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