xref: /linux-6.15/include/linux/memory.h (revision 4e57b681)
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/sysdev.h>
19 #include <linux/node.h>
20 #include <linux/compiler.h>
21 
22 #include <asm/semaphore.h>
23 
24 struct memory_block {
25 	unsigned long phys_index;
26 	unsigned long state;
27 	/*
28 	 * This serializes all state change requests.  It isn't
29 	 * held during creation because the control files are
30 	 * created long after the critical areas during
31 	 * initialization.
32 	 */
33 	struct semaphore state_sem;
34 	int phys_device;		/* to which fru does this belong? */
35 	void *hw;			/* optional pointer to fw/hw data */
36 	int (*phys_callback)(struct memory_block *);
37 	struct sys_device sysdev;
38 };
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 
45 /*
46  * All of these states are currently kernel-internal for notifying
47  * kernel components and architectures.
48  *
49  * For MEM_MAPPING_INVALID, all notifier chains with priority >0
50  * are called before pfn_to_page() becomes invalid.  The priority=0
51  * entry is reserved for the function that actually makes
52  * pfn_to_page() stop working.  Any notifiers that want to be called
53  * after that should have priority <0.
54  */
55 #define	MEM_MAPPING_INVALID	(1<<3)
56 
57 #ifndef CONFIG_MEMORY_HOTPLUG
58 static inline int memory_dev_init(void)
59 {
60 	return 0;
61 }
62 static inline int register_memory_notifier(struct notifier_block *nb)
63 {
64 	return 0;
65 }
66 static inline void unregister_memory_notifier(struct notifier_block *nb)
67 {
68 }
69 #else
70 extern int register_memory(struct memory_block *, struct mem_section *section, struct node *);
71 extern int register_new_memory(struct mem_section *);
72 extern int unregister_memory_section(struct mem_section *);
73 extern int memory_dev_init(void);
74 extern int register_memory_notifier(struct notifier_block *nb);
75 extern void unregister_memory_notifier(struct notifier_block *nb);
76 
77 #define CONFIG_MEM_BLOCK_SIZE	(PAGES_PER_SECTION<<PAGE_SHIFT)
78 
79 extern int invalidate_phys_mapping(unsigned long, unsigned long);
80 struct notifier_block;
81 
82 extern int register_memory_notifier(struct notifier_block *nb);
83 extern void unregister_memory_notifier(struct notifier_block *nb);
84 
85 extern struct sysdev_class memory_sysdev_class;
86 #endif /* CONFIG_MEMORY_HOTPLUG */
87 
88 #define hotplug_memory_notifier(fn, pri) {			\
89 	static struct notifier_block fn##_mem_nb =		\
90 		{ .notifier_call = fn, .priority = pri };	\
91 	register_memory_notifier(&fn##_mem_nb);			\
92 }
93 
94 #endif /* _LINUX_MEMORY_H_ */
95