Commit a1f3e4d6 authored by Dan Williams's avatar Dan Williams
Browse files

libnvdimm, region: update nd_region_available_dpa() for multi-pmem support 



The free dpa (dimm-physical-address) space calculation reports how much
free space is available with consideration for aliased BLK + PMEM
regions.  Recall that BLK capacity is allocated from high addresses and
PMEM is allocated from low addresses in their respective regions.

nd_region_available_dpa() accounts for the fact that the largest
encroachment (lowest starting address) into PMEM capacity by a BLK
allocation limits the available capacity to that point, regardless if
there is BLK allocation hole at a higher address.  Similarly, for the
multi-pmem case we need to track the largest encroachment (highest
 ending address) of a PMEM allocation in BLK capacity regardless of
whether there is an allocation hole that a BLK allocation could fill at
a lower address.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 6ff3e912

drivers/nvdimm/dimm_devs.c

+136 −38
Original line number Diff line number Diff line
@@ -386,40 +386,148 @@ struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data, 
}

EXPORT_SYMBOL_GPL(nvdimm_create);



struct blk_alloc_info {

	struct nd_mapping *nd_mapping;

	resource_size_t available, busy;

	struct resource *res;

};



static int alias_dpa_busy(struct device *dev, void *data)

{

	resource_size_t map_end, blk_start, new, busy;

	struct blk_alloc_info *info = data;

	struct nd_mapping *nd_mapping;

	struct nd_region *nd_region;

	struct nvdimm_drvdata *ndd;

	struct resource *res;

	int i;



	if (!is_nd_pmem(dev))

		return 0;



	nd_region = to_nd_region(dev);

	for (i = 0; i < nd_region->ndr_mappings; i++) {

		nd_mapping  = &nd_region->mapping[i];

		if (nd_mapping->nvdimm == info->nd_mapping->nvdimm)

			break;

	}



	if (i >= nd_region->ndr_mappings)

		return 0;



	ndd = to_ndd(nd_mapping);

	map_end = nd_mapping->start + nd_mapping->size - 1;

	blk_start = nd_mapping->start;

 retry:

	/*

	 * Find the free dpa from the end of the last pmem allocation to

	 * the end of the interleave-set mapping that is not already

	 * covered by a blk allocation.

	 */

	busy = 0;

	for_each_dpa_resource(ndd, res) {

		if ((res->start >= blk_start && res->start < map_end)

				|| (res->end >= blk_start

					&& res->end <= map_end)) {

			if (strncmp(res->name, "pmem", 4) == 0) {

				new = max(blk_start, min(map_end + 1,

							res->end + 1));

				if (new != blk_start) {

					blk_start = new;

					goto retry;

				}

			} else

				busy += min(map_end, res->end)

					- max(nd_mapping->start, res->start) + 1;

		} else if (nd_mapping->start > res->start

				&& map_end < res->end) {

			/* total eclipse of the PMEM region mapping */

			busy += nd_mapping->size;

			break;

		}

	}



	info->available -= blk_start - nd_mapping->start + busy;

	return 0;

}



static int blk_dpa_busy(struct device *dev, void *data)

{

	struct blk_alloc_info *info = data;

	struct nd_mapping *nd_mapping;

	struct nd_region *nd_region;

	resource_size_t map_end;

	int i;



	if (!is_nd_pmem(dev))

		return 0;



	nd_region = to_nd_region(dev);

	for (i = 0; i < nd_region->ndr_mappings; i++) {

		nd_mapping  = &nd_region->mapping[i];

		if (nd_mapping->nvdimm == info->nd_mapping->nvdimm)

			break;

	}



	if (i >= nd_region->ndr_mappings)

		return 0;



	map_end = nd_mapping->start + nd_mapping->size - 1;

	if (info->res->start >= nd_mapping->start

			&& info->res->start < map_end) {

		if (info->res->end <= map_end) {

			info->busy = 0;

			return 1;

		} else {

			info->busy -= info->res->end - map_end;

			return 0;

		}

	} else if (info->res->end >= nd_mapping->start

			&& info->res->end <= map_end) {

		info->busy -= nd_mapping->start - info->res->start;

		return 0;

	} else {

		info->busy -= nd_mapping->size;

		return 0;

	}

}



/**

 * nd_blk_available_dpa - account the unused dpa of BLK region

 * @nd_mapping: container of dpa-resource-root + labels

 *

 * Unlike PMEM, BLK namespaces can occupy discontiguous DPA ranges.

 * Unlike PMEM, BLK namespaces can occupy discontiguous DPA ranges, but

 * we arrange for them to never start at an lower dpa than the last

 * PMEM allocation in an aliased region.

 */

resource_size_t nd_blk_available_dpa(struct nd_mapping *nd_mapping)

resource_size_t nd_blk_available_dpa(struct nd_region *nd_region)

{

	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);

	struct nd_mapping *nd_mapping = &nd_region->mapping[0];

	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);

	resource_size_t map_end, busy = 0, available;

	struct blk_alloc_info info = {

		.nd_mapping = nd_mapping,

		.available = nd_mapping->size,

	};

	struct resource *res;



	if (!ndd)

		return 0;



	map_end = nd_mapping->start + nd_mapping->size - 1;

	for_each_dpa_resource(ndd, res)

		if (res->start >= nd_mapping->start && res->start < map_end) {

			resource_size_t end = min(map_end, res->end);

	device_for_each_child(&nvdimm_bus->dev, &info, alias_dpa_busy);



			busy += end - res->start + 1;

		} else if (res->end >= nd_mapping->start

				&& res->end <= map_end) {

			busy += res->end - nd_mapping->start;

		} else if (nd_mapping->start > res->start

				&& nd_mapping->start < res->end) {

			/* total eclipse of the BLK region mapping */

			busy += nd_mapping->size;

	/* now account for busy blk allocations in unaliased dpa */

	for_each_dpa_resource(ndd, res) {

		if (strncmp(res->name, "blk", 3) != 0)

			continue;



		info.res = res;

		info.busy = resource_size(res);

		device_for_each_child(&nvdimm_bus->dev, &info, blk_dpa_busy);

		info.available -= info.busy;

	}



	available = map_end - nd_mapping->start + 1;

	if (busy < available)

		return available - busy;

	return 0;

	return info.available;

}



/**
@@ -451,21 +559,16 @@ resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region, 
	map_start = nd_mapping->start;

	map_end = map_start + nd_mapping->size - 1;

	blk_start = max(map_start, map_end + 1 - *overlap);

	for_each_dpa_resource(ndd, res)

	for_each_dpa_resource(ndd, res) {

		if (res->start >= map_start && res->start < map_end) {

			if (strncmp(res->name, "blk", 3) == 0)

				blk_start = min(blk_start, res->start);

			else if (res->start != map_start) {

				blk_start = min(blk_start,

						max(map_start, res->start));

			else if (res->end > map_end) {

				reason = "misaligned to iset";

				goto err;

			} else {

				if (busy) {

					reason = "duplicate overlapping PMEM reservations?";

					goto err;

				}

			} else

				busy += resource_size(res);

				continue;

			}

		} else if (res->end >= map_start && res->end <= map_end) {

			if (strncmp(res->name, "blk", 3) == 0) {

				/*
@@ -474,15 +577,14 @@ resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region, 
				 * be used for BLK.

				 */

				blk_start = map_start;

			} else {

				reason = "misaligned to iset";

				goto err;

			}

			} else

				busy += resource_size(res);

		} else if (map_start > res->start && map_start < res->end) {

			/* total eclipse of the mapping */

			busy += nd_mapping->size;

			blk_start = map_start;

		}

	}



	*overlap = map_end + 1 - blk_start;

	available = blk_start - map_start;
@@ -491,10 +593,6 @@ resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region, 
	return 0;



 err:

	/*

	 * Something is wrong, PMEM must align with the start of the

	 * interleave set, and there can only be one allocation per set.

	 */

	nd_dbg_dpa(nd_region, ndd, res, "%s\n", reason);

	return 0;

}

drivers/nvdimm/nd-core.h

+1 −1
Original line number Diff line number Diff line
@@ -76,7 +76,7 @@ struct nd_mapping; 
void nd_mapping_free_labels(struct nd_mapping *nd_mapping);

resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region,

		struct nd_mapping *nd_mapping, resource_size_t *overlap);

resource_size_t nd_blk_available_dpa(struct nd_mapping *nd_mapping);

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);

drivers/nvdimm/region_devs.c

+2 −3
Original line number Diff line number Diff line
@@ -294,9 +294,8 @@ resource_size_t nd_region_available_dpa(struct nd_region *nd_region) 
				blk_max_overlap = overlap;

				goto retry;

			}

		} else if (is_nd_blk(&nd_region->dev)) {

			available += nd_blk_available_dpa(nd_mapping);

		}

		} else if (is_nd_blk(&nd_region->dev))

			available += nd_blk_available_dpa(nd_region);

	}



	return available;

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