xref: /openbmc/linux/include/linux/memory.h (revision 93f14468)
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 #include <linux/notifier.h>
22 
23 #define MIN_MEMORY_BLOCK_SIZE     (1UL << SECTION_SIZE_BITS)
24 
25 struct memory_block {
26 	unsigned long start_section_nr;
27 	unsigned long end_section_nr;
28 	unsigned long state;
29 	int section_count;
30 
31 	/*
32 	 * This serializes all state change requests.  It isn't
33 	 * held during creation because the control files are
34 	 * created long after the critical areas during
35 	 * initialization.
36 	 */
37 	struct mutex state_mutex;
38 	int phys_device;		/* to which fru does this belong? */
39 	void *hw;			/* optional pointer to fw/hw data */
40 	int (*phys_callback)(struct memory_block *);
41 	struct device dev;
42 };
43 
44 int arch_get_memory_phys_device(unsigned long start_pfn);
45 
46 /* These states are exposed to userspace as text strings in sysfs */
47 #define	MEM_ONLINE		(1<<0) /* exposed to userspace */
48 #define	MEM_GOING_OFFLINE	(1<<1) /* exposed to userspace */
49 #define	MEM_OFFLINE		(1<<2) /* exposed to userspace */
50 #define	MEM_GOING_ONLINE	(1<<3)
51 #define	MEM_CANCEL_ONLINE	(1<<4)
52 #define	MEM_CANCEL_OFFLINE	(1<<5)
53 
54 struct memory_notify {
55 	unsigned long start_pfn;
56 	unsigned long nr_pages;
57 	int status_change_nid_normal;
58 	int status_change_nid_high;
59 	int status_change_nid;
60 };
61 
62 /*
63  * During pageblock isolation, count the number of pages within the
64  * range [start_pfn, start_pfn + nr_pages) which are owned by code
65  * in the notifier chain.
66  */
67 #define MEM_ISOLATE_COUNT	(1<<0)
68 
69 struct memory_isolate_notify {
70 	unsigned long start_pfn;	/* Start of range to check */
71 	unsigned int nr_pages;		/* # pages in range to check */
72 	unsigned int pages_found;	/* # pages owned found by callbacks */
73 };
74 
75 struct notifier_block;
76 struct mem_section;
77 
78 /*
79  * Priorities for the hotplug memory callback routines (stored in decreasing
80  * order in the callback chain)
81  */
82 #define SLAB_CALLBACK_PRI       1
83 #define IPC_CALLBACK_PRI        10
84 
85 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
86 static inline int memory_dev_init(void)
87 {
88 	return 0;
89 }
90 static inline int register_memory_notifier(struct notifier_block *nb)
91 {
92 	return 0;
93 }
94 static inline void unregister_memory_notifier(struct notifier_block *nb)
95 {
96 }
97 static inline int memory_notify(unsigned long val, void *v)
98 {
99 	return 0;
100 }
101 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
102 {
103 	return 0;
104 }
105 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
106 {
107 }
108 static inline int memory_isolate_notify(unsigned long val, void *v)
109 {
110 	return 0;
111 }
112 #else
113 extern int register_memory_notifier(struct notifier_block *nb);
114 extern void unregister_memory_notifier(struct notifier_block *nb);
115 extern int register_memory_isolate_notifier(struct notifier_block *nb);
116 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
117 extern int register_new_memory(int, struct mem_section *);
118 #ifdef CONFIG_MEMORY_HOTREMOVE
119 extern int unregister_memory_section(struct mem_section *);
120 #endif
121 extern int memory_dev_init(void);
122 extern int memory_notify(unsigned long val, void *v);
123 extern int memory_isolate_notify(unsigned long val, void *v);
124 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
125 							struct memory_block *);
126 extern struct memory_block *find_memory_block(struct mem_section *);
127 #define CONFIG_MEM_BLOCK_SIZE	(PAGES_PER_SECTION<<PAGE_SHIFT)
128 enum mem_add_context { BOOT, HOTPLUG };
129 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
130 
131 #ifdef CONFIG_MEMORY_HOTPLUG
132 #define hotplug_memory_notifier(fn, pri) ({		\
133 	static __meminitdata struct notifier_block fn##_mem_nb =\
134 		{ .notifier_call = fn, .priority = pri };\
135 	register_memory_notifier(&fn##_mem_nb);			\
136 })
137 #define register_hotmemory_notifier(nb)		register_memory_notifier(nb)
138 #define unregister_hotmemory_notifier(nb) 	unregister_memory_notifier(nb)
139 #else
140 #define hotplug_memory_notifier(fn, pri)	({ 0; })
141 /* These aren't inline functions due to a GCC bug. */
142 #define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
143 #define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
144 #endif
145 
146 /*
147  * 'struct memory_accessor' is a generic interface to provide
148  * in-kernel access to persistent memory such as i2c or SPI EEPROMs
149  */
150 struct memory_accessor {
151 	ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
152 			size_t count);
153 	ssize_t (*write)(struct memory_accessor *, const char *buf,
154 			 off_t offset, size_t count);
155 };
156 
157 /*
158  * Kernel text modification mutex, used for code patching. Users of this lock
159  * can sleep.
160  */
161 extern struct mutex text_mutex;
162 
163 #endif /* _LINUX_MEMORY_H_ */
164