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 section_count;              /* serialized by mem_sysfs_mutex */
  30        int online_type;                /* for passing data to online routine */
  31        int phys_device;                /* to which fru does this belong? */
  32        void *hw;                       /* optional pointer to fw/hw data */
  33        int (*phys_callback)(struct memory_block *);
  34        struct device dev;
  35        int nid;                        /* NID for this memory block */
  36};
  37
  38int arch_get_memory_phys_device(unsigned long start_pfn);
  39unsigned long memory_block_size_bytes(void);
  40int set_memory_block_size_order(unsigned int order);
  41
  42/* These states are exposed to userspace as text strings in sysfs */
  43#define MEM_ONLINE              (1<<0) /* exposed to userspace */
  44#define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  45#define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  46#define MEM_GOING_ONLINE        (1<<3)
  47#define MEM_CANCEL_ONLINE       (1<<4)
  48#define MEM_CANCEL_OFFLINE      (1<<5)
  49
  50struct memory_notify {
  51        unsigned long start_pfn;
  52        unsigned long nr_pages;
  53        int status_change_nid_normal;
  54        int status_change_nid_high;
  55        int status_change_nid;
  56};
  57
  58/*
  59 * During pageblock isolation, count the number of pages within the
  60 * range [start_pfn, start_pfn + nr_pages) which are owned by code
  61 * in the notifier chain.
  62 */
  63#define MEM_ISOLATE_COUNT       (1<<0)
  64
  65struct memory_isolate_notify {
  66        unsigned long start_pfn;        /* Start of range to check */
  67        unsigned int nr_pages;          /* # pages in range to check */
  68        unsigned int pages_found;       /* # pages owned found by callbacks */
  69};
  70
  71struct notifier_block;
  72struct mem_section;
  73
  74/*
  75 * Priorities for the hotplug memory callback routines (stored in decreasing
  76 * order in the callback chain)
  77 */
  78#define SLAB_CALLBACK_PRI       1
  79#define IPC_CALLBACK_PRI        10
  80
  81#ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  82static inline void memory_dev_init(void)
  83{
  84        return;
  85}
  86static inline int register_memory_notifier(struct notifier_block *nb)
  87{
  88        return 0;
  89}
  90static inline void unregister_memory_notifier(struct notifier_block *nb)
  91{
  92}
  93static inline int memory_notify(unsigned long val, void *v)
  94{
  95        return 0;
  96}
  97static inline int register_memory_isolate_notifier(struct notifier_block *nb)
  98{
  99        return 0;
 100}
 101static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 102{
 103}
 104static inline int memory_isolate_notify(unsigned long val, void *v)
 105{
 106        return 0;
 107}
 108#else
 109extern int register_memory_notifier(struct notifier_block *nb);
 110extern void unregister_memory_notifier(struct notifier_block *nb);
 111extern int register_memory_isolate_notifier(struct notifier_block *nb);
 112extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 113int create_memory_block_devices(unsigned long start, unsigned long size);
 114void remove_memory_block_devices(unsigned long start, unsigned long size);
 115extern void memory_dev_init(void);
 116extern int memory_notify(unsigned long val, void *v);
 117extern int memory_isolate_notify(unsigned long val, void *v);
 118extern struct memory_block *find_memory_block(struct mem_section *);
 119typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
 120extern int walk_memory_blocks(unsigned long start, unsigned long size,
 121                              void *arg, walk_memory_blocks_func_t func);
 122extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
 123#define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 124#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 125
 126#ifdef CONFIG_MEMORY_HOTPLUG
 127#define hotplug_memory_notifier(fn, pri) ({             \
 128        static __meminitdata struct notifier_block fn##_mem_nb =\
 129                { .notifier_call = fn, .priority = pri };\
 130        register_memory_notifier(&fn##_mem_nb);                 \
 131})
 132#define register_hotmemory_notifier(nb)         register_memory_notifier(nb)
 133#define unregister_hotmemory_notifier(nb)       unregister_memory_notifier(nb)
 134#else
 135#define hotplug_memory_notifier(fn, pri)        ({ 0; })
 136/* These aren't inline functions due to a GCC bug. */
 137#define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
 138#define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
 139#endif
 140
 141/*
 142 * Kernel text modification mutex, used for code patching. Users of this lock
 143 * can sleep.
 144 */
 145extern struct mutex text_mutex;
 146
 147#endif /* _LINUX_MEMORY_H_ */
 148