libnvdimm, nfit: add interleave-set state-tracking infrastructure
On platforms that have firmware support for reading/writing per-dimm
label space, a portion of the dimm may be accessible via an interleave
set PMEM mapping in addition to the dimm's BLK (block-data-window
aperture(s)) interface. A label, stored in a "configuration data
region" on the dimm, disambiguates which dimm addresses are accessed
through which exclusive interface.
Add infrastructure that allows the kernel to block modifications to a
label in the set while any member dimm is active. Note that this is
meant only for enforcing "no modifications of active labels" via the
coarse ioctl command. Adding/deleting namespaces from an active
interleave set is always possible via sysfs.
Another aspect of tracking interleave sets is tracking their integrity
when DIMMs in a set are physically re-ordered. For this purpose we
generate an "interleave-set cookie" that can be recorded in a label and
validated against the current configuration. It is the bus provider
implementation's responsibility to calculate the interleave set cookie
and attach it to a given region.
Cc: Neil Brown <neilb@suse.de>
Cc: <linux-acpi@vger.kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index b3ae86f..bdf8241 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -185,7 +185,24 @@
}
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 @@
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;