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-rw-r--r--drivers/nvdimm/claim.c338
1 files changed, 338 insertions, 0 deletions
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
new file mode 100644
index 0000000000..030dbde6b0
--- /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);
+}