linux/drivers/dax/bus.h
Vishal Verma 4eca0ef49a dax/kmem: allow kmem to add memory with memmap_on_memory
Large amounts of memory managed by the kmem driver may come in via CXL,
and it is often desirable to have the memmap for this memory on the new
memory itself.

Enroll kmem-managed memory for memmap_on_memory semantics if the dax
region originates via CXL.  For non-CXL dax regions, retain the existing
default behavior of hot adding without memmap_on_memory semantics.

Link: https://lkml.kernel.org/r/20231107-vv-kmem_memmap-v10-3-1253ec050ed0@intel.com
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Tested-by: Li Zhijian <lizhijian@fujitsu.com>	[cxl.kmem and nvdimm.kmem]
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Fan Ni <fan.ni@samsung.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:35 -08:00

57 lines
1.5 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;
/* dax bus specific ioresource flags */
#define IORESOURCE_DAX_STATIC BIT(0)
#define IORESOURCE_DAX_KMEM BIT(1)
struct dax_region *alloc_dax_region(struct device *parent, int region_id,
struct range *range, int target_node, unsigned int align,
unsigned long flags);
struct dev_dax_data {
struct dax_region *dax_region;
struct dev_pagemap *pgmap;
resource_size_t size;
int id;
bool memmap_on_memory;
};
struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data);
enum dax_driver_type {
DAXDRV_KMEM_TYPE,
DAXDRV_DEVICE_TYPE,
};
struct dax_device_driver {
struct device_driver drv;
struct list_head ids;
enum dax_driver_type type;
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);
#define MODULE_ALIAS_DAX_DEVICE(type) \
MODULE_ALIAS("dax:t" __stringify(type) "*")
#define DAX_DEVICE_MODALIAS_FMT "dax:t%d"
#endif /* __DAX_BUS_H__ */