3 files changed, 205 insertions, 36 deletions

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 878d5c09d15b..78dc6f624d52 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -68,9 +68,14 @@ MODULE_PARM_DESC(streams, "turn on support for Streams write directives");
 struct workqueue_struct *nvme_wq;
 EXPORT_SYMBOL_GPL(nvme_wq);
 
+static DEFINE_IDA(nvme_subsystems_ida);
+static LIST_HEAD(nvme_subsystems);
+static DEFINE_MUTEX(nvme_subsystems_lock);
+
 static DEFINE_IDA(nvme_instance_ida);
 static dev_t nvme_chr_devt;
 static struct class *nvme_class;
+static struct class *nvme_subsys_class;
 
 static void nvme_ns_remove(struct nvme_ns *ns);
 static int nvme_revalidate_disk(struct gendisk *disk);
@@ -1804,14 +1809,15 @@ static bool quirk_matches(const struct nvme_id_ctrl *id,
 		string_matches(id->fr, q->fr, sizeof(id->fr));
 }
 
-static void nvme_init_subnqn(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
+static void nvme_init_subnqn(struct nvme_subsystem *subsys, struct nvme_ctrl *ctrl,
+		struct nvme_id_ctrl *id)
 {
 	size_t nqnlen;
 	int off;
 
 	nqnlen = strnlen(id->subnqn, NVMF_NQN_SIZE);
 	if (nqnlen > 0 && nqnlen < NVMF_NQN_SIZE) {
-		strncpy(ctrl->subnqn, id->subnqn, NVMF_NQN_SIZE);
+		strncpy(subsys->subnqn, id->subnqn, NVMF_NQN_SIZE);
 		return;
 	}
 
@@ -1819,14 +1825,140 @@ static void nvme_init_subnqn(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 		dev_warn(ctrl->device, "missing or invalid SUBNQN field.\n");
 
 	/* Generate a "fake" NQN per Figure 254 in NVMe 1.3 + ECN 001 */
-	off = snprintf(ctrl->subnqn, NVMF_NQN_SIZE,
+	off = snprintf(subsys->subnqn, NVMF_NQN_SIZE,
 			"nqn.2014.08.org.nvmexpress:%4x%4x",
 			le16_to_cpu(id->vid), le16_to_cpu(id->ssvid));
-	memcpy(ctrl->subnqn + off, id->sn, sizeof(id->sn));
+	memcpy(subsys->subnqn + off, id->sn, sizeof(id->sn));
 	off += sizeof(id->sn);
-	memcpy(ctrl->subnqn + off, id->mn, sizeof(id->mn));
+	memcpy(subsys->subnqn + off, id->mn, sizeof(id->mn));
 	off += sizeof(id->mn);
-	memset(ctrl->subnqn + off, 0, sizeof(ctrl->subnqn) - off);
+	memset(subsys->subnqn + off, 0, sizeof(subsys->subnqn) - off);
+}
+
+static void __nvme_release_subsystem(struct nvme_subsystem *subsys)
+{
+	ida_simple_remove(&nvme_subsystems_ida, subsys->instance);
+	kfree(subsys);
+}
+
+static void nvme_release_subsystem(struct device *dev)
+{
+	__nvme_release_subsystem(container_of(dev, struct nvme_subsystem, dev));
+}
+
+static void nvme_destroy_subsystem(struct kref *ref)
+{
+	struct nvme_subsystem *subsys =
+			container_of(ref, struct nvme_subsystem, ref);
+
+	mutex_lock(&nvme_subsystems_lock);
+	list_del(&subsys->entry);
+	mutex_unlock(&nvme_subsystems_lock);
+
+	device_del(&subsys->dev);
+	put_device(&subsys->dev);
+}
+
+static void nvme_put_subsystem(struct nvme_subsystem *subsys)
+{
+	kref_put(&subsys->ref, nvme_destroy_subsystem);
+}
+
+static struct nvme_subsystem *__nvme_find_get_subsystem(const char *subsysnqn)
+{
+	struct nvme_subsystem *subsys;
+
+	lockdep_assert_held(&nvme_subsystems_lock);
+
+	list_for_each_entry(subsys, &nvme_subsystems, entry) {
+		if (strcmp(subsys->subnqn, subsysnqn))
+			continue;
+		if (!kref_get_unless_zero(&subsys->ref))
+			continue;
+		return subsys;
+	}
+
+	return NULL;
+}
+
+static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
+{
+	struct nvme_subsystem *subsys, *found;
+	int ret;
+
+	subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
+	if (!subsys)
+		return -ENOMEM;
+	ret = ida_simple_get(&nvme_subsystems_ida, 0, 0, GFP_KERNEL);
+	if (ret < 0) {
+		kfree(subsys);
+		return ret;
+	}
+	subsys->instance = ret;
+	mutex_init(&subsys->lock);
+	kref_init(&subsys->ref);
+	INIT_LIST_HEAD(&subsys->ctrls);
+	nvme_init_subnqn(subsys, ctrl, id);
+	memcpy(subsys->serial, id->sn, sizeof(subsys->serial));
+	memcpy(subsys->model, id->mn, sizeof(subsys->model));
+	memcpy(subsys->firmware_rev, id->fr, sizeof(subsys->firmware_rev));
+	subsys->vendor_id = le16_to_cpu(id->vid);
+	subsys->cmic = id->cmic;
+
+	subsys->dev.class = nvme_subsys_class;
+	subsys->dev.release = nvme_release_subsystem;
+	dev_set_name(&subsys->dev, "nvme-subsys%d", subsys->instance);
+	device_initialize(&subsys->dev);
+
+	mutex_lock(&nvme_subsystems_lock);
+	found = __nvme_find_get_subsystem(subsys->subnqn);
+	if (found) {
+		/*
+		 * Verify that the subsystem actually supports multiple
+		 * controllers, else bail out.
+		 */
+		if (!(id->cmic & (1 << 1))) {
+			dev_err(ctrl->device,
+				"ignoring ctrl due to duplicate subnqn (%s).\n",
+				found->subnqn);
+			nvme_put_subsystem(found);
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+
+		__nvme_release_subsystem(subsys);
+		subsys = found;
+	} else {
+		ret = device_add(&subsys->dev);
+		if (ret) {
+			dev_err(ctrl->device,
+				"failed to register subsystem device.\n");
+			goto out_unlock;
+		}
+		list_add_tail(&subsys->entry, &nvme_subsystems);
+	}
+
+	ctrl->subsys = subsys;
+	mutex_unlock(&nvme_subsystems_lock);
+
+	if (sysfs_create_link(&subsys->dev.kobj, &ctrl->device->kobj,
+			dev_name(ctrl->device))) {
+		dev_err(ctrl->device,
+			"failed to create sysfs link from subsystem.\n");
+		/* the transport driver will eventually put the subsystem */
+		return -EINVAL;
+	}
+
+	mutex_lock(&subsys->lock);
+	list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
+	mutex_unlock(&subsys->lock);
+
+	return 0;
+
+out_unlock:
+	mutex_unlock(&nvme_subsystems_lock);
+	put_device(&subsys->dev);
+	return ret;
 }
 
 static int nvme_get_log(struct nvme_ctrl *ctrl, u8 log_page, void *log,
@@ -1901,9 +2033,13 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
 			return ret;
 	}
 
-	nvme_init_subnqn(ctrl, id);
-
 	if (!ctrl->identified) {
+		int i;
+
+		ret = nvme_init_subsystem(ctrl, id);
+		if (ret)
+			goto out_free;
+
 		/*
 		 * Check for quirks.  Quirk can depend on firmware version,
 		 * so, in principle, the set of quirks present can change
@@ -1912,9 +2048,6 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
 		 * the device, but we'd have to make sure that the driver
 		 * behaves intelligently if the quirks change.
 		 */
-
-		int i;
-
 		for (i = 0; i < ARRAY_SIZE(core_quirks); i++) {
 			if (quirk_matches(id, &core_quirks[i]))
 				ctrl->quirks |= core_quirks[i].quirks;
@@ -1927,14 +2060,10 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
 	}
 
 	ctrl->oacs = le16_to_cpu(id->oacs);
-	ctrl->vid = le16_to_cpu(id->vid);
 	ctrl->oncs = le16_to_cpup(&id->oncs);
 	atomic_set(&ctrl->abort_limit, id->acl + 1);
 	ctrl->vwc = id->vwc;
 	ctrl->cntlid = le16_to_cpup(&id->cntlid);
-	memcpy(ctrl->serial, id->sn, sizeof(id->sn));
-	memcpy(ctrl->model, id->mn, sizeof(id->mn));
-	memcpy(ctrl->firmware_rev, id->fr, sizeof(id->fr));
 	if (id->mdts)
 		max_hw_sectors = 1 << (id->mdts + page_shift - 9);
 	else
@@ -2137,9 +2266,9 @@ static ssize_t wwid_show(struct device *dev, struct device_attribute *attr,
 								char *buf)
 {
 	struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
-	struct nvme_ctrl *ctrl = ns->ctrl;
-	int serial_len = sizeof(ctrl->serial);
-	int model_len = sizeof(ctrl->model);
+	struct nvme_subsystem *subsys = ns->ctrl->subsys;
+	int serial_len = sizeof(subsys->serial);
+	int model_len = sizeof(subsys->model);
 
 	if (!uuid_is_null(&ns->uuid))
 		return sprintf(buf, "uuid.%pU\n", &ns->uuid);
@@ -2150,15 +2279,16 @@ static ssize_t wwid_show(struct device *dev, struct device_attribute *attr,
 	if (memchr_inv(ns->eui, 0, sizeof(ns->eui)))
 		return sprintf(buf, "eui.%8phN\n", ns->eui);
 
-	while (serial_len > 0 && (ctrl->serial[serial_len - 1] == ' ' ||
-				  ctrl->serial[serial_len - 1] == '\0'))
+	while (serial_len > 0 && (subsys->serial[serial_len - 1] == ' ' ||
+				  subsys->serial[serial_len - 1] == '\0'))
 		serial_len--;
-	while (model_len > 0 && (ctrl->model[model_len - 1] == ' ' ||
-				 ctrl->model[model_len - 1] == '\0'))
+	while (model_len > 0 && (subsys->model[model_len - 1] == ' ' ||
+				 subsys->model[model_len - 1] == '\0'))
 		model_len--;
 
-	return sprintf(buf, "nvme.%04x-%*phN-%*phN-%08x\n", ctrl->vid,
-		serial_len, ctrl->serial, model_len, ctrl->model, ns->ns_id);
+	return sprintf(buf, "nvme.%04x-%*phN-%*phN-%08x\n", subsys->vendor_id,
+		serial_len, subsys->serial, model_len, subsys->model,
+		ns->ns_id);
 }
 static DEVICE_ATTR(wwid, S_IRUGO, wwid_show, NULL);
 
@@ -2244,10 +2374,15 @@ static ssize_t  field##_show(struct device *dev,				\
 			    struct device_attribute *attr, char *buf)		\
 {										\
         struct nvme_ctrl *ctrl = dev_get_drvdata(dev);				\
-        return sprintf(buf, "%.*s\n", (int)sizeof(ctrl->field), ctrl->field);	\
+        return sprintf(buf, "%.*s\n",						\
+		(int)sizeof(ctrl->subsys->field), ctrl->subsys->field);		\
 }										\
 static DEVICE_ATTR(field, S_IRUGO, field##_show, NULL);
 
+nvme_show_str_function(model);
+nvme_show_str_function(serial);
+nvme_show_str_function(firmware_rev);
+
 #define nvme_show_int_function(field)						\
 static ssize_t  field##_show(struct device *dev,				\
 			    struct device_attribute *attr, char *buf)		\
@@ -2257,9 +2392,6 @@ static ssize_t  field##_show(struct device *dev,				\
 }										\
 static DEVICE_ATTR(field, S_IRUGO, field##_show, NULL);
 
-nvme_show_str_function(model);
-nvme_show_str_function(serial);
-nvme_show_str_function(firmware_rev);
 nvme_show_int_function(cntlid);
 
 static ssize_t nvme_sysfs_delete(struct device *dev,
@@ -2313,7 +2445,7 @@ static ssize_t nvme_sysfs_show_subsysnqn(struct device *dev,
 {
 	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
 
-	return snprintf(buf, PAGE_SIZE, "%s\n", ctrl->subnqn);
+	return snprintf(buf, PAGE_SIZE, "%s\n", ctrl->subsys->subnqn);
 }
 static DEVICE_ATTR(subsysnqn, S_IRUGO, nvme_sysfs_show_subsysnqn, NULL);
 
@@ -2817,12 +2949,23 @@ static void nvme_free_ctrl(struct device *dev)
 {
 	struct nvme_ctrl *ctrl =
 		container_of(dev, struct nvme_ctrl, ctrl_device);
+	struct nvme_subsystem *subsys = ctrl->subsys;
 
 	ida_simple_remove(&nvme_instance_ida, ctrl->instance);
 	ida_destroy(&ctrl->ns_ida);
 	kfree(ctrl->effects);
 
+	if (subsys) {
+		mutex_lock(&subsys->lock);
+		list_del(&ctrl->subsys_entry);
+		mutex_unlock(&subsys->lock);
+		sysfs_remove_link(&subsys->dev.kobj, dev_name(ctrl->device));
+	}
+
 	ctrl->ops->free_ctrl(ctrl);
+
+	if (subsys)
+		nvme_put_subsystem(subsys);
 }
 
 /*
@@ -3022,8 +3165,15 @@ int __init nvme_core_init(void)
 		goto unregister_chrdev;
 	}
 
+	nvme_subsys_class = class_create(THIS_MODULE, "nvme-subsystem");
+	if (IS_ERR(nvme_subsys_class)) {
+		result = PTR_ERR(nvme_subsys_class);
+		goto destroy_class;
+	}
 	return 0;
 
+destroy_class:
+	class_destroy(nvme_class);
 unregister_chrdev:
 	unregister_chrdev_region(nvme_chr_devt, NVME_MINORS);
 destroy_wq:
@@ -3033,6 +3183,8 @@ destroy_wq:
 
 void nvme_core_exit(void)
 {
+	ida_destroy(&nvme_subsystems_ida);
+	class_destroy(nvme_subsys_class);
 	class_destroy(nvme_class);
 	unregister_chrdev_region(nvme_chr_devt, NVME_MINORS);
 	destroy_workqueue(nvme_wq);
diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index a4967de5bb25..76b4fe6816a0 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -882,10 +882,10 @@ nvmf_create_ctrl(struct device *dev, const char *buf, size_t count)
 		goto out_unlock;
 	}
 
-	if (strcmp(ctrl->subnqn, opts->subsysnqn)) {
+	if (strcmp(ctrl->subsys->subnqn, opts->subsysnqn)) {
 		dev_warn(ctrl->device,
 			"controller returned incorrect NQN: \"%s\".\n",
-			ctrl->subnqn);
+			ctrl->subsys->subnqn);
 		up_read(&nvmf_transports_rwsem);
 		nvme_delete_ctrl_sync(ctrl);
 		return ERR_PTR(-EINVAL);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 23b8504ace7f..6ae50979c3aa 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -140,13 +140,12 @@ struct nvme_ctrl {
 	struct work_struct reset_work;
 	struct work_struct delete_work;
 
+	struct nvme_subsystem *subsys;
+	struct list_head subsys_entry;
+
 	struct opal_dev *opal_dev;
 
 	char name[12];
-	char serial[20];
-	char model[40];
-	char firmware_rev[8];
-	char subnqn[NVMF_NQN_SIZE];
 	u16 cntlid;
 
 	u32 ctrl_config;
@@ -157,7 +156,6 @@ struct nvme_ctrl {
 	u32 page_size;
 	u32 max_hw_sectors;
 	u16 oncs;
-	u16 vid;
 	u16 oacs;
 	u16 nssa;
 	u16 nr_streams;
@@ -200,6 +198,25 @@ struct nvme_ctrl {
 	struct nvmf_ctrl_options *opts;
 };
 
+struct nvme_subsystem {
+	int			instance;
+	struct device		dev;
+	/*
+	 * Because we unregister the device on the last put we need
+	 * a separate refcount.
+	 */
+	struct kref		ref;
+	struct list_head	entry;
+	struct mutex		lock;
+	struct list_head	ctrls;
+	char			subnqn[NVMF_NQN_SIZE];
+	char			serial[20];
+	char			model[40];
+	char			firmware_rev[8];
+	u8			cmic;
+	u16			vendor_id;
+};
+
 struct nvme_ns {
 	struct list_head list;