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memory.h
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1 /*
2  * include/linux/memory.h - generic memory definition
3  *
4  * This is mainly for topological representation. We define the
5  * basic "struct memory_block" here, which can be embedded in per-arch
6  * definitions or NUMA information.
7  *
8  * Basic handling of the devices is done in drivers/base/memory.c
9  * and system devices are handled in drivers/base/sys.c.
10  *
11  * Memory block are exported via sysfs in the class/memory/devices/
12  * directory.
13  *
14  */
15 #ifndef _LINUX_MEMORY_H_
16 #define _LINUX_MEMORY_H_
17 
18 #include <linux/node.h>
19 #include <linux/compiler.h>
20 #include <linux/mutex.h>
21 
22 #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
23 
24 struct memory_block {
25  unsigned long start_section_nr;
26  unsigned long end_section_nr;
27  unsigned long state;
29 
30  /*
31  * This serializes all state change requests. It isn't
32  * held during creation because the control files are
33  * created long after the critical areas during
34  * initialization.
35  */
37  int phys_device; /* to which fru does this belong? */
38  void *hw; /* optional pointer to fw/hw data */
40  struct device dev;
41 };
42 
43 int arch_get_memory_phys_device(unsigned long start_pfn);
44 
45 /* These states are exposed to userspace as text strings in sysfs */
46 #define MEM_ONLINE (1<<0) /* exposed to userspace */
47 #define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
48 #define MEM_OFFLINE (1<<2) /* exposed to userspace */
49 #define MEM_GOING_ONLINE (1<<3)
50 #define MEM_CANCEL_ONLINE (1<<4)
51 #define MEM_CANCEL_OFFLINE (1<<5)
52 
53 struct memory_notify {
54  unsigned long start_pfn;
55  unsigned long nr_pages;
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 
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
83 static inline int memory_dev_init(void)
84 {
85  return 0;
86 }
87 static inline int register_memory_notifier(struct notifier_block *nb)
88 {
89  return 0;
90 }
91 static inline void unregister_memory_notifier(struct notifier_block *nb)
92 {
93 }
94 static inline int memory_notify(unsigned long val, void *v)
95 {
96  return 0;
97 }
98 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
99 {
100  return 0;
101 }
102 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
103 {
104 }
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 extern int register_new_memory(int, struct mem_section *);
115 extern int unregister_memory_section(struct mem_section *);
116 extern int memory_dev_init(void);
117 extern int remove_memory_block(unsigned long, struct mem_section *, int);
118 extern int memory_notify(unsigned long val, void *v);
119 extern int memory_isolate_notify(unsigned long val, void *v);
120 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
121  struct memory_block *);
122 extern struct memory_block *find_memory_block(struct mem_section *);
123 #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
124 enum mem_add_context { BOOT, HOTPLUG };
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 #else
134 #define hotplug_memory_notifier(fn, pri) do { } while (0)
135 #endif
136 
137 /*
138  * 'struct memory_accessor' is a generic interface to provide
139  * in-kernel access to persistent memory such as i2c or SPI EEPROMs
140  */
143  size_t count);
144  ssize_t (*write)(struct memory_accessor *, const char *buf,
145  off_t offset, size_t count);
146 };
147 
148 /*
149  * Kernel text modification mutex, used for code patching. Users of this lock
150  * can sleep.
151  */
152 extern struct mutex text_mutex;
153 
154 #endif /* _LINUX_MEMORY_H_ */