FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_map.h

     /*-
      * Copyright (c) 1991, 1993
      *      The Regents of the University of California.  All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
      * The Mach Operating System project at Carnegie-Mellon University.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)vm_map.h    8.9 (Berkeley) 5/17/95
     *
     *
     * Copyright (c) 1987, 1990 Carnegie-Mellon University.
     * All rights reserved.
     *
     * Authors: Avadis Tevanian, Jr., Michael Wayne Young
     *
     * Permission to use, copy, modify and distribute this software and
     * its documentation is hereby granted, provided that both the copyright
     * notice and this permission notice appear in all copies of the
     * software, derivative works or modified versions, and any portions
     * thereof, and that both notices appear in supporting documentation.
     *
     * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     *
     * Carnegie Mellon requests users of this software to return to
     *
     *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
     *  School of Computer Science
     *  Carnegie Mellon University
     *  Pittsburgh PA 15213-3890
     *
     * any improvements or extensions that they make and grant Carnegie the
     * rights to redistribute these changes.
     *
     * $FreeBSD$
     */
    
    /*
     *      Virtual memory map module definitions.
     */
    #ifndef _VM_MAP_
    #define _VM_MAP_
    
    #include <sys/lock.h>
    #include <sys/sx.h>
    #include <sys/_mutex.h>
    
    /*
     *      Types defined:
     *
     *      vm_map_t                the high-level address map data structure.
     *      vm_map_entry_t          an entry in an address map.
     */
    
    typedef u_char vm_flags_t;
    typedef u_int vm_eflags_t;
    
    /*
     *      Objects which live in maps may be either VM objects, or
     *      another map (called a "sharing map") which denotes read-write
     *      sharing with other maps.
     */
    union vm_map_object {
            struct vm_object *vm_object;    /* object object */
            struct vm_map *sub_map;         /* belongs to another map */
    };
    
    /*
     *      Address map entries consist of start and end addresses,
     *      a VM object (or sharing map) and offset into that object,
     *      and user-exported inheritance and protection information.
     *      Also included is control information for virtual copy operations.
     */
    struct vm_map_entry {
           struct vm_map_entry *prev;      /* previous entry */
           struct vm_map_entry *next;      /* next entry */
           struct vm_map_entry *left;      /* left child in binary search tree */
           struct vm_map_entry *right;     /* right child in binary search tree */
           vm_offset_t start;              /* start address */
           vm_offset_t end;                /* end address */
           vm_offset_t pad0;
           vm_offset_t next_read;          /* vaddr of the next sequential read */
           vm_size_t adj_free;             /* amount of adjacent free space */
           vm_size_t max_free;             /* max free space in subtree */
           union vm_map_object object;     /* object I point to */
           vm_ooffset_t offset;            /* offset into object */
           vm_eflags_t eflags;             /* map entry flags */
           vm_prot_t protection;           /* protection code */
           vm_prot_t max_protection;       /* maximum protection */
           vm_inherit_t inheritance;       /* inheritance */
           uint8_t read_ahead;             /* pages in the read-ahead window */
           int wired_count;                /* can be paged if = 0 */
           struct ucred *cred;             /* tmp storage for creator ref */
           struct thread *wiring_thread;
   };
   
   #define MAP_ENTRY_NOSYNC                0x0001
   #define MAP_ENTRY_IS_SUB_MAP            0x0002
   #define MAP_ENTRY_COW                   0x0004
   #define MAP_ENTRY_NEEDS_COPY            0x0008
   #define MAP_ENTRY_NOFAULT               0x0010
   #define MAP_ENTRY_USER_WIRED            0x0020
   
   #define MAP_ENTRY_BEHAV_NORMAL          0x0000  /* default behavior */
   #define MAP_ENTRY_BEHAV_SEQUENTIAL      0x0040  /* expect sequential access */
   #define MAP_ENTRY_BEHAV_RANDOM          0x0080  /* expect random access */
   #define MAP_ENTRY_BEHAV_RESERVED        0x00C0  /* future use */
   
   #define MAP_ENTRY_BEHAV_MASK            0x00C0
   
   #define MAP_ENTRY_IN_TRANSITION         0x0100  /* entry being changed */
   #define MAP_ENTRY_NEEDS_WAKEUP          0x0200  /* waiters in transition */
   #define MAP_ENTRY_NOCOREDUMP            0x0400  /* don't include in a core */
   
   #define MAP_ENTRY_GROWS_DOWN            0x1000  /* Top-down stacks */
   #define MAP_ENTRY_GROWS_UP              0x2000  /* Bottom-up stacks */
   
   #define MAP_ENTRY_WIRE_SKIPPED          0x4000
   #define MAP_ENTRY_VN_WRITECNT           0x8000  /* writeable vnode mapping */
   #define MAP_ENTRY_GUARD                 0x10000
   #define MAP_ENTRY_STACK_GAP_DN          0x20000
   #define MAP_ENTRY_STACK_GAP_UP          0x40000
   
   #ifdef  _KERNEL
   static __inline u_char
   vm_map_entry_behavior(vm_map_entry_t entry)
   {
           return (entry->eflags & MAP_ENTRY_BEHAV_MASK);
   }
   
   static __inline int
   vm_map_entry_user_wired_count(vm_map_entry_t entry)
   {
           if (entry->eflags & MAP_ENTRY_USER_WIRED)
                   return (1);
           return (0);
   }
   
   static __inline int
   vm_map_entry_system_wired_count(vm_map_entry_t entry)
   {
           return (entry->wired_count - vm_map_entry_user_wired_count(entry));
   }
   #endif  /* _KERNEL */
   
   /*
    *      A map is a set of map entries.  These map entries are
    *      organized both as a binary search tree and as a doubly-linked
    *      list.  Both structures are ordered based upon the start and
    *      end addresses contained within each map entry.
    *
    *      Counterintuitively, the map's min offset value is stored in
    *      map->header.end, and its max offset value is stored in
    *      map->header.start.
    *
    *      The list header has max start value and min end value to act
    *      as sentinels for sequential search of the doubly-linked list.
    *      Sleator and Tarjan's top-down splay algorithm is employed to
    *      control height imbalance in the binary search tree.
    *
    *      List of locks
    *      (c)     const until freed
    */
   struct vm_map {
           struct vm_map_entry header;     /* List of entries */
   /*
           map min_offset  header.end      (c)
           map max_offset  header.start    (c)
   */
           struct sx lock;                 /* Lock for map data */
           struct mtx system_mtx;
           int nentries;                   /* Number of entries */
           vm_size_t size;                 /* virtual size */
           u_int timestamp;                /* Version number */
           u_char needs_wakeup;
           u_char system_map;              /* (c) Am I a system map? */
           vm_flags_t flags;               /* flags for this vm_map */
           vm_map_entry_t root;            /* Root of a binary search tree */
           pmap_t pmap;                    /* (c) Physical map */
           int busy;
   };
   
   /*
    * vm_flags_t values
    */
   #define MAP_WIREFUTURE          0x01    /* wire all future pages */
   #define MAP_BUSY_WAKEUP         0x02
   
   #ifdef  _KERNEL
   #ifdef KLD_MODULE
   #define vm_map_max(map)         vm_map_max_KBI((map))
   #define vm_map_min(map)         vm_map_min_KBI((map))
   #define vm_map_pmap(map)        vm_map_pmap_KBI((map))
   #else
   static __inline vm_offset_t
   vm_map_max(const struct vm_map *map)
   {
   
           return (map->header.start);
   }
   
   static __inline vm_offset_t
   vm_map_min(const struct vm_map *map)
   {
   
           return (map->header.end);
   }
   
   static __inline pmap_t
   vm_map_pmap(vm_map_t map)
   {
           return (map->pmap);
   }
   
   static __inline void
   vm_map_modflags(vm_map_t map, vm_flags_t set, vm_flags_t clear)
   {
           map->flags = (map->flags | set) & ~clear;
   }
   #endif  /* KLD_MODULE */
   #endif  /* _KERNEL */
   
   /*
    * Shareable process virtual address space.
    *
    * List of locks
    *      (c)     const until freed
    */
   struct vmspace {
           struct vm_map vm_map;   /* VM address map */
           struct shmmap_state *vm_shm;    /* SYS5 shared memory private data XXX */
           segsz_t vm_swrss;       /* resident set size before last swap */
           segsz_t vm_tsize;       /* text size (pages) XXX */
           segsz_t vm_dsize;       /* data size (pages) XXX */
           segsz_t vm_ssize;       /* stack size (pages) */
           caddr_t vm_taddr;       /* (c) user virtual address of text */
           caddr_t vm_daddr;       /* (c) user virtual address of data */
           caddr_t vm_maxsaddr;    /* user VA at max stack growth */
           volatile int vm_refcnt; /* number of references */
           /*
            * Keep the PMAP last, so that CPU-specific variations of that
            * structure on a single architecture don't result in offset
            * variations of the machine-independent fields in the vmspace.
            */
           struct pmap vm_pmap;    /* private physical map */
   };
   
   #ifdef  _KERNEL
   static __inline pmap_t
   vmspace_pmap(struct vmspace *vmspace)
   {
           return &vmspace->vm_pmap;
   }
   #endif  /* _KERNEL */
   
   #ifdef  _KERNEL
   /*
    *      Macros:         vm_map_lock, etc.
    *      Function:
    *              Perform locking on the data portion of a map.  Note that
    *              these macros mimic procedure calls returning void.  The
    *              semicolon is supplied by the user of these macros, not
    *              by the macros themselves.  The macros can safely be used
    *              as unbraced elements in a higher level statement.
    */
   
   void _vm_map_lock(vm_map_t map, const char *file, int line);
   void _vm_map_unlock(vm_map_t map, const char *file, int line);
   int _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line);
   void _vm_map_lock_read(vm_map_t map, const char *file, int line);
   void _vm_map_unlock_read(vm_map_t map, const char *file, int line);
   int _vm_map_trylock(vm_map_t map, const char *file, int line);
   int _vm_map_trylock_read(vm_map_t map, const char *file, int line);
   int _vm_map_lock_upgrade(vm_map_t map, const char *file, int line);
   void _vm_map_lock_downgrade(vm_map_t map, const char *file, int line);
   int vm_map_locked(vm_map_t map);
   void vm_map_wakeup(vm_map_t map);
   void vm_map_busy(vm_map_t map);
   void vm_map_unbusy(vm_map_t map);
   void vm_map_wait_busy(vm_map_t map);
   vm_offset_t vm_map_max_KBI(const struct vm_map *map);
   vm_offset_t vm_map_min_KBI(const struct vm_map *map);
   pmap_t vm_map_pmap_KBI(vm_map_t map);
   
   #define vm_map_lock(map)        _vm_map_lock(map, LOCK_FILE, LOCK_LINE)
   #define vm_map_unlock(map)      _vm_map_unlock(map, LOCK_FILE, LOCK_LINE)
   #define vm_map_unlock_and_wait(map, timo)       \
                           _vm_map_unlock_and_wait(map, timo, LOCK_FILE, LOCK_LINE)
   #define vm_map_lock_read(map)   _vm_map_lock_read(map, LOCK_FILE, LOCK_LINE)
   #define vm_map_unlock_read(map) _vm_map_unlock_read(map, LOCK_FILE, LOCK_LINE)
   #define vm_map_trylock(map)     _vm_map_trylock(map, LOCK_FILE, LOCK_LINE)
   #define vm_map_trylock_read(map)        \
                           _vm_map_trylock_read(map, LOCK_FILE, LOCK_LINE)
   #define vm_map_lock_upgrade(map)        \
                           _vm_map_lock_upgrade(map, LOCK_FILE, LOCK_LINE)
   #define vm_map_lock_downgrade(map)      \
                           _vm_map_lock_downgrade(map, LOCK_FILE, LOCK_LINE)
   
   long vmspace_resident_count(struct vmspace *vmspace);
   #endif  /* _KERNEL */
   
   
   /* XXX: number of kernel maps to statically allocate */
   #define MAX_KMAP        10
   
   /*
    * Copy-on-write flags for vm_map operations
    */
   #define MAP_INHERIT_SHARE       0x0001
   #define MAP_COPY_ON_WRITE       0x0002
   #define MAP_NOFAULT             0x0004
   #define MAP_PREFAULT            0x0008
   #define MAP_PREFAULT_PARTIAL    0x0010
   #define MAP_DISABLE_SYNCER      0x0020
   #define MAP_CHECK_EXCL          0x0040
   #define MAP_CREATE_GUARD        0x0080
   #define MAP_DISABLE_COREDUMP    0x0100
   #define MAP_PREFAULT_MADVISE    0x0200  /* from (user) madvise request */
   #define MAP_VN_WRITECOUNT       0x0400
   #define MAP_REMAP               0x0800
   #define MAP_STACK_GROWS_DOWN    0x1000
   #define MAP_STACK_GROWS_UP      0x2000
   #define MAP_ACC_CHARGED         0x4000
   #define MAP_ACC_NO_CHARGE       0x8000
   #define MAP_CREATE_STACK_GAP_UP 0x10000
   #define MAP_CREATE_STACK_GAP_DN 0x20000
   
   /*
    * vm_fault option flags
    */
   #define VM_FAULT_NORMAL 0               /* Nothing special */
   #define VM_FAULT_WIRE   1               /* Wire the mapped page */
   #define VM_FAULT_DIRTY  2               /* Dirty the page; use w/VM_PROT_COPY */
   
   /*
    * Initially, mappings are slightly sequential.  The maximum window size must
    * account for the map entry's "read_ahead" field being defined as an uint8_t.
    */
   #define VM_FAULT_READ_AHEAD_MIN         7
   #define VM_FAULT_READ_AHEAD_INIT        15
   #define VM_FAULT_READ_AHEAD_MAX         min(atop(MAXPHYS) - 1, UINT8_MAX)
   
   /*
    * The following "find_space" options are supported by vm_map_find().
    *
    * For VMFS_ALIGNED_SPACE, the desired alignment is specified to
    * the macro argument as log base 2 of the desired alignment.
    */
   #define VMFS_NO_SPACE           0       /* don't find; use the given range */
   #define VMFS_ANY_SPACE          1       /* find a range with any alignment */
   #define VMFS_OPTIMAL_SPACE      2       /* find a range with optimal alignment*/
   #define VMFS_SUPER_SPACE        3       /* find a superpage-aligned range */
   #define VMFS_ALIGNED_SPACE(x)   ((x) << 8) /* find a range with fixed alignment */
   
   /*
    * vm_map_wire and vm_map_unwire option flags
    */
   #define VM_MAP_WIRE_SYSTEM      0       /* wiring in a kernel map */
   #define VM_MAP_WIRE_USER        1       /* wiring in a user map */
   
   #define VM_MAP_WIRE_NOHOLES     0       /* region must not have holes */
   #define VM_MAP_WIRE_HOLESOK     2       /* region may have holes */
   
   #define VM_MAP_WIRE_WRITE       4       /* Validate writable. */
   
   #ifdef _KERNEL
   boolean_t vm_map_check_protection (vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t);
   vm_map_t vm_map_create(pmap_t, vm_offset_t, vm_offset_t);
   int vm_map_delete(vm_map_t, vm_offset_t, vm_offset_t);
   int vm_map_find(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *, vm_size_t,
       vm_offset_t, int, vm_prot_t, vm_prot_t, int);
   int vm_map_find_min(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *,
       vm_size_t, vm_offset_t, vm_offset_t, int, vm_prot_t, vm_prot_t, int);
   int vm_map_fixed(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t, vm_size_t,
       vm_prot_t, vm_prot_t, int);
   int vm_map_findspace (vm_map_t, vm_offset_t, vm_size_t, vm_offset_t *);
   int vm_map_inherit (vm_map_t, vm_offset_t, vm_offset_t, vm_inherit_t);
   void vm_map_init(vm_map_t, pmap_t, vm_offset_t, vm_offset_t);
   int vm_map_insert (vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t, vm_offset_t, vm_prot_t, vm_prot_t, int);
   int vm_map_lookup (vm_map_t *, vm_offset_t, vm_prot_t, vm_map_entry_t *, vm_object_t *,
       vm_pindex_t *, vm_prot_t *, boolean_t *);
   int vm_map_lookup_locked(vm_map_t *, vm_offset_t, vm_prot_t, vm_map_entry_t *, vm_object_t *,
       vm_pindex_t *, vm_prot_t *, boolean_t *);
   void vm_map_lookup_done (vm_map_t, vm_map_entry_t);
   boolean_t vm_map_lookup_entry (vm_map_t, vm_offset_t, vm_map_entry_t *);
   int vm_map_protect (vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t, boolean_t);
   int vm_map_remove (vm_map_t, vm_offset_t, vm_offset_t);
   void vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry);
   void vm_map_startup (void);
   int vm_map_submap (vm_map_t, vm_offset_t, vm_offset_t, vm_map_t);
   int vm_map_sync(vm_map_t, vm_offset_t, vm_offset_t, boolean_t, boolean_t);
   int vm_map_madvise (vm_map_t, vm_offset_t, vm_offset_t, int);
   int vm_map_stack (vm_map_t, vm_offset_t, vm_size_t, vm_prot_t, vm_prot_t, int);
   int vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
       int flags);
   int vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
       int flags);
   long vmspace_swap_count(struct vmspace *vmspace);
   #endif                          /* _KERNEL */
   #endif                          /* _VM_MAP_ */

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