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 phys_device; /* to which fru does this belong? */
31 struct device dev;
32 int nid; /* NID for this memory block */
33 };
34
35 int arch_get_memory_phys_device(unsigned long start_pfn);
36 unsigned long memory_block_size_bytes(void);
37 int set_memory_block_size_order(unsigned int order);
38
39 /* These states are exposed to userspace as text strings in sysfs */
40 #define MEM_ONLINE (1<<0) /* exposed to userspace */
41 #define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
42 #define MEM_OFFLINE (1<<2) /* exposed to userspace */
43 #define MEM_GOING_ONLINE (1<<3)
44 #define MEM_CANCEL_ONLINE (1<<4)
45 #define MEM_CANCEL_OFFLINE (1<<5)
46
47 struct memory_notify {
48 unsigned long start_pfn;
49 unsigned long nr_pages;
50 int status_change_nid_normal;
51 int status_change_nid_high;
52 int status_change_nid;
53 };
54
55 struct notifier_block;
56 struct mem_section;
57
58 /*
59 * Priorities for the hotplug memory callback routines (stored in decreasing
60 * order in the callback chain)
61 */
62 #define SLAB_CALLBACK_PRI 1
63 #define IPC_CALLBACK_PRI 10
64
65 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
memory_dev_init(void)66 static inline void memory_dev_init(void)
67 {
68 return;
69 }
register_memory_notifier(struct notifier_block * nb)70 static inline int register_memory_notifier(struct notifier_block *nb)
71 {
72 return 0;
73 }
unregister_memory_notifier(struct notifier_block * nb)74 static inline void unregister_memory_notifier(struct notifier_block *nb)
75 {
76 }
memory_notify(unsigned long val,void * v)77 static inline int memory_notify(unsigned long val, void *v)
78 {
79 return 0;
80 }
81 #else
82 extern int register_memory_notifier(struct notifier_block *nb);
83 extern void unregister_memory_notifier(struct notifier_block *nb);
84 int create_memory_block_devices(unsigned long start, unsigned long size);
85 void remove_memory_block_devices(unsigned long start, unsigned long size);
86 extern void memory_dev_init(void);
87 extern int memory_notify(unsigned long val, void *v);
88 extern struct memory_block *find_memory_block(struct mem_section *);
89 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
90 extern int walk_memory_blocks(unsigned long start, unsigned long size,
91 void *arg, walk_memory_blocks_func_t func);
92 extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
93 #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
94 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
95
96 #ifdef CONFIG_MEMORY_HOTPLUG
97 #define hotplug_memory_notifier(fn, pri) ({ \
98 static __meminitdata struct notifier_block fn##_mem_nb =\
99 { .notifier_call = fn, .priority = pri };\
100 register_memory_notifier(&fn##_mem_nb); \
101 })
102 #define register_hotmemory_notifier(nb) register_memory_notifier(nb)
103 #define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb)
104 #else
105 #define hotplug_memory_notifier(fn, pri) ({ 0; })
106 /* These aren't inline functions due to a GCC bug. */
107 #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; })
108 #define unregister_hotmemory_notifier(nb) ({ (void)(nb); })
109 #endif
110
111 /*
112 * Kernel text modification mutex, used for code patching. Users of this lock
113 * can sleep.
114 */
115 extern struct mutex text_mutex;
116
117 #endif /* _LINUX_MEMORY_H_ */
118
