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