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