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         int nid;                        /* NID for this memory block */
  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 /*
  60  * During pageblock isolation, count the number of pages within the
  61  * range [start_pfn, start_pfn + nr_pages) which are owned by code
  62  * in the notifier chain.
  63  */
  64 #define MEM_ISOLATE_COUNT       (1<<0)
  65
  66 struct memory_isolate_notify {
  67         unsigned long start_pfn;        /* Start of range to check */
  68         unsigned int nr_pages;          /* # pages in range to check */
  69         unsigned int pages_found;       /* # pages owned found by callbacks */
  70 };
  71
  72 struct notifier_block;
  73 struct mem_section;
  74
  75 /*
  76  * Priorities for the hotplug memory callback routines (stored in decreasing
  77  * order in the callback chain)
  78  */
  79 #define SLAB_CALLBACK_PRI       1
  80 #define IPC_CALLBACK_PRI        10
  81
  82 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  83 static inline int memory_dev_init(void)
  84 {
  85         return 0;
  86 }
  87 static inline int register_memory_notifier(struct notifier_block *nb)
  88 {
  89         return 0;
  90 }
  91 static inline void unregister_memory_notifier(struct notifier_block *nb)
  92 {
  93 }
  94 static inline int memory_notify(unsigned long val, void *v)
  95 {
  96         return 0;
  97 }
  98 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
  99 {
 100         return 0;
 101 }
 102 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 103 {
 104 }
 105 static inline int memory_isolate_notify(unsigned long val, void *v)
 106 {
 107         return 0;
 108 }
 109 #else
 110 extern int register_memory_notifier(struct notifier_block *nb);
 111 extern void unregister_memory_notifier(struct notifier_block *nb);
 112 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 113 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 114 int hotplug_memory_register(int nid, struct mem_section *section);
 115 #ifdef CONFIG_MEMORY_HOTREMOVE
 116 extern void unregister_memory_section(struct mem_section *);
 117 #endif
 118 extern int memory_dev_init(void);
 119 extern int memory_notify(unsigned long val, void *v);
 120 extern int memory_isolate_notify(unsigned long val, void *v);
 121 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
 122                                                         struct memory_block *);
 123 extern struct memory_block *find_memory_block(struct mem_section *);
 124 #define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 125 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 126
 127 #ifdef CONFIG_MEMORY_HOTPLUG
 128 #define hotplug_memory_notifier(fn, pri) ({             \
 129         static __meminitdata struct notifier_block fn##_mem_nb =\
 130                 { .notifier_call = fn, .priority = pri };\
 131         register_memory_notifier(&fn##_mem_nb);                 \
 132 })
 133 #define register_hotmemory_notifier(nb)         register_memory_notifier(nb)
 134 #define unregister_hotmemory_notifier(nb)       unregister_memory_notifier(nb)
 135 #else
 136 #define hotplug_memory_notifier(fn, pri)        ({ 0; })
 137 /* These aren't inline functions due to a GCC bug. */
 138 #define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
 139 #define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
 140 #endif
 141
 142 /*
 143  * Kernel text modification mutex, used for code patching. Users of this lock
 144  * can sleep.
 145  */
 146 extern struct mutex text_mutex;
 147
 148 #endif /* _LINUX_MEMORY_H_ */