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