LXR linux/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
  26struct 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
  38int arch_get_memory_phys_device(unsigned long start_pfn);
  39unsigned 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
  49struct 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
  64struct 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
  70struct notifier_block;
  71struct 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
  81static inline int memory_dev_init(void)
  82{
  83        return 0;
  84}
  85static inline int register_memory_notifier(struct notifier_block *nb)
  86{
  87        return 0;
  88}
  89static inline void unregister_memory_notifier(struct notifier_block *nb)
  90{
  91}
  92static inline int memory_notify(unsigned long val, void *v)
  93{
  94        return 0;
  95}
  96static inline int register_memory_isolate_notifier(struct notifier_block *nb)
  97{
  98        return 0;
  99}
 100static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 101{
 102}
 103static inline int memory_isolate_notify(unsigned long val, void *v)
 104{
 105        return 0;
 106}
 107#else
 108extern int register_memory_notifier(struct notifier_block *nb);
 109extern void unregister_memory_notifier(struct notifier_block *nb);
 110extern int register_memory_isolate_notifier(struct notifier_block *nb);
 111extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 112extern int register_new_memory(int, struct mem_section *);
 113#ifdef CONFIG_MEMORY_HOTREMOVE
 114extern int unregister_memory_section(struct mem_section *);
 115#endif
 116extern int memory_dev_init(void);
 117extern int memory_notify(unsigned long val, void *v);
 118extern int memory_isolate_notify(unsigned long val, void *v);
 119extern struct memory_block *find_memory_block_hinted(struct mem_section *,
 120                                                        struct memory_block *);
 121extern 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 */
 144extern struct mutex text_mutex;
 145
 146#endif /* _LINUX_MEMORY_H_ */
 147