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
  22 #include <asm/semaphore.h>
  23
  24 struct memory_block {
  25         unsigned long phys_index;
  26         unsigned long state;
  27         /*
  28          * This serializes all state change requests.  It isn't
  29          * held during creation because the control files are
  30          * created long after the critical areas during
  31          * initialization.
  32          */
  33         struct semaphore state_sem;
  34         int phys_device;                /* to which fru does this belong? */
  35         void *hw;                       /* optional pointer to fw/hw data */
  36         int (*phys_callback)(struct memory_block *);
  37         struct sys_device sysdev;
  38 };
  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
  45 /*
  46  * All of these states are currently kernel-internal for notifying
  47  * kernel components and architectures.
  48  *
  49  * For MEM_MAPPING_INVALID, all notifier chains with priority >0
  50  * are called before pfn_to_page() becomes invalid.  The priority=0
  51  * entry is reserved for the function that actually makes
  52  * pfn_to_page() stop working.  Any notifiers that want to be called
  53  * after that should have priority <0.
  54  */
  55 #define MEM_MAPPING_INVALID     (1<<3)
  56
  57 struct notifier_block;
  58 struct mem_section;
  59
  60 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  61 static inline int memory_dev_init(void)
  62 {
  63         return 0;
  64 }
  65 static inline int register_memory_notifier(struct notifier_block *nb)
  66 {
  67         return 0;
  68 }
  69 static inline void unregister_memory_notifier(struct notifier_block *nb)
  70 {
  71 }
  72 #else
  73 extern int register_new_memory(struct mem_section *);
  74 extern int unregister_memory_section(struct mem_section *);
  75 extern int memory_dev_init(void);
  76 extern int remove_memory_block(unsigned long, struct mem_section *, int);
  77
  78 #define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
  79
  80
  81 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
  82
  83 #define hotplug_memory_notifier(fn, pri) {                      \
  84         static struct notifier_block fn##_mem_nb =              \
  85                 { .notifier_call = fn, .priority = pri };       \
  86         register_memory_notifier(&fn##_mem_nb);                 \
  87 }
  88
  89 #endif /* _LINUX_MEMORY_H_ */