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libnvdimm, dax: introduce device-dax infrastructure

Browse Source 
Device DAX is the device-centric analogue of Filesystem DAX
(CONFIG_FS_DAX).  It allows persistent memory ranges to be allocated and
mapped without need of an intervening file system.  This initial
infrastructure arranges for a libnvdimm pfn-device to be represented as
a different device-type so that it can be attached to a driver other
than the pmem driver.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2016-03-11 10:15:36 -08:00
parent 0bfb8dd3ed
commit cd03412a51
13 changed files with 264 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/nvdimm/Kconfig
View File

@ -88,4 +88,17 @@ config NVDIMM_PFN
Select Y if unsure
config NVDIMM_DAX
bool "NVDIMM DAX: Raw access to persistent memory"
default LIBNVDIMM
depends on NVDIMM_PFN
help
Support raw device dax access to a persistent memory
namespace. For environments that want to hard partition
peristent memory, this capability provides a mechanism to
sub-divide a namespace into character devices that can only be
accessed via DAX (mmap(2)).
Select Y if unsure
endif

1
drivers/nvdimm/Makefile
View File

@ -23,3 +23,4 @@ libnvdimm-y += label.o
libnvdimm-$(CONFIG_ND_CLAIM) += claim.o
libnvdimm-$(CONFIG_BTT) += btt_devs.o
libnvdimm-$(CONFIG_NVDIMM_PFN) += pfn_devs.o
libnvdimm-$(CONFIG_NVDIMM_DAX) += dax_devs.o

4
drivers/nvdimm/bus.c
View File

@ -40,6 +40,8 @@ static int to_nd_device_type(struct device *dev)
return ND_DEVICE_REGION_PMEM;
else if (is_nd_blk(dev))
return ND_DEVICE_REGION_BLK;
else if (is_nd_dax(dev))
return ND_DEVICE_DAX_PMEM;
else if (is_nd_pmem(dev->parent) || is_nd_blk(dev->parent))
return nd_region_to_nstype(to_nd_region(dev->parent));
@ -246,6 +248,8 @@ static void nd_async_device_unregister(void *d, async_cookie_t cookie)
void __nd_device_register(struct device *dev)
{
if (!dev)
return;
dev->bus = &nvdimm_bus_type;
get_device(dev);
async_schedule_domain(nd_async_device_register, dev,

2
drivers/nvdimm/claim.c
View File

@ -85,6 +85,8 @@ static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
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;

99
drivers/nvdimm/dax_devs.c Normal file
View File

@ -0,0 +1,99 @@
/*
* Copyright(c) 2013-2016 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/device.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include "nd-core.h"
#include "nd.h"
static void nd_dax_release(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct nd_dax *nd_dax = to_nd_dax(dev);
struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
dev_dbg(dev, "%s\n", __func__);
nd_detach_ndns(dev, &nd_pfn->ndns);
ida_simple_remove(&nd_region->dax_ida, nd_pfn->id);
kfree(nd_pfn->uuid);
kfree(nd_dax);
}
static struct device_type nd_dax_device_type = {
.name = "nd_dax",
.release = nd_dax_release,
};
bool is_nd_dax(struct device *dev)
{
return dev ? dev->type == &nd_dax_device_type : false;
}
EXPORT_SYMBOL(is_nd_dax);
struct nd_dax *to_nd_dax(struct device *dev)
{
struct nd_dax *nd_dax = container_of(dev, struct nd_dax, nd_pfn.dev);
WARN_ON(!is_nd_dax(dev));
return nd_dax;
}
EXPORT_SYMBOL(to_nd_dax);
static const struct attribute_group *nd_dax_attribute_groups[] = {
&nd_pfn_attribute_group,
&nd_device_attribute_group,
&nd_numa_attribute_group,
NULL,
};
static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
{
struct nd_pfn *nd_pfn;
struct nd_dax *nd_dax;
struct device *dev;
nd_dax = kzalloc(sizeof(*nd_dax), GFP_KERNEL);
if (!nd_dax)
return NULL;
nd_pfn = &nd_dax->nd_pfn;
nd_pfn->id = ida_simple_get(&nd_region->dax_ida, 0, 0, GFP_KERNEL);
if (nd_pfn->id < 0) {
kfree(nd_dax);
return NULL;
}
dev = &nd_pfn->dev;
dev_set_name(dev, "dax%d.%d", nd_region->id, nd_pfn->id);
dev->groups = nd_dax_attribute_groups;
dev->type = &nd_dax_device_type;
dev->parent = &nd_region->dev;
return nd_dax;
}
struct device *nd_dax_create(struct nd_region *nd_region)
{
struct device *dev = NULL;
struct nd_dax *nd_dax;
if (!is_nd_pmem(&nd_region->dev))
return NULL;
nd_dax = nd_dax_alloc(nd_region);
if (nd_dax)
dev = nd_pfn_devinit(&nd_dax->nd_pfn, NULL);
__nd_device_register(dev);
return dev;
}

19
drivers/nvdimm/namespace_devs.c
View File

@ -1288,6 +1288,8 @@ static ssize_t mode_show(struct device *dev,
mode = "safe";
else if (claim && is_nd_pfn(claim))
mode = "memory";
else if (claim && is_nd_dax(claim))
mode = "dax";
else if (!claim && pmem_should_map_pages(dev))
mode = "memory";
else
@ -1379,14 +1381,17 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
{
struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
struct nd_namespace_common *ndns = NULL;
resource_size_t size;
if (nd_btt || nd_pfn) {
if (nd_btt || nd_pfn || nd_dax) {
if (nd_btt)
ndns = nd_btt->ndns;
else if (nd_pfn)
ndns = nd_pfn->ndns;
else if (nd_dax)
ndns = nd_dax->nd_pfn.ndns;
if (!ndns)
return ERR_PTR(-ENODEV);
@ -1779,6 +1784,18 @@ void nd_region_create_blk_seed(struct nd_region *nd_region)
nd_device_register(nd_region->ns_seed);
}
void nd_region_create_dax_seed(struct nd_region *nd_region)
{
WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
nd_region->dax_seed = nd_dax_create(nd_region);
/*
* Seed creation failures are not fatal, provisioning is simply
* disabled until memory becomes available
*/
if (!nd_region->dax_seed)
dev_err(&nd_region->dev, "failed to create dax namespace\n");
}
void nd_region_create_pfn_seed(struct nd_region *nd_region)
{
WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));

1
drivers/nvdimm/nd-core.h
View File

@ -54,6 +54,7 @@ struct nd_region;
void nd_region_create_blk_seed(struct nd_region *nd_region);
void nd_region_create_btt_seed(struct nd_region *nd_region);
void nd_region_create_pfn_seed(struct nd_region *nd_region);
void nd_region_create_dax_seed(struct nd_region *nd_region);
void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev);
int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus);
void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus);

25
drivers/nvdimm/nd.h
View File

@ -101,10 +101,12 @@ struct nd_region {
struct ida ns_ida;
struct ida btt_ida;
struct ida pfn_ida;
struct ida dax_ida;
unsigned long flags;
struct device *ns_seed;
struct device *btt_seed;
struct device *pfn_seed;
struct device *dax_seed;
u16 ndr_mappings;
u64 ndr_size;
u64 ndr_start;
@ -161,6 +163,10 @@ struct nd_pfn {
struct nd_namespace_common *ndns;
};
struct nd_dax {
struct nd_pfn nd_pfn;
};
enum nd_async_mode {
ND_SYNC,
ND_ASYNC,
@ -224,7 +230,10 @@ struct nd_pfn *to_nd_pfn(struct device *dev);
int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns);
bool is_nd_pfn(struct device *dev);
struct device *nd_pfn_create(struct nd_region *nd_region);
struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
struct nd_namespace_common *ndns);
int nd_pfn_validate(struct nd_pfn *nd_pfn);
extern struct attribute_group nd_pfn_attribute_group;
#else
static inline int nd_pfn_probe(struct device *dev,
struct nd_namespace_common *ndns)
@ -248,6 +257,22 @@ static inline int nd_pfn_validate(struct nd_pfn *nd_pfn)
}
#endif
struct nd_dax *to_nd_dax(struct device *dev);
#if IS_ENABLED(CONFIG_NVDIMM_DAX)
bool is_nd_dax(struct device *dev);
struct device *nd_dax_create(struct nd_region *nd_region);
#else
static inline bool is_nd_dax(struct device *dev)
{
return false;
}
static inline struct device *nd_dax_create(struct nd_region *nd_region)
{
return NULL;
}
#endif
struct nd_region *to_nd_region(struct device *dev);
int nd_region_to_nstype(struct nd_region *nd_region);
int nd_region_register_namespaces(struct nd_region *nd_region, int *err);

100
drivers/nvdimm/pfn_devs.c
View File

@ -1,5 +1,5 @@
/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
* Copyright(c) 2013-2016 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
@ -54,10 +54,29 @@ struct nd_pfn *to_nd_pfn(struct device *dev)
}
EXPORT_SYMBOL(to_nd_pfn);
static 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 ssize_t mode_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_pfn *nd_pfn = to_nd_pfn(dev);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
switch (nd_pfn->mode) {
case PFN_MODE_RAM:
@ -72,7 +91,7 @@ static ssize_t mode_show(struct device *dev,
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);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc = 0;
device_lock(dev);
@ -106,7 +125,7 @@ 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(dev);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
return sprintf(buf, "%lx\n", nd_pfn->align);
}
@ -134,7 +153,7 @@ static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
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(dev);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;
device_lock(dev);
@ -152,7 +171,7 @@ 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(dev);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
if (nd_pfn->uuid)
return sprintf(buf, "%pUb\n", nd_pfn->uuid);
@ -162,7 +181,7 @@ static ssize_t uuid_show(struct device *dev,
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);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;
device_lock(dev);
@ -178,7 +197,7 @@ 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);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;
nvdimm_bus_lock(dev);
@ -191,7 +210,7 @@ static ssize_t namespace_show(struct device *dev,
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);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;
device_lock(dev);
@ -209,7 +228,7 @@ 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(dev);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;
device_lock(dev);
@ -235,7 +254,7 @@ static DEVICE_ATTR_RO(resource);
static ssize_t size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_pfn *nd_pfn = to_nd_pfn(dev);
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;
device_lock(dev);
@ -270,7 +289,7 @@ static struct attribute *nd_pfn_attributes[] = {
NULL,
};
static struct attribute_group nd_pfn_attribute_group = {
struct attribute_group nd_pfn_attribute_group = {
.attrs = nd_pfn_attributes,
};
@ -281,16 +300,32 @@ static const struct attribute_group *nd_pfn_attribute_groups[] = {
NULL,
};
static struct device *__nd_pfn_create(struct nd_region *nd_region,
struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
struct nd_namespace_common *ndns)
{
struct device *dev = &nd_pfn->dev;
if (!nd_pfn)
return NULL;
nd_pfn->mode = PFN_MODE_NONE;
nd_pfn->align = HPAGE_SIZE;
dev = &nd_pfn->dev;
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;
}
static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
{
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;
@ -301,29 +336,27 @@ static struct device *__nd_pfn_create(struct nd_region *nd_region,
return NULL;
}
nd_pfn->mode = PFN_MODE_NONE;
nd_pfn->align = HPAGE_SIZE;
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;
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 device *dev = __nd_pfn_create(nd_region, NULL);
struct nd_pfn *nd_pfn;
struct device *dev;
if (dev)
__nd_device_register(dev);
if (!is_nd_pmem(&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;
}
@ -423,7 +456,8 @@ int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
return -ENODEV;
nvdimm_bus_lock(&ndns->dev);
pfn_dev = __nd_pfn_create(nd_region, ndns);
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;

2
drivers/nvdimm/region.c
View File

@ -54,6 +54,7 @@ static int nd_region_probe(struct device *dev)
nd_region->btt_seed = nd_btt_create(nd_region);
nd_region->pfn_seed = nd_pfn_create(nd_region);
nd_region->dax_seed = nd_dax_create(nd_region);
if (err == 0)
return 0;
@ -86,6 +87,7 @@ static int nd_region_remove(struct device *dev)
nd_region->ns_seed = NULL;
nd_region->btt_seed = NULL;
nd_region->pfn_seed = NULL;
nd_region->dax_seed = NULL;
dev_set_drvdata(dev, NULL);
nvdimm_bus_unlock(dev);

29
drivers/nvdimm/region_devs.c
View File

@ -306,6 +306,23 @@ static ssize_t pfn_seed_show(struct device *dev,
}
static DEVICE_ATTR_RO(pfn_seed);
static ssize_t dax_seed_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nd_region *nd_region = to_nd_region(dev);
ssize_t rc;
nvdimm_bus_lock(dev);
if (nd_region->dax_seed)
rc = sprintf(buf, "%s\n", dev_name(nd_region->dax_seed));
else
rc = sprintf(buf, "\n");
nvdimm_bus_unlock(dev);
return rc;
}
static DEVICE_ATTR_RO(dax_seed);
static ssize_t read_only_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@ -335,6 +352,7 @@ static struct attribute *nd_region_attributes[] = {
&dev_attr_mappings.attr,
&dev_attr_btt_seed.attr,
&dev_attr_pfn_seed.attr,
&dev_attr_dax_seed.attr,
&dev_attr_read_only.attr,
&dev_attr_set_cookie.attr,
&dev_attr_available_size.attr,
@ -353,6 +371,9 @@ static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
if (!is_nd_pmem(dev) && a == &dev_attr_pfn_seed.attr)
return 0;
if (!is_nd_pmem(dev) && a == &dev_attr_dax_seed.attr)
return 0;
if (a != &dev_attr_set_cookie.attr
&& a != &dev_attr_available_size.attr)
return a->mode;
@ -441,6 +462,13 @@ static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
nd_region_create_pfn_seed(nd_region);
nvdimm_bus_unlock(dev);
}
if (is_nd_dax(dev) && probe) {
nd_region = to_nd_region(dev->parent);
nvdimm_bus_lock(dev);
if (nd_region->dax_seed == dev)
nd_region_create_dax_seed(nd_region);
nvdimm_bus_unlock(dev);
}
}
void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev)
@ -718,6 +746,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
ida_init(&nd_region->ns_ida);
ida_init(&nd_region->btt_ida);
ida_init(&nd_region->pfn_ida);
ida_init(&nd_region->dax_ida);
dev = &nd_region->dev;
dev_set_name(dev, "region%d", nd_region->id);
dev->parent = &nvdimm_bus->dev;

2
include/uapi/linux/ndctl.h
View File

@ -206,6 +206,7 @@ static inline const char *nvdimm_cmd_name(unsigned cmd)
#define ND_DEVICE_NAMESPACE_IO 4 /* legacy persistent memory */
#define ND_DEVICE_NAMESPACE_PMEM 5 /* PMEM namespace (may alias with BLK) */
#define ND_DEVICE_NAMESPACE_BLK 6 /* BLK namespace (may alias with PMEM) */
#define ND_DEVICE_DAX_PMEM 7 /* Device DAX interface to pmem */
enum nd_driver_flags {
ND_DRIVER_DIMM = 1 << ND_DEVICE_DIMM,
@ -214,6 +215,7 @@ enum nd_driver_flags {
ND_DRIVER_NAMESPACE_IO = 1 << ND_DEVICE_NAMESPACE_IO,
ND_DRIVER_NAMESPACE_PMEM = 1 << ND_DEVICE_NAMESPACE_PMEM,
ND_DRIVER_NAMESPACE_BLK = 1 << ND_DEVICE_NAMESPACE_BLK,
ND_DRIVER_DAX_PMEM = 1 << ND_DEVICE_DAX_PMEM,
};
enum {

1
tools/testing/nvdimm/Kbuild
View File

@ -50,6 +50,7 @@ libnvdimm-y += $(NVDIMM_SRC)/label.o
libnvdimm-$(CONFIG_ND_CLAIM) += $(NVDIMM_SRC)/claim.o
libnvdimm-$(CONFIG_BTT) += $(NVDIMM_SRC)/btt_devs.o
libnvdimm-$(CONFIG_NVDIMM_PFN) += $(NVDIMM_SRC)/pfn_devs.o
libnvdimm-$(CONFIG_NVDIMM_DAX) += $(NVDIMM_SRC)/dax_devs.o
libnvdimm-y += config_check.o
obj-m += test/