include/linux/memory.h

   1 /*
   2  * include/linux/memory.h - generic memory definition
   3  *
   4  * This is mainly for topological representation. We define the
   5  * basic "struct memory_block" here, which can be embedded in per-arch
   6  * definitions or NUMA information.
   7  *
   8  * Basic handling of the devices is done in drivers/base/memory.c
   9  * and system devices are handled in drivers/base/sys.c.
  10  *
  11  * Memory block are exported via sysfs in the class/memory/devices/
  12  * directory.
  13  *
  14  */
  15 #ifndef _LINUX_MEMORY_H_
  16 #define _LINUX_MEMORY_H_
  17
  18 #include <linux/sysdev.h>
  19 #include <linux/node.h>
  20 #include <linux/compiler.h>
  21 #include <linux/mutex.h>
  22
  23 struct memory_block {
  24         unsigned long start_section_nr;
  25         unsigned long end_section_nr;
  26         unsigned long state;
  27         int section_count;
  28
  29         /*
  30          * This serializes all state change requests.  It isn't
  31          * held during creation because the control files are
  32          * created long after the critical areas during
  33          * initialization.
  34          */
  35         struct mutex state_mutex;
  36         int phys_device;                /* to which fru does this belong? */
  37         void *hw;                       /* optional pointer to fw/hw data */
  38         int (*phys_callback)(struct memory_block *);
  39         struct sys_device sysdev;
  40 };
  41
  42 int arch_get_memory_phys_device(unsigned long start_pfn);
  43
  44 /* These states are exposed to userspace as text strings in sysfs */
  45 #define MEM_ONLINE              (1<<0) /* exposed to userspace */
  46 #define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  47 #define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  48 #define MEM_GOING_ONLINE        (1<<3)
  49 #define MEM_CANCEL_ONLINE       (1<<4)
  50 #define MEM_CANCEL_OFFLINE      (1<<5)
  51
  52 struct memory_notify {
  53         unsigned long start_pfn;
  54         unsigned long nr_pages;
  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
  65 struct 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
  71 struct notifier_block;
  72 struct 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
  82 static inline int memory_dev_init(void)
  83 {
  84         return 0;
  85 }
  86 static inline int register_memory_notifier(struct notifier_block *nb)
  87 {
  88         return 0;
  89 }
  90 static inline void unregister_memory_notifier(struct notifier_block *nb)
  91 {
  92 }
  93 static inline int memory_notify(unsigned long val, void *v)
  94 {
  95         return 0;
  96 }
  97 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
  98 {
  99         return 0;
 100 }
 101 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 102 {
 103 }
 104 static inline int memory_isolate_notify(unsigned long val, void *v)
 105 {
 106         return 0;
 107 }
 108 #else
 109 extern int register_memory_notifier(struct notifier_block *nb);
 110 extern void unregister_memory_notifier(struct notifier_block *nb);
 111 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 112 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 113 extern int register_new_memory(int, struct mem_section *);
 114 extern int unregister_memory_section(struct mem_section *);
 115 extern int memory_dev_init(void);
 116 extern int remove_memory_block(unsigned long, struct mem_section *, int);
 117 extern int memory_notify(unsigned long val, void *v);
 118 extern int memory_isolate_notify(unsigned long val, void *v);
 119 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
 120                                                         struct memory_block *);
 121 extern struct memory_block *find_memory_block(struct mem_section *);
 122 #define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 123 enum mem_add_context { BOOT, HOTPLUG };
 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 #else
 133 #define hotplug_memory_notifier(fn, pri) do { } while (0)
 134 #endif
 135
 136 /*
 137  * 'struct memory_accessor' is a generic interface to provide
 138  * in-kernel access to persistent memory such as i2c or SPI EEPROMs
 139  */
 140 struct memory_accessor {
 141         ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
 142                         size_t count);
 143         ssize_t (*write)(struct memory_accessor *, const char *buf,
 144                          off_t offset, size_t count);
 145 };
 146
 147 /*
 148  * Kernel text modification mutex, used for code patching. Users of this lock
 149  * can sleep.
 150  */
 151 extern struct mutex text_mutex;
 152
 153 #endif /* _LINUX_MEMORY_H_ */