include/linux/memory.h

   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 end_section_nr;
  29         unsigned long state;            /* serialized by the dev->lock */
  30         int section_count;              /* serialized by mem_sysfs_mutex */
  31         int online_type;                /* for passing data to online routine */
  32         int phys_device;                /* to which fru does this belong? */
  33         void *hw;                       /* optional pointer to fw/hw data */
  34         int (*phys_callback)(struct memory_block *);
  35         struct device dev;
  36 };
  37
  38 int arch_get_memory_phys_device(unsigned long start_pfn);
  39 unsigned long memory_block_size_bytes(void);
  40
  41 /* These states are exposed to userspace as text strings in sysfs */
  42 #define MEM_ONLINE              (1<<0) /* exposed to userspace */
  43 #define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  44 #define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  45 #define MEM_GOING_ONLINE        (1<<3)
  46 #define MEM_CANCEL_ONLINE       (1<<4)
  47 #define MEM_CANCEL_OFFLINE      (1<<5)
  48
  49 struct memory_notify {
  50         unsigned long start_pfn;
  51         unsigned long nr_pages;
  52         int status_change_nid_normal;
  53         int status_change_nid_high;
  54         int status_change_nid;
  55 };
  56
  57 /*
  58  * During pageblock isolation, count the number of pages within the
  59  * range [start_pfn, start_pfn + nr_pages) which are owned by code
  60  * in the notifier chain.
  61  */
  62 #define MEM_ISOLATE_COUNT       (1<<0)
  63
  64 struct memory_isolate_notify {
  65         unsigned long start_pfn;        /* Start of range to check */
  66         unsigned int nr_pages;          /* # pages in range to check */
  67         unsigned int pages_found;       /* # pages owned found by callbacks */
  68 };
  69
  70 struct notifier_block;
  71 struct mem_section;
  72
  73 /*
  74  * Priorities for the hotplug memory callback routines (stored in decreasing
  75  * order in the callback chain)
  76  */
  77 #define SLAB_CALLBACK_PRI       1
  78 #define IPC_CALLBACK_PRI        10
  79
  80 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  81 static inline int memory_dev_init(void)
  82 {
  83         return 0;
  84 }
  85 static inline int register_memory_notifier(struct notifier_block *nb)
  86 {
  87         return 0;
  88 }
  89 static inline void unregister_memory_notifier(struct notifier_block *nb)
  90 {
  91 }
  92 static inline int memory_notify(unsigned long val, void *v)
  93 {
  94         return 0;
  95 }
  96 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
  97 {
  98         return 0;
  99 }
 100 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 101 {
 102 }
 103 static inline int memory_isolate_notify(unsigned long val, void *v)
 104 {
 105         return 0;
 106 }
 107 #else
 108 extern int register_memory_notifier(struct notifier_block *nb);
 109 extern void unregister_memory_notifier(struct notifier_block *nb);
 110 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 111 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 112 extern int register_new_memory(int, struct mem_section *);
 113 #ifdef CONFIG_MEMORY_HOTREMOVE
 114 extern int unregister_memory_section(struct mem_section *);
 115 #endif
 116 extern int memory_dev_init(void);
 117 extern int memory_notify(unsigned long val, void *v);
 118 extern int memory_isolate_notify(unsigned long val, void *v);
 119 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
 120                                                         struct memory_block *);
 121 extern struct memory_block *find_memory_block(struct mem_section *);
 122 #define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 123 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 124
 125 #ifdef CONFIG_MEMORY_HOTPLUG
 126 #define hotplug_memory_notifier(fn, pri) ({             \
 127         static __meminitdata struct notifier_block fn##_mem_nb =\
 128                 { .notifier_call = fn, .priority = pri };\
 129         register_memory_notifier(&fn##_mem_nb);                 \
 130 })
 131 #define register_hotmemory_notifier(nb)         register_memory_notifier(nb)
 132 #define unregister_hotmemory_notifier(nb)       unregister_memory_notifier(nb)
 133 #else
 134 #define hotplug_memory_notifier(fn, pri)        ({ 0; })
 135 /* These aren't inline functions due to a GCC bug. */
 136 #define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
 137 #define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
 138 #endif
 139
 140 /*
 141  * Kernel text modification mutex, used for code patching. Users of this lock
 142  * can sleep.
 143  */
 144 extern struct mutex text_mutex;
 145
 146 #endif /* _LINUX_MEMORY_H_ */