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 int nid; /* NID for this memory block */
37 };
38
39 int arch_get_memory_phys_device(unsigned long start_pfn);
40 unsigned long memory_block_size_bytes(void);
41 int 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
51 struct 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
66 struct 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
72 struct notifier_block;
73 struct 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
memory_dev_init(void)83 static inline int memory_dev_init(void)
84 {
85 return 0;
86 }
register_memory_notifier(struct notifier_block * nb)87 static inline int register_memory_notifier(struct notifier_block *nb)
88 {
89 return 0;
90 }
unregister_memory_notifier(struct notifier_block * nb)91 static inline void unregister_memory_notifier(struct notifier_block *nb)
92 {
93 }
memory_notify(unsigned long val,void * v)94 static inline int memory_notify(unsigned long val, void *v)
95 {
96 return 0;
97 }
register_memory_isolate_notifier(struct notifier_block * nb)98 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
99 {
100 return 0;
101 }
unregister_memory_isolate_notifier(struct notifier_block * nb)102 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
103 {
104 }
memory_isolate_notify(unsigned long val,void * v)105 static inline int memory_isolate_notify(unsigned long val, void *v)
106 {
107 return 0;
108 }
109 #else
110 extern int register_memory_notifier(struct notifier_block *nb);
111 extern void unregister_memory_notifier(struct notifier_block *nb);
112 extern int register_memory_isolate_notifier(struct notifier_block *nb);
113 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
114 int hotplug_memory_register(int nid, struct mem_section *section);
115 #ifdef CONFIG_MEMORY_HOTREMOVE
116 extern int unregister_memory_section(struct mem_section *);
117 #endif
118 extern int memory_dev_init(void);
119 extern int memory_notify(unsigned long val, void *v);
120 extern int memory_isolate_notify(unsigned long val, void *v);
121 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
122 struct memory_block *);
123 extern 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 */
146 extern struct mutex text_mutex;
147
148 #endif /* _LINUX_MEMORY_H_ */
149
