nvmet: expose IEEE OUI to configfs

Allow user to set OUI for the controller vendor.
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Dmitriy Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Aleksandr Miloserdov <a.miloserdov@yadro.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/admin-cmd.c

@@ -372,6 +372,8 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 	memcpy_and_pad(id->fr, sizeof(id->fr),
 		       UTS_RELEASE, strlen(UTS_RELEASE), ' ');
 
+	put_unaligned_le24(subsys->ieee_oui, id->ieee);
+
 	id->rab = 6;
 
 	if (nvmet_is_disc_subsys(ctrl->subsys))
@@ -379,11 +381,6 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 	else
 		id->cntrltype = NVME_CTRL_IO;
 
-	/*
-	 * XXX: figure out how we can assign a IEEE OUI, but until then
-	 * the safest is to leave it as zeroes.
-	 */
-
 	/* we support multiple ports, multiples hosts and ANA: */
 	id->cmic = NVME_CTRL_CMIC_MULTI_PORT | NVME_CTRL_CMIC_MULTI_CTRL |
 		NVME_CTRL_CMIC_ANA;

drivers/nvme/target/configfs.c

@@ -1259,6 +1259,54 @@ static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
 }
 CONFIGFS_ATTR(nvmet_subsys_, attr_model);
 
+static ssize_t nvmet_subsys_attr_ieee_oui_show(struct config_item *item,
+					    char *page)
+{
+	struct nvmet_subsys *subsys = to_subsys(item);
+
+	return sysfs_emit(page, "0x%06x\n", subsys->ieee_oui);
+}
+
+static ssize_t nvmet_subsys_attr_ieee_oui_store_locked(struct nvmet_subsys *subsys,
+		const char *page, size_t count)
+{
+	uint32_t val = 0;
+	int ret;
+
+	if (subsys->subsys_discovered) {
+		pr_err("Can't set IEEE OUI. 0x%06x is already assigned\n",
+		      subsys->ieee_oui);
+		return -EINVAL;
+	}
+
+	ret = kstrtou32(page, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val >= 0x1000000)
+		return -EINVAL;
+
+	subsys->ieee_oui = val;
+
+	return count;
+}
+
+static ssize_t nvmet_subsys_attr_ieee_oui_store(struct config_item *item,
+					     const char *page, size_t count)
+{
+	struct nvmet_subsys *subsys = to_subsys(item);
+	ssize_t ret;
+
+	down_write(&nvmet_config_sem);
+	mutex_lock(&subsys->lock);
+	ret = nvmet_subsys_attr_ieee_oui_store_locked(subsys, page, count);
+	mutex_unlock(&subsys->lock);
+	up_write(&nvmet_config_sem);
+
+	return ret;
+}
+CONFIGFS_ATTR(nvmet_subsys_, attr_ieee_oui);
+
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 static ssize_t nvmet_subsys_attr_pi_enable_show(struct config_item *item,
 						char *page)
@@ -1320,6 +1368,7 @@ static struct configfs_attribute *nvmet_subsys_attrs[] = {
 	&nvmet_subsys_attr_attr_cntlid_max,
 	&nvmet_subsys_attr_attr_model,
 	&nvmet_subsys_attr_attr_qid_max,
+	&nvmet_subsys_attr_attr_ieee_oui,
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 	&nvmet_subsys_attr_attr_pi_enable,
 #endif

drivers/nvme/target/core.c

@@ -1561,6 +1561,8 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 		goto free_subsys;
 	}
 
+	subsys->ieee_oui = 0;
+
 	switch (type) {
 	case NVME_NQN_NVME:
 		subsys->max_qid = NVMET_NR_QUEUES;

drivers/nvme/target/nvmet.h

@@ -263,6 +263,7 @@ struct nvmet_subsys {
 	struct config_group	allowed_hosts_group;
 
 	char			*model_number;
+	u32			ieee_oui;
 
 #ifdef CONFIG_NVME_TARGET_PASSTHRU
 	struct nvme_ctrl	*passthru_ctrl;