1 files changed, 371 insertions, 0 deletions

diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
new file mode 100644
index 000000000..fabbb31f2
--- /dev/null
+++ b/drivers/nvdimm/btt_devs.c
@@ -0,0 +1,371 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
+ */
+#include <linux/blkdev.h>
+#include <linux/device.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include "nd-core.h"
+#include "btt.h"
+#include "nd.h"
+
+static void nd_btt_release(struct device *dev)
+{
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+
+	dev_dbg(dev, "trace\n");
+	nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
+	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
+	kfree(nd_btt->uuid);
+	kfree(nd_btt);
+}
+
+struct nd_btt *to_nd_btt(struct device *dev)
+{
+	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
+
+	WARN_ON(!is_nd_btt(dev));
+	return nd_btt;
+}
+EXPORT_SYMBOL(to_nd_btt);
+
+static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
+	4096, 4104, 4160, 4224, 0 };
+
+static ssize_t sector_size_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+
+	return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
+}
+
+static ssize_t sector_size_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+	ssize_t rc;
+
+	device_lock(dev);
+	nvdimm_bus_lock(dev);
+	rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
+			btt_lbasize_supported);
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
+	nvdimm_bus_unlock(dev);
+	device_unlock(dev);
+
+	return rc ? rc : len;
+}
+static DEVICE_ATTR_RW(sector_size);
+
+static ssize_t uuid_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+
+	if (nd_btt->uuid)
+		return sprintf(buf, "%pUb\n", nd_btt->uuid);
+	return sprintf(buf, "\n");
+}
+
+static ssize_t uuid_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+	ssize_t rc;
+
+	device_lock(dev);
+	rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
+	device_unlock(dev);
+
+	return rc ? rc : len;
+}
+static DEVICE_ATTR_RW(uuid);
+
+static ssize_t namespace_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+	ssize_t rc;
+
+	nvdimm_bus_lock(dev);
+	rc = sprintf(buf, "%s\n", nd_btt->ndns
+			? dev_name(&nd_btt->ndns->dev) : "");
+	nvdimm_bus_unlock(dev);
+	return rc;
+}
+
+static ssize_t namespace_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+	ssize_t rc;
+
+	device_lock(dev);
+	nvdimm_bus_lock(dev);
+	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
+	nvdimm_bus_unlock(dev);
+	device_unlock(dev);
+
+	return rc;
+}
+static DEVICE_ATTR_RW(namespace);
+
+static ssize_t size_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_btt *nd_btt = to_nd_btt(dev);
+	ssize_t rc;
+
+	device_lock(dev);
+	if (dev->driver)
+		rc = sprintf(buf, "%llu\n", nd_btt->size);
+	else {
+		/* no size to convey if the btt instance is disabled */
+		rc = -ENXIO;
+	}
+	device_unlock(dev);
+
+	return rc;
+}
+static DEVICE_ATTR_RO(size);
+
+static ssize_t log_zero_flags_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "Y\n");
+}
+static DEVICE_ATTR_RO(log_zero_flags);
+
+static struct attribute *nd_btt_attributes[] = {
+	&dev_attr_sector_size.attr,
+	&dev_attr_namespace.attr,
+	&dev_attr_uuid.attr,
+	&dev_attr_size.attr,
+	&dev_attr_log_zero_flags.attr,
+	NULL,
+};
+
+static struct attribute_group nd_btt_attribute_group = {
+	.attrs = nd_btt_attributes,
+};
+
+static const struct attribute_group *nd_btt_attribute_groups[] = {
+	&nd_btt_attribute_group,
+	&nd_device_attribute_group,
+	&nd_numa_attribute_group,
+	NULL,
+};
+
+static const struct device_type nd_btt_device_type = {
+	.name = "nd_btt",
+	.release = nd_btt_release,
+	.groups = nd_btt_attribute_groups,
+};
+
+bool is_nd_btt(struct device *dev)
+{
+	return dev->type == &nd_btt_device_type;
+}
+EXPORT_SYMBOL(is_nd_btt);
+
+static struct lock_class_key nvdimm_btt_key;
+
+static struct device *__nd_btt_create(struct nd_region *nd_region,
+				      unsigned long lbasize, uuid_t *uuid,
+				      struct nd_namespace_common *ndns)
+{
+	struct nd_btt *nd_btt;
+	struct device *dev;
+
+	nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
+	if (!nd_btt)
+		return NULL;
+
+	nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
+	if (nd_btt->id < 0)
+		goto out_nd_btt;
+
+	nd_btt->lbasize = lbasize;
+	if (uuid) {
+		uuid = kmemdup(uuid, 16, GFP_KERNEL);
+		if (!uuid)
+			goto out_put_id;
+	}
+	nd_btt->uuid = uuid;
+	dev = &nd_btt->dev;
+	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
+	dev->parent = &nd_region->dev;
+	dev->type = &nd_btt_device_type;
+	device_initialize(&nd_btt->dev);
+	lockdep_set_class(&nd_btt->dev.mutex, &nvdimm_btt_key);
+	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
+		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
+				dev_name(ndns->claim));
+		put_device(dev);
+		return NULL;
+	}
+	return dev;
+
+out_put_id:
+	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
+
+out_nd_btt:
+	kfree(nd_btt);
+	return NULL;
+}
+
+struct device *nd_btt_create(struct nd_region *nd_region)
+{
+	struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
+
+	nd_device_register(dev);
+	return dev;
+}
+
+/**
+ * nd_btt_arena_is_valid - check if the metadata layout is valid
+ * @nd_btt:	device with BTT geometry and backing device info
+ * @super:	pointer to the arena's info block being tested
+ *
+ * Check consistency of the btt info block with itself by validating
+ * the checksum, and with the parent namespace by verifying the
+ * parent_uuid contained in the info block with the one supplied in.
+ *
+ * Returns:
+ * false for an invalid info block, true for a valid one
+ */
+bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
+{
+	const uuid_t *ns_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
+	uuid_t parent_uuid;
+	u64 checksum;
+
+	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
+		return false;
+
+	import_uuid(&parent_uuid, super->parent_uuid);
+	if (!uuid_is_null(&parent_uuid))
+		if (!uuid_equal(&parent_uuid, ns_uuid))
+			return false;
+
+	checksum = le64_to_cpu(super->checksum);
+	super->checksum = 0;
+	if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
+		return false;
+	super->checksum = cpu_to_le64(checksum);
+
+	/* TODO: figure out action for this */
+	if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
+		dev_info(&nd_btt->dev, "Found arena with an error flag\n");
+
+	return true;
+}
+EXPORT_SYMBOL(nd_btt_arena_is_valid);
+
+int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns,
+		struct btt_sb *btt_sb)
+{
+	if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
+		/* Probe/setup for BTT v2.0 */
+		nd_btt->initial_offset = 0;
+		nd_btt->version_major = 2;
+		nd_btt->version_minor = 0;
+		if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
+			return -ENXIO;
+		if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
+			return -ENODEV;
+		if ((le16_to_cpu(btt_sb->version_major) != 2) ||
+				(le16_to_cpu(btt_sb->version_minor) != 0))
+			return -ENODEV;
+	} else {
+		/*
+		 * Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
+		 * NVDIMM_CCLASS_BTT)
+		 */
+		nd_btt->initial_offset = SZ_4K;
+		nd_btt->version_major = 1;
+		nd_btt->version_minor = 1;
+		if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
+			return -ENXIO;
+		if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
+			return -ENODEV;
+		if ((le16_to_cpu(btt_sb->version_major) != 1) ||
+				(le16_to_cpu(btt_sb->version_minor) != 1))
+			return -ENODEV;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(nd_btt_version);
+
+static int __nd_btt_probe(struct nd_btt *nd_btt,
+		struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
+{
+	int rc;
+
+	if (!btt_sb || !ndns || !nd_btt)
+		return -ENODEV;
+
+	if (nvdimm_namespace_capacity(ndns) < SZ_16M)
+		return -ENXIO;
+
+	rc = nd_btt_version(nd_btt, ndns, btt_sb);
+	if (rc < 0)
+		return rc;
+
+	nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
+	nd_btt->uuid = kmemdup(&btt_sb->uuid, sizeof(uuid_t), GFP_KERNEL);
+	if (!nd_btt->uuid)
+		return -ENOMEM;
+
+	nd_device_register(&nd_btt->dev);
+
+	return 0;
+}
+
+int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
+{
+	int rc;
+	struct device *btt_dev;
+	struct btt_sb *btt_sb;
+	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
+
+	if (ndns->force_raw)
+		return -ENODEV;
+
+	switch (ndns->claim_class) {
+	case NVDIMM_CCLASS_NONE:
+	case NVDIMM_CCLASS_BTT:
+	case NVDIMM_CCLASS_BTT2:
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	nvdimm_bus_lock(&ndns->dev);
+	btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
+	nvdimm_bus_unlock(&ndns->dev);
+	if (!btt_dev)
+		return -ENOMEM;
+	btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
+	rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
+	dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
+	if (rc < 0) {
+		struct nd_btt *nd_btt = to_nd_btt(btt_dev);
+
+		nd_detach_ndns(btt_dev, &nd_btt->ndns);
+		put_device(btt_dev);
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL(nd_btt_probe);