linux/include/linux/mm_types.h
<<
>>
Prefs
   1#ifndef _LINUX_MM_TYPES_H
   2#define _LINUX_MM_TYPES_H
   3
   4#include <linux/auxvec.h>
   5#include <linux/types.h>
   6#include <linux/threads.h>
   7#include <linux/list.h>
   8#include <linux/spinlock.h>
   9#include <linux/prio_tree.h>
  10#include <linux/rbtree.h>
  11#include <linux/rwsem.h>
  12#include <linux/completion.h>
  13#include <linux/cpumask.h>
  14#include <linux/page-debug-flags.h>
  15#include <asm/page.h>
  16#include <asm/mmu.h>
  17
  18#ifndef AT_VECTOR_SIZE_ARCH
  19#define AT_VECTOR_SIZE_ARCH 0
  20#endif
  21#define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
  22
  23struct address_space;
  24
  25#define USE_SPLIT_PTLOCKS       (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
  26
  27#if USE_SPLIT_PTLOCKS
  28typedef atomic_long_t mm_counter_t;
  29#else  /* !USE_SPLIT_PTLOCKS */
  30typedef unsigned long mm_counter_t;
  31#endif /* !USE_SPLIT_PTLOCKS */
  32
  33/*
  34 * Each physical page in the system has a struct page associated with
  35 * it to keep track of whatever it is we are using the page for at the
  36 * moment. Note that we have no way to track which tasks are using
  37 * a page, though if it is a pagecache page, rmap structures can tell us
  38 * who is mapping it.
  39 */
  40struct page {
  41        unsigned long flags;            /* Atomic flags, some possibly
  42                                         * updated asynchronously */
  43        atomic_t _count;                /* Usage count, see below. */
  44        union {
  45                atomic_t _mapcount;     /* Count of ptes mapped in mms,
  46                                         * to show when page is mapped
  47                                         * & limit reverse map searches.
  48                                         */
  49                struct {                /* SLUB */
  50                        u16 inuse;
  51                        u16 objects;
  52                };
  53        };
  54        union {
  55            struct {
  56                unsigned long private;          /* Mapping-private opaque data:
  57                                                 * usually used for buffer_heads
  58                                                 * if PagePrivate set; used for
  59                                                 * swp_entry_t if PageSwapCache;
  60                                                 * indicates order in the buddy
  61                                                 * system if PG_buddy is set.
  62                                                 */
  63                struct address_space *mapping;  /* If low bit clear, points to
  64                                                 * inode address_space, or NULL.
  65                                                 * If page mapped as anonymous
  66                                                 * memory, low bit is set, and
  67                                                 * it points to anon_vma object:
  68                                                 * see PAGE_MAPPING_ANON below.
  69                                                 */
  70            };
  71#if USE_SPLIT_PTLOCKS
  72            spinlock_t ptl;
  73#endif
  74            struct kmem_cache *slab;    /* SLUB: Pointer to slab */
  75            struct page *first_page;    /* Compound tail pages */
  76        };
  77        union {
  78                pgoff_t index;          /* Our offset within mapping. */
  79                void *freelist;         /* SLUB: freelist req. slab lock */
  80        };
  81        struct list_head lru;           /* Pageout list, eg. active_list
  82                                         * protected by zone->lru_lock !
  83                                         */
  84        /*
  85         * On machines where all RAM is mapped into kernel address space,
  86         * we can simply calculate the virtual address. On machines with
  87         * highmem some memory is mapped into kernel virtual memory
  88         * dynamically, so we need a place to store that address.
  89         * Note that this field could be 16 bits on x86 ... ;)
  90         *
  91         * Architectures with slow multiplication can define
  92         * WANT_PAGE_VIRTUAL in asm/page.h
  93         */
  94#if defined(WANT_PAGE_VIRTUAL)
  95        void *virtual;                  /* Kernel virtual address (NULL if
  96                                           not kmapped, ie. highmem) */
  97#endif /* WANT_PAGE_VIRTUAL */
  98#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
  99        unsigned long debug_flags;      /* Use atomic bitops on this */
 100#endif
 101
 102#ifdef CONFIG_KMEMCHECK
 103        /*
 104         * kmemcheck wants to track the status of each byte in a page; this
 105         * is a pointer to such a status block. NULL if not tracked.
 106         */
 107        void *shadow;
 108#endif
 109};
 110
 111/*
 112 * A region containing a mapping of a non-memory backed file under NOMMU
 113 * conditions.  These are held in a global tree and are pinned by the VMAs that
 114 * map parts of them.
 115 */
 116struct vm_region {
 117        struct rb_node  vm_rb;          /* link in global region tree */
 118        unsigned long   vm_flags;       /* VMA vm_flags */
 119        unsigned long   vm_start;       /* start address of region */
 120        unsigned long   vm_end;         /* region initialised to here */
 121        unsigned long   vm_top;         /* region allocated to here */
 122        unsigned long   vm_pgoff;       /* the offset in vm_file corresponding to vm_start */
 123        struct file     *vm_file;       /* the backing file or NULL */
 124
 125        atomic_t        vm_usage;       /* region usage count */
 126};
 127
 128/*
 129 * This struct defines a memory VMM memory area. There is one of these
 130 * per VM-area/task.  A VM area is any part of the process virtual memory
 131 * space that has a special rule for the page-fault handlers (ie a shared
 132 * library, the executable area etc).
 133 */
 134struct vm_area_struct {
 135        struct mm_struct * vm_mm;       /* The address space we belong to. */
 136        unsigned long vm_start;         /* Our start address within vm_mm. */
 137        unsigned long vm_end;           /* The first byte after our end address
 138                                           within vm_mm. */
 139
 140        /* linked list of VM areas per task, sorted by address */
 141        struct vm_area_struct *vm_next;
 142
 143        pgprot_t vm_page_prot;          /* Access permissions of this VMA. */
 144        unsigned long vm_flags;         /* Flags, see mm.h. */
 145
 146        struct rb_node vm_rb;
 147
 148        /*
 149         * For areas with an address space and backing store,
 150         * linkage into the address_space->i_mmap prio tree, or
 151         * linkage to the list of like vmas hanging off its node, or
 152         * linkage of vma in the address_space->i_mmap_nonlinear list.
 153         */
 154        union {
 155                struct {
 156                        struct list_head list;
 157                        void *parent;   /* aligns with prio_tree_node parent */
 158                        struct vm_area_struct *head;
 159                } vm_set;
 160
 161                struct raw_prio_tree_node prio_tree_node;
 162        } shared;
 163
 164        /*
 165         * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
 166         * list, after a COW of one of the file pages.  A MAP_SHARED vma
 167         * can only be in the i_mmap tree.  An anonymous MAP_PRIVATE, stack
 168         * or brk vma (with NULL file) can only be in an anon_vma list.
 169         */
 170        struct list_head anon_vma_node; /* Serialized by anon_vma->lock */
 171        struct anon_vma *anon_vma;      /* Serialized by page_table_lock */
 172
 173        /* Function pointers to deal with this struct. */
 174        const struct vm_operations_struct *vm_ops;
 175
 176        /* Information about our backing store: */
 177        unsigned long vm_pgoff;         /* Offset (within vm_file) in PAGE_SIZE
 178                                           units, *not* PAGE_CACHE_SIZE */
 179        struct file * vm_file;          /* File we map to (can be NULL). */
 180        void * vm_private_data;         /* was vm_pte (shared mem) */
 181        unsigned long vm_truncate_count;/* truncate_count or restart_addr */
 182
 183#ifndef CONFIG_MMU
 184        struct vm_region *vm_region;    /* NOMMU mapping region */
 185#endif
 186#ifdef CONFIG_NUMA
 187        struct mempolicy *vm_policy;    /* NUMA policy for the VMA */
 188#endif
 189};
 190
 191struct core_thread {
 192        struct task_struct *task;
 193        struct core_thread *next;
 194};
 195
 196struct core_state {
 197        atomic_t nr_threads;
 198        struct core_thread dumper;
 199        struct completion startup;
 200};
 201
 202struct mm_struct {
 203        struct vm_area_struct * mmap;           /* list of VMAs */
 204        struct rb_root mm_rb;
 205        struct vm_area_struct * mmap_cache;     /* last find_vma result */
 206        unsigned long (*get_unmapped_area) (struct file *filp,
 207                                unsigned long addr, unsigned long len,
 208                                unsigned long pgoff, unsigned long flags);
 209        void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
 210        unsigned long mmap_base;                /* base of mmap area */
 211        unsigned long task_size;                /* size of task vm space */
 212        unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
 213        unsigned long free_area_cache;          /* first hole of size cached_hole_size or larger */
 214        pgd_t * pgd;
 215        atomic_t mm_users;                      /* How many users with user space? */
 216        atomic_t mm_count;                      /* How many references to "struct mm_struct" (users count as 1) */
 217        int map_count;                          /* number of VMAs */
 218        struct rw_semaphore mmap_sem;
 219        spinlock_t page_table_lock;             /* Protects page tables and some counters */
 220
 221        struct list_head mmlist;                /* List of maybe swapped mm's.  These are globally strung
 222                                                 * together off init_mm.mmlist, and are protected
 223                                                 * by mmlist_lock
 224                                                 */
 225
 226        /* Special counters, in some configurations protected by the
 227         * page_table_lock, in other configurations by being atomic.
 228         */
 229        mm_counter_t _file_rss;
 230        mm_counter_t _anon_rss;
 231
 232        unsigned long hiwater_rss;      /* High-watermark of RSS usage */
 233        unsigned long hiwater_vm;       /* High-water virtual memory usage */
 234
 235        unsigned long total_vm, locked_vm, shared_vm, exec_vm;
 236        unsigned long stack_vm, reserved_vm, def_flags, nr_ptes;
 237        unsigned long start_code, end_code, start_data, end_data;
 238        unsigned long start_brk, brk, start_stack;
 239        unsigned long arg_start, arg_end, env_start, env_end;
 240
 241        unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
 242
 243        struct linux_binfmt *binfmt;
 244
 245        cpumask_t cpu_vm_mask;
 246
 247        /* Architecture-specific MM context */
 248        mm_context_t context;
 249
 250        /* Swap token stuff */
 251        /*
 252         * Last value of global fault stamp as seen by this process.
 253         * In other words, this value gives an indication of how long
 254         * it has been since this task got the token.
 255         * Look at mm/thrash.c
 256         */
 257        unsigned int faultstamp;
 258        unsigned int token_priority;
 259        unsigned int last_interval;
 260
 261        unsigned long flags; /* Must use atomic bitops to access the bits */
 262
 263        struct core_state *core_state; /* coredumping support */
 264#ifdef CONFIG_AIO
 265        spinlock_t              ioctx_lock;
 266        struct hlist_head       ioctx_list;
 267#endif
 268#ifdef CONFIG_MM_OWNER
 269        /*
 270         * "owner" points to a task that is regarded as the canonical
 271         * user/owner of this mm. All of the following must be true in
 272         * order for it to be changed:
 273         *
 274         * current == mm->owner
 275         * current->mm != mm
 276         * new_owner->mm == mm
 277         * new_owner->alloc_lock is held
 278         */
 279        struct task_struct *owner;
 280#endif
 281
 282#ifdef CONFIG_PROC_FS
 283        /* store ref to file /proc/<pid>/exe symlink points to */
 284        struct file *exe_file;
 285        unsigned long num_exe_file_vmas;
 286#endif
 287#ifdef CONFIG_MMU_NOTIFIER
 288        struct mmu_notifier_mm *mmu_notifier_mm;
 289#endif
 290};
 291
 292/* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
 293#define mm_cpumask(mm) (&(mm)->cpu_vm_mask)
 294
 295#endif /* _LINUX_MM_TYPES_H */
 296