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