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