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
  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 device dev;
  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_normal;
  58         int status_change_nid_high;
  59         int status_change_nid;
  60 };
  61
  62 /*
  63  * During pageblock isolation, count the number of pages within the
  64  * range [start_pfn, start_pfn + nr_pages) which are owned by code
  65  * in the notifier chain.
  66  */
  67 #define MEM_ISOLATE_COUNT       (1<<0)
  68
  69 struct memory_isolate_notify {
  70         unsigned long start_pfn;        /* Start of range to check */
  71         unsigned int nr_pages;          /* # pages in range to check */
  72         unsigned int pages_found;       /* # pages owned found by callbacks */
  73 };
  74
  75 struct notifier_block;
  76 struct mem_section;
  77
  78 /*
  79  * Priorities for the hotplug memory callback routines (stored in decreasing
  80  * order in the callback chain)
  81  */
  82 #define SLAB_CALLBACK_PRI       1
  83 #define IPC_CALLBACK_PRI        10
  84
  85 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
  86 static inline int memory_dev_init(void)
  87 {
  88         return 0;
  89 }
  90 static inline int register_memory_notifier(struct notifier_block *nb)
  91 {
  92         return 0;
  93 }
  94 static inline void unregister_memory_notifier(struct notifier_block *nb)
  95 {
  96 }
  97 static inline int memory_notify(unsigned long val, void *v)
  98 {
  99         return 0;
 100 }
 101 static inline int register_memory_isolate_notifier(struct notifier_block *nb)
 102 {
 103         return 0;
 104 }
 105 static inline void unregister_memory_isolate_notifier(struct notifier_block *nb)
 106 {
 107 }
 108 static inline int memory_isolate_notify(unsigned long val, void *v)
 109 {
 110         return 0;
 111 }
 112 #else
 113 extern int register_memory_notifier(struct notifier_block *nb);
 114 extern void unregister_memory_notifier(struct notifier_block *nb);
 115 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 116 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
 117 extern int register_new_memory(int, struct mem_section *);
 118 #ifdef CONFIG_MEMORY_HOTREMOVE
 119 extern int unregister_memory_section(struct mem_section *);
 120 #endif
 121 extern int memory_dev_init(void);
 122 extern int memory_notify(unsigned long val, void *v);
 123 extern int memory_isolate_notify(unsigned long val, void *v);
 124 extern struct memory_block *find_memory_block_hinted(struct mem_section *,
 125                                                         struct memory_block *);
 126 extern struct memory_block *find_memory_block(struct mem_section *);
 127 #define CONFIG_MEM_BLOCK_SIZE   (PAGES_PER_SECTION<<PAGE_SHIFT)
 128 enum mem_add_context { BOOT, HOTPLUG };
 129 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 130
 131 #ifdef CONFIG_MEMORY_HOTPLUG
 132 #define hotplug_memory_notifier(fn, pri) ({             \
 133         static __meminitdata struct notifier_block fn##_mem_nb =\
 134                 { .notifier_call = fn, .priority = pri };\
 135         register_memory_notifier(&fn##_mem_nb);                 \
 136 })
 137 #define register_hotmemory_notifier(nb)         register_memory_notifier(nb)
 138 #define unregister_hotmemory_notifier(nb)       unregister_memory_notifier(nb)
 139 #else
 140 #define hotplug_memory_notifier(fn, pri)        ({ 0; })
 141 /* These aren't inline functions due to a GCC bug. */
 142 #define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
 143 #define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
 144 #endif
 145
 146 /*
 147  * 'struct memory_accessor' is a generic interface to provide
 148  * in-kernel access to persistent memory such as i2c or SPI EEPROMs
 149  */
 150 struct memory_accessor {
 151         ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
 152                         size_t count);
 153         ssize_t (*write)(struct memory_accessor *, const char *buf,
 154                          off_t offset, size_t count);
 155 };
 156
 157 /*
 158  * Kernel text modification mutex, used for code patching. Users of this lock
 159  * can sleep.
 160  */
 161 extern struct mutex text_mutex;
 162
 163 #endif /* _LINUX_MEMORY_H_ */