libnvdimm, nfit: add interleave-set state-tracking infrastructure

[deliverable/linux.git] / drivers / nvdimm / dimm_devs.c

diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index b3ae86f2e1dad80228dcfd7593ef95b5cda6e24a..bdf8241b6525cf0d87b395dc56ec1763a6e9e072 100644 (file)
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -185,7 +185,24 @@ static ssize_t commands_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(commands);
 
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+               char *buf)
+{
+       struct nvdimm *nvdimm = to_nvdimm(dev);
+
+       /*
+        * The state may be in the process of changing, userspace should
+        * quiesce probing if it wants a static answer
+        */
+       nvdimm_bus_lock(dev);
+       nvdimm_bus_unlock(dev);
+       return sprintf(buf, "%s\n", atomic_read(&nvdimm->busy)
+                       ? "active" : "idle");
+}
+static DEVICE_ATTR_RO(state);
+
 static struct attribute *nvdimm_attributes[] = {
+       &dev_attr_state.attr,
        &dev_attr_commands.attr,
        NULL,
 };
@@ -213,7 +230,7 @@ struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
        nvdimm->provider_data = provider_data;
        nvdimm->flags = flags;
        nvdimm->dsm_mask = dsm_mask;
-
+       atomic_set(&nvdimm->busy, 0);
        dev = &nvdimm->dev;
        dev_set_name(dev, "nmem%d", nvdimm->id);
        dev->parent = &nvdimm_bus->dev;