Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "This update has successfully completed a 0day-kbuild run and has
  appeared in a linux-next release.  The changes outside of the typical
  drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the
  removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and
  the introduction of ZONE_DEVICE + devm_memremap_pages().

  Summary:

   - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic
     mechanism for adding device-driver-discovered memory regions to the
     kernel's direct map.

     This facility is used by the pmem driver to enable pfn_to_page()
     operations on the page frames returned by DAX ('direct_access' in
     'struct block_device_operations').

     For now, the 'memmap' allocation for these "device" pages comes
     from "System RAM".  Support for allocating the memmap from device
     memory will arrive in a later kernel.

   - Introduce memremap() to replace usages of ioremap_cache() and
     ioremap_wt().  memremap() drops the __iomem annotation for these
     mappings to memory that do not have i/o side effects.  The
     replacement of ioremap_cache() with memremap() is limited to the
     pmem driver to ease merging the api change in v4.3.

     Completion of the conversion is targeted for v4.4.

   - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem
     driver, update the VFS DAX implementation and PMEM api to provide
     persistence guarantees for kernel operations on a DAX mapping.

   - Convert the ACPI NFIT 'BLK' driver to map the block apertures as
     cacheable to improve performance.

   - Miscellaneous updates and fixes to libnvdimm including support for
     issuing "address range scrub" commands, clarifying the optimal
     'sector size' of pmem devices, a clarification of the usage of the
     ACPI '_STA' (status) property for DIMM devices, and other minor
     fixes"

* tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits)
  libnvdimm, pmem: direct map legacy pmem by default
  libnvdimm, pmem: 'struct page' for pmem
  libnvdimm, pfn: 'struct page' provider infrastructure
  x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB
  add devm_memremap_pages
  mm: ZONE_DEVICE for "device memory"
  mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h
  dax: drop size parameter to ->direct_access()
  nd_blk: change aperture mapping from WC to WB
  nvdimm: change to use generic kvfree()
  pmem, dax: have direct_access use __pmem annotation
  dax: update I/O path to do proper PMEM flushing
  pmem: add copy_from_iter_pmem() and clear_pmem()
  pmem, x86: clean up conditional pmem includes
  pmem: remove layer when calling arch_has_wmb_pmem()
  pmem, x86: move x86 PMEM API to new pmem.h header
  libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option
  pmem: switch to devm_ allocations
  devres: add devm_memremap
  libnvdimm, btt: write and validate parent_uuid
  ...

1 files changed, 337 insertions, 0 deletions

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
new file mode 100644
index 000000000000..3fd7d0d81a47
--- /dev/null
+++ b/drivers/nvdimm/pfn_devs.c
@@ -0,0 +1,337 @@
+/*
+ * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+#include <linux/blkdev.h>
+#include <linux/device.h>
+#include <linux/genhd.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include "nd-core.h"
+#include "pfn.h"
+#include "nd.h"
+
+static void nd_pfn_release(struct device *dev)
+{
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+
+	dev_dbg(dev, "%s\n", __func__);
+	nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
+	ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
+	kfree(nd_pfn->uuid);
+	kfree(nd_pfn);
+}
+
+static struct device_type nd_pfn_device_type = {
+	.name = "nd_pfn",
+	.release = nd_pfn_release,
+};
+
+bool is_nd_pfn(struct device *dev)
+{
+	return dev ? dev->type == &nd_pfn_device_type : false;
+}
+EXPORT_SYMBOL(is_nd_pfn);
+
+struct nd_pfn *to_nd_pfn(struct device *dev)
+{
+	struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
+
+	WARN_ON(!is_nd_pfn(dev));
+	return nd_pfn;
+}
+EXPORT_SYMBOL(to_nd_pfn);
+
+static ssize_t mode_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+
+	switch (nd_pfn->mode) {
+	case PFN_MODE_RAM:
+		return sprintf(buf, "ram\n");
+	case PFN_MODE_PMEM:
+		return sprintf(buf, "pmem\n");
+	default:
+		return sprintf(buf, "none\n");
+	}
+}
+
+static ssize_t mode_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+	ssize_t rc = 0;
+
+	device_lock(dev);
+	nvdimm_bus_lock(dev);
+	if (dev->driver)
+		rc = -EBUSY;
+	else {
+		size_t n = len - 1;
+
+		if (strncmp(buf, "pmem\n", n) == 0
+				|| strncmp(buf, "pmem", n) == 0) {
+			/* TODO: allocate from PMEM support */
+			rc = -ENOTTY;
+		} else if (strncmp(buf, "ram\n", n) == 0
+				|| strncmp(buf, "ram", n) == 0)
+			nd_pfn->mode = PFN_MODE_RAM;
+		else if (strncmp(buf, "none\n", n) == 0
+				|| strncmp(buf, "none", n) == 0)
+			nd_pfn->mode = PFN_MODE_NONE;
+		else
+			rc = -EINVAL;
+	}
+	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
+			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	nvdimm_bus_unlock(dev);
+	device_unlock(dev);
+
+	return rc ? rc : len;
+}
+static DEVICE_ATTR_RW(mode);
+
+static ssize_t uuid_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+
+	if (nd_pfn->uuid)
+		return sprintf(buf, "%pUb\n", nd_pfn->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_pfn *nd_pfn = to_nd_pfn(dev);
+	ssize_t rc;
+
+	device_lock(dev);
+	rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
+	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
+			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_pfn *nd_pfn = to_nd_pfn(dev);
+	ssize_t rc;
+
+	nvdimm_bus_lock(dev);
+	rc = sprintf(buf, "%s\n", nd_pfn->ndns
+			? dev_name(&nd_pfn->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_pfn *nd_pfn = to_nd_pfn(dev);
+	ssize_t rc;
+
+	nvdimm_bus_lock(dev);
+	device_lock(dev);
+	rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
+	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
+			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	device_unlock(dev);
+	nvdimm_bus_unlock(dev);
+
+	return rc;
+}
+static DEVICE_ATTR_RW(namespace);
+
+static struct attribute *nd_pfn_attributes[] = {
+	&dev_attr_mode.attr,
+	&dev_attr_namespace.attr,
+	&dev_attr_uuid.attr,
+	NULL,
+};
+
+static struct attribute_group nd_pfn_attribute_group = {
+	.attrs = nd_pfn_attributes,
+};
+
+static const struct attribute_group *nd_pfn_attribute_groups[] = {
+	&nd_pfn_attribute_group,
+	&nd_device_attribute_group,
+	&nd_numa_attribute_group,
+	NULL,
+};
+
+static struct device *__nd_pfn_create(struct nd_region *nd_region,
+		u8 *uuid, enum nd_pfn_mode mode,
+		struct nd_namespace_common *ndns)
+{
+	struct nd_pfn *nd_pfn;
+	struct device *dev;
+
+	/* we can only create pages for contiguous ranged of pmem */
+	if (!is_nd_pmem(&nd_region->dev))
+		return NULL;
+
+	nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
+	if (!nd_pfn)
+		return NULL;
+
+	nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
+	if (nd_pfn->id < 0) {
+		kfree(nd_pfn);
+		return NULL;
+	}
+
+	nd_pfn->mode = mode;
+	if (uuid)
+		uuid = kmemdup(uuid, 16, GFP_KERNEL);
+	nd_pfn->uuid = uuid;
+	dev = &nd_pfn->dev;
+	dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
+	dev->parent = &nd_region->dev;
+	dev->type = &nd_pfn_device_type;
+	dev->groups = nd_pfn_attribute_groups;
+	device_initialize(&nd_pfn->dev);
+	if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
+		dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
+				__func__, dev_name(ndns->claim));
+		put_device(dev);
+		return NULL;
+	}
+	return dev;
+}
+
+struct device *nd_pfn_create(struct nd_region *nd_region)
+{
+	struct device *dev = __nd_pfn_create(nd_region, NULL, PFN_MODE_NONE,
+			NULL);
+
+	if (dev)
+		__nd_device_register(dev);
+	return dev;
+}
+
+int nd_pfn_validate(struct nd_pfn *nd_pfn)
+{
+	struct nd_namespace_common *ndns = nd_pfn->ndns;
+	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+	struct nd_namespace_io *nsio;
+	u64 checksum, offset;
+
+	if (!pfn_sb || !ndns)
+		return -ENODEV;
+
+	if (!is_nd_pmem(nd_pfn->dev.parent))
+		return -ENODEV;
+
+	/* section alignment for simple hotplug */
+	if (nvdimm_namespace_capacity(ndns) < ND_PFN_ALIGN)
+		return -ENODEV;
+
+	if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)))
+		return -ENXIO;
+
+	if (memcmp(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN) != 0)
+		return -ENODEV;
+
+	checksum = le64_to_cpu(pfn_sb->checksum);
+	pfn_sb->checksum = 0;
+	if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
+		return -ENODEV;
+	pfn_sb->checksum = cpu_to_le64(checksum);
+
+	switch (le32_to_cpu(pfn_sb->mode)) {
+	case PFN_MODE_RAM:
+		break;
+	case PFN_MODE_PMEM:
+		/* TODO: allocate from PMEM support */
+		return -ENOTTY;
+	default:
+		return -ENXIO;
+	}
+
+	if (!nd_pfn->uuid) {
+		/* from probe we allocate */
+		nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
+		if (!nd_pfn->uuid)
+			return -ENOMEM;
+	} else {
+		/* from init we validate */
+		if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
+			return -EINVAL;
+	}
+
+	/*
+	 * These warnings are verbose because they can only trigger in
+	 * the case where the physical address alignment of the
+	 * namespace has changed since the pfn superblock was
+	 * established.
+	 */
+	offset = le64_to_cpu(pfn_sb->dataoff);
+	nsio = to_nd_namespace_io(&ndns->dev);
+	if (nsio->res.start & ND_PFN_MASK) {
+		dev_err(&nd_pfn->dev,
+				"init failed: %s not section aligned\n",
+				dev_name(&ndns->dev));
+		return -EBUSY;
+	} else if (offset >= resource_size(&nsio->res)) {
+		dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
+				dev_name(&ndns->dev));
+		return -EBUSY;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(nd_pfn_validate);
+
+int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
+{
+	int rc;
+	struct device *dev;
+	struct nd_pfn *nd_pfn;
+	struct nd_pfn_sb *pfn_sb;
+	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
+
+	if (ndns->force_raw)
+		return -ENODEV;
+
+	nvdimm_bus_lock(&ndns->dev);
+	dev = __nd_pfn_create(nd_region, NULL, PFN_MODE_NONE, ndns);
+	nvdimm_bus_unlock(&ndns->dev);
+	if (!dev)
+		return -ENOMEM;
+	dev_set_drvdata(dev, drvdata);
+	pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
+	nd_pfn = to_nd_pfn(dev);
+	nd_pfn->pfn_sb = pfn_sb;
+	rc = nd_pfn_validate(nd_pfn);
+	nd_pfn->pfn_sb = NULL;
+	kfree(pfn_sb);
+	dev_dbg(&ndns->dev, "%s: pfn: %s\n", __func__,
+			rc == 0 ? dev_name(dev) : "<none>");
+	if (rc < 0) {
+		__nd_detach_ndns(dev, &nd_pfn->ndns);
+		put_device(dev);
+	} else
+		__nd_device_register(&nd_pfn->dev);
+
+	return rc;
+}
+EXPORT_SYMBOL(nd_pfn_probe);