1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * include/linux/memory.h - generic memory definition
4 *
5 * This is mainly for topological representation. We define the
6 * basic "struct memory_block" here, which can be embedded in per-arch
7 * definitions or NUMA information.
8 *
9 * Basic handling of the devices is done in drivers/base/memory.c
10 * and system devices are handled in drivers/base/sys.c.
11 *
12 * Memory block are exported via sysfs in the class/memory/devices/
13 * directory.
14 *
15 */
16 #ifndef _LINUX_MEMORY_H_
17 #define _LINUX_MEMORY_H_
18
19 #include <linux/node.h>
20 #include <linux/compiler.h>
21 #include <linux/mutex.h>
22 #include <linux/notifier.h>
23
24 #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
25
26 struct memory_block {
27 unsigned long start_section_nr;
28 unsigned long state; /* serialized by the dev->lock */
29 int online_type; /* for passing data to online routine */
30 int nid; /* NID for this memory block */
31 struct device dev;
32 };
33
34 int arch_get_memory_phys_device(unsigned long start_pfn);
35 unsigned long memory_block_size_bytes(void);
36 int set_memory_block_size_order(unsigned int order);
37
38 /* These states are exposed to userspace as text strings in sysfs */
39 #define MEM_ONLINE (1<<0) /* exposed to userspace */
40 #define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
41 #define MEM_OFFLINE (1<<2) /* exposed to userspace */
42 #define MEM_GOING_ONLINE (1<<3)
43 #define MEM_CANCEL_ONLINE (1<<4)
44 #define MEM_CANCEL_OFFLINE (1<<5)
45
46 struct memory_notify {
47 unsigned long start_pfn;
48 unsigned long nr_pages;
49 int status_change_nid_normal;
50 int status_change_nid_high;
51 int status_change_nid;
52 };
53
54 struct notifier_block;
55 struct mem_section;
56
57 /*
58 * Priorities for the hotplug memory callback routines (stored in decreasing
59 * order in the callback chain)
60 */
61 #define SLAB_CALLBACK_PRI 1
62 #define IPC_CALLBACK_PRI 10
63
64 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
memory_dev_init(void)65 static inline void memory_dev_init(void)
66 {
67 return;
68 }
register_memory_notifier(struct notifier_block * nb)69 static inline int register_memory_notifier(struct notifier_block *nb)
70 {
71 return 0;
72 }
unregister_memory_notifier(struct notifier_block * nb)73 static inline void unregister_memory_notifier(struct notifier_block *nb)
74 {
75 }
memory_notify(unsigned long val,void * v)76 static inline int memory_notify(unsigned long val, void *v)
77 {
78 return 0;
79 }
80 #else
81 extern int register_memory_notifier(struct notifier_block *nb);
82 extern void unregister_memory_notifier(struct notifier_block *nb);
83 int create_memory_block_devices(unsigned long start, unsigned long size);
84 void remove_memory_block_devices(unsigned long start, unsigned long size);
85 extern void memory_dev_init(void);
86 extern int memory_notify(unsigned long val, void *v);
87 extern struct memory_block *find_memory_block(struct mem_section *);
88 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
89 extern int walk_memory_blocks(unsigned long start, unsigned long size,
90 void *arg, walk_memory_blocks_func_t func);
91 extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
92 #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
93 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
94
95 #ifdef CONFIG_MEMORY_HOTPLUG
96 #define hotplug_memory_notifier(fn, pri) ({ \
97 static __meminitdata struct notifier_block fn##_mem_nb =\
98 { .notifier_call = fn, .priority = pri };\
99 register_memory_notifier(&fn##_mem_nb); \
100 })
101 #define register_hotmemory_notifier(nb) register_memory_notifier(nb)
102 #define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb)
103 #else
104 #define hotplug_memory_notifier(fn, pri) ({ 0; })
105 /* These aren't inline functions due to a GCC bug. */
106 #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; })
107 #define unregister_hotmemory_notifier(nb) ({ (void)(nb); })
108 #endif
109
110 /*
111 * Kernel text modification mutex, used for code patching. Users of this lock
112 * can sleep.
113 */
114 extern struct mutex text_mutex;
115
116 #endif /* _LINUX_MEMORY_H_ */
117