libnvdimm: namespace indices: read and validate

This on media label format [1] consists of two index blocks followed by
an array of labels.  None of these structures are ever updated in place.
A sequence number tracks the current active index and the next one to
write, while labels are written to free slots.

    +------------+
    |            |
    |  nsindex0  |
    |            |
    +------------+
    |            |
    |  nsindex1  |
    |            |
    +------------+
    |   label0   |
    +------------+
    |   label1   |
    +------------+
    |            |
     ....nslot...
    |            |
    +------------+
    |   labelN   |
    +------------+

After reading valid labels, store the dpa ranges they claim into
per-dimm resource trees.

[1]: http://pmem.io/documents/NVDIMM_Namespace_Spec.pdf

Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 0285e4588b03..401fa0d5b6ea 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -16,11 +16,15 @@
 #include <linux/device.h>
 #include <linux/mutex.h>
 #include <linux/ndctl.h>
+#include "label.h"
 
 struct nvdimm_drvdata {
 	struct device *dev;
+	int nsindex_size;
 	struct nd_cmd_get_config_size nsarea;
 	void *data;
+	int ns_current, ns_next;
+	struct resource dpa;
 };
 
 struct nd_region_namespaces {
@@ -28,6 +32,37 @@ struct nd_region_namespaces {
 	int active;
 };
 
+static inline struct nd_namespace_index *to_namespace_index(
+		struct nvdimm_drvdata *ndd, int i)
+{
+	if (i < 0)
+		return NULL;
+
+	return ndd->data + sizeof_namespace_index(ndd) * i;
+}
+
+static inline struct nd_namespace_index *to_current_namespace_index(
+		struct nvdimm_drvdata *ndd)
+{
+	return to_namespace_index(ndd, ndd->ns_current);
+}
+
+static inline struct nd_namespace_index *to_next_namespace_index(
+		struct nvdimm_drvdata *ndd)
+{
+	return to_namespace_index(ndd, ndd->ns_next);
+}
+
+#define nd_dbg_dpa(r, d, res, fmt, arg...) \
+	dev_dbg((r) ? &(r)->dev : (d)->dev, "%s: %.13s: %#llx @ %#llx " fmt, \
+		(r) ? dev_name((d)->dev) : "", res ? res->name : "null", \
+		(unsigned long long) (res ? resource_size(res) : 0), \
+		(unsigned long long) (res ? res->start : 0), ##arg)
+
+#define for_each_dpa_resource_safe(ndd, res, next) \
+	for (res = (ndd)->dpa.child, next = res ? res->sibling : NULL; \
+			res; res = next, next = next ? next->sibling : NULL)
+
 struct nd_region {
 	struct device dev;
 	u16 ndr_mappings;
@@ -39,6 +74,15 @@ struct nd_region {
 	struct nd_mapping mapping[0];
 };
 
+/*
+ * Lookup next in the repeating sequence of 01, 10, and 11.
+ */
+static inline unsigned nd_inc_seq(unsigned seq)
+{
+	static const unsigned next[] = { 0, 2, 3, 1 };
+
+	return next[seq & 3];
+}
 enum nd_async_mode {
 	ND_SYNC,
 	ND_ASYNC,
@@ -58,4 +102,9 @@ int nd_region_register_namespaces(struct nd_region *nd_region, int *err);
 void nvdimm_bus_lock(struct device *dev);
 void nvdimm_bus_unlock(struct device *dev);
 bool is_nvdimm_bus_locked(struct device *dev);
+int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd);
+void nvdimm_free_dpa(struct nvdimm_drvdata *ndd, struct resource *res);
+struct resource *nvdimm_allocate_dpa(struct nvdimm_drvdata *ndd,
+		struct nd_label_id *label_id, resource_size_t start,
+		resource_size_t n);
 #endif /* __ND_H__ */