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