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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * include/linux/memory.h - generic memory definition
4 *
5 * This is mainly for topological representation. We define the
6 * basic "struct memory_block" here, which can be embedded in per-arch
7 * definitions or NUMA information.
8 *
9 * Basic handling of the devices is done in drivers/base/memory.c
10 * and system devices are handled in drivers/base/sys.c.
11 *
12 * Memory block are exported via sysfs in the class/memory/devices/
13 * directory.
14 *
15 */
16#ifndef _LINUX_MEMORY_H_
17#define _LINUX_MEMORY_H_
18
19#include <linux/node.h>
20#include <linux/compiler.h>
21#include <linux/mutex.h>
22#include <linux/notifier.h>
23
24#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
25
26struct memory_block {
27 unsigned long start_section_nr;
28 unsigned long state; /* serialized by the dev->lock */
29 int online_type; /* for passing data to online routine */
30 int phys_device; /* to which fru does this belong? */
31 struct device dev;
32 int nid; /* NID for this memory block */
33};
34
35int arch_get_memory_phys_device(unsigned long start_pfn);
36unsigned long memory_block_size_bytes(void);
37int set_memory_block_size_order(unsigned int order);
38
39/* These states are exposed to userspace as text strings in sysfs */
40#define MEM_ONLINE (1<<0) /* exposed to userspace */
41#define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
42#define MEM_OFFLINE (1<<2) /* exposed to userspace */
43#define MEM_GOING_ONLINE (1<<3)
44#define MEM_CANCEL_ONLINE (1<<4)
45#define MEM_CANCEL_OFFLINE (1<<5)
46
47struct memory_notify {
48 unsigned long start_pfn;
49 unsigned long nr_pages;
50 int status_change_nid_normal;
51 int status_change_nid_high;
52 int status_change_nid;
53};
54
55struct notifier_block;
56struct mem_section;
57
58/*
59 * Priorities for the hotplug memory callback routines (stored in decreasing
60 * order in the callback chain)
61 */
62#define SLAB_CALLBACK_PRI 1
63#define IPC_CALLBACK_PRI 10
64
65#ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
66static inline void memory_dev_init(void)
67{
68 return;
69}
70static inline int register_memory_notifier(struct notifier_block *nb)
71{
72 return 0;
73}
74static inline void unregister_memory_notifier(struct notifier_block *nb)
75{
76}
77static inline int memory_notify(unsigned long val, void *v)
78{
79 return 0;
80}
81#else
82extern int register_memory_notifier(struct notifier_block *nb);
83extern void unregister_memory_notifier(struct notifier_block *nb);
84int create_memory_block_devices(unsigned long start, unsigned long size);
85void remove_memory_block_devices(unsigned long start, unsigned long size);
86extern void memory_dev_init(void);
87extern int memory_notify(unsigned long val, void *v);
88extern struct memory_block *find_memory_block(struct mem_section *);
89typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
90extern int walk_memory_blocks(unsigned long start, unsigned long size,
91 void *arg, walk_memory_blocks_func_t func);
92extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
93#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
94#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
95
96#ifdef CONFIG_MEMORY_HOTPLUG
97#define hotplug_memory_notifier(fn, pri) ({ \
98 static __meminitdata struct notifier_block fn##_mem_nb =\
99 { .notifier_call = fn, .priority = pri };\
100 register_memory_notifier(&fn##_mem_nb); \
101})
102#define register_hotmemory_notifier(nb) register_memory_notifier(nb)
103#define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb)
104#else
105#define hotplug_memory_notifier(fn, pri) ({ 0; })
106/* These aren't inline functions due to a GCC bug. */
107#define register_hotmemory_notifier(nb) ({ (void)(nb); 0; })
108#define unregister_hotmemory_notifier(nb) ({ (void)(nb); })
109#endif
110
111/*
112 * Kernel text modification mutex, used for code patching. Users of this lock
113 * can sleep.
114 */
115extern struct mutex text_mutex;
116
117#endif /* _LINUX_MEMORY_H_ */