libnvdimm, namespace: enable allocation of multiple pmem namespaces

Now that we have nd_region_available_dpa() able to handle the presence
of multiple PMEM allocations in aliased PMEM regions, reuse that same
infrastructure to track allocations from free space.  In particular
handle allocating from an aliased PMEM region in the case where there
are dis-contiguous holes.  The allocation for BLK and PMEM are
documented in the space_valid() helper:

    BLK-space is valid as long as it does not precede a PMEM
    allocation in a given region. PMEM-space must be contiguous
    and adjacent to an existing existing allocation (if one
    exists).

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 7c2196a1d56f..3ba0b96ce7de 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -44,6 +44,23 @@ struct nvdimm {
 	struct resource *flush_wpq;
 };
 
+/**
+ * struct blk_alloc_info - tracking info for BLK dpa scanning
+ * @nd_mapping: blk region mapping boundaries
+ * @available: decremented in alias_dpa_busy as aliased PMEM is scanned
+ * @busy: decremented in blk_dpa_busy to account for ranges already
+ * 	  handled by alias_dpa_busy
+ * @res: alias_dpa_busy interprets this a free space range that needs to
+ * 	 be truncated to the valid BLK allocation starting DPA, blk_dpa_busy
+ * 	 treats it as a busy range that needs the aliased PMEM ranges
+ * 	 truncated.
+ */
+struct blk_alloc_info {
+	struct nd_mapping *nd_mapping;
+	resource_size_t available, busy;
+	struct resource *res;
+};
+
 bool is_nvdimm(struct device *dev);
 bool is_nd_pmem(struct device *dev);
 bool is_nd_blk(struct device *dev);
@@ -80,6 +97,7 @@ resource_size_t nd_blk_available_dpa(struct nd_region *nd_region);
 resource_size_t nd_region_available_dpa(struct nd_region *nd_region);
 resource_size_t nvdimm_allocated_dpa(struct nvdimm_drvdata *ndd,
 		struct nd_label_id *label_id);
+int alias_dpa_busy(struct device *dev, void *data);
 struct resource *nsblk_add_resource(struct nd_region *nd_region,
 		struct nvdimm_drvdata *ndd, struct nd_namespace_blk *nsblk,
 		resource_size_t start);