libnvdimm: write pmem label set

After 'uuid', 'size', and optionally 'alt_name' have been set to valid
values the labels on the dimms can be updated.

Write procedure is:
1/ Allocate and write new labels in the "next" index
2/ Free the old labels in the working copy
3/ Write the bitmap and the label space on the dimm
4/ Write the index to make the update valid

Label ranges directly mirror the dpa resource values for the given
label_id of the namespace.

Cc: Greg KH <gregkh@linuxfoundation.org>
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, 325 insertions, 3 deletions

diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index 1a3bcd27a57a..ffa85d700459 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -12,6 +12,7 @@
  */
 #include <linux/device.h>
 #include <linux/ndctl.h>
+#include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/nd.h>
 #include "nd-core.h"
@@ -55,6 +56,11 @@ size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
 	return ndd->nsindex_size;
 }
 
+static int nvdimm_num_label_slots(struct nvdimm_drvdata *ndd)
+{
+	return ndd->nsarea.config_size / 129;
+}
+
 int nd_label_validate(struct nvdimm_drvdata *ndd)
 {
 	/*
@@ -201,25 +207,32 @@ static struct nd_namespace_label *nd_label_base(struct nvdimm_drvdata *ndd)
 	return base + 2 * sizeof_namespace_index(ndd);
 }
 
+static int to_slot(struct nvdimm_drvdata *ndd,
+		struct nd_namespace_label *nd_label)
+{
+	return nd_label - nd_label_base(ndd);
+}
+
 #define for_each_clear_bit_le(bit, addr, size) \
 	for ((bit) = find_next_zero_bit_le((addr), (size), 0);  \
 	     (bit) < (size);                                    \
 	     (bit) = find_next_zero_bit_le((addr), (size), (bit) + 1))
 
 /**
- * preamble_current - common variable initialization for nd_label_* routines
+ * preamble_index - common variable initialization for nd_label_* routines
  * @ndd: dimm container for the relevant label set
+ * @idx: namespace_index index
  * @nsindex_out: on return set to the currently active namespace index
  * @free: on return set to the free label bitmap in the index
  * @nslot: on return set to the number of slots in the label space
  */
-static bool preamble_current(struct nvdimm_drvdata *ndd,
+static bool preamble_index(struct nvdimm_drvdata *ndd, int idx,
 		struct nd_namespace_index **nsindex_out,
 		unsigned long **free, u32 *nslot)
 {
 	struct nd_namespace_index *nsindex;
 
-	nsindex = to_current_namespace_index(ndd);
+	nsindex = to_namespace_index(ndd, idx);
 	if (nsindex == NULL)
 		return false;
 
@@ -239,6 +252,22 @@ char *nd_label_gen_id(struct nd_label_id *label_id, u8 *uuid, u32 flags)
 	return label_id->id;
 }
 
+static bool preamble_current(struct nvdimm_drvdata *ndd,
+		struct nd_namespace_index **nsindex,
+		unsigned long **free, u32 *nslot)
+{
+	return preamble_index(ndd, ndd->ns_current, nsindex,
+			free, nslot);
+}
+
+static bool preamble_next(struct nvdimm_drvdata *ndd,
+		struct nd_namespace_index **nsindex,
+		unsigned long **free, u32 *nslot)
+{
+	return preamble_index(ndd, ndd->ns_next, nsindex,
+			free, nslot);
+}
+
 static bool slot_valid(struct nd_namespace_label *nd_label, u32 slot)
 {
 	/* check that we are written where we expect to be written */
@@ -341,3 +370,296 @@ struct nd_namespace_label *nd_label_active(struct nvdimm_drvdata *ndd, int n)
 
 	return NULL;
 }
+
+static u32 nd_label_alloc_slot(struct nvdimm_drvdata *ndd)
+{
+	struct nd_namespace_index *nsindex;
+	unsigned long *free;
+	u32 nslot, slot;
+
+	if (!preamble_next(ndd, &nsindex, &free, &nslot))
+		return UINT_MAX;
+
+	WARN_ON(!is_nvdimm_bus_locked(ndd->dev));
+
+	slot = find_next_bit_le(free, nslot, 0);
+	if (slot == nslot)
+		return UINT_MAX;
+
+	clear_bit_le(slot, free);
+
+	return slot;
+}
+
+static bool nd_label_free_slot(struct nvdimm_drvdata *ndd, u32 slot)
+{
+	struct nd_namespace_index *nsindex;
+	unsigned long *free;
+	u32 nslot;
+
+	if (!preamble_next(ndd, &nsindex, &free, &nslot))
+		return false;
+
+	WARN_ON(!is_nvdimm_bus_locked(ndd->dev));
+
+	if (slot < nslot)
+		return !test_and_set_bit_le(slot, free);
+	return false;
+}
+
+u32 nd_label_nfree(struct nvdimm_drvdata *ndd)
+{
+	struct nd_namespace_index *nsindex;
+	unsigned long *free;
+	u32 nslot;
+
+	WARN_ON(!is_nvdimm_bus_locked(ndd->dev));
+
+	if (!preamble_next(ndd, &nsindex, &free, &nslot))
+		return 0;
+
+	return bitmap_weight(free, nslot);
+}
+
+static int nd_label_write_index(struct nvdimm_drvdata *ndd, int index, u32 seq,
+		unsigned long flags)
+{
+	struct nd_namespace_index *nsindex;
+	unsigned long offset;
+	u64 checksum;
+	u32 nslot;
+	int rc;
+
+	nsindex = to_namespace_index(ndd, index);
+	if (flags & ND_NSINDEX_INIT)
+		nslot = nvdimm_num_label_slots(ndd);
+	else
+		nslot = __le32_to_cpu(nsindex->nslot);
+
+	memcpy(nsindex->sig, NSINDEX_SIGNATURE, NSINDEX_SIG_LEN);
+	nsindex->flags = __cpu_to_le32(0);
+	nsindex->seq = __cpu_to_le32(seq);
+	offset = (unsigned long) nsindex
+		- (unsigned long) to_namespace_index(ndd, 0);
+	nsindex->myoff = __cpu_to_le64(offset);
+	nsindex->mysize = __cpu_to_le64(sizeof_namespace_index(ndd));
+	offset = (unsigned long) to_namespace_index(ndd,
+			nd_label_next_nsindex(index))
+		- (unsigned long) to_namespace_index(ndd, 0);
+	nsindex->otheroff = __cpu_to_le64(offset);
+	offset = (unsigned long) nd_label_base(ndd)
+		- (unsigned long) to_namespace_index(ndd, 0);
+	nsindex->labeloff = __cpu_to_le64(offset);
+	nsindex->nslot = __cpu_to_le32(nslot);
+	nsindex->major = __cpu_to_le16(1);
+	nsindex->minor = __cpu_to_le16(1);
+	nsindex->checksum = __cpu_to_le64(0);
+	if (flags & ND_NSINDEX_INIT) {
+		unsigned long *free = (unsigned long *) nsindex->free;
+		u32 nfree = ALIGN(nslot, BITS_PER_LONG);
+		int last_bits, i;
+
+		memset(nsindex->free, 0xff, nfree / 8);
+		for (i = 0, last_bits = nfree - nslot; i < last_bits; i++)
+			clear_bit_le(nslot + i, free);
+	}
+	checksum = nd_fletcher64(nsindex, sizeof_namespace_index(ndd), 1);
+	nsindex->checksum = __cpu_to_le64(checksum);
+	rc = nvdimm_set_config_data(ndd, __le64_to_cpu(nsindex->myoff),
+			nsindex, sizeof_namespace_index(ndd));
+	if (rc < 0)
+		return rc;
+
+	if (flags & ND_NSINDEX_INIT)
+		return 0;
+
+	/* copy the index we just wrote to the new 'next' */
+	WARN_ON(index != ndd->ns_next);
+	nd_label_copy(ndd, to_current_namespace_index(ndd), nsindex);
+	ndd->ns_current = nd_label_next_nsindex(ndd->ns_current);
+	ndd->ns_next = nd_label_next_nsindex(ndd->ns_next);
+	WARN_ON(ndd->ns_current == ndd->ns_next);
+
+	return 0;
+}
+
+static unsigned long nd_label_offset(struct nvdimm_drvdata *ndd,
+		struct nd_namespace_label *nd_label)
+{
+	return (unsigned long) nd_label
+		- (unsigned long) to_namespace_index(ndd, 0);
+}
+
+static int __pmem_label_update(struct nd_region *nd_region,
+		struct nd_mapping *nd_mapping, struct nd_namespace_pmem *nspm,
+		int pos)
+{
+	u64 cookie = nd_region_interleave_set_cookie(nd_region), rawsize;
+	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
+	struct nd_namespace_label *victim_label;
+	struct nd_namespace_label *nd_label;
+	struct nd_namespace_index *nsindex;
+	unsigned long *free;
+	u32 nslot, slot;
+	size_t offset;
+	int rc;
+
+	if (!preamble_next(ndd, &nsindex, &free, &nslot))
+		return -ENXIO;
+
+	/* allocate and write the label to the staging (next) index */
+	slot = nd_label_alloc_slot(ndd);
+	if (slot == UINT_MAX)
+		return -ENXIO;
+	dev_dbg(ndd->dev, "%s: allocated: %d\n", __func__, slot);
+
+	nd_label = nd_label_base(ndd) + slot;
+	memset(nd_label, 0, sizeof(struct nd_namespace_label));
+	memcpy(nd_label->uuid, nspm->uuid, NSLABEL_UUID_LEN);
+	if (nspm->alt_name)
+		memcpy(nd_label->name, nspm->alt_name, NSLABEL_NAME_LEN);
+	nd_label->flags = __cpu_to_le32(NSLABEL_FLAG_UPDATING);
+	nd_label->nlabel = __cpu_to_le16(nd_region->ndr_mappings);
+	nd_label->position = __cpu_to_le16(pos);
+	nd_label->isetcookie = __cpu_to_le64(cookie);
+	rawsize = div_u64(resource_size(&nspm->nsio.res),
+			nd_region->ndr_mappings);
+	nd_label->rawsize = __cpu_to_le64(rawsize);
+	nd_label->dpa = __cpu_to_le64(nd_mapping->start);
+	nd_label->slot = __cpu_to_le32(slot);
+
+	/* update label */
+	offset = nd_label_offset(ndd, nd_label);
+	rc = nvdimm_set_config_data(ndd, offset, nd_label,
+			sizeof(struct nd_namespace_label));
+	if (rc < 0)
+		return rc;
+
+	/* Garbage collect the previous label */
+	victim_label = nd_mapping->labels[0];
+	if (victim_label) {
+		slot = to_slot(ndd, victim_label);
+		nd_label_free_slot(ndd, slot);
+		dev_dbg(ndd->dev, "%s: free: %d\n", __func__, slot);
+	}
+
+	/* update index */
+	rc = nd_label_write_index(ndd, ndd->ns_next,
+			nd_inc_seq(__le32_to_cpu(nsindex->seq)), 0);
+	if (rc < 0)
+		return rc;
+
+	nd_mapping->labels[0] = nd_label;
+
+	return 0;
+}
+
+static int init_labels(struct nd_mapping *nd_mapping)
+{
+	int i;
+	struct nd_namespace_index *nsindex;
+	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
+
+	if (!nd_mapping->labels)
+		nd_mapping->labels = kcalloc(2, sizeof(void *), GFP_KERNEL);
+
+	if (!nd_mapping->labels)
+		return -ENOMEM;
+
+	if (ndd->ns_current == -1 || ndd->ns_next == -1)
+		/* pass */;
+	else
+		return 0;
+
+	nsindex = to_namespace_index(ndd, 0);
+	memset(nsindex, 0, ndd->nsarea.config_size);
+	for (i = 0; i < 2; i++) {
+		int rc = nd_label_write_index(ndd, i, i*2, ND_NSINDEX_INIT);
+
+		if (rc)
+			return rc;
+	}
+	ndd->ns_next = 1;
+	ndd->ns_current = 0;
+
+	return 0;
+}
+
+static int del_labels(struct nd_mapping *nd_mapping, u8 *uuid)
+{
+	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
+	struct nd_namespace_label *nd_label;
+	struct nd_namespace_index *nsindex;
+	u8 label_uuid[NSLABEL_UUID_LEN];
+	int l, num_freed = 0;
+	unsigned long *free;
+	u32 nslot, slot;
+
+	if (!uuid)
+		return 0;
+
+	/* no index || no labels == nothing to delete */
+	if (!preamble_next(ndd, &nsindex, &free, &nslot)
+			|| !nd_mapping->labels)
+		return 0;
+
+	for_each_label(l, nd_label, nd_mapping->labels) {
+		int j;
+
+		memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN);
+		if (memcmp(label_uuid, uuid, NSLABEL_UUID_LEN) != 0)
+			continue;
+		slot = to_slot(ndd, nd_label);
+		nd_label_free_slot(ndd, slot);
+		dev_dbg(ndd->dev, "%s: free: %d\n", __func__, slot);
+		for (j = l; nd_mapping->labels[j + 1]; j++) {
+			struct nd_namespace_label *next_label;
+
+			next_label = nd_mapping->labels[j + 1];
+			nd_mapping->labels[j] = next_label;
+		}
+		nd_mapping->labels[j] = NULL;
+		num_freed++;
+	}
+
+	if (num_freed > l) {
+		/*
+		 * num_freed will only ever be > l when we delete the last
+		 * label
+		 */
+		kfree(nd_mapping->labels);
+		nd_mapping->labels = NULL;
+		dev_dbg(ndd->dev, "%s: no more labels\n", __func__);
+	}
+
+	return nd_label_write_index(ndd, ndd->ns_next,
+			nd_inc_seq(__le32_to_cpu(nsindex->seq)), 0);
+}
+
+int nd_pmem_namespace_label_update(struct nd_region *nd_region,
+		struct nd_namespace_pmem *nspm, resource_size_t size)
+{
+	int i;
+
+	for (i = 0; i < nd_region->ndr_mappings; i++) {
+		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
+		int rc;
+
+		if (size == 0) {
+			rc = del_labels(nd_mapping, nspm->uuid);
+			if (rc)
+				return rc;
+			continue;
+		}
+
+		rc = init_labels(nd_mapping);
+		if (rc)
+			return rc;
+
+		rc = __pmem_label_update(nd_region, nd_mapping, nspm, i);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}