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/node.h>
  19#include <linux/compiler.h>
  20#include <linux/mutex.h>
  21#include <linux/notifier.h>
  22
  23#define MIN_MEMORY_BLOCK_SIZE     (1UL << SECTION_SIZE_BITS)
  24
  25struct memory_block {
  26        unsigned long start_section_nr;
  27        unsigned long end_section_nr;
  28        unsigned long state;            /* serialized by the dev->lock */
  29        int section_count;              /* serialized by mem_sysfs_mutex */
  30        int online_type;                /* for passing data to online routine */
  31        int phys_device;                /* to which fru does this belong? */
  32        void *hw;                       /* optional pointer to fw/hw data */
  33        int (*phys_callback)(struct memory_block *);
  34        struct device dev;
  35};
  36
  37int arch_get_memory_phys_device(unsigned long start_pfn);
  38unsigned long memory_block_size_bytes(void);
  39
  40/* These states are exposed to userspace as text strings in sysfs */
  41#define MEM_ONLINE              (1<<0) /* exposed to userspace */
  42#define MEM_GOING_OFFLINE       (1<<1) /* exposed to userspace */
  43#define MEM_OFFLINE             (1<<2) /* exposed to userspace */
  44#define MEM_GOING_ONLINE        (1<<3)
  45#define MEM_CANCEL_ONLINE       (1<<4)
  46#define MEM_CANCEL_OFFLINE      (1<<5)
  47
  48struct memory_notify {
  49        unsigned long start_pfn;
  50        unsigned long nr_pages;
  51        int status_change_nid_normal;
  52        int status_change_nid_high;
  53        int status_change_nid;
  54};
  55
  56/*
  57 * During pageblock isolation, count the number of pages within the
  58 * range [start_pfn, start_pfn + nr_pages) which are owned by code
  59 * in the notifier chain.
  60 */
  61#define MEM_ISOLATE_COUNT       (1<<0)
  62
  63struct memory_isolate_notify {
  64        unsigned long start_pfn;        /* Start of range to check */
  65        unsigned int nr_pages;          /* # pages in range to check */
  66        unsigned int pages_found;       /* # pages owned found by callbacks */
  67};
  68
  69struct notifier_block;
  70struct mem_section;
  71
  72/*
  73 * Priorities for the hotplug memory callback routines (stored in decreasing
  74 * order in the callback chain)
  75 */
  76#define SLAB_CALLBACK_PRI       1
  77#define IPC_CALLBACK_PRI        10
  78
  79#ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  80static inline int memory_dev_init(void)
  81{
  82        return 0;
  83}
  84static inline int register_memory_notifier(struct notifier_block *nb)
  85{
  86        return 0;
  87}
  88static inline void unregister_memory_notifier(struct notifier_block *nb)
  89{
  90}
  91static inline int memory_notify(unsigned long val, void *v)
  92{
  93        return 0;
  94}
  95static inline int register_memory_isolate_notifier(struct notifier_block *nb)
  96{
  97        return 0;
  98}
  99static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 100{
 101}
 102static inline int memory_isolate_notify(unsigned long val, void *v)
 103{
 104        return 0;
 105}
 106#else
 107extern int register_memory_notifier(struct notifier_block *nb);
 108extern void unregister_memory_notifier(struct notifier_block *nb);
 109extern int register_memory_isolate_notifier(struct notifier_block *nb);
 110extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 111extern int register_new_memory(int, struct mem_section *);
 112#ifdef CONFIG_MEMORY_HOTREMOVE
 113extern int unregister_memory_section(struct mem_section *);
 114#endif
 115extern int memory_dev_init(void);
 116extern int memory_notify(unsigned long val, void *v);
 117extern int memory_isolate_notify(unsigned long val, void *v);
 118extern struct memory_block *find_memory_block_hinted(struct mem_section *,
 119                                                        struct memory_block *);
 120extern struct memory_block *find_memory_block(struct mem_section *);
 121#define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 122#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 123
 124#ifdef CONFIG_MEMORY_HOTPLUG
 125#define hotplug_memory_notifier(fn, pri) ({             \
 126        static __meminitdata struct notifier_block fn##_mem_nb =\
 127                { .notifier_call = fn, .priority = pri };\
 128        register_memory_notifier(&fn##_mem_nb);                 \
 129})
 130#define register_hotmemory_notifier(nb)         register_memory_notifier(nb)
 131#define unregister_hotmemory_notifier(nb)       unregister_memory_notifier(nb)
 132#else
 133#define hotplug_memory_notifier(fn, pri)        ({ 0; })
 134/* These aren't inline functions due to a GCC bug. */
 135#define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
 136#define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
 137#endif
 138
 139/*
 140 * 'struct memory_accessor' is a generic interface to provide
 141 * in-kernel access to persistent memory such as i2c or SPI EEPROMs
 142 */
 143struct memory_accessor {
 144        ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
 145                        size_t count);
 146        ssize_t (*write)(struct memory_accessor *, const char *buf,
 147                         off_t offset, size_t count);
 148};
 149
 150/*
 151 * Kernel text modification mutex, used for code patching. Users of this lock
 152 * can sleep.
 153 */
 154extern struct mutex text_mutex;
 155
 156#endif /* _LINUX_MEMORY_H_ */
 157