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 phys_index;
  25         unsigned long state;
  26         int section_count;
  27
  28         /*
  29          * This serializes all state change requests.  It isn't
  30          * held during creation because the control files are
  31          * created long after the critical areas during
  32          * initialization.
  33          */
  34         struct mutex state_mutex;
  35         int phys_device;                /* to which fru does this belong? */
  36         void *hw;                       /* optional pointer to fw/hw data */
  37         int (*phys_callback)(struct memory_block *);
  38         struct sys_device sysdev;
  39 };
  40
  41 int arch_get_memory_phys_device(unsigned long start_pfn);
  42
  43 /* These states are exposed to userspace as text strings in sysfs */
  44 #define MEM_ONLINE              (1<<0) /* exposed to userspace */
  45 #define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  46 #define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  47 #define MEM_GOING_ONLINE        (1<<3)
  48 #define MEM_CANCEL_ONLINE       (1<<4)
  49 #define MEM_CANCEL_OFFLINE      (1<<5)
  50
  51 struct memory_notify {
  52         unsigned long start_pfn;
  53         unsigned long nr_pages;
  54         int status_change_nid;
  55 };
  56
  57 /*
  58  * During pageblock isolation, count the number of pages within the
  59  * range [start_pfn, start_pfn + nr_pages) which are owned by code
  60  * in the notifier chain.
  61  */
  62 #define MEM_ISOLATE_COUNT       (1<<0)
  63
  64 struct memory_isolate_notify {
  65         unsigned long start_pfn;        /* Start of range to check */
  66         unsigned int nr_pages;          /* # pages in range to check */
  67         unsigned int pages_found;       /* # pages owned found by callbacks */
  68 };
  69
  70 struct notifier_block;
  71 struct mem_section;
  72
  73 /*
  74  * Priorities for the hotplug memory callback routines (stored in decreasing
  75  * order in the callback chain)
  76  */
  77 #define SLAB_CALLBACK_PRI       1
  78 #define IPC_CALLBACK_PRI        10
  79
  80 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  81 static inline int memory_dev_init(void)
  82 {
  83         return 0;
  84 }
  85 static inline int register_memory_notifier(struct notifier_block *nb)
  86 {
  87         return 0;
  88 }
  89 static inline void unregister_memory_notifier(struct notifier_block *nb)
  90 {
  91 }
  92 static inline int memory_notify(unsigned long val, void *v)
  93 {
  94         return 0;
  95 }
  96 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
  97 {
  98         return 0;
  99 }
 100 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 101 {
 102 }
 103 static inline int memory_isolate_notify(unsigned long val, void *v)
 104 {
 105         return 0;
 106 }
 107 #else
 108 extern int register_memory_notifier(struct notifier_block *nb);
 109 extern void unregister_memory_notifier(struct notifier_block *nb);
 110 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 111 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 112 extern int register_new_memory(int, struct mem_section *);
 113 extern int unregister_memory_section(struct mem_section *);
 114 extern int memory_dev_init(void);
 115 extern int remove_memory_block(unsigned long, struct mem_section *, int);
 116 extern int memory_notify(unsigned long val, void *v);
 117 extern int memory_isolate_notify(unsigned long val, void *v);
 118 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
 119                                                         struct memory_block *);
 120 extern struct memory_block *find_memory_block(struct mem_section *);
 121 #define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 122 enum mem_add_context { BOOT, HOTPLUG };
 123 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 124
 125 #ifdef CONFIG_MEMORY_HOTPLUG
 126 #define hotplug_memory_notifier(fn, pri) {                      \
 127         static __meminitdata struct notifier_block fn##_mem_nb =\
 128                 { .notifier_call = fn, .priority = pri };       \
 129         register_memory_notifier(&fn##_mem_nb);                 \
 130 }
 131 #else
 132 #define hotplug_memory_notifier(fn, pri) do { } while (0)
 133 #endif
 134
 135 /*
 136  * 'struct memory_accessor' is a generic interface to provide
 137  * in-kernel access to persistent memory such as i2c or SPI EEPROMs
 138  */
 139 struct memory_accessor {
 140         ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
 141                         size_t count);
 142         ssize_t (*write)(struct memory_accessor *, const char *buf,
 143                          off_t offset, size_t count);
 144 };
 145
 146 /*
 147  * Kernel text modification mutex, used for code patching. Users of this lock
 148  * can sleep.
 149  */
 150 extern struct mutex text_mutex;
 151
 152 #endif /* _LINUX_MEMORY_H_ */