linux/drivers/dax/bus.h
Joao Martins fc65c4eb0b device-dax: ensure dev_dax->pgmap is valid for dynamic devices
Right now, only static dax regions have a valid @pgmap pointer in its
struct dev_dax.  Dynamic dax case however, do not.

In preparation for device-dax compound devmap support, make sure that
dev_dax pgmap field is set after it has been allocated and initialized.

dynamic dax device have the @pgmap is allocated at probe() and it's
managed by devm (contrast to static dax region which a pgmap is provided
and dax core kfrees it).  So in addition to ensure a valid @pgmap, clear
the pgmap when the dynamic dax device is released to avoid the same
pgmap ranges to be re-requested across multiple region device reconfigs.

Add a static_dev_dax() and use that helper in dev_dax_probe() to ensure
the initialization differences between dynamic and static regions are
more explicit.  While at it, consolidate the ranges initialization when
we allocate the @pgmap for the dynamic dax region case.  Also take the
opportunity to document the differences between static and dynamic da
regions.

Link: https://lkml.kernel.org/r/20211202204422.26777-8-joao.m.martins@oracle.com
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15 16:30:25 +02:00

69 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
#ifndef __DAX_BUS_H__
#define __DAX_BUS_H__
#include <linux/device.h>
#include <linux/range.h>
struct dev_dax;
struct resource;
struct dax_device;
struct dax_region;
void dax_region_put(struct dax_region *dax_region);
#define IORESOURCE_DAX_STATIC (1UL << 0)
struct dax_region *alloc_dax_region(struct device *parent, int region_id,
struct range *range, int target_node, unsigned int align,
unsigned long flags);
enum dev_dax_subsys {
DEV_DAX_BUS = 0, /* zeroed dev_dax_data picks this by default */
DEV_DAX_CLASS,
};
struct dev_dax_data {
struct dax_region *dax_region;
struct dev_pagemap *pgmap;
enum dev_dax_subsys subsys;
resource_size_t size;
int id;
};
struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data);
/* to be deleted when DEV_DAX_CLASS is removed */
struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys);
struct dax_device_driver {
struct device_driver drv;
struct list_head ids;
int match_always;
int (*probe)(struct dev_dax *dev);
void (*remove)(struct dev_dax *dev);
};
int __dax_driver_register(struct dax_device_driver *dax_drv,
struct module *module, const char *mod_name);
#define dax_driver_register(driver) \
__dax_driver_register(driver, THIS_MODULE, KBUILD_MODNAME)
void dax_driver_unregister(struct dax_device_driver *dax_drv);
void kill_dev_dax(struct dev_dax *dev_dax);
bool static_dev_dax(struct dev_dax *dev_dax);
#if IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT)
int dev_dax_probe(struct dev_dax *dev_dax);
#endif
/*
* While run_dax() is potentially a generic operation that could be
* defined in include/linux/dax.h we don't want to grow any users
* outside of drivers/dax/
*/
void run_dax(struct dax_device *dax_dev);
#define MODULE_ALIAS_DAX_DEVICE(type) \
MODULE_ALIAS("dax:t" __stringify(type) "*")
#define DAX_DEVICE_MODALIAS_FMT "dax:t%d"
#endif /* __DAX_BUS_H__ */