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/node.h>
  19 #include <linux/compiler.h>
  20 #include <linux/mutex.h>
  21
  22 #define MIN_MEMORY_BLOCK_SIZE     (1 << SECTION_SIZE_BITS)
  23
  24 struct memory_block {
  25         unsigned long start_section_nr;
  26         unsigned long end_section_nr;
  27         unsigned long state;
  28         int section_count;
  29
  30         /*
  31          * This serializes all state change requests.  It isn't
  32          * held during creation because the control files are
  33          * created long after the critical areas during
  34          * initialization.
  35          */
  36         struct mutex state_mutex;
  37         int phys_device;                /* to which fru does this belong? */
  38         void *hw;                       /* optional pointer to fw/hw data */
  39         int (*phys_callback)(struct memory_block *);
  40         struct device dev;
  41 };
  42
  43 int arch_get_memory_phys_device(unsigned long start_pfn);
  44
  45 /* These states are exposed to userspace as text strings in sysfs */
  46 #define MEM_ONLINE              (1<<0) /* exposed to userspace */
  47 #define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  48 #define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  49 #define MEM_GOING_ONLINE        (1<<3)
  50 #define MEM_CANCEL_ONLINE       (1<<4)
  51 #define MEM_CANCEL_OFFLINE      (1<<5)
  52
  53 struct memory_notify {
  54         unsigned long start_pfn;
  55         unsigned long nr_pages;
  56         int status_change_nid;
  57 };
  58
  59 /*
  60  * During pageblock isolation, count the number of pages within the
  61  * range [start_pfn, start_pfn + nr_pages) which are owned by code
  62  * in the notifier chain.
  63  */
  64 #define MEM_ISOLATE_COUNT       (1<<0)
  65
  66 struct memory_isolate_notify {
  67         unsigned long start_pfn;        /* Start of range to check */
  68         unsigned int nr_pages;          /* # pages in range to check */
  69         unsigned int pages_found;       /* # pages owned found by callbacks */
  70 };
  71
  72 struct notifier_block;
  73 struct mem_section;
  74
  75 /*
  76  * Priorities for the hotplug memory callback routines (stored in decreasing
  77  * order in the callback chain)
  78  */
  79 #define SLAB_CALLBACK_PRI       1
  80 #define IPC_CALLBACK_PRI        10
  81
  82 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  83 static inline int memory_dev_init(void)
  84 {
  85         return 0;
  86 }
  87 static inline int register_memory_notifier(struct notifier_block *nb)
  88 {
  89         return 0;
  90 }
  91 static inline void unregister_memory_notifier(struct notifier_block *nb)
  92 {
  93 }
  94 static inline int memory_notify(unsigned long val, void *v)
  95 {
  96         return 0;
  97 }
  98 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
  99 {
 100         return 0;
 101 }
 102 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 103 {
 104 }
 105 static inline int memory_isolate_notify(unsigned long val, void *v)
 106 {
 107         return 0;
 108 }
 109 #else
 110 extern int register_memory_notifier(struct notifier_block *nb);
 111 extern void unregister_memory_notifier(struct notifier_block *nb);
 112 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 113 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 114 extern int register_new_memory(int, struct mem_section *);
 115 extern int unregister_memory_section(struct mem_section *);
 116 extern int memory_dev_init(void);
 117 extern int remove_memory_block(unsigned long, struct mem_section *, int);
 118 extern int memory_notify(unsigned long val, void *v);
 119 extern int memory_isolate_notify(unsigned long val, void *v);
 120 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
 121                                                         struct memory_block *);
 122 extern struct memory_block *find_memory_block(struct mem_section *);
 123 #define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 124 enum mem_add_context { BOOT, HOTPLUG };
 125 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 126
 127 #ifdef CONFIG_MEMORY_HOTPLUG
 128 #define hotplug_memory_notifier(fn, pri) {                      \
 129         static __meminitdata struct notifier_block fn##_mem_nb =\
 130                 { .notifier_call = fn, .priority = pri };       \
 131         register_memory_notifier(&fn##_mem_nb);                 \
 132 }
 133 #else
 134 #define hotplug_memory_notifier(fn, pri) do { } while (0)
 135 #endif
 136
 137 /*
 138  * 'struct memory_accessor' is a generic interface to provide
 139  * in-kernel access to persistent memory such as i2c or SPI EEPROMs
 140  */
 141 struct memory_accessor {
 142         ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
 143                         size_t count);
 144         ssize_t (*write)(struct memory_accessor *, const char *buf,
 145                          off_t offset, size_t count);
 146 };
 147
 148 /*
 149  * Kernel text modification mutex, used for code patching. Users of this lock
 150  * can sleep.
 151  */
 152 extern struct mutex text_mutex;
 153
 154 #endif /* _LINUX_MEMORY_H_ */