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
  23 #define MIN_MEMORY_BLOCK_SIZE     (1UL << SECTION_SIZE_BITS)
  24
  25 /**
  26  * struct memory_group - a logical group of memory blocks
  27  * @nid: The node id for all memory blocks inside the memory group.
  28  * @blocks: List of all memory blocks belonging to this memory group.
  29  * @present_kernel_pages: Present (online) memory outside ZONE_MOVABLE of this
  30  *                        memory group.
  31  * @present_movable_pages: Present (online) memory in ZONE_MOVABLE of this
  32  *                         memory group.
  33  * @is_dynamic: The memory group type: static vs. dynamic
  34  * @s.max_pages: Valid with &memory_group.is_dynamic == false. The maximum
  35  *               number of pages we'll have in this static memory group.
  36  * @d.unit_pages: Valid with &memory_group.is_dynamic == true. Unit in pages
  37  *                in which memory is added/removed in this dynamic memory group.
  38  *                This granularity defines the alignment of a unit in physical
  39  *                address space; it has to be at least as big as a single
  40  *                memory block.
  41  *
  42  * A memory group logically groups memory blocks; each memory block
  43  * belongs to at most one memory group. A memory group corresponds to
  44  * a memory device, such as a DIMM or a NUMA node, which spans multiple
  45  * memory blocks and might even span multiple non-contiguous physical memory
  46  * ranges.
  47  *
  48  * Modification of members after registration is serialized by memory
  49  * hot(un)plug code.
  50  */
  51 struct memory_group {
  52         int nid;
  53         struct list_head memory_blocks;
  54         unsigned long present_kernel_pages;
  55         unsigned long present_movable_pages;
  56         bool is_dynamic;
  57         union {
  58                 struct {
  59                         unsigned long max_pages;
  60                 } s;
  61                 struct {
  62                         unsigned long unit_pages;
  63                 } d;
  64         };
  65 };
  66
  67 struct memory_block {
  68         unsigned long start_section_nr;
  69         unsigned long state;            /* serialized by the dev->lock */
  70         int online_type;                /* for passing data to online routine */
  71         int nid;                        /* NID for this memory block */
  72         /*
  73          * The single zone of this memory block if all PFNs of this memory block
  74          * that are System RAM (not a memory hole, not ZONE_DEVICE ranges) are
  75          * managed by a single zone. NULL if multiple zones (including nodes)
  76          * apply.
  77          */
  78         struct zone *zone;
  79         struct device dev;
  80         struct vmem_altmap *altmap;
  81         struct memory_group *group;     /* group (if any) for this block */
  82         struct list_head group_next;    /* next block inside memory group */
  83 #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
  84         atomic_long_t nr_hwpoison;
  85 #endif
  86 };
  87
  88 int arch_get_memory_phys_device(unsigned long start_pfn);
  89 unsigned long memory_block_size_bytes(void);
  90 int set_memory_block_size_order(unsigned int order);
  91
  92 /* These states are exposed to userspace as text strings in sysfs */
  93 #define MEM_ONLINE              (1<<0) /* exposed to userspace */
  94 #define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  95 #define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  96 #define MEM_GOING_ONLINE        (1<<3)
  97 #define MEM_CANCEL_ONLINE       (1<<4)
  98 #define MEM_CANCEL_OFFLINE      (1<<5)
  99 #define MEM_PREPARE_ONLINE      (1<<6)
 100 #define MEM_FINISH_OFFLINE      (1<<7)
 101
 102 struct memory_notify {
 103         /*
 104          * The altmap_start_pfn and altmap_nr_pages fields are designated for
 105          * specifying the altmap range and are exclusively intended for use in
 106          * MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers.
 107          */
 108         unsigned long altmap_start_pfn;
 109         unsigned long altmap_nr_pages;
 110         unsigned long start_pfn;
 111         unsigned long nr_pages;
 112         int status_change_nid_normal;
 113         int status_change_nid;
 114 };
 115
 116 struct notifier_block;
 117 struct mem_section;
 118
 119 /*
 120  * Priorities for the hotplug memory callback routines (stored in decreasing
 121  * order in the callback chain)
 122  */
 123 #define DEFAULT_CALLBACK_PRI    0
 124 #define SLAB_CALLBACK_PRI       1
 125 #define HMAT_CALLBACK_PRI       2
 126 #define CXL_CALLBACK_PRI        5
 127 #define MM_COMPUTE_BATCH_PRI    10
 128 #define CPUSET_CALLBACK_PRI     10
 129 #define MEMTIER_HOTPLUG_PRI     100
 130 #define KSM_CALLBACK_PRI        100
 131
 132 #ifndef CONFIG_MEMORY_HOTPLUG
 133 static inline void memory_dev_init(void)
 134 {
 135         return;
 136 }
 137 static inline int register_memory_notifier(struct notifier_block *nb)
 138 {
 139         return 0;
 140 }
 141 static inline void unregister_memory_notifier(struct notifier_block *nb)
 142 {
 143 }
 144 static inline int memory_notify(unsigned long val, void *v)
 145 {
 146         return 0;
 147 }
 148 static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri)
 149 {
 150         return 0;
 151 }
 152 #else /* CONFIG_MEMORY_HOTPLUG */
 153 extern int register_memory_notifier(struct notifier_block *nb);
 154 extern void unregister_memory_notifier(struct notifier_block *nb);
 155 int create_memory_block_devices(unsigned long start, unsigned long size,
 156                                 struct vmem_altmap *altmap,
 157                                 struct memory_group *group);
 158 void remove_memory_block_devices(unsigned long start, unsigned long size);
 159 extern void memory_dev_init(void);
 160 extern int memory_notify(unsigned long val, void *v);
 161 extern struct memory_block *find_memory_block(unsigned long section_nr);
 162 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
 163 extern int walk_memory_blocks(unsigned long start, unsigned long size,
 164                               void *arg, walk_memory_blocks_func_t func);
 165 extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
 166
 167 extern int memory_group_register_static(int nid, unsigned long max_pages);
 168 extern int memory_group_register_dynamic(int nid, unsigned long unit_pages);
 169 extern int memory_group_unregister(int mgid);
 170 struct memory_group *memory_group_find_by_id(int mgid);
 171 typedef int (*walk_memory_groups_func_t)(struct memory_group *, void *);
 172 int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
 173                                struct memory_group *excluded, void *arg);
 174 #define hotplug_memory_notifier(fn, pri) ({             \
 175         static __meminitdata struct notifier_block fn##_mem_nb =\
 176                 { .notifier_call = fn, .priority = pri };\
 177         register_memory_notifier(&fn##_mem_nb);                 \
 178 })
 179
 180 #ifdef CONFIG_NUMA
 181 void memory_block_add_nid(struct memory_block *mem, int nid,
 182                           enum meminit_context context);
 183 #endif /* CONFIG_NUMA */
 184 #endif  /* CONFIG_MEMORY_HOTPLUG */
 185
 186 /*
 187  * Kernel text modification mutex, used for code patching. Users of this lock
 188  * can sleep.
 189  */
 190 extern struct mutex text_mutex;
 191
 192 #endif /* _LINUX_MEMORY_H_ */