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 * @memory_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 struct vmem_altmap *altmap;
81 struct memory_group *group; /* group (if any) for this block */
82 struct list_head group_next; /* next block inside memory group */
83#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
84 atomic_long_t nr_hwpoison;
85#endif
86};
87
88int arch_get_memory_phys_device(unsigned long start_pfn);
89unsigned long memory_block_size_bytes(void);
90int set_memory_block_size_order(unsigned int order);
91
92/* These states are exposed to userspace as text strings in sysfs */
93#define MEM_ONLINE (1<<0) /* exposed to userspace */
94#define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
95#define MEM_OFFLINE (1<<2) /* exposed to userspace */
96#define MEM_GOING_ONLINE (1<<3)
97#define MEM_CANCEL_ONLINE (1<<4)
98#define MEM_CANCEL_OFFLINE (1<<5)
99#define MEM_PREPARE_ONLINE (1<<6)
100#define MEM_FINISH_OFFLINE (1<<7)
101
102struct memory_notify {
103 /*
104 * The altmap_start_pfn and altmap_nr_pages fields are designated for
105 * specifying the altmap range and are exclusively intended for use in
106 * MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers.
107 */
108 unsigned long altmap_start_pfn;
109 unsigned long altmap_nr_pages;
110 unsigned long start_pfn;
111 unsigned long nr_pages;
112};
113
114struct notifier_block;
115struct mem_section;
116
117/*
118 * Priorities for the hotplug memory callback routines. Invoked from
119 * high to low. Higher priorities correspond to higher numbers.
120 */
121#define DEFAULT_CALLBACK_PRI 0
122#define SLAB_CALLBACK_PRI 1
123#define CXL_CALLBACK_PRI 5
124#define HMAT_CALLBACK_PRI 6
125#define MM_COMPUTE_BATCH_PRI 10
126#define CPUSET_CALLBACK_PRI 10
127#define MEMTIER_HOTPLUG_PRI 100
128#define KSM_CALLBACK_PRI 100
129
130#ifndef CONFIG_MEMORY_HOTPLUG
131static inline void memory_dev_init(void)
132{
133 return;
134}
135static inline int register_memory_notifier(struct notifier_block *nb)
136{
137 return 0;
138}
139static inline void unregister_memory_notifier(struct notifier_block *nb)
140{
141}
142static inline int memory_notify(unsigned long val, void *v)
143{
144 return 0;
145}
146static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri)
147{
148 return 0;
149}
150static inline int memory_block_advise_max_size(unsigned long size)
151{
152 return -ENODEV;
153}
154static inline unsigned long memory_block_advised_max_size(void)
155{
156 return 0;
157}
158#else /* CONFIG_MEMORY_HOTPLUG */
159extern int register_memory_notifier(struct notifier_block *nb);
160extern void unregister_memory_notifier(struct notifier_block *nb);
161int create_memory_block_devices(unsigned long start, unsigned long size,
162 int nid, struct vmem_altmap *altmap,
163 struct memory_group *group);
164void remove_memory_block_devices(unsigned long start, unsigned long size);
165extern void memory_dev_init(void);
166extern int memory_notify(unsigned long val, void *v);
167extern struct memory_block *find_memory_block(unsigned long section_nr);
168typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
169extern int walk_memory_blocks(unsigned long start, unsigned long size,
170 void *arg, walk_memory_blocks_func_t func);
171extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
172
173extern int memory_group_register_static(int nid, unsigned long max_pages);
174extern int memory_group_register_dynamic(int nid, unsigned long unit_pages);
175extern int memory_group_unregister(int mgid);
176struct memory_group *memory_group_find_by_id(int mgid);
177typedef int (*walk_memory_groups_func_t)(struct memory_group *, void *);
178int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
179 struct memory_group *excluded, void *arg);
180struct memory_block *find_memory_block_by_id(unsigned long block_id);
181#define hotplug_memory_notifier(fn, pri) ({ \
182 static __meminitdata struct notifier_block fn##_mem_nb =\
183 { .notifier_call = fn, .priority = pri };\
184 register_memory_notifier(&fn##_mem_nb); \
185})
186
187extern int sections_per_block;
188
189static inline unsigned long memory_block_id(unsigned long section_nr)
190{
191 return section_nr / sections_per_block;
192}
193
194static inline unsigned long pfn_to_block_id(unsigned long pfn)
195{
196 return memory_block_id(pfn_to_section_nr(pfn));
197}
198
199static inline unsigned long phys_to_block_id(unsigned long phys)
200{
201 return pfn_to_block_id(PFN_DOWN(phys));
202}
203
204#ifdef CONFIG_NUMA
205void memory_block_add_nid_early(struct memory_block *mem, int nid);
206#endif /* CONFIG_NUMA */
207int memory_block_advise_max_size(unsigned long size);
208unsigned long memory_block_advised_max_size(void);
209#endif /* CONFIG_MEMORY_HOTPLUG */
210
211/*
212 * Kernel text modification mutex, used for code patching. Users of this lock
213 * can sleep.
214 */
215extern struct mutex text_mutex;
216
217#endif /* _LINUX_MEMORY_H_ */
218