nvme: introduce a controller state machine

[linux-block.git] / drivers / nvme / host / core.c

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 20559ad98be13dc65f4753d6ceec1a67bb2756f8..bd8f598d0c37209cda4cee43ca41a6e1bc253d97 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -58,6 +58,55 @@ static DEFINE_SPINLOCK(dev_list_lock);
 
 static struct class *nvme_class;
 
+bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
+               enum nvme_ctrl_state new_state)
+{
+       enum nvme_ctrl_state old_state = ctrl->state;
+       bool changed = false;
+
+       spin_lock_irq(&ctrl->lock);
+       switch (new_state) {
+       case NVME_CTRL_LIVE:
+               switch (old_state) {
+               case NVME_CTRL_RESETTING:
+                       changed = true;
+                       /* FALLTHRU */
+               default:
+                       break;
+               }
+               break;
+       case NVME_CTRL_RESETTING:
+               switch (old_state) {
+               case NVME_CTRL_NEW:
+               case NVME_CTRL_LIVE:
+                       changed = true;
+                       /* FALLTHRU */
+               default:
+                       break;
+               }
+               break;
+       case NVME_CTRL_DELETING:
+               switch (old_state) {
+               case NVME_CTRL_LIVE:
+               case NVME_CTRL_RESETTING:
+                       changed = true;
+                       /* FALLTHRU */
+               default:
+                       break;
+               }
+               break;
+       default:
+               break;
+       }
+       spin_unlock_irq(&ctrl->lock);
+
+       if (changed)
+               ctrl->state = new_state;
+
+       return changed;
+}
+EXPORT_SYMBOL_GPL(nvme_change_ctrl_state);
+
 static void nvme_free_ns(struct kref *kref)
 {
        struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);
@@ -1583,6 +1632,8 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
 {
        int ret;
 
+       ctrl->state = NVME_CTRL_NEW;
+       spin_lock_init(&ctrl->lock);
        INIT_LIST_HEAD(&ctrl->namespaces);
        mutex_init(&ctrl->namespaces_mutex);
        kref_init(&ctrl->kref);