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 end_section_nr;
29 unsigned long state; /* serialized by the dev->lock */
30 int section_count; /* serialized by mem_sysfs_mutex */
31 int online_type; /* for passing data to online routine */
32 int phys_device; /* to which fru does this belong? */
33 void *hw; /* optional pointer to fw/hw data */
34 int (*phys_callback)(struct memory_block *);
35 struct device dev;
36 int nid; /* NID for this memory block */
37};
38
39int arch_get_memory_phys_device(unsigned long start_pfn);
40unsigned long memory_block_size_bytes(void);
41int set_memory_block_size_order(unsigned int order);
42
43/* These states are exposed to userspace as text strings in sysfs */
44#define MEM_ONLINE (1<<0) /* exposed to userspace */
45#define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
46#define MEM_OFFLINE (1<<2) /* exposed to userspace */
47#define MEM_GOING_ONLINE (1<<3)
48#define MEM_CANCEL_ONLINE (1<<4)
49#define MEM_CANCEL_OFFLINE (1<<5)
50
51struct memory_notify {
52 unsigned long start_pfn;
53 unsigned long nr_pages;
54 int status_change_nid_normal;
55 int status_change_nid_high;
56 int status_change_nid;
57};
58
59/*
60 * During pageblock isolation, count the number of pages within the
61 * range [start_pfn, start_pfn + nr_pages) which are owned by code
62 * in the notifier chain.
63 */
64#define MEM_ISOLATE_COUNT (1<<0)
65
66struct memory_isolate_notify {
67 unsigned long start_pfn; /* Start of range to check */
68 unsigned int nr_pages; /* # pages in range to check */
69 unsigned int pages_found; /* # pages owned found by callbacks */
70};
71
72struct notifier_block;
73struct mem_section;
74
75/*
76 * Priorities for the hotplug memory callback routines (stored in decreasing
77 * order in the callback chain)
78 */
79#define SLAB_CALLBACK_PRI 1
80#define IPC_CALLBACK_PRI 10
81
82#ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
83static inline int memory_dev_init(void)
84{
85 return 0;
86}
87static inline int register_memory_notifier(struct notifier_block *nb)
88{
89 return 0;
90}
91static inline void unregister_memory_notifier(struct notifier_block *nb)
92{
93}
94static inline int memory_notify(unsigned long val, void *v)
95{
96 return 0;
97}
98static inline int register_memory_isolate_notifier(struct notifier_block *nb)
99{
100 return 0;
101}
102static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
103{
104}
105static inline int memory_isolate_notify(unsigned long val, void *v)
106{
107 return 0;
108}
109#else
110extern int register_memory_notifier(struct notifier_block *nb);
111extern void unregister_memory_notifier(struct notifier_block *nb);
112extern int register_memory_isolate_notifier(struct notifier_block *nb);
113extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
114int hotplug_memory_register(int nid, struct mem_section *section);
115#ifdef CONFIG_MEMORY_HOTREMOVE
116extern int unregister_memory_section(struct mem_section *);
117#endif
118extern int memory_dev_init(void);
119extern int memory_notify(unsigned long val, void *v);
120extern int memory_isolate_notify(unsigned long val, void *v);
121extern struct memory_block *find_memory_block_hinted(struct mem_section *,
122 struct memory_block *);
123extern struct memory_block *find_memory_block(struct mem_section *);
124#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
125#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
126
127#ifdef CONFIG_MEMORY_HOTPLUG
128#define hotplug_memory_notifier(fn, pri) ({ \
129 static __meminitdata struct notifier_block fn##_mem_nb =\
130 { .notifier_call = fn, .priority = pri };\
131 register_memory_notifier(&fn##_mem_nb); \
132})
133#define register_hotmemory_notifier(nb) register_memory_notifier(nb)
134#define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb)
135#else
136#define hotplug_memory_notifier(fn, pri) ({ 0; })
137/* These aren't inline functions due to a GCC bug. */
138#define register_hotmemory_notifier(nb) ({ (void)(nb); 0; })
139#define unregister_hotmemory_notifier(nb) ({ (void)(nb); })
140#endif
141
142/*
143 * Kernel text modification mutex, used for code patching. Users of this lock
144 * can sleep.
145 */
146extern struct mutex text_mutex;
147
148#endif /* _LINUX_MEMORY_H_ */
149