nvme: expose subsys attribute to sysfs

We should be exposing the subsystem attributes like 'model' and
'subsysnqn' to sysfs to allow for easier identification of the
subsystem.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index c3182aa654fd6388f81f018f82d17256a29cbd14..7b3bbc1a9ac49bcb0d2fc94615c9064f4951cd1d 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1999,6 +1999,53 @@ static struct nvme_subsystem *__nvme_find_get_subsystem(const char *subsysnqn)
        return NULL;
 }
 
+#define SUBSYS_ATTR_RO(_name, _mode, _show)                    \
+       struct device_attribute subsys_attr_##_name = \
+               __ATTR(_name, _mode, _show, NULL)
+
+static ssize_t nvme_subsys_show_nqn(struct device *dev,
+                                   struct device_attribute *attr,
+                                   char *buf)
+{
+       struct nvme_subsystem *subsys =
+               container_of(dev, struct nvme_subsystem, dev);
+
+       return snprintf(buf, PAGE_SIZE, "%s\n", subsys->subnqn);
+}
+static SUBSYS_ATTR_RO(subsysnqn, S_IRUGO, nvme_subsys_show_nqn);
+
+#define nvme_subsys_show_str_function(field)                           \
+static ssize_t subsys_##field##_show(struct device *dev,               \
+                           struct device_attribute *attr, char *buf)   \
+{                                                                      \
+       struct nvme_subsystem *subsys =                                 \
+               container_of(dev, struct nvme_subsystem, dev);          \
+       return sprintf(buf, "%.*s\n",                                   \
+                      (int)sizeof(subsys->field), subsys->field);      \
+}                                                                      \
+static SUBSYS_ATTR_RO(field, S_IRUGO, subsys_##field##_show);
+
+nvme_subsys_show_str_function(model);
+nvme_subsys_show_str_function(serial);
+nvme_subsys_show_str_function(firmware_rev);
+
+static struct attribute *nvme_subsys_attrs[] = {
+       &subsys_attr_model.attr,
+       &subsys_attr_serial.attr,
+       &subsys_attr_firmware_rev.attr,
+       &subsys_attr_subsysnqn.attr,
+       NULL,
+};
+
+static struct attribute_group nvme_subsys_attrs_group = {
+       .attrs = nvme_subsys_attrs,
+};
+
+static const struct attribute_group *nvme_subsys_attrs_groups[] = {
+       &nvme_subsys_attrs_group,
+       NULL,
+};
+
 static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 {
        struct nvme_subsystem *subsys, *found;
@@ -2026,6 +2073,7 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 
        subsys->dev.class = nvme_subsys_class;
        subsys->dev.release = nvme_release_subsystem;
+       subsys->dev.groups = nvme_subsys_attrs_groups;
        dev_set_name(&subsys->dev, "nvme-subsys%d", subsys->instance);
        device_initialize(&subsys->dev);