LXR linux/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
  23struct memory_block {
  24        unsigned long phys_index;
  25        unsigned long state;
  26        /*
  27         * This serializes all state change requests.  It isn't
  28         * held during creation because the control files are
  29         * created long after the critical areas during
  30         * initialization.
  31         */
  32        struct mutex state_mutex;
  33        int phys_device;                /* to which fru does this belong? */
  34        void *hw;                       /* optional pointer to fw/hw data */
  35        int (*phys_callback)(struct memory_block *);
  36        struct sys_device sysdev;
  37};
  38
  39/* These states are exposed to userspace as text strings in sysfs */
  40#define MEM_ONLINE              (1<<0) /* exposed to userspace */
  41#define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  42#define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  43#define MEM_GOING_ONLINE        (1<<3)
  44#define MEM_CANCEL_ONLINE       (1<<4)
  45#define MEM_CANCEL_OFFLINE      (1<<5)
  46
  47struct memory_notify {
  48        unsigned long start_pfn;
  49        unsigned long nr_pages;
  50        int status_change_nid;
  51};
  52
  53struct notifier_block;
  54struct mem_section;
  55
  56/*
  57 * Priorities for the hotplug memory callback routines (stored in decreasing
  58 * order in the callback chain)
  59 */
  60#define SLAB_CALLBACK_PRI       1
  61#define IPC_CALLBACK_PRI        10
  62
  63#ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  64static inline int memory_dev_init(void)
  65{
  66        return 0;
  67}
  68static inline int register_memory_notifier(struct notifier_block *nb)
  69{
  70        return 0;
  71}
  72static inline void unregister_memory_notifier(struct notifier_block *nb)
  73{
  74}
  75static inline int memory_notify(unsigned long val, void *v)
  76{
  77        return 0;
  78}
  79#else
  80extern int register_memory_notifier(struct notifier_block *nb);
  81extern void unregister_memory_notifier(struct notifier_block *nb);
  82extern int register_new_memory(int, struct mem_section *);
  83extern int unregister_memory_section(struct mem_section *);
  84extern int memory_dev_init(void);
  85extern int remove_memory_block(unsigned long, struct mem_section *, int);
  86extern int memory_notify(unsigned long val, void *v);
  87extern struct memory_block *find_memory_block(struct mem_section *);
  88#define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
  89enum mem_add_context { BOOT, HOTPLUG };
  90#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
  91
  92#ifdef CONFIG_MEMORY_HOTPLUG
  93#define hotplug_memory_notifier(fn, pri) {                      \
  94        static __meminitdata struct notifier_block fn##_mem_nb =\
  95                { .notifier_call = fn, .priority = pri };       \
  96        register_memory_notifier(&fn##_mem_nb);                 \
  97}
  98#else
  99#define hotplug_memory_notifier(fn, pri) do { } while (0)
 100#endif
 101
 102/*
 103 * 'struct memory_accessor' is a generic interface to provide
 104 * in-kernel access to persistent memory such as i2c or SPI EEPROMs
 105 */
 106struct memory_accessor {
 107        ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
 108                        size_t count);
 109        ssize_t (*write)(struct memory_accessor *, const char *buf,
 110                         off_t offset, size_t count);
 111};
 112
 113/*
 114 * Kernel text modification mutex, used for code patching. Users of this lock
 115 * can sleep.
 116 */
 117extern struct mutex text_mutex;
 118
 119#endif /* _LINUX_MEMORY_H_ */
 120