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