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 */
51 struct 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
67 enum memory_block_state {
68 /* These states are exposed to userspace as text strings in sysfs */
69 MEM_ONLINE, /* exposed to userspace */
70 MEM_GOING_OFFLINE, /* exposed to userspace */
71 MEM_OFFLINE, /* exposed to userspace */
72 MEM_GOING_ONLINE,
73 MEM_CANCEL_ONLINE,
74 MEM_CANCEL_OFFLINE,
75 };
76
77 struct memory_block {
78 unsigned long start_section_nr;
79 enum memory_block_state state; /* serialized by the dev->lock */
80 int online_type; /* for passing data to online routine */
81 int nid; /* NID for this memory block */
82 /*
83 * The single zone of this memory block if all PFNs of this memory block
84 * that are System RAM (not a memory hole, not ZONE_DEVICE ranges) are
85 * managed by a single zone. NULL if multiple zones (including nodes)
86 * apply.
87 */
88 struct zone *zone;
89 struct device dev;
90 struct vmem_altmap *altmap;
91 struct memory_group *group; /* group (if any) for this block */
92 struct list_head group_next; /* next block inside memory group */
93 #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
94 atomic_long_t nr_hwpoison;
95 #endif
96 };
97
98 int arch_get_memory_phys_device(unsigned long start_pfn);
99 unsigned long memory_block_size_bytes(void);
100 int set_memory_block_size_order(unsigned int order);
101
102 struct memory_notify {
103 unsigned long start_pfn;
104 unsigned long nr_pages;
105 };
106
107 struct notifier_block;
108 struct mem_section;
109
110 /*
111 * Priorities for the hotplug memory callback routines. Invoked from
112 * high to low. Higher priorities correspond to higher numbers.
113 */
114 #define DEFAULT_CALLBACK_PRI 0
115 #define SLAB_CALLBACK_PRI 1
116 #define CXL_CALLBACK_PRI 5
117 #define HMAT_CALLBACK_PRI 6
118 #define MM_COMPUTE_BATCH_PRI 10
119 #define CPUSET_CALLBACK_PRI 10
120 #define MEMTIER_HOTPLUG_PRI 100
121 #define KSM_CALLBACK_PRI 100
122
123 #ifndef CONFIG_MEMORY_HOTPLUG
memory_dev_init(void)124 static inline void memory_dev_init(void)
125 {
126 return;
127 }
register_memory_notifier(struct notifier_block * nb)128 static inline int register_memory_notifier(struct notifier_block *nb)
129 {
130 return 0;
131 }
unregister_memory_notifier(struct notifier_block * nb)132 static inline void unregister_memory_notifier(struct notifier_block *nb)
133 {
134 }
memory_notify(enum memory_block_state state,void * v)135 static inline int memory_notify(enum memory_block_state state, void *v)
136 {
137 return 0;
138 }
hotplug_memory_notifier(notifier_fn_t fn,int pri)139 static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri)
140 {
141 return 0;
142 }
memory_block_advise_max_size(unsigned long size)143 static inline int memory_block_advise_max_size(unsigned long size)
144 {
145 return -ENODEV;
146 }
memory_block_advised_max_size(void)147 static inline unsigned long memory_block_advised_max_size(void)
148 {
149 return 0;
150 }
151 #else /* CONFIG_MEMORY_HOTPLUG */
152 extern int register_memory_notifier(struct notifier_block *nb);
153 extern void unregister_memory_notifier(struct notifier_block *nb);
154 int create_memory_block_devices(unsigned long start, unsigned long size,
155 int nid, struct vmem_altmap *altmap,
156 struct memory_group *group);
157 void remove_memory_block_devices(unsigned long start, unsigned long size);
158 extern void memory_dev_init(void);
159 extern int memory_notify(enum memory_block_state state, void *v);
160 extern struct memory_block *find_memory_block(unsigned long section_nr);
161 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
162 extern int walk_memory_blocks(unsigned long start, unsigned long size,
163 void *arg, walk_memory_blocks_func_t func);
164 extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
165
166 extern int memory_group_register_static(int nid, unsigned long max_pages);
167 extern int memory_group_register_dynamic(int nid, unsigned long unit_pages);
168 extern int memory_group_unregister(int mgid);
169 struct memory_group *memory_group_find_by_id(int mgid);
170 typedef int (*walk_memory_groups_func_t)(struct memory_group *, void *);
171 int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
172 struct memory_group *excluded, void *arg);
173 struct memory_block *find_memory_block_by_id(unsigned long block_id);
174 #define hotplug_memory_notifier(fn, pri) ({ \
175 static __meminitdata struct notifier_block fn##_mem_nb =\
176 { .notifier_call = fn, .priority = pri };\
177 register_memory_notifier(&fn##_mem_nb); \
178 })
179
180 extern int sections_per_block;
181
memory_block_id(unsigned long section_nr)182 static inline unsigned long memory_block_id(unsigned long section_nr)
183 {
184 return section_nr / sections_per_block;
185 }
186
pfn_to_block_id(unsigned long pfn)187 static inline unsigned long pfn_to_block_id(unsigned long pfn)
188 {
189 return memory_block_id(pfn_to_section_nr(pfn));
190 }
191
phys_to_block_id(unsigned long phys)192 static inline unsigned long phys_to_block_id(unsigned long phys)
193 {
194 return pfn_to_block_id(PFN_DOWN(phys));
195 }
196
197 #ifdef CONFIG_NUMA
198 void memory_block_add_nid_early(struct memory_block *mem, int nid);
199 #endif /* CONFIG_NUMA */
200 int memory_block_advise_max_size(unsigned long size);
201 unsigned long memory_block_advised_max_size(void);
202 #endif /* CONFIG_MEMORY_HOTPLUG */
203
204 /*
205 * Kernel text modification mutex, used for code patching. Users of this lock
206 * can sleep.
207 */
208 extern struct mutex text_mutex;
209
210 #endif /* _LINUX_MEMORY_H_ */
211