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
  26/**
  27 * struct memory_group - a logical group of memory blocks
  28 * @nid: The node id for all memory blocks inside the memory group.
  29 * @blocks: List of all memory blocks belonging to this memory group.
  30 * @present_kernel_pages: Present (online) memory outside ZONE_MOVABLE of this
  31 *                        memory group.
  32 * @present_movable_pages: Present (online) memory in ZONE_MOVABLE of this
  33 *                         memory group.
  34 * @is_dynamic: The memory group type: static vs. dynamic
  35 * @s.max_pages: Valid with &memory_group.is_dynamic == false. The maximum
  36 *               number of pages we'll have in this static memory group.
  37 * @d.unit_pages: Valid with &memory_group.is_dynamic == true. Unit in pages
  38 *                in which memory is added/removed in this dynamic memory group.
  39 *                This granularity defines the alignment of a unit in physical
  40 *                address space; it has to be at least as big as a single
  41 *                memory block.
  42 *
  43 * A memory group logically groups memory blocks; each memory block
  44 * belongs to at most one memory group. A memory group corresponds to
  45 * a memory device, such as a DIMM or a NUMA node, which spans multiple
  46 * memory blocks and might even span multiple non-contiguous physical memory
  47 * ranges.
  48 *
  49 * Modification of members after registration is serialized by memory
  50 * hot(un)plug code.
  51 */
  52struct memory_group {
  53        int nid;
  54        struct list_head memory_blocks;
  55        unsigned long present_kernel_pages;
  56        unsigned long present_movable_pages;
  57        bool is_dynamic;
  58        union {
  59                struct {
  60                        unsigned long max_pages;
  61                } s;
  62                struct {
  63                        unsigned long unit_pages;
  64                } d;
  65        };
  66};
  67
  68struct memory_block {
  69        unsigned long start_section_nr;
  70        unsigned long state;            /* serialized by the dev->lock */
  71        int online_type;                /* for passing data to online routine */
  72        int nid;                        /* NID for this memory block */
  73        struct device dev;
  74        /*
  75         * Number of vmemmap pages. These pages
  76         * lay at the beginning of the memory block.
  77         */
  78        unsigned long nr_vmemmap_pages;
  79        struct memory_group *group;     /* group (if any) for this block */
  80        struct list_head group_next;    /* next block inside memory group */
  81};
  82
  83int arch_get_memory_phys_device(unsigned long start_pfn);
  84unsigned long memory_block_size_bytes(void);
  85int set_memory_block_size_order(unsigned int order);
  86
  87/* These states are exposed to userspace as text strings in sysfs */
  88#define MEM_ONLINE              (1<<0) /* exposed to userspace */
  89#define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  90#define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  91#define MEM_GOING_ONLINE        (1<<3)
  92#define MEM_CANCEL_ONLINE       (1<<4)
  93#define MEM_CANCEL_OFFLINE      (1<<5)
  94
  95struct memory_notify {
  96        unsigned long start_pfn;
  97        unsigned long nr_pages;
  98        int status_change_nid_normal;
  99        int status_change_nid_high;
 100        int status_change_nid;
 101};
 102
 103struct notifier_block;
 104struct mem_section;
 105
 106/*
 107 * Priorities for the hotplug memory callback routines (stored in decreasing
 108 * order in the callback chain)
 109 */
 110#define SLAB_CALLBACK_PRI       1
 111#define IPC_CALLBACK_PRI        10
 112
 113#ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
 114static inline void memory_dev_init(void)
 115{
 116        return;
 117}
 118static inline int register_memory_notifier(struct notifier_block *nb)
 119{
 120        return 0;
 121}
 122static inline void unregister_memory_notifier(struct notifier_block *nb)
 123{
 124}
 125static inline int memory_notify(unsigned long val, void *v)
 126{
 127        return 0;
 128}
 129#else
 130extern int register_memory_notifier(struct notifier_block *nb);
 131extern void unregister_memory_notifier(struct notifier_block *nb);
 132int create_memory_block_devices(unsigned long start, unsigned long size,
 133                                unsigned long vmemmap_pages,
 134                                struct memory_group *group);
 135void remove_memory_block_devices(unsigned long start, unsigned long size);
 136extern void memory_dev_init(void);
 137extern int memory_notify(unsigned long val, void *v);
 138extern struct memory_block *find_memory_block(unsigned long section_nr);
 139typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
 140extern int walk_memory_blocks(unsigned long start, unsigned long size,
 141                              void *arg, walk_memory_blocks_func_t func);
 142extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
 143#define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 144
 145extern int memory_group_register_static(int nid, unsigned long max_pages);
 146extern int memory_group_register_dynamic(int nid, unsigned long unit_pages);
 147extern int memory_group_unregister(int mgid);
 148struct memory_group *memory_group_find_by_id(int mgid);
 149typedef int (*walk_memory_groups_func_t)(struct memory_group *, void *);
 150int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
 151                               struct memory_group *excluded, void *arg);
 152#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 153
 154#ifdef CONFIG_MEMORY_HOTPLUG
 155#define hotplug_memory_notifier(fn, pri) ({             \
 156        static __meminitdata struct notifier_block fn##_mem_nb =\
 157                { .notifier_call = fn, .priority = pri };\
 158        register_memory_notifier(&fn##_mem_nb);                 \
 159})
 160#define register_hotmemory_notifier(nb)         register_memory_notifier(nb)
 161#define unregister_hotmemory_notifier(nb)       unregister_memory_notifier(nb)
 162#else
 163static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri)
 164{
 165        return 0;
 166}
 167/* These aren't inline functions due to a GCC bug. */
 168#define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
 169#define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
 170#endif
 171
 172/*
 173 * Kernel text modification mutex, used for code patching. Users of this lock
 174 * can sleep.
 175 */
 176extern struct mutex text_mutex;
 177
 178#endif /* _LINUX_MEMORY_H_ */
 179