smc_lo_create_seid(&SMC_LO_SEID);
+}
+
+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;
+
+ /* rgid should equal to lgid in loopback */
+ if (!ldev || rgid->gid != ldev->local_gid.gid ||
+ rgid->gid_ext != ldev->local_gid.gid_ext)
+ return -ENETUNREACH;
+ return 0;
+}
+
+static int smc_lo_supports_v2(void)
+{
+ return SMC_LO_SUPPORTS_V2;
+}
+
+static u8 *smc_lo_get_system_eid(void)
+{
+ return SMC_LO_SEID.seid_string;
+}
+
+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 u16 smc_lo_get_chid(struct smcd_dev *smcd)
+{
+ return ((struct smc_lo_dev *)smcd->priv)->chid;
+}
+
+static struct device *smc_lo_get_dev(struct smcd_dev *smcd)
+{
+ return &((struct smc_lo_dev *)smcd->priv)->dev;
+}
+
static const struct smcd_ops lo_ops = {
- .query_remote_gid = NULL,
+ .query_remote_gid = smc_lo_query_rgid,
.register_dmb = NULL,
.unregister_dmb = NULL,
.add_vlan_id = NULL,
@@ -31,11 +112,11 @@
.reset_vlan_required = NULL,
.signal_event = NULL,
.move_data = NULL,
- .supports_v2 = NULL,
- .get_system_eid = NULL,
- .get_local_gid = NULL,
- .get_chid = NULL,
- .get_dev = NULL,
+ .supports_v2 = smc_lo_supports_v2,
+ .get_system_eid = smc_lo_get_system_eid,
+ .get_local_gid = smc_lo_get_local_gid,
+ .get_chid = smc_lo_get_chid,
+ .get_dev = smc_lo_get_dev,
};

static struct smcd_dev *smcd_lo_alloc_dev(const struct smcd_ops *ops,
@@ -103,6 +184,8 @@ static void smc_lo_dev_release(struct device *dev)

static int smc_lo_dev_init(struct smc_lo_dev *ldev)
{
+ smc_lo_generate_id(ldev);
+
return smcd_lo_register_dev(ldev);
}

diff --git a/net/smc/smc_loopback.h b/net/smc/smc_loopback.h
index 0f7583c..2156f22 100644
--- a/net/smc/smc_loopback.h
+++ b/net/smc/smc_loopback.h
@@ -18,11 +18,14 @@
#include <linux/err.h>
#include <net/smc.h>

+#define SMC_LO_CHID 0xFFFF
#define SMC_LODEV_MAX_DMBS 5000

struct smc_lo_dev {
struct smcd_dev *smcd;
struct device dev;
+ u16 chid;
+ struct smcd_gid local_gid;
};

int smc_loopback_init(void);
--
1.8.3.1