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/region_devs.c b/drivers/nvdimm/region_devs.c
index b5c5b90..1571424 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -10,7 +10,10 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
+#include <linux/scatterlist.h>
+#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/sort.h>
#include <linux/io.h>
#include "nd-core.h"
#include "nd.h"
@@ -133,6 +136,21 @@
}
static DEVICE_ATTR_RO(nstype);
+static ssize_t set_cookie_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nd_region *nd_region = to_nd_region(dev);
+ struct nd_interleave_set *nd_set = nd_region->nd_set;
+
+ if (is_nd_pmem(dev) && nd_set)
+ /* pass, should be precluded by region_visible */;
+ else
+ return -ENXIO;
+
+ return sprintf(buf, "%#llx\n", nd_set->cookie);
+}
+static DEVICE_ATTR_RO(set_cookie);
+
static ssize_t init_namespaces_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -154,15 +172,65 @@
&dev_attr_size.attr,
&dev_attr_nstype.attr,
&dev_attr_mappings.attr,
+ &dev_attr_set_cookie.attr,
&dev_attr_init_namespaces.attr,
NULL,
};
+static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, typeof(*dev), kobj);
+ struct nd_region *nd_region = to_nd_region(dev);
+ struct nd_interleave_set *nd_set = nd_region->nd_set;
+
+ if (a != &dev_attr_set_cookie.attr)
+ return a->mode;
+
+ if (is_nd_pmem(dev) && nd_set)
+ return a->mode;
+
+ return 0;
+}
+
struct attribute_group nd_region_attribute_group = {
.attrs = nd_region_attributes,
+ .is_visible = region_visible,
};
EXPORT_SYMBOL_GPL(nd_region_attribute_group);
+/*
+ * Upon successful probe/remove, take/release a reference on the
+ * associated interleave set (if present)
+ */
+static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
+ struct device *dev, bool probe)
+{
+ if (is_nd_pmem(dev) || is_nd_blk(dev)) {
+ struct nd_region *nd_region = to_nd_region(dev);
+ int i;
+
+ for (i = 0; i < nd_region->ndr_mappings; i++) {
+ struct nd_mapping *nd_mapping = &nd_region->mapping[i];
+ struct nvdimm *nvdimm = nd_mapping->nvdimm;
+
+ if (probe)
+ atomic_inc(&nvdimm->busy);
+ else
+ atomic_dec(&nvdimm->busy);
+ }
+ }
+}
+
+void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev)
+{
+ nd_region_notify_driver_action(nvdimm_bus, dev, true);
+}
+
+void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev)
+{
+ nd_region_notify_driver_action(nvdimm_bus, dev, false);
+}
+
static ssize_t mappingN(struct device *dev, char *buf, int n)
{
struct nd_region *nd_region = to_nd_region(dev);
@@ -322,6 +390,7 @@
}
nd_region->ndr_mappings = ndr_desc->num_mappings;
nd_region->provider_data = ndr_desc->provider_data;
+ nd_region->nd_set = ndr_desc->nd_set;
dev = &nd_region->dev;
dev_set_name(dev, "region%d", nd_region->id);
dev->parent = &nvdimm_bus->dev;