xref: /openbmc/linux/include/linux/memory.h (revision 1a8c64e1)
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  */
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 struct 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 
88 int arch_get_memory_phys_device(unsigned long start_pfn);
89 unsigned long memory_block_size_bytes(void);
90 int 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 
100 struct memory_notify {
101 	unsigned long start_pfn;
102 	unsigned long nr_pages;
103 	int status_change_nid_normal;
104 	int status_change_nid;
105 };
106 
107 struct notifier_block;
108 struct mem_section;
109 
110 /*
111  * Priorities for the hotplug memory callback routines (stored in decreasing
112  * order in the callback chain)
113  */
114 #define DEFAULT_CALLBACK_PRI	0
115 #define SLAB_CALLBACK_PRI	1
116 #define HMAT_CALLBACK_PRI	2
117 #define MM_COMPUTE_BATCH_PRI	10
118 #define CPUSET_CALLBACK_PRI	10
119 #define MEMTIER_HOTPLUG_PRI	100
120 #define KSM_CALLBACK_PRI	100
121 
122 #ifndef CONFIG_MEMORY_HOTPLUG
memory_dev_init(void)123 static inline void memory_dev_init(void)
124 {
125 	return;
126 }
register_memory_notifier(struct notifier_block * nb)127 static inline int register_memory_notifier(struct notifier_block *nb)
128 {
129 	return 0;
130 }
unregister_memory_notifier(struct notifier_block * nb)131 static inline void unregister_memory_notifier(struct notifier_block *nb)
132 {
133 }
memory_notify(unsigned long val,void * v)134 static inline int memory_notify(unsigned long val, void *v)
135 {
136 	return 0;
137 }
hotplug_memory_notifier(notifier_fn_t fn,int pri)138 static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri)
139 {
140 	return 0;
141 }
142 #else /* CONFIG_MEMORY_HOTPLUG */
143 extern int register_memory_notifier(struct notifier_block *nb);
144 extern void unregister_memory_notifier(struct notifier_block *nb);
145 int create_memory_block_devices(unsigned long start, unsigned long size,
146 				struct vmem_altmap *altmap,
147 				struct memory_group *group);
148 void remove_memory_block_devices(unsigned long start, unsigned long size);
149 extern void memory_dev_init(void);
150 extern int memory_notify(unsigned long val, void *v);
151 extern struct memory_block *find_memory_block(unsigned long section_nr);
152 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
153 extern int walk_memory_blocks(unsigned long start, unsigned long size,
154 			      void *arg, walk_memory_blocks_func_t func);
155 extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
156 
157 extern int memory_group_register_static(int nid, unsigned long max_pages);
158 extern int memory_group_register_dynamic(int nid, unsigned long unit_pages);
159 extern int memory_group_unregister(int mgid);
160 struct memory_group *memory_group_find_by_id(int mgid);
161 typedef int (*walk_memory_groups_func_t)(struct memory_group *, void *);
162 int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
163 			       struct memory_group *excluded, void *arg);
164 #define hotplug_memory_notifier(fn, pri) ({		\
165 	static __meminitdata struct notifier_block fn##_mem_nb =\
166 		{ .notifier_call = fn, .priority = pri };\
167 	register_memory_notifier(&fn##_mem_nb);			\
168 })
169 
170 #ifdef CONFIG_NUMA
171 void memory_block_add_nid(struct memory_block *mem, int nid,
172 			  enum meminit_context context);
173 #endif /* CONFIG_NUMA */
174 #endif	/* CONFIG_MEMORY_HOTPLUG */
175 
176 /*
177  * Kernel text modification mutex, used for code patching. Users of this lock
178  * can sleep.
179  */
180 extern struct mutex text_mutex;
181 
182 #endif /* _LINUX_MEMORY_H_ */
183