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 struct memory_block { 27 unsigned long start_section_nr; 28 unsigned long state; /* serialized by the dev->lock */ 29 int online_type; /* for passing data to online routine */ 30 int nid; /* NID for this memory block */ 31 struct device dev; 32 /* 33 * Number of vmemmap pages. These pages 34 * lay at the beginning of the memory block. 35 */ 36 unsigned long nr_vmemmap_pages; 37 }; 38 39 int arch_get_memory_phys_device(unsigned long start_pfn); 40 unsigned long memory_block_size_bytes(void); 41 int set_memory_block_size_order(unsigned int order); 42 43 /* These states are exposed to userspace as text strings in sysfs */ 44 #define MEM_ONLINE (1<<0) /* exposed to userspace */ 45 #define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */ 46 #define MEM_OFFLINE (1<<2) /* exposed to userspace */ 47 #define MEM_GOING_ONLINE (1<<3) 48 #define MEM_CANCEL_ONLINE (1<<4) 49 #define MEM_CANCEL_OFFLINE (1<<5) 50 51 struct memory_notify { 52 unsigned long start_pfn; 53 unsigned long nr_pages; 54 int status_change_nid_normal; 55 int status_change_nid_high; 56 int status_change_nid; 57 }; 58 59 struct notifier_block; 60 struct mem_section; 61 62 /* 63 * Priorities for the hotplug memory callback routines (stored in decreasing 64 * order in the callback chain) 65 */ 66 #define SLAB_CALLBACK_PRI 1 67 #define IPC_CALLBACK_PRI 10 68 69 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE 70 static inline void memory_dev_init(void) 71 { 72 return; 73 } 74 static inline int register_memory_notifier(struct notifier_block *nb) 75 { 76 return 0; 77 } 78 static inline void unregister_memory_notifier(struct notifier_block *nb) 79 { 80 } 81 static inline int memory_notify(unsigned long val, void *v) 82 { 83 return 0; 84 } 85 #else 86 extern int register_memory_notifier(struct notifier_block *nb); 87 extern void unregister_memory_notifier(struct notifier_block *nb); 88 int create_memory_block_devices(unsigned long start, unsigned long size, 89 unsigned long vmemmap_pages); 90 void remove_memory_block_devices(unsigned long start, unsigned long size); 91 extern void memory_dev_init(void); 92 extern int memory_notify(unsigned long val, void *v); 93 extern struct memory_block *find_memory_block(struct mem_section *); 94 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *); 95 extern int walk_memory_blocks(unsigned long start, unsigned long size, 96 void *arg, walk_memory_blocks_func_t func); 97 extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func); 98 #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT) 99 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 100 101 #ifdef CONFIG_MEMORY_HOTPLUG 102 #define hotplug_memory_notifier(fn, pri) ({ \ 103 static __meminitdata struct notifier_block fn##_mem_nb =\ 104 { .notifier_call = fn, .priority = pri };\ 105 register_memory_notifier(&fn##_mem_nb); \ 106 }) 107 #define register_hotmemory_notifier(nb) register_memory_notifier(nb) 108 #define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb) 109 #else 110 #define hotplug_memory_notifier(fn, pri) ({ 0; }) 111 /* These aren't inline functions due to a GCC bug. */ 112 #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) 113 #define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) 114 #endif 115 116 /* 117 * Kernel text modification mutex, used for code patching. Users of this lock 118 * can sleep. 119 */ 120 extern struct mutex text_mutex; 121 122 #endif /* _LINUX_MEMORY_H_ */ 123