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         /*
  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
  47 struct memory_notify {
  48         unsigned long start_pfn;
  49         unsigned long nr_pages;
  50         int status_change_nid;
  51 };
  52
  53 struct notifier_block;
  54 struct 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
  64 static inline int memory_dev_init(void)
  65 {
  66         return 0;
  67 }
  68 static inline int register_memory_notifier(struct notifier_block *nb)
  69 {
  70         return 0;
  71 }
  72 static inline void unregister_memory_notifier(struct notifier_block *nb)
  73 {
  74 }
  75 static inline int memory_notify(unsigned long val, void *v)
  76 {
  77         return 0;
  78 }
  79 #else
  80 extern int register_memory_notifier(struct notifier_block *nb);
  81 extern void unregister_memory_notifier(struct notifier_block *nb);
  82 extern int register_new_memory(int, struct mem_section *);
  83 extern int unregister_memory_section(struct mem_section *);
  84 extern int memory_dev_init(void);
  85 extern int remove_memory_block(unsigned long, struct mem_section *, int);
  86 extern int memory_notify(unsigned long val, void *v);
  87 extern struct memory_block *find_memory_block(struct mem_section *);
  88 #define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
  89 enum 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  */
 106 struct 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  */
 117 extern struct mutex text_mutex;
 118
 119 #endif /* _LINUX_MEMORY_H_ */