alistair23-linux/drivers/nvdimm/nd.h
Linus Torvalds f67e3fb489 device-dax for 5.1
* Replace the /sys/class/dax device model with /sys/bus/dax, and include
   a compat driver so distributions can opt-in to the new ABI.
 
 * Allow for an alternative driver for the device-dax address-range
 
 * Introduce the 'kmem' driver to hotplug / assign a device-dax
   address-range to the core-mm.
 
 * Arrange for the device-dax target-node to be onlined so that the newly
   added memory range can be uniquely referenced by numa apis.
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Merge tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull device-dax updates from Dan Williams:
 "New device-dax infrastructure to allow persistent memory and other
  "reserved" / performance differentiated memories, to be assigned to
  the core-mm as "System RAM".

  Some users want to use persistent memory as additional volatile
  memory. They are willing to cope with potential performance
  differences, for example between DRAM and 3D Xpoint, and want to use
  typical Linux memory management apis rather than a userspace memory
  allocator layered over an mmap() of a dax file. The administration
  model is to decide how much Persistent Memory (pmem) to use as System
  RAM, create a device-dax-mode namespace of that size, and then assign
  it to the core-mm. The rationale for device-dax is that it is a
  generic memory-mapping driver that can be layered over any "special
  purpose" memory, not just pmem. On subsequent boots udev rules can be
  used to restore the memory assignment.

  One implication of using pmem as RAM is that mlock() no longer keeps
  data off persistent media. For this reason it is recommended to enable
  NVDIMM Security (previously merged for 5.0) to encrypt pmem contents
  at rest. We considered making this recommendation an actively enforced
  requirement, but in the end decided to leave it as a distribution /
  administrator policy to allow for emulation and test environments that
  lack security capable NVDIMMs.

  Summary:

   - Replace the /sys/class/dax device model with /sys/bus/dax, and
     include a compat driver so distributions can opt-in to the new ABI.

   - Allow for an alternative driver for the device-dax address-range

   - Introduce the 'kmem' driver to hotplug / assign a device-dax
     address-range to the core-mm.

   - Arrange for the device-dax target-node to be onlined so that the
     newly added memory range can be uniquely referenced by numa apis"

NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because
we currently have special - and very annoying rules in the kernel about
accessing PMEM only with the "MC safe" accessors, because machine checks
inside the regular repeat string copy functions can be fatal in some
(not described) circumstances.

And apparently the PMEM modules can cause that a lot more than regular
RAM.  The argument is that this happens because PMEM doesn't necessarily
get scrubbed at boot like RAM does, but that is planned to be added for
the user space tooling.

Quoting Dan from another email:
 "The exposure can be reduced in the volatile-RAM case by scanning for
  and clearing errors before it is onlined as RAM. The userspace tooling
  for that can be in place before v5.1-final. There's also runtime
  notifications of errors via acpi_nfit_uc_error_notify() from
  background scrubbers on the DIMM devices. With that mechanism the
  kernel could proactively clear newly discovered poison in the volatile
  case, but that would be additional development more suitable for v5.2.

  I understand the concern, and the need to highlight this issue by
  tapping the brakes on feature development, but I don't see PMEM as RAM
  making the situation worse when the exposure is also there via DAX in
  the PMEM case. Volatile-RAM is arguably a safer use case since it's
  possible to repair pages where the persistent case needs active
  application coordination"

* tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: "Hotplug" persistent memory for use like normal RAM
  mm/resource: Let walk_system_ram_range() search child resources
  mm/memory-hotplug: Allow memory resources to be children
  mm/resource: Move HMM pr_debug() deeper into resource code
  mm/resource: Return real error codes from walk failures
  device-dax: Add a 'modalias' attribute to DAX 'bus' devices
  device-dax: Add a 'target_node' attribute
  device-dax: Auto-bind device after successful new_id
  acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node
  device-dax: Add /sys/class/dax backwards compatibility
  device-dax: Add support for a dax override driver
  device-dax: Move resource pinning+mapping into the common driver
  device-dax: Introduce bus + driver model
  device-dax: Start defining a dax bus model
  device-dax: Remove multi-resource infrastructure
  device-dax: Kill dax_region base
  device-dax: Kill dax_region ida
2019-03-16 13:05:32 -07:00

438 lines
12 KiB
C

/*
* 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.
*/
#ifndef __ND_H__
#define __ND_H__
#include <linux/libnvdimm.h>
#include <linux/badblocks.h>
#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/ndctl.h>
#include <linux/types.h>
#include <linux/nd.h>
#include "label.h"
enum {
/*
* Limits the maximum number of block apertures a dimm can
* support and is an input to the geometry/on-disk-format of a
* BTT instance
*/
ND_MAX_LANES = 256,
INT_LBASIZE_ALIGNMENT = 64,
NVDIMM_IO_ATOMIC = 1,
};
struct nvdimm_drvdata {
struct device *dev;
int nslabel_size;
struct nd_cmd_get_config_size nsarea;
void *data;
int ns_current, ns_next;
struct resource dpa;
struct kref kref;
};
struct nd_region_data {
int ns_count;
int ns_active;
unsigned int hints_shift;
void __iomem *flush_wpq[0];
};
static inline void __iomem *ndrd_get_flush_wpq(struct nd_region_data *ndrd,
int dimm, int hint)
{
unsigned int num = 1 << ndrd->hints_shift;
unsigned int mask = num - 1;
return ndrd->flush_wpq[dimm * num + (hint & mask)];
}
static inline void ndrd_set_flush_wpq(struct nd_region_data *ndrd, int dimm,
int hint, void __iomem *flush)
{
unsigned int num = 1 << ndrd->hints_shift;
unsigned int mask = num - 1;
ndrd->flush_wpq[dimm * num + (hint & mask)] = flush;
}
static inline struct nd_namespace_index *to_namespace_index(
struct nvdimm_drvdata *ndd, int i)
{
if (i < 0)
return NULL;
return ndd->data + sizeof_namespace_index(ndd) * i;
}
static inline struct nd_namespace_index *to_current_namespace_index(
struct nvdimm_drvdata *ndd)
{
return to_namespace_index(ndd, ndd->ns_current);
}
static inline struct nd_namespace_index *to_next_namespace_index(
struct nvdimm_drvdata *ndd)
{
return to_namespace_index(ndd, ndd->ns_next);
}
unsigned sizeof_namespace_label(struct nvdimm_drvdata *ndd);
#define namespace_label_has(ndd, field) \
(offsetof(struct nd_namespace_label, field) \
< sizeof_namespace_label(ndd))
#define nd_dbg_dpa(r, d, res, fmt, arg...) \
dev_dbg((r) ? &(r)->dev : (d)->dev, "%s: %.13s: %#llx @ %#llx " fmt, \
(r) ? dev_name((d)->dev) : "", res ? res->name : "null", \
(unsigned long long) (res ? resource_size(res) : 0), \
(unsigned long long) (res ? res->start : 0), ##arg)
#define for_each_dpa_resource(ndd, res) \
for (res = (ndd)->dpa.child; res; res = res->sibling)
#define for_each_dpa_resource_safe(ndd, res, next) \
for (res = (ndd)->dpa.child, next = res ? res->sibling : NULL; \
res; res = next, next = next ? next->sibling : NULL)
struct nd_percpu_lane {
int count;
spinlock_t lock;
};
struct nd_label_ent {
struct list_head list;
struct nd_namespace_label *label;
};
enum nd_mapping_lock_class {
ND_MAPPING_CLASS0,
ND_MAPPING_UUID_SCAN,
};
struct nd_mapping {
struct nvdimm *nvdimm;
u64 start;
u64 size;
int position;
struct list_head labels;
struct mutex lock;
/*
* @ndd is for private use at region enable / disable time for
* get_ndd() + put_ndd(), all other nd_mapping to ndd
* conversions use to_ndd() which respects enabled state of the
* nvdimm.
*/
struct nvdimm_drvdata *ndd;
};
struct nd_region {
struct device dev;
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;
int id, num_lanes, ro, numa_node, target_node;
void *provider_data;
struct kernfs_node *bb_state;
struct badblocks bb;
struct nd_interleave_set *nd_set;
struct nd_percpu_lane __percpu *lane;
struct nd_mapping mapping[0];
};
struct nd_blk_region {
int (*enable)(struct nvdimm_bus *nvdimm_bus, struct device *dev);
int (*do_io)(struct nd_blk_region *ndbr, resource_size_t dpa,
void *iobuf, u64 len, int rw);
void *blk_provider_data;
struct nd_region nd_region;
};
/*
* Lookup next in the repeating sequence of 01, 10, and 11.
*/
static inline unsigned nd_inc_seq(unsigned seq)
{
static const unsigned next[] = { 0, 2, 3, 1 };
return next[seq & 3];
}
struct btt;
struct nd_btt {
struct device dev;
struct nd_namespace_common *ndns;
struct btt *btt;
unsigned long lbasize;
u64 size;
u8 *uuid;
int id;
int initial_offset;
u16 version_major;
u16 version_minor;
};
enum nd_pfn_mode {
PFN_MODE_NONE,
PFN_MODE_RAM,
PFN_MODE_PMEM,
};
struct nd_pfn {
int id;
u8 *uuid;
struct device dev;
unsigned long align;
unsigned long npfns;
enum nd_pfn_mode mode;
struct nd_pfn_sb *pfn_sb;
struct nd_namespace_common *ndns;
};
struct nd_dax {
struct nd_pfn nd_pfn;
};
enum nd_async_mode {
ND_SYNC,
ND_ASYNC,
};
int nd_integrity_init(struct gendisk *disk, unsigned long meta_size);
void wait_nvdimm_bus_probe_idle(struct device *dev);
void nd_device_register(struct device *dev);
void nd_device_unregister(struct device *dev, enum nd_async_mode mode);
void nd_device_notify(struct device *dev, enum nvdimm_event event);
int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
size_t len);
ssize_t nd_size_select_show(unsigned long current_size,
const unsigned long *supported, char *buf);
ssize_t nd_size_select_store(struct device *dev, const char *buf,
unsigned long *current_size, const unsigned long *supported);
int __init nvdimm_init(void);
int __init nd_region_init(void);
int __init nd_label_init(void);
void nvdimm_exit(void);
void nd_region_exit(void);
struct nvdimm;
struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping);
int nvdimm_check_config_data(struct device *dev);
int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd);
int nvdimm_init_config_data(struct nvdimm_drvdata *ndd);
int nvdimm_get_config_data(struct nvdimm_drvdata *ndd, void *buf,
size_t offset, size_t len);
int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
void *buf, size_t len);
long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
unsigned int len);
void nvdimm_set_aliasing(struct device *dev);
void nvdimm_set_locked(struct device *dev);
void nvdimm_clear_locked(struct device *dev);
int nvdimm_security_setup_events(struct device *dev);
#if IS_ENABLED(CONFIG_NVDIMM_KEYS)
int nvdimm_security_unlock(struct device *dev);
#else
static inline int nvdimm_security_unlock(struct device *dev)
{
return 0;
}
#endif
struct nd_btt *to_nd_btt(struct device *dev);
struct nd_gen_sb {
char reserved[SZ_4K - 8];
__le64 checksum;
};
u64 nd_sb_checksum(struct nd_gen_sb *sb);
#if IS_ENABLED(CONFIG_BTT)
int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns);
bool is_nd_btt(struct device *dev);
struct device *nd_btt_create(struct nd_region *nd_region);
#else
static inline int nd_btt_probe(struct device *dev,
struct nd_namespace_common *ndns)
{
return -ENODEV;
}
static inline bool is_nd_btt(struct device *dev)
{
return false;
}
static inline struct device *nd_btt_create(struct nd_region *nd_region)
{
return NULL;
}
#endif
struct nd_pfn *to_nd_pfn(struct device *dev);
#if IS_ENABLED(CONFIG_NVDIMM_PFN)
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define PFN_DEFAULT_ALIGNMENT HPAGE_PMD_SIZE
#else
#define PFN_DEFAULT_ALIGNMENT PAGE_SIZE
#endif
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, const char *sig);
extern struct attribute_group nd_pfn_attribute_group;
#else
static inline int nd_pfn_probe(struct device *dev,
struct nd_namespace_common *ndns)
{
return -ENODEV;
}
static inline bool is_nd_pfn(struct device *dev)
{
return false;
}
static inline struct device *nd_pfn_create(struct nd_region *nd_region)
{
return NULL;
}
static inline int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
{
return -ENODEV;
}
#endif
struct nd_dax *to_nd_dax(struct device *dev);
#if IS_ENABLED(CONFIG_NVDIMM_DAX)
int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns);
bool is_nd_dax(struct device *dev);
struct device *nd_dax_create(struct nd_region *nd_region);
#else
static inline int nd_dax_probe(struct device *dev,
struct nd_namespace_common *ndns)
{
return -ENODEV;
}
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
int nd_region_to_nstype(struct nd_region *nd_region);
int nd_region_register_namespaces(struct nd_region *nd_region, int *err);
u64 nd_region_interleave_set_cookie(struct nd_region *nd_region,
struct nd_namespace_index *nsindex);
u64 nd_region_interleave_set_altcookie(struct nd_region *nd_region);
void nvdimm_bus_lock(struct device *dev);
void nvdimm_bus_unlock(struct device *dev);
bool is_nvdimm_bus_locked(struct device *dev);
int nvdimm_revalidate_disk(struct gendisk *disk);
void nvdimm_drvdata_release(struct kref *kref);
void put_ndd(struct nvdimm_drvdata *ndd);
int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd);
void nvdimm_free_dpa(struct nvdimm_drvdata *ndd, struct resource *res);
struct resource *nvdimm_allocate_dpa(struct nvdimm_drvdata *ndd,
struct nd_label_id *label_id, resource_size_t start,
resource_size_t n);
resource_size_t nvdimm_namespace_capacity(struct nd_namespace_common *ndns);
bool nvdimm_namespace_locked(struct nd_namespace_common *ndns);
struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev);
int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns);
int nvdimm_namespace_detach_btt(struct nd_btt *nd_btt);
const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
char *name);
unsigned int pmem_sector_size(struct nd_namespace_common *ndns);
void nvdimm_badblocks_populate(struct nd_region *nd_region,
struct badblocks *bb, const struct resource *res);
#if IS_ENABLED(CONFIG_ND_CLAIM)
int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap);
int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio);
void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio);
#else
static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
struct dev_pagemap *pgmap)
{
return -ENXIO;
}
static inline int devm_nsio_enable(struct device *dev,
struct nd_namespace_io *nsio)
{
return -ENXIO;
}
static inline void devm_nsio_disable(struct device *dev,
struct nd_namespace_io *nsio)
{
}
#endif
int nd_blk_region_init(struct nd_region *nd_region);
int nd_region_activate(struct nd_region *nd_region);
void __nd_iostat_start(struct bio *bio, unsigned long *start);
static inline bool nd_iostat_start(struct bio *bio, unsigned long *start)
{
struct gendisk *disk = bio->bi_disk;
if (!blk_queue_io_stat(disk->queue))
return false;
*start = jiffies;
generic_start_io_acct(disk->queue, bio_op(bio), bio_sectors(bio),
&disk->part0);
return true;
}
static inline void nd_iostat_end(struct bio *bio, unsigned long start)
{
struct gendisk *disk = bio->bi_disk;
generic_end_io_acct(disk->queue, bio_op(bio), &disk->part0, start);
}
static inline bool is_bad_pmem(struct badblocks *bb, sector_t sector,
unsigned int len)
{
if (bb->count) {
sector_t first_bad;
int num_bad;
return !!badblocks_check(bb, sector, len / 512, &first_bad,
&num_bad);
}
return false;
}
resource_size_t nd_namespace_blk_validate(struct nd_namespace_blk *nsblk);
const u8 *nd_dev_to_uuid(struct device *dev);
bool pmem_should_map_pages(struct device *dev);
#endif /* __ND_H__ */