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 * @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 */ 52 struct 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 68 struct memory_block { 69 unsigned long start_section_nr; 70 unsigned long state; /* serialized by the dev->lock */ 71 int online_type; /* for passing data to online routine */ 72 int nid; /* NID for this memory block */ 73 /* 74 * The single zone of this memory block if all PFNs of this memory block 75 * that are System RAM (not a memory hole, not ZONE_DEVICE ranges) are 76 * managed by a single zone. NULL if multiple zones (including nodes) 77 * apply. 78 */ 79 struct zone *zone; 80 struct device dev; 81 /* 82 * Number of vmemmap pages. These pages 83 * lay at the beginning of the memory block. 84 */ 85 unsigned long nr_vmemmap_pages; 86 struct memory_group *group; /* group (if any) for this block */ 87 struct list_head group_next; /* next block inside memory group */ 88 }; 89 90 int arch_get_memory_phys_device(unsigned long start_pfn); 91 unsigned long memory_block_size_bytes(void); 92 int set_memory_block_size_order(unsigned int order); 93 94 /* These states are exposed to userspace as text strings in sysfs */ 95 #define MEM_ONLINE (1<<0) /* exposed to userspace */ 96 #define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */ 97 #define MEM_OFFLINE (1<<2) /* exposed to userspace */ 98 #define MEM_GOING_ONLINE (1<<3) 99 #define MEM_CANCEL_ONLINE (1<<4) 100 #define MEM_CANCEL_OFFLINE (1<<5) 101 102 struct memory_notify { 103 unsigned long start_pfn; 104 unsigned long nr_pages; 105 int status_change_nid_normal; 106 int status_change_nid; 107 }; 108 109 struct notifier_block; 110 struct mem_section; 111 112 /* 113 * Priorities for the hotplug memory callback routines (stored in decreasing 114 * order in the callback chain) 115 */ 116 #define SLAB_CALLBACK_PRI 1 117 #define IPC_CALLBACK_PRI 10 118 119 #ifndef CONFIG_MEMORY_HOTPLUG 120 static inline void memory_dev_init(void) 121 { 122 return; 123 } 124 static inline int register_memory_notifier(struct notifier_block *nb) 125 { 126 return 0; 127 } 128 static inline void unregister_memory_notifier(struct notifier_block *nb) 129 { 130 } 131 static inline int memory_notify(unsigned long val, void *v) 132 { 133 return 0; 134 } 135 static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri) 136 { 137 return 0; 138 } 139 /* These aren't inline functions due to a GCC bug. */ 140 #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) 141 #define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) 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 unsigned long vmemmap_pages, 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 #define register_hotmemory_notifier(nb) register_memory_notifier(nb) 170 #define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb) 171 172 #ifdef CONFIG_NUMA 173 void memory_block_add_nid(struct memory_block *mem, int nid, 174 enum meminit_context context); 175 #endif /* CONFIG_NUMA */ 176 #endif /* CONFIG_MEMORY_HOTPLUG */ 177 178 /* 179 * Kernel text modification mutex, used for code patching. Users of this lock 180 * can sleep. 181 */ 182 extern struct mutex text_mutex; 183 184 #endif /* _LINUX_MEMORY_H_ */ 185