linux/drivers/nvdimm/pfn_devs.c
Dan Williams c91d713630 nvdimm: Support sizeof(struct page) > MAX_STRUCT_PAGE_SIZE
Commit 6e9f05dc66 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE")

...updated MAX_STRUCT_PAGE_SIZE to account for sizeof(struct page)
potentially doubling in the case of CONFIG_KMSAN=y. Unfortunately this
doubles the amount of capacity stolen from user addressable capacity for
everyone, regardless of whether they are using the debug option. Revert
that change, mandate that MAX_STRUCT_PAGE_SIZE never exceed 64, but
allow for debug scenarios to proceed with creating debug sized page maps
with a compile option to support debug scenarios.

Note that this only applies to cases where the page map is permanent,
i.e. stored in a reservation of the pmem itself ("--map=dev" in "ndctl
create-namespace" terms). For the "--map=mem" case, since the allocation
is ephemeral for the lifespan of the namespace, there are no explicit
restriction. However, the implicit restriction, of having enough
available "System RAM" to store the page map for the typically large
pmem, still applies.

Fixes: 6e9f05dc66 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE")
Cc: <stable@vger.kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Link: https://lore.kernel.org/r/167467815773.463042.7022545814443036382.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-01-28 15:32:36 -08:00

864 lines
22 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
*/
#include <linux/memremap.h>
#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 "pfn.h"
#include "nd.h"
static const bool page_struct_override = IS_ENABLED(CONFIG_NVDIMM_KMSAN);
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, "trace\n");
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);
}
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_safe(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_safe(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) {
nd_pfn->mode = PFN_MODE_PMEM;
} 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, "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(mode);
static ssize_t align_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
return sprintf(buf, "%ld\n", nd_pfn->align);
}
static unsigned long *nd_pfn_supported_alignments(unsigned long *alignments)
{
alignments[0] = PAGE_SIZE;
if (has_transparent_hugepage()) {
alignments[1] = HPAGE_PMD_SIZE;
if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
alignments[2] = HPAGE_PUD_SIZE;
}
return alignments;
}
/*
* Use pmd mapping if supported as default alignment
*/
static unsigned long nd_pfn_default_alignment(void)
{
if (has_transparent_hugepage())
return HPAGE_PMD_SIZE;
return PAGE_SIZE;
}
static ssize_t align_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
unsigned long aligns[MAX_NVDIMM_ALIGN] = { [0] = 0, };
ssize_t rc;
device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_size_select_store(dev, buf, &nd_pfn->align,
nd_pfn_supported_alignments(aligns));
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(align);
static ssize_t uuid_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_pfn *nd_pfn = to_nd_pfn_safe(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_safe(dev);
ssize_t rc;
device_lock(dev);
rc = nd_uuid_store(dev, &nd_pfn->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_pfn *nd_pfn = to_nd_pfn_safe(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_safe(dev);
ssize_t rc;
device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_namespace_store(dev, &nd_pfn->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 resource_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;
device_lock(dev);
if (dev->driver) {
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
u64 offset = __le64_to_cpu(pfn_sb->dataoff);
struct nd_namespace_common *ndns = nd_pfn->ndns;
u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start
+ start_pad + offset);
} else {
/* no address to convey if the pfn instance is disabled */
rc = -ENXIO;
}
device_unlock(dev);
return rc;
}
static DEVICE_ATTR_ADMIN_RO(resource);
static ssize_t size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;
device_lock(dev);
if (dev->driver) {
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
u64 offset = __le64_to_cpu(pfn_sb->dataoff);
struct nd_namespace_common *ndns = nd_pfn->ndns;
u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
rc = sprintf(buf, "%llu\n", (unsigned long long)
resource_size(&nsio->res) - start_pad
- end_trunc - offset);
} else {
/* no size to convey if the pfn instance is disabled */
rc = -ENXIO;
}
device_unlock(dev);
return rc;
}
static DEVICE_ATTR_RO(size);
static ssize_t supported_alignments_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned long aligns[MAX_NVDIMM_ALIGN] = { [0] = 0, };
return nd_size_select_show(0,
nd_pfn_supported_alignments(aligns), buf);
}
static DEVICE_ATTR_RO(supported_alignments);
static struct attribute *nd_pfn_attributes[] = {
&dev_attr_mode.attr,
&dev_attr_namespace.attr,
&dev_attr_uuid.attr,
&dev_attr_align.attr,
&dev_attr_resource.attr,
&dev_attr_size.attr,
&dev_attr_supported_alignments.attr,
NULL,
};
static struct attribute_group nd_pfn_attribute_group = {
.attrs = nd_pfn_attributes,
};
const struct attribute_group *nd_pfn_attribute_groups[] = {
&nd_pfn_attribute_group,
&nd_device_attribute_group,
&nd_numa_attribute_group,
NULL,
};
static const struct device_type nd_pfn_device_type = {
.name = "nd_pfn",
.release = nd_pfn_release,
.groups = nd_pfn_attribute_groups,
};
bool is_nd_pfn(struct device *dev)
{
return dev ? dev->type == &nd_pfn_device_type : false;
}
EXPORT_SYMBOL(is_nd_pfn);
static struct lock_class_key nvdimm_pfn_key;
struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
struct nd_namespace_common *ndns)
{
struct device *dev;
if (!nd_pfn)
return NULL;
nd_pfn->mode = PFN_MODE_NONE;
nd_pfn->align = nd_pfn_default_alignment();
dev = &nd_pfn->dev;
device_initialize(&nd_pfn->dev);
lockdep_set_class(&nd_pfn->dev.mutex, &nvdimm_pfn_key);
if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
dev_name(ndns->claim));
put_device(dev);
return NULL;
}
return dev;
}
static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
{
struct nd_pfn *nd_pfn;
struct device *dev;
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;
}
dev = &nd_pfn->dev;
dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
dev->type = &nd_pfn_device_type;
dev->parent = &nd_region->dev;
return nd_pfn;
}
struct device *nd_pfn_create(struct nd_region *nd_region)
{
struct nd_pfn *nd_pfn;
struct device *dev;
if (!is_memory(&nd_region->dev))
return NULL;
nd_pfn = nd_pfn_alloc(nd_region);
dev = nd_pfn_devinit(nd_pfn, NULL);
nd_device_register(dev);
return dev;
}
/*
* nd_pfn_clear_memmap_errors() clears any errors in the volatile memmap
* space associated with the namespace. If the memmap is set to DRAM, then
* this is a no-op. Since the memmap area is freshly initialized during
* probe, we have an opportunity to clear any badblocks in this area.
*/
static int nd_pfn_clear_memmap_errors(struct nd_pfn *nd_pfn)
{
struct nd_region *nd_region = to_nd_region(nd_pfn->dev.parent);
struct nd_namespace_common *ndns = nd_pfn->ndns;
void *zero_page = page_address(ZERO_PAGE(0));
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
int num_bad, meta_num, rc, bb_present;
sector_t first_bad, meta_start;
struct nd_namespace_io *nsio;
if (nd_pfn->mode != PFN_MODE_PMEM)
return 0;
nsio = to_nd_namespace_io(&ndns->dev);
meta_start = (SZ_4K + sizeof(*pfn_sb)) >> 9;
meta_num = (le64_to_cpu(pfn_sb->dataoff) >> 9) - meta_start;
/*
* re-enable the namespace with correct size so that we can access
* the device memmap area.
*/
devm_namespace_disable(&nd_pfn->dev, ndns);
rc = devm_namespace_enable(&nd_pfn->dev, ndns, le64_to_cpu(pfn_sb->dataoff));
if (rc)
return rc;
do {
unsigned long zero_len;
u64 nsoff;
bb_present = badblocks_check(&nd_region->bb, meta_start,
meta_num, &first_bad, &num_bad);
if (bb_present) {
dev_dbg(&nd_pfn->dev, "meta: %x badblocks at %llx\n",
num_bad, first_bad);
nsoff = ALIGN_DOWN((nd_region->ndr_start
+ (first_bad << 9)) - nsio->res.start,
PAGE_SIZE);
zero_len = ALIGN(num_bad << 9, PAGE_SIZE);
while (zero_len) {
unsigned long chunk = min(zero_len, PAGE_SIZE);
rc = nvdimm_write_bytes(ndns, nsoff, zero_page,
chunk, 0);
if (rc)
break;
zero_len -= chunk;
nsoff += chunk;
}
if (rc) {
dev_err(&nd_pfn->dev,
"error clearing %x badblocks at %llx\n",
num_bad, first_bad);
return rc;
}
}
} while (bb_present);
return 0;
}
static bool nd_supported_alignment(unsigned long align)
{
int i;
unsigned long supported[MAX_NVDIMM_ALIGN] = { [0] = 0, };
if (align == 0)
return false;
nd_pfn_supported_alignments(supported);
for (i = 0; supported[i]; i++)
if (align == supported[i])
return true;
return false;
}
/**
* nd_pfn_validate - read and validate info-block
* @nd_pfn: fsdax namespace runtime state / properties
* @sig: 'devdax' or 'fsdax' signature
*
* Upon return the info-block buffer contents (->pfn_sb) are
* indeterminate when validation fails, and a coherent info-block
* otherwise.
*/
int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
{
u64 checksum, offset;
struct resource *res;
enum nd_pfn_mode mode;
struct nd_namespace_io *nsio;
unsigned long align, start_pad;
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
struct nd_namespace_common *ndns = nd_pfn->ndns;
const uuid_t *parent_uuid = nd_dev_to_uuid(&ndns->dev);
if (!pfn_sb || !ndns)
return -ENODEV;
if (!is_memory(nd_pfn->dev.parent))
return -ENODEV;
if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0))
return -ENXIO;
if (memcmp(pfn_sb->signature, 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);
if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
return -ENODEV;
if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
pfn_sb->start_pad = 0;
pfn_sb->end_trunc = 0;
}
if (__le16_to_cpu(pfn_sb->version_minor) < 2)
pfn_sb->align = 0;
if (__le16_to_cpu(pfn_sb->version_minor) < 4) {
pfn_sb->page_struct_size = cpu_to_le16(64);
pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
}
switch (le32_to_cpu(pfn_sb->mode)) {
case PFN_MODE_RAM:
case PFN_MODE_PMEM:
break;
default:
return -ENXIO;
}
align = le32_to_cpu(pfn_sb->align);
offset = le64_to_cpu(pfn_sb->dataoff);
start_pad = le32_to_cpu(pfn_sb->start_pad);
if (align == 0)
align = 1UL << ilog2(offset);
mode = le32_to_cpu(pfn_sb->mode);
if ((le32_to_cpu(pfn_sb->page_size) > PAGE_SIZE) &&
(mode == PFN_MODE_PMEM)) {
dev_err(&nd_pfn->dev,
"init failed, page size mismatch %d\n",
le32_to_cpu(pfn_sb->page_size));
return -EOPNOTSUPP;
}
if ((le16_to_cpu(pfn_sb->page_struct_size) < sizeof(struct page)) &&
(mode == PFN_MODE_PMEM)) {
dev_err(&nd_pfn->dev,
"init failed, struct page size mismatch %d\n",
le16_to_cpu(pfn_sb->page_struct_size));
return -EOPNOTSUPP;
}
/*
* Check whether the we support the alignment. For Dax if the
* superblock alignment is not matching, we won't initialize
* the device.
*/
if (!nd_supported_alignment(align) &&
!memcmp(pfn_sb->signature, DAX_SIG, PFN_SIG_LEN)) {
dev_err(&nd_pfn->dev, "init failed, alignment mismatch: "
"%ld:%ld\n", nd_pfn->align, align);
return -EOPNOTSUPP;
}
if (!nd_pfn->uuid) {
/*
* When probing a namepace via nd_pfn_probe() the uuid
* is NULL (see: nd_pfn_devinit()) we init settings from
* pfn_sb
*/
nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
if (!nd_pfn->uuid)
return -ENOMEM;
nd_pfn->align = align;
nd_pfn->mode = mode;
} else {
/*
* When probing a pfn / dax instance we validate the
* live settings against the pfn_sb
*/
if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
return -ENODEV;
/*
* If the uuid validates, but other settings mismatch
* return EINVAL because userspace has managed to change
* the configuration without specifying new
* identification.
*/
if (nd_pfn->align != align || nd_pfn->mode != mode) {
dev_err(&nd_pfn->dev,
"init failed, settings mismatch\n");
dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
nd_pfn->align, align, nd_pfn->mode,
mode);
return -EOPNOTSUPP;
}
}
if (align > nvdimm_namespace_capacity(ndns)) {
dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
align, nvdimm_namespace_capacity(ndns));
return -EOPNOTSUPP;
}
/*
* 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.
*/
nsio = to_nd_namespace_io(&ndns->dev);
res = &nsio->res;
if (offset >= resource_size(res)) {
dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
dev_name(&ndns->dev));
return -EOPNOTSUPP;
}
if ((align && !IS_ALIGNED(res->start + offset + start_pad, align))
|| !IS_ALIGNED(offset, PAGE_SIZE)) {
dev_err(&nd_pfn->dev,
"bad offset: %#llx dax disabled align: %#lx\n",
offset, align);
return -EOPNOTSUPP;
}
if (!IS_ALIGNED(res->start + le32_to_cpu(pfn_sb->start_pad),
memremap_compat_align())) {
dev_err(&nd_pfn->dev, "resource start misaligned\n");
return -EOPNOTSUPP;
}
if (!IS_ALIGNED(res->end + 1 - le32_to_cpu(pfn_sb->end_trunc),
memremap_compat_align())) {
dev_err(&nd_pfn->dev, "resource end misaligned\n");
return -EOPNOTSUPP;
}
return 0;
}
EXPORT_SYMBOL(nd_pfn_validate);
int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
{
int rc;
struct nd_pfn *nd_pfn;
struct device *pfn_dev;
struct nd_pfn_sb *pfn_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_PFN:
break;
default:
return -ENODEV;
}
nvdimm_bus_lock(&ndns->dev);
nd_pfn = nd_pfn_alloc(nd_region);
pfn_dev = nd_pfn_devinit(nd_pfn, ndns);
nvdimm_bus_unlock(&ndns->dev);
if (!pfn_dev)
return -ENOMEM;
pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
nd_pfn = to_nd_pfn(pfn_dev);
nd_pfn->pfn_sb = pfn_sb;
rc = nd_pfn_validate(nd_pfn, PFN_SIG);
dev_dbg(dev, "pfn: %s\n", rc == 0 ? dev_name(pfn_dev) : "<none>");
if (rc < 0) {
nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
put_device(pfn_dev);
} else
nd_device_register(pfn_dev);
return rc;
}
EXPORT_SYMBOL(nd_pfn_probe);
/*
* We hotplug memory at sub-section granularity, pad the reserved area
* from the previous section base to the namespace base address.
*/
static unsigned long init_altmap_base(resource_size_t base)
{
unsigned long base_pfn = PHYS_PFN(base);
return SUBSECTION_ALIGN_DOWN(base_pfn);
}
static unsigned long init_altmap_reserve(resource_size_t base)
{
unsigned long reserve = nd_info_block_reserve() >> PAGE_SHIFT;
unsigned long base_pfn = PHYS_PFN(base);
reserve += base_pfn - SUBSECTION_ALIGN_DOWN(base_pfn);
return reserve;
}
static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
{
struct range *range = &pgmap->range;
struct vmem_altmap *altmap = &pgmap->altmap;
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
u64 offset = le64_to_cpu(pfn_sb->dataoff);
u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
u32 reserve = nd_info_block_reserve();
struct nd_namespace_common *ndns = nd_pfn->ndns;
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
resource_size_t base = nsio->res.start + start_pad;
resource_size_t end = nsio->res.end - end_trunc;
struct vmem_altmap __altmap = {
.base_pfn = init_altmap_base(base),
.reserve = init_altmap_reserve(base),
.end_pfn = PHYS_PFN(end),
};
*range = (struct range) {
.start = nsio->res.start + start_pad,
.end = nsio->res.end - end_trunc,
};
pgmap->nr_range = 1;
if (nd_pfn->mode == PFN_MODE_RAM) {
if (offset < reserve)
return -EINVAL;
nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
} else if (nd_pfn->mode == PFN_MODE_PMEM) {
nd_pfn->npfns = PHYS_PFN((range_len(range) - offset));
if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
dev_info(&nd_pfn->dev,
"number of pfns truncated from %lld to %ld\n",
le64_to_cpu(nd_pfn->pfn_sb->npfns),
nd_pfn->npfns);
memcpy(altmap, &__altmap, sizeof(*altmap));
altmap->free = PHYS_PFN(offset - reserve);
altmap->alloc = 0;
pgmap->flags |= PGMAP_ALTMAP_VALID;
} else
return -ENXIO;
return 0;
}
static int nd_pfn_init(struct nd_pfn *nd_pfn)
{
struct nd_namespace_common *ndns = nd_pfn->ndns;
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
resource_size_t start, size;
struct nd_region *nd_region;
unsigned long npfns, align;
u32 end_trunc;
struct nd_pfn_sb *pfn_sb;
phys_addr_t offset;
const char *sig;
u64 checksum;
int rc;
pfn_sb = devm_kmalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL);
if (!pfn_sb)
return -ENOMEM;
nd_pfn->pfn_sb = pfn_sb;
if (is_nd_dax(&nd_pfn->dev))
sig = DAX_SIG;
else
sig = PFN_SIG;
rc = nd_pfn_validate(nd_pfn, sig);
if (rc == 0)
return nd_pfn_clear_memmap_errors(nd_pfn);
if (rc != -ENODEV)
return rc;
/* no info block, do init */;
memset(pfn_sb, 0, sizeof(*pfn_sb));
nd_region = to_nd_region(nd_pfn->dev.parent);
if (nd_region->ro) {
dev_info(&nd_pfn->dev,
"%s is read-only, unable to init metadata\n",
dev_name(&nd_region->dev));
return -ENXIO;
}
start = nsio->res.start;
size = resource_size(&nsio->res);
npfns = PHYS_PFN(size - SZ_8K);
align = max(nd_pfn->align, memremap_compat_align());
/*
* When @start is misaligned fail namespace creation. See
* the 'struct nd_pfn_sb' commentary on why ->start_pad is not
* an option.
*/
if (!IS_ALIGNED(start, memremap_compat_align())) {
dev_err(&nd_pfn->dev, "%s: start %pa misaligned to %#lx\n",
dev_name(&ndns->dev), &start,
memremap_compat_align());
return -EINVAL;
}
end_trunc = start + size - ALIGN_DOWN(start + size, align);
if (nd_pfn->mode == PFN_MODE_PMEM) {
unsigned long page_map_size = MAX_STRUCT_PAGE_SIZE * npfns;
/*
* The altmap should be padded out to the block size used
* when populating the vmemmap. This *should* be equal to
* PMD_SIZE for most architectures.
*
* Also make sure size of struct page is less than
* MAX_STRUCT_PAGE_SIZE. The goal here is compatibility in the
* face of production kernel configurations that reduce the
* 'struct page' size below MAX_STRUCT_PAGE_SIZE. For debug
* kernel configurations that increase the 'struct page' size
* above MAX_STRUCT_PAGE_SIZE, the page_struct_override allows
* for continuing with the capacity that will be wasted when
* reverting to a production kernel configuration. Otherwise,
* those configurations are blocked by default.
*/
if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE) {
if (page_struct_override)
page_map_size = sizeof(struct page) * npfns;
else {
dev_err(&nd_pfn->dev,
"Memory debug options prevent using pmem for the page map\n");
return -EINVAL;
}
}
offset = ALIGN(start + SZ_8K + page_map_size, align) - start;
} else if (nd_pfn->mode == PFN_MODE_RAM)
offset = ALIGN(start + SZ_8K, align) - start;
else
return -ENXIO;
if (offset >= size) {
dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
dev_name(&ndns->dev));
return -ENXIO;
}
npfns = PHYS_PFN(size - offset - end_trunc);
pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
pfn_sb->dataoff = cpu_to_le64(offset);
pfn_sb->npfns = cpu_to_le64(npfns);
memcpy(pfn_sb->signature, sig, PFN_SIG_LEN);
memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
pfn_sb->version_major = cpu_to_le16(1);
pfn_sb->version_minor = cpu_to_le16(4);
pfn_sb->end_trunc = cpu_to_le32(end_trunc);
pfn_sb->align = cpu_to_le32(nd_pfn->align);
if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE && page_struct_override)
pfn_sb->page_struct_size = cpu_to_le16(sizeof(struct page));
else
pfn_sb->page_struct_size = cpu_to_le16(MAX_STRUCT_PAGE_SIZE);
pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
pfn_sb->checksum = cpu_to_le64(checksum);
rc = nd_pfn_clear_memmap_errors(nd_pfn);
if (rc)
return rc;
return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0);
}
/*
* Determine the effective resource range and vmem_altmap from an nd_pfn
* instance.
*/
int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
{
int rc;
if (!nd_pfn->uuid || !nd_pfn->ndns)
return -ENODEV;
rc = nd_pfn_init(nd_pfn);
if (rc)
return rc;
/* we need a valid pfn_sb before we can init a dev_pagemap */
return __nvdimm_setup_pfn(nd_pfn, pgmap);
}
EXPORT_SYMBOL_GPL(nvdimm_setup_pfn);