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
25struct memory_block {
26	unsigned long start_section_nr;
27	unsigned long end_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};
36
37int arch_get_memory_phys_device(unsigned long start_pfn);
38unsigned long memory_block_size_bytes(void);
39
40/* These states are exposed to userspace as text strings in sysfs */
41#define	MEM_ONLINE		(1<<0) /* exposed to userspace */
42#define	MEM_GOING_OFFLINE	(1<<1) /* exposed to userspace */
43#define	MEM_OFFLINE		(1<<2) /* exposed to userspace */
44#define	MEM_GOING_ONLINE	(1<<3)
45#define	MEM_CANCEL_ONLINE	(1<<4)
46#define	MEM_CANCEL_OFFLINE	(1<<5)
47
48struct memory_notify {
49	unsigned long start_pfn;
50	unsigned long nr_pages;
51	int status_change_nid_normal;
52	int status_change_nid_high;
53	int status_change_nid;
54};
55
56/*
57 * During pageblock isolation, count the number of pages within the
58 * range [start_pfn, start_pfn + nr_pages) which are owned by code
59 * in the notifier chain.
60 */
61#define MEM_ISOLATE_COUNT	(1<<0)
62
63struct memory_isolate_notify {
64	unsigned long start_pfn;	/* Start of range to check */
65	unsigned int nr_pages;		/* # pages in range to check */
66	unsigned int pages_found;	/* # pages owned found by callbacks */
67};
68
69struct notifier_block;
70struct mem_section;
71
72/*
73 * Priorities for the hotplug memory callback routines (stored in decreasing
74 * order in the callback chain)
75 */
76#define SLAB_CALLBACK_PRI       1
77#define IPC_CALLBACK_PRI        10
78
79#ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
80static inline int memory_dev_init(void)
81{
82	return 0;
83}
84static inline int register_memory_notifier(struct notifier_block *nb)
85{
86	return 0;
87}
88static inline void unregister_memory_notifier(struct notifier_block *nb)
89{
90}
91static inline int memory_notify(unsigned long val, void *v)
92{
93	return 0;
94}
95static inline int register_memory_isolate_notifier(struct notifier_block *nb)
96{
97	return 0;
98}
99static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
100{
101}
102static inline int memory_isolate_notify(unsigned long val, void *v)
103{
104	return 0;
105}
106#else
107extern int register_memory_notifier(struct notifier_block *nb);
108extern void unregister_memory_notifier(struct notifier_block *nb);
109extern int register_memory_isolate_notifier(struct notifier_block *nb);
110extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
111extern int register_new_memory(int, struct mem_section *);
112#ifdef CONFIG_MEMORY_HOTREMOVE
113extern int unregister_memory_section(struct mem_section *);
114#endif
115extern int 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_hinted(struct mem_section *,
119							struct memory_block *);
120extern struct memory_block *find_memory_block(struct mem_section *);
121#define CONFIG_MEM_BLOCK_SIZE	(PAGES_PER_SECTION<<PAGE_SHIFT)
122#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
123
124#ifdef CONFIG_MEMORY_HOTPLUG
125#define hotplug_memory_notifier(fn, pri) ({		\
126	static __meminitdata struct notifier_block fn##_mem_nb =\
127		{ .notifier_call = fn, .priority = pri };\
128	register_memory_notifier(&fn##_mem_nb);			\
129})
130#define register_hotmemory_notifier(nb)		register_memory_notifier(nb)
131#define unregister_hotmemory_notifier(nb) 	unregister_memory_notifier(nb)
132#else
133#define hotplug_memory_notifier(fn, pri)	({ 0; })
134/* These aren't inline functions due to a GCC bug. */
135#define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
136#define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
137#endif
138
139/*
140 * 'struct memory_accessor' is a generic interface to provide
141 * in-kernel access to persistent memory such as i2c or SPI EEPROMs
142 */
143struct memory_accessor {
144	ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
145			size_t count);
146	ssize_t (*write)(struct memory_accessor *, const char *buf,
147			 off_t offset, size_t count);
148};
149
150/*
151 * Kernel text modification mutex, used for code patching. Users of this lock
152 * can sleep.
153 */
154extern struct mutex text_mutex;
155
156#endif /* _LINUX_MEMORY_H_ */
157