1 files changed, 338 insertions, 0 deletions
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
new file mode 100644
index 000000000..030dbde6b
--- /dev/null
+++ b/drivers/nvdimm/claim.c
@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
+ */
+#include <linux/device.h>
+#include <linux/sizes.h>
+#include <linux/badblocks.h>
+#include "nd-core.h"
+#include "pmem.h"
+#include "pfn.h"
+#include "btt.h"
+#include "nd.h"
+
+void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
+{
+	struct nd_namespace_common *ndns = *_ndns;
+	struct nvdimm_bus *nvdimm_bus;
+
+	if (!ndns)
+		return;
+
+	nvdimm_bus = walk_to_nvdimm_bus(&ndns->dev);
+	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
+	dev_WARN_ONCE(dev, ndns->claim != dev, "%s: invalid claim\n", __func__);
+	ndns->claim = NULL;
+	*_ndns = NULL;
+	put_device(&ndns->dev);
+}
+
+void nd_detach_ndns(struct device *dev,
+		struct nd_namespace_common **_ndns)
+{
+	struct nd_namespace_common *ndns = *_ndns;
+
+	if (!ndns)
+		return;
+	get_device(&ndns->dev);
+	nvdimm_bus_lock(&ndns->dev);
+	__nd_detach_ndns(dev, _ndns);
+	nvdimm_bus_unlock(&ndns->dev);
+	put_device(&ndns->dev);
+}
+
+bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
+		struct nd_namespace_common **_ndns)
+{
+	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&attach->dev);
+
+	if (attach->claim)
+		return false;
+	lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
+	dev_WARN_ONCE(dev, *_ndns, "%s: invalid claim\n", __func__);
+	attach->claim = dev;
+	*_ndns = attach;
+	get_device(&attach->dev);
+	return true;
+}
+
+bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
+		struct nd_namespace_common **_ndns)
+{
+	bool claimed;
+
+	nvdimm_bus_lock(&attach->dev);
+	claimed = __nd_attach_ndns(dev, attach, _ndns);
+	nvdimm_bus_unlock(&attach->dev);
+	return claimed;
+}
+
+static int namespace_match(struct device *dev, void *data)
+{
+	char *name = data;
+
+	return strcmp(name, dev_name(dev)) == 0;
+}
+
+static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
+{
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+	struct device *seed = NULL;
+
+	if (is_nd_btt(dev))
+		seed = nd_region->btt_seed;
+	else if (is_nd_pfn(dev))
+		seed = nd_region->pfn_seed;
+	else if (is_nd_dax(dev))
+		seed = nd_region->dax_seed;
+
+	if (seed == dev || ndns || dev->driver)
+		return false;
+	return true;
+}
+
+struct nd_pfn *to_nd_pfn_safe(struct device *dev)
+{
+	/*
+	 * pfn device attributes are re-used by dax device instances, so we
+	 * need to be careful to correct device-to-nd_pfn conversion.
+	 */
+	if (is_nd_pfn(dev))
+		return to_nd_pfn(dev);
+
+	if (is_nd_dax(dev)) {
+		struct nd_dax *nd_dax = to_nd_dax(dev);
+
+		return &nd_dax->nd_pfn;
+	}
+
+	WARN_ON(1);
+	return NULL;
+}
+
+static void nd_detach_and_reset(struct device *dev,
+		struct nd_namespace_common **_ndns)
+{
+	/* detach the namespace and destroy / reset the device */
+	__nd_detach_ndns(dev, _ndns);
+	if (is_idle(dev, *_ndns)) {
+		nd_device_unregister(dev, ND_ASYNC);
+	} else if (is_nd_btt(dev)) {
+		struct nd_btt *nd_btt = to_nd_btt(dev);
+
+		nd_btt->lbasize = 0;
+		kfree(nd_btt->uuid);
+		nd_btt->uuid = NULL;
+	} else if (is_nd_pfn(dev) || is_nd_dax(dev)) {
+		struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
+
+		kfree(nd_pfn->uuid);
+		nd_pfn->uuid = NULL;
+		nd_pfn->mode = PFN_MODE_NONE;
+	}
+}
+
+ssize_t nd_namespace_store(struct device *dev,
+		struct nd_namespace_common **_ndns, const char *buf,
+		size_t len)
+{
+	struct nd_namespace_common *ndns;
+	struct device *found;
+	char *name;
+
+	if (dev->driver) {
+		dev_dbg(dev, "namespace already active\n");
+		return -EBUSY;
+	}
+
+	name = kstrndup(buf, len, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+	strim(name);
+
+	if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
+		/* pass */;
+	else {
+		len = -EINVAL;
+		goto out;
+	}
+
+	ndns = *_ndns;
+	if (strcmp(name, "") == 0) {
+		nd_detach_and_reset(dev, _ndns);
+		goto out;
+	} else if (ndns) {
+		dev_dbg(dev, "namespace already set to: %s\n",
+				dev_name(&ndns->dev));
+		len = -EBUSY;
+		goto out;
+	}
+
+	found = device_find_child(dev->parent, name, namespace_match);
+	if (!found) {
+		dev_dbg(dev, "'%s' not found under %s\n", name,
+				dev_name(dev->parent));
+		len = -ENODEV;
+		goto out;
+	}
+
+	ndns = to_ndns(found);
+
+	switch (ndns->claim_class) {
+	case NVDIMM_CCLASS_NONE:
+		break;
+	case NVDIMM_CCLASS_BTT:
+	case NVDIMM_CCLASS_BTT2:
+		if (!is_nd_btt(dev)) {
+			len = -EBUSY;
+			goto out_attach;
+		}
+		break;
+	case NVDIMM_CCLASS_PFN:
+		if (!is_nd_pfn(dev)) {
+			len = -EBUSY;
+			goto out_attach;
+		}
+		break;
+	case NVDIMM_CCLASS_DAX:
+		if (!is_nd_dax(dev)) {
+			len = -EBUSY;
+			goto out_attach;
+		}
+		break;
+	default:
+		len = -EBUSY;
+		goto out_attach;
+		break;
+	}
+
+	if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
+		dev_dbg(dev, "%s too small to host\n", name);
+		len = -ENXIO;
+		goto out_attach;
+	}
+
+	WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
+	if (!__nd_attach_ndns(dev, ndns, _ndns)) {
+		dev_dbg(dev, "%s already claimed\n",
+				dev_name(&ndns->dev));
+		len = -EBUSY;
+	}
+
+ out_attach:
+	put_device(&ndns->dev); /* from device_find_child */
+ out:
+	kfree(name);
+	return len;
+}
+
+/*
+ * nd_sb_checksum: compute checksum for a generic info block
+ *
+ * Returns a fletcher64 checksum of everything in the given info block
+ * except the last field (since that's where the checksum lives).
+ */
+u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
+{
+	u64 sum;
+	__le64 sum_save;
+
+	BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
+	BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
+	BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
+
+	sum_save = nd_gen_sb->checksum;
+	nd_gen_sb->checksum = 0;
+	sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
+	nd_gen_sb->checksum = sum_save;
+	return sum;
+}
+EXPORT_SYMBOL(nd_sb_checksum);
+
+static int nsio_rw_bytes(struct nd_namespace_common *ndns,
+		resource_size_t offset, void *buf, size_t size, int rw,
+		unsigned long flags)
+{
+	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+	unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
+	sector_t sector = offset >> 9;
+	int rc = 0, ret = 0;
+
+	if (unlikely(!size))
+		return 0;
+
+	if (unlikely(offset + size > nsio->size)) {
+		dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
+		return -EFAULT;
+	}
+
+	if (rw == READ) {
+		if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
+			return -EIO;
+		if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
+			return -EIO;
+		return 0;
+	}
+
+	if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
+		if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
+				&& !(flags & NVDIMM_IO_ATOMIC)) {
+			long cleared;
+
+			might_sleep();
+			cleared = nvdimm_clear_poison(&ndns->dev,
+					nsio->res.start + offset, size);
+			if (cleared < size)
+				rc = -EIO;
+			if (cleared > 0 && cleared / 512) {
+				cleared /= 512;
+				badblocks_clear(&nsio->bb, sector, cleared);
+			}
+			arch_invalidate_pmem(nsio->addr + offset, size);
+		} else
+			rc = -EIO;
+	}
+
+	memcpy_flushcache(nsio->addr + offset, buf, size);
+	ret = nvdimm_flush(to_nd_region(ndns->dev.parent), NULL);
+	if (ret)
+		rc = ret;
+
+	return rc;
+}
+
+int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
+		resource_size_t size)
+{
+	struct nd_namespace_common *ndns = &nsio->common;
+	struct range range = {
+		.start = nsio->res.start,
+		.end = nsio->res.end,
+	};
+
+	nsio->size = size;
+	if (!devm_request_mem_region(dev, range.start, size,
+				dev_name(&ndns->dev))) {
+		dev_warn(dev, "could not reserve region %pR\n", &nsio->res);
+		return -EBUSY;
+	}
+
+	ndns->rw_bytes = nsio_rw_bytes;
+	if (devm_init_badblocks(dev, &nsio->bb))
+		return -ENOMEM;
+	nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
+			&range);
+
+	nsio->addr = devm_memremap(dev, range.start, size, ARCH_MEMREMAP_PMEM);
+
+	return PTR_ERR_OR_ZERO(nsio->addr);
+}
+
+void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
+{
+	struct resource *res = &nsio->res;
+
+	devm_memunmap(dev, nsio->addr);
+	devm_exit_badblocks(dev, &nsio->bb);
+	devm_release_mem_region(dev, res->start, nsio->size);
+}