[PATCH net-next v4 10/18] net/smc: implement ID-related operations of loopback

[Wen Gu]

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@xxxxxxxxxxxxxxxxx>
---
 include/net/smc.h      |  6 ++++
 net/smc/smc_ism.h      |  2 ++
 net/smc/smc_loopback.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++----
 net/smc/smc_loopback.h |  3 ++
 4 files changed, 101 insertions(+), 6 deletions(-)

diff --git a/include/net/smc.h b/include/net/smc.h
index d8db5e1..7c2d35c 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 4631236..610af99 100644
--- a/net/smc/smc_loopback.c
+++ b/net/smc/smc_loopback.c
@@ -13,17 +13,99 @@
 
 #include <linux/device.h>
 #include <linux/types.h>
+#include <linux/smc.h>
 #include <net/smc.h>
 
 #include "smc_ism.h"
 #include "smc_loopback.h"
 
 #if IS_ENABLED(CONFIG_SMC_LO)
+#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,
@@ -32,11 +114,11 @@
 	.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,
@@ -104,6 +186,8 @@ 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 39aa1dc..71a52da 100644
--- a/net/smc/smc_loopback.h
+++ b/net/smc/smc_loopback.h
@@ -19,11 +19,14 @@
 #include <net/smc.h>
 
 #if IS_ENABLED(CONFIG_SMC_LO)
+#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;
 };
 #endif
 
-- 
1.8.3.1