linux-stable/include/linux/libnvdimm.h
Dan Williams f284a4f237 libnvdimm: introduce nvdimm_flush() and nvdimm_has_flush()
nvdimm_flush() is a replacement for the x86 'pcommit' instruction.  It is
an optional write flushing mechanism that an nvdimm bus can provide for
the pmem driver to consume.  In the case of the NFIT nvdimm-bus-provider
nvdimm_flush() is implemented as a series of flush-hint-address [1]
writes to each dimm in the interleave set (region) that backs the
namespace.

The nvdimm_has_flush() routine relies on platform firmware to describe
the flushing capabilities of a platform.  It uses the heuristic of
whether an nvdimm bus provider provides flush address data to return a
ternary result:

      1: flush addresses defined
      0: dimm topology described without flush addresses (assume ADR)
 -errno: no topology information, unable to determine flush mechanism

The pmem driver is expected to take the following actions on this ternary
result:

      1: nvdimm_flush() in response to REQ_FUA / REQ_FLUSH and shutdown
      0: do not set, WC or FUA on the queue, take no further action
 -errno: warn and then operate as if nvdimm_has_flush() returned '0'

The caveat of this heuristic is that it can not distinguish the "dimm
does not have flush address" case from the "platform firmware is broken
and failed to describe a flush address".  Given we are already
explicitly trusting the NFIT there's not much more we can do beyond
blacklisting broken firmwares if they are ever encountered.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-07-11 16:13:42 -07:00

171 lines
5.9 KiB
C

/*
* libnvdimm - Non-volatile-memory Devices Subsystem
*
* 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 __LIBNVDIMM_H__
#define __LIBNVDIMM_H__
#include <linux/kernel.h>
#include <linux/sizes.h>
#include <linux/types.h>
enum {
/* when a dimm supports both PMEM and BLK access a label is required */
NDD_ALIASING = 1 << 0,
/* unarmed memory devices may not persist writes */
NDD_UNARMED = 1 << 1,
/* need to set a limit somewhere, but yes, this is likely overkill */
ND_IOCTL_MAX_BUFLEN = SZ_4M,
ND_CMD_MAX_ELEM = 5,
ND_CMD_MAX_ENVELOPE = 256,
ND_MAX_MAPPINGS = 32,
/* region flag indicating to direct-map persistent memory by default */
ND_REGION_PAGEMAP = 0,
/* mark newly adjusted resources as requiring a label update */
DPA_RESOURCE_ADJUSTED = 1 << 0,
};
extern struct attribute_group nvdimm_bus_attribute_group;
extern struct attribute_group nvdimm_attribute_group;
extern struct attribute_group nd_device_attribute_group;
extern struct attribute_group nd_numa_attribute_group;
extern struct attribute_group nd_region_attribute_group;
extern struct attribute_group nd_mapping_attribute_group;
struct nvdimm;
struct nvdimm_bus_descriptor;
typedef int (*ndctl_fn)(struct nvdimm_bus_descriptor *nd_desc,
struct nvdimm *nvdimm, unsigned int cmd, void *buf,
unsigned int buf_len, int *cmd_rc);
struct nd_namespace_label;
struct nvdimm_drvdata;
struct nd_mapping {
struct nvdimm *nvdimm;
struct nd_namespace_label **labels;
u64 start;
u64 size;
/*
* @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 nvdimm_bus_descriptor {
const struct attribute_group **attr_groups;
unsigned long cmd_mask;
char *provider_name;
ndctl_fn ndctl;
int (*flush_probe)(struct nvdimm_bus_descriptor *nd_desc);
int (*clear_to_send)(struct nvdimm_bus_descriptor *nd_desc,
struct nvdimm *nvdimm, unsigned int cmd);
};
struct nd_cmd_desc {
int in_num;
int out_num;
u32 in_sizes[ND_CMD_MAX_ELEM];
int out_sizes[ND_CMD_MAX_ELEM];
};
struct nd_interleave_set {
u64 cookie;
};
struct nd_region_desc {
struct resource *res;
struct nd_mapping *nd_mapping;
u16 num_mappings;
const struct attribute_group **attr_groups;
struct nd_interleave_set *nd_set;
void *provider_data;
int num_lanes;
int numa_node;
unsigned long flags;
};
struct device;
void *devm_nvdimm_memremap(struct device *dev, resource_size_t offset,
size_t size, unsigned long flags);
static inline void __iomem *devm_nvdimm_ioremap(struct device *dev,
resource_size_t offset, size_t size)
{
return (void __iomem *) devm_nvdimm_memremap(dev, offset, size, 0);
}
struct nvdimm_bus;
struct module;
struct device;
struct nd_blk_region;
struct nd_blk_region_desc {
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);
struct nd_region_desc ndr_desc;
};
static inline struct nd_blk_region_desc *to_blk_region_desc(
struct nd_region_desc *ndr_desc)
{
return container_of(ndr_desc, struct nd_blk_region_desc, ndr_desc);
}
int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length);
struct nvdimm_bus *__nvdimm_bus_register(struct device *parent,
struct nvdimm_bus_descriptor *nfit_desc, struct module *module);
#define nvdimm_bus_register(parent, desc) \
__nvdimm_bus_register(parent, desc, THIS_MODULE)
void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus);
struct nvdimm_bus *to_nvdimm_bus(struct device *dev);
struct nvdimm *to_nvdimm(struct device *dev);
struct nd_region *to_nd_region(struct device *dev);
struct nd_blk_region *to_nd_blk_region(struct device *dev);
struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus);
const char *nvdimm_name(struct nvdimm *nvdimm);
unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm);
void *nvdimm_provider_data(struct nvdimm *nvdimm);
struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
const struct attribute_group **groups, unsigned long flags,
unsigned long cmd_mask, int num_flush,
struct resource *flush_wpq);
const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd);
const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd);
u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
const struct nd_cmd_desc *desc, int idx, void *buf);
u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
const u32 *out_field);
int nvdimm_bus_check_dimm_count(struct nvdimm_bus *nvdimm_bus, int dimm_count);
struct nd_region *nvdimm_pmem_region_create(struct nvdimm_bus *nvdimm_bus,
struct nd_region_desc *ndr_desc);
struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
struct nd_region_desc *ndr_desc);
struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
struct nd_region_desc *ndr_desc);
void *nd_region_provider_data(struct nd_region *nd_region);
void *nd_blk_region_provider_data(struct nd_blk_region *ndbr);
void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data);
struct nvdimm *nd_blk_region_to_dimm(struct nd_blk_region *ndbr);
unsigned int nd_region_acquire_lane(struct nd_region *nd_region);
void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane);
u64 nd_fletcher64(void *addr, size_t len, bool le);
void nvdimm_flush(struct nd_region *nd_region);
int nvdimm_has_flush(struct nd_region *nd_region);
#endif /* __LIBNVDIMM_H__ */