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     (1 << SECTION_SIZE_BITS)
23
24struct memory_block {
25	unsigned long start_section_nr;
26	unsigned long end_section_nr;
27	unsigned long state;
28	int section_count;
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	 */
36	struct mutex state_mutex;
37	int phys_device;		/* to which fru does this belong? */
38	void *hw;			/* optional pointer to fw/hw data */
39	int (*phys_callback)(struct memory_block *);
40	struct device dev;
41};
42
43int 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
53struct memory_notify {
54	unsigned long start_pfn;
55	unsigned long nr_pages;
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
66struct 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
72struct notifier_block;
73struct 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
83static inline int memory_dev_init(void)
84{
85	return 0;
86}
87static inline int register_memory_notifier(struct notifier_block *nb)
88{
89	return 0;
90}
91static inline void unregister_memory_notifier(struct notifier_block *nb)
92{
93}
94static inline int memory_notify(unsigned long val, void *v)
95{
96	return 0;
97}
98static inline int register_memory_isolate_notifier(struct notifier_block *nb)
99{
100	return 0;
101}
102static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
103{
104}
105static inline int memory_isolate_notify(unsigned long val, void *v)
106{
107	return 0;
108}
109#else
110extern int register_memory_notifier(struct notifier_block *nb);
111extern void unregister_memory_notifier(struct notifier_block *nb);
112extern int register_memory_isolate_notifier(struct notifier_block *nb);
113extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
114extern int register_new_memory(int, struct mem_section *);
115extern int unregister_memory_section(struct mem_section *);
116extern int memory_dev_init(void);
117extern int remove_memory_block(unsigned long, struct mem_section *, int);
118extern int memory_notify(unsigned long val, void *v);
119extern int memory_isolate_notify(unsigned long val, void *v);
120extern struct memory_block *find_memory_block_hinted(struct mem_section *,
121							struct memory_block *);
122extern struct memory_block *find_memory_block(struct mem_section *);
123#define CONFIG_MEM_BLOCK_SIZE	(PAGES_PER_SECTION<<PAGE_SHIFT)
124enum 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 */
141struct memory_accessor {
142	ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
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 */
152extern struct mutex text_mutex;
153
154#endif /* _LINUX_MEMORY_H_ */
155