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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
23#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
24
25/**
26 * struct memory_group - a logical group of memory blocks
27 * @nid: The node id for all memory blocks inside the memory group.
28 * @blocks: List of all memory blocks belonging to this memory group.
29 * @present_kernel_pages: Present (online) memory outside ZONE_MOVABLE of this
30 * memory group.
31 * @present_movable_pages: Present (online) memory in ZONE_MOVABLE of this
32 * memory group.
33 * @is_dynamic: The memory group type: static vs. dynamic
34 * @s.max_pages: Valid with &memory_group.is_dynamic == false. The maximum
35 * number of pages we'll have in this static memory group.
36 * @d.unit_pages: Valid with &memory_group.is_dynamic == true. Unit in pages
37 * in which memory is added/removed in this dynamic memory group.
38 * This granularity defines the alignment of a unit in physical
39 * address space; it has to be at least as big as a single
40 * memory block.
41 *
42 * A memory group logically groups memory blocks; each memory block
43 * belongs to at most one memory group. A memory group corresponds to
44 * a memory device, such as a DIMM or a NUMA node, which spans multiple
45 * memory blocks and might even span multiple non-contiguous physical memory
46 * ranges.
47 *
48 * Modification of members after registration is serialized by memory
49 * hot(un)plug code.
50 */
51struct memory_group {
52 int nid;
53 struct list_head memory_blocks;
54 unsigned long present_kernel_pages;
55 unsigned long present_movable_pages;
56 bool is_dynamic;
57 union {
58 struct {
59 unsigned long max_pages;
60 } s;
61 struct {
62 unsigned long unit_pages;
63 } d;
64 };
65};
66
67struct memory_block {
68 unsigned long start_section_nr;
69 unsigned long state; /* serialized by the dev->lock */
70 int online_type; /* for passing data to online routine */
71 int nid; /* NID for this memory block */
72 /*
73 * The single zone of this memory block if all PFNs of this memory block
74 * that are System RAM (not a memory hole, not ZONE_DEVICE ranges) are
75 * managed by a single zone. NULL if multiple zones (including nodes)
76 * apply.
77 */
78 struct zone *zone;
79 struct device dev;
80 /*
81 * Number of vmemmap pages. These pages
82 * lay at the beginning of the memory block.
83 */
84 unsigned long nr_vmemmap_pages;
85 struct memory_group *group; /* group (if any) for this block */
86 struct list_head group_next; /* next block inside memory group */
87#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
88 atomic_long_t nr_hwpoison;
89#endif
90};
91
92int arch_get_memory_phys_device(unsigned long start_pfn);
93unsigned long memory_block_size_bytes(void);
94int set_memory_block_size_order(unsigned int order);
95
96/* These states are exposed to userspace as text strings in sysfs */
97#define MEM_ONLINE (1<<0) /* exposed to userspace */
98#define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
99#define MEM_OFFLINE (1<<2) /* exposed to userspace */
100#define MEM_GOING_ONLINE (1<<3)
101#define MEM_CANCEL_ONLINE (1<<4)
102#define MEM_CANCEL_OFFLINE (1<<5)
103
104struct memory_notify {
105 unsigned long start_pfn;
106 unsigned long nr_pages;
107 int status_change_nid_normal;
108 int status_change_nid;
109};
110
111struct notifier_block;
112struct mem_section;
113
114/*
115 * Priorities for the hotplug memory callback routines (stored in decreasing
116 * order in the callback chain)
117 */
118#define DEFAULT_CALLBACK_PRI 0
119#define SLAB_CALLBACK_PRI 1
120#define HMAT_CALLBACK_PRI 2
121#define MM_COMPUTE_BATCH_PRI 10
122#define CPUSET_CALLBACK_PRI 10
123#define MEMTIER_HOTPLUG_PRI 100
124#define KSM_CALLBACK_PRI 100
125
126#ifndef CONFIG_MEMORY_HOTPLUG
127static inline void memory_dev_init(void)
128{
129 return;
130}
131static inline int register_memory_notifier(struct notifier_block *nb)
132{
133 return 0;
134}
135static inline void unregister_memory_notifier(struct notifier_block *nb)
136{
137}
138static inline int memory_notify(unsigned long val, void *v)
139{
140 return 0;
141}
142static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri)
143{
144 return 0;
145}
146#else /* CONFIG_MEMORY_HOTPLUG */
147extern int register_memory_notifier(struct notifier_block *nb);
148extern void unregister_memory_notifier(struct notifier_block *nb);
149int create_memory_block_devices(unsigned long start, unsigned long size,
150 unsigned long vmemmap_pages,
151 struct memory_group *group);
152void remove_memory_block_devices(unsigned long start, unsigned long size);
153extern void memory_dev_init(void);
154extern int memory_notify(unsigned long val, void *v);
155extern struct memory_block *find_memory_block(unsigned long section_nr);
156typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
157extern int walk_memory_blocks(unsigned long start, unsigned long size,
158 void *arg, walk_memory_blocks_func_t func);
159extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
160
161extern int memory_group_register_static(int nid, unsigned long max_pages);
162extern int memory_group_register_dynamic(int nid, unsigned long unit_pages);
163extern int memory_group_unregister(int mgid);
164struct memory_group *memory_group_find_by_id(int mgid);
165typedef int (*walk_memory_groups_func_t)(struct memory_group *, void *);
166int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
167 struct memory_group *excluded, void *arg);
168#define hotplug_memory_notifier(fn, pri) ({ \
169 static __meminitdata struct notifier_block fn##_mem_nb =\
170 { .notifier_call = fn, .priority = pri };\
171 register_memory_notifier(&fn##_mem_nb); \
172})
173
174#ifdef CONFIG_NUMA
175void memory_block_add_nid(struct memory_block *mem, int nid,
176 enum meminit_context context);
177#endif /* CONFIG_NUMA */
178#endif /* CONFIG_MEMORY_HOTPLUG */
179
180/*
181 * Kernel text modification mutex, used for code patching. Users of this lock
182 * can sleep.
183 */
184extern struct mutex text_mutex;
185
186#endif /* _LINUX_MEMORY_H_ */