Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/memory_hotplug.h>
23
24#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
25
26/**
27 * struct memory_group - a logical group of memory blocks
28 * @nid: The node id for all memory blocks inside the memory group.
29 * @memory_blocks: List of all memory blocks belonging to this memory group.
30 * @present_kernel_pages: Present (online) memory outside ZONE_MOVABLE of this
31 * memory group.
32 * @present_movable_pages: Present (online) memory in ZONE_MOVABLE of this
33 * memory group.
34 * @is_dynamic: The memory group type: static vs. dynamic
35 * @s.max_pages: Valid with &memory_group.is_dynamic == false. The maximum
36 * number of pages we'll have in this static memory group.
37 * @d.unit_pages: Valid with &memory_group.is_dynamic == true. Unit in pages
38 * in which memory is added/removed in this dynamic memory group.
39 * This granularity defines the alignment of a unit in physical
40 * address space; it has to be at least as big as a single
41 * memory block.
42 *
43 * A memory group logically groups memory blocks; each memory block
44 * belongs to at most one memory group. A memory group corresponds to
45 * a memory device, such as a DIMM or a NUMA node, which spans multiple
46 * memory blocks and might even span multiple non-contiguous physical memory
47 * ranges.
48 *
49 * Modification of members after registration is serialized by memory
50 * hot(un)plug code.
51 */
52struct memory_group {
53 int nid;
54 struct list_head memory_blocks;
55 unsigned long present_kernel_pages;
56 unsigned long present_movable_pages;
57 bool is_dynamic;
58 union {
59 struct {
60 unsigned long max_pages;
61 } s;
62 struct {
63 unsigned long unit_pages;
64 } d;
65 };
66};
67
68enum memory_block_state {
69 /* These states are exposed to userspace as text strings in sysfs */
70 MEM_ONLINE, /* exposed to userspace */
71 MEM_GOING_OFFLINE, /* exposed to userspace */
72 MEM_OFFLINE, /* exposed to userspace */
73 MEM_GOING_ONLINE,
74 MEM_CANCEL_ONLINE,
75 MEM_CANCEL_OFFLINE,
76};
77
78struct memory_block {
79 unsigned long start_section_nr;
80 enum memory_block_state state; /* serialized by the dev->lock */
81 enum mmop online_type; /* for passing data to online routine */
82 int nid; /* NID for this memory block */
83 /*
84 * The single zone of this memory block if all PFNs of this memory block
85 * that are System RAM (not a memory hole, not ZONE_DEVICE ranges) are
86 * managed by a single zone. NULL if multiple zones (including nodes)
87 * apply.
88 */
89 struct zone *zone;
90 struct device dev;
91 struct vmem_altmap *altmap;
92 struct memory_group *group; /* group (if any) for this block */
93 struct list_head group_next; /* next block inside memory group */
94#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
95 atomic_long_t nr_hwpoison;
96#endif
97};
98
99int arch_get_memory_phys_device(unsigned long start_pfn);
100unsigned long memory_block_size_bytes(void);
101int set_memory_block_size_order(unsigned int order);
102
103struct memory_notify {
104 unsigned long start_pfn;
105 unsigned long nr_pages;
106};
107
108struct notifier_block;
109struct mem_section;
110
111/*
112 * Priorities for the hotplug memory callback routines. Invoked from
113 * high to low. Higher priorities correspond to higher numbers.
114 */
115#define DEFAULT_CALLBACK_PRI 0
116#define SLAB_CALLBACK_PRI 1
117#define CXL_CALLBACK_PRI 5
118#define HMAT_CALLBACK_PRI 6
119#define MM_COMPUTE_BATCH_PRI 10
120#define CPUSET_CALLBACK_PRI 10
121#define MEMTIER_HOTPLUG_PRI 100
122#define KSM_CALLBACK_PRI 100
123
124#ifndef CONFIG_MEMORY_HOTPLUG
125static inline void memory_dev_init(void)
126{
127 return;
128}
129static inline int register_memory_notifier(struct notifier_block *nb)
130{
131 return 0;
132}
133static inline void unregister_memory_notifier(struct notifier_block *nb)
134{
135}
136static inline int memory_notify(enum memory_block_state state, void *v)
137{
138 return 0;
139}
140static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri)
141{
142 return 0;
143}
144static inline int memory_block_advise_max_size(unsigned long size)
145{
146 return -ENODEV;
147}
148static inline unsigned long memory_block_advised_max_size(void)
149{
150 return 0;
151}
152#else /* CONFIG_MEMORY_HOTPLUG */
153extern int register_memory_notifier(struct notifier_block *nb);
154extern void unregister_memory_notifier(struct notifier_block *nb);
155int create_memory_block_devices(unsigned long start, unsigned long size,
156 int nid, struct vmem_altmap *altmap,
157 struct memory_group *group);
158void remove_memory_block_devices(unsigned long start, unsigned long size);
159extern void memory_dev_init(void);
160extern int memory_notify(enum memory_block_state state, void *v);
161extern struct memory_block *find_memory_block(unsigned long section_nr);
162typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
163extern int walk_memory_blocks(unsigned long start, unsigned long size,
164 void *arg, walk_memory_blocks_func_t func);
165extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
166
167extern int memory_group_register_static(int nid, unsigned long max_pages);
168extern int memory_group_register_dynamic(int nid, unsigned long unit_pages);
169extern int memory_group_unregister(int mgid);
170struct memory_group *memory_group_find_by_id(int mgid);
171typedef int (*walk_memory_groups_func_t)(struct memory_group *, void *);
172int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
173 struct memory_group *excluded, void *arg);
174struct memory_block *find_memory_block_by_id(unsigned long block_id);
175#define hotplug_memory_notifier(fn, pri) ({ \
176 static __meminitdata struct notifier_block fn##_mem_nb =\
177 { .notifier_call = fn, .priority = pri };\
178 register_memory_notifier(&fn##_mem_nb); \
179})
180
181extern int sections_per_block;
182
183static inline unsigned long memory_block_id(unsigned long section_nr)
184{
185 return section_nr / sections_per_block;
186}
187
188static inline unsigned long pfn_to_block_id(unsigned long pfn)
189{
190 return memory_block_id(pfn_to_section_nr(pfn));
191}
192
193static inline unsigned long phys_to_block_id(unsigned long phys)
194{
195 return pfn_to_block_id(PFN_DOWN(phys));
196}
197
198#ifdef CONFIG_NUMA
199void memory_block_add_nid_early(struct memory_block *mem, int nid);
200#endif /* CONFIG_NUMA */
201int memory_block_advise_max_size(unsigned long size);
202unsigned long memory_block_advised_max_size(void);
203#endif /* CONFIG_MEMORY_HOTPLUG */
204
205/*
206 * Kernel text modification mutex, used for code patching. Users of this lock
207 * can sleep.
208 */
209extern struct mutex text_mutex;
210
211#endif /* _LINUX_MEMORY_H_ */