vm_object.h

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/*-
 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
 *
 * 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.
 * 3. 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.
 *
 *      from: @(#)vm_object.h   8.3 (Berkeley) 1/12/94
 *
 *
 * 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 object module definitions.
 */
 
#ifndef _VM_OBJECT_
#define _VM_OBJECT_
 
#include <sys/queue.h>
#include <sys/_blockcount.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/_pctrie.h>
#include <sys/_rwlock.h>
#include <sys/_domainset.h>
 
#include <vm/_vm_radix.h>
 
/*
 *      Types defined:
 *
 *      vm_object_t             Virtual memory object.
 *
 * List of locks
 *      (a)     atomic
 *      (c)     const until freed
 *      (o)     per-object lock 
 *      (f)     free pages queue mutex
 *
 */
 
#ifndef VM_PAGE_HAVE_PGLIST
TAILQ_HEAD(pglist, vm_page);
#define VM_PAGE_HAVE_PGLIST
#endif
 
struct vm_object {
        struct rwlock lock;
        TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
        LIST_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
        LIST_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
        struct pglist memq;             /* list of resident pages */
        struct vm_radix rtree;          /* root of the resident page radix trie*/
        vm_pindex_t size;               /* Object size */
        struct domainset_ref domain;    /* NUMA policy. */
        volatile int generation;        /* generation ID */
        int cleangeneration;            /* Generation at clean time */
        volatile u_int ref_count;       /* How many refs?? */
        int shadow_count;               /* how many objects that this is a shadow for */
        vm_memattr_t memattr;           /* default memory attribute for pages */
        objtype_t type;                 /* type of pager */
        u_short flags;                  /* see below */
        u_short pg_color;               /* (c) color of first page in obj */
        blockcount_t paging_in_progress; /* (a) Paging (in or out) so don't collapse or destroy */
        blockcount_t busy;              /* (a) object is busy, disallow page busy. */
        int resident_page_count;        /* number of resident pages */
        struct vm_object *backing_object; /* object that I'm a shadow of */
        vm_ooffset_t backing_object_offset;/* Offset in backing object */
        TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
        LIST_HEAD(, vm_reserv) rvq;     /* list of reservations */
        void *handle;
        union {
                /*
                 * VNode pager
                 *
                 *      vnp_size - current size of file
                 */
                struct {
                        off_t vnp_size;
                        vm_ooffset_t writemappings;
                } vnp;
 
                /*
                 * Device pager
                 *
                 *      devp_pglist - list of allocated pages
                 */
                struct {
                        TAILQ_HEAD(, vm_page) devp_pglist;
                        const struct cdev_pager_ops *ops;
                        struct cdev *dev;
                } devp;
 
                /*
                 * SG pager
                 *
                 *      sgp_pglist - list of allocated pages
                 */
                struct {
                        TAILQ_HEAD(, vm_page) sgp_pglist;
                } sgp;
 
                /*
                 * Swap pager
                 *
                 *      swp_tmpfs - back-pointer to the tmpfs vnode,
                 *                   if any, which uses the vm object
                 *                   as backing store.  The handle
                 *                   cannot be reused for linking,
                 *                   because the vnode can be
                 *                   reclaimed and recreated, making
                 *                   the handle changed and hash-chain
                 *                   invalid.
                 *
                 *      swp_blks -   pc-trie of the allocated swap blocks.
                 *
                 */
                struct {
                        void *swp_tmpfs;
                        struct pctrie swp_blks;
                        vm_ooffset_t writemappings;
                } swp;
 
                /*
                 * Phys pager
                 */
                struct {
                        const struct phys_pager_ops *ops;
                        union {
                                void *data_ptr;
                                uintptr_t data_val;
                        };
                } phys;
        } un_pager;
        struct ucred *cred;
        vm_ooffset_t charge;
        void *umtx_data;
};
 
/*
 * Flags
 */
#define OBJ_FICTITIOUS  0x0001          /* (c) contains fictitious pages */
#define OBJ_UNMANAGED   0x0002          /* (c) contains unmanaged pages */
#define OBJ_POPULATE    0x0004          /* pager implements populate() */
#define OBJ_DEAD        0x0008          /* dead objects (during rundown) */
#define OBJ_ANON        0x0010          /* (c) contains anonymous memory */
#define OBJ_UMTXDEAD    0x0020          /* umtx pshared was terminated */
#define OBJ_SIZEVNLOCK  0x0040          /* lock vnode to check obj size */
#define OBJ_PG_DTOR     0x0080          /* dont reset object, leave that for dtor */
#define OBJ_SHADOWLIST  0x0100          /* Object is on the shadow list. */
#define OBJ_SWAP        0x0200          /* object swaps */
#define OBJ_SPLIT       0x0400          /* object is being split */
#define OBJ_COLLAPSING  0x0800          /* Parent of collapse. */
#define OBJ_COLORED     0x1000          /* pg_color is defined */
#define OBJ_ONEMAPPING  0x2000          /* One USE (a single, non-forked) mapping flag */
#define OBJ_PAGERPRIV1  0x4000          /* Pager private */
#define OBJ_PAGERPRIV2  0x8000          /* Pager private */
 
/*
 * Helpers to perform conversion between vm_object page indexes and offsets.
 * IDX_TO_OFF() converts an index into an offset.
 * OFF_TO_IDX() converts an offset into an index.
 * OBJ_MAX_SIZE specifies the maximum page index corresponding to the
 *   maximum unsigned offset.
 */
#define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
#define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
#define OBJ_MAX_SIZE    (OFF_TO_IDX(UINT64_MAX) + 1)
 
#ifdef  _KERNEL
 
#define OBJPC_SYNC      0x1                     /* sync I/O */
#define OBJPC_INVAL     0x2                     /* invalidate */
#define OBJPC_NOSYNC    0x4                     /* skip if PGA_NOSYNC */
 
/*
 * The following options are supported by vm_object_page_remove().
 */
#define OBJPR_CLEANONLY 0x1             /* Don't remove dirty pages. */
#define OBJPR_NOTMAPPED 0x2             /* Don't unmap pages. */
#define OBJPR_VALIDONLY 0x4             /* Ignore invalid pages. */
 
TAILQ_HEAD(object_q, vm_object);
 
extern struct object_q vm_object_list;  /* list of allocated objects */
extern struct mtx vm_object_list_mtx;   /* lock for object list and count */
 
extern struct vm_object kernel_object_store;
 
/* kernel and kmem are aliased for backwards KPI compat. */
#define kernel_object   (&kernel_object_store)
#define kmem_object     (&kernel_object_store)
 
#define VM_OBJECT_ASSERT_LOCKED(object)                                 \
        rw_assert(&(object)->lock, RA_LOCKED)
#define VM_OBJECT_ASSERT_RLOCKED(object)                                \
        rw_assert(&(object)->lock, RA_RLOCKED)
#define VM_OBJECT_ASSERT_WLOCKED(object)                                \
        rw_assert(&(object)->lock, RA_WLOCKED)
#define VM_OBJECT_ASSERT_UNLOCKED(object)                               \
        rw_assert(&(object)->lock, RA_UNLOCKED)
#define VM_OBJECT_LOCK_DOWNGRADE(object)                                \
        rw_downgrade(&(object)->lock)
#define VM_OBJECT_RLOCK(object)                                         \
        rw_rlock(&(object)->lock)
#define VM_OBJECT_RUNLOCK(object)                                       \
        rw_runlock(&(object)->lock)
#define VM_OBJECT_SLEEP(object, wchan, pri, wmesg, timo)                \
        rw_sleep((wchan), &(object)->lock, (pri), (wmesg), (timo))
#define VM_OBJECT_TRYRLOCK(object)                                      \
        rw_try_rlock(&(object)->lock)
#define VM_OBJECT_TRYWLOCK(object)                                      \
        rw_try_wlock(&(object)->lock)
#define VM_OBJECT_TRYUPGRADE(object)                                    \
        rw_try_upgrade(&(object)->lock)
#define VM_OBJECT_WLOCK(object)                                         \
        rw_wlock(&(object)->lock)
#define VM_OBJECT_WOWNED(object)                                        \
        rw_wowned(&(object)->lock)
#define VM_OBJECT_WUNLOCK(object)                                       \
        rw_wunlock(&(object)->lock)
#define VM_OBJECT_DROP(object)                                          \
        lock_class_rw.lc_unlock(&(object)->lock.lock_object)
#define VM_OBJECT_PICKUP(object, state)                                 \
        lock_class_rw.lc_lock(&(object)->lock.lock_object, (state))
 
#define VM_OBJECT_ASSERT_PAGING(object)                                 \
        KASSERT(blockcount_read(&(object)->paging_in_progress) != 0,    \
            ("vm_object %p is not paging", object))
#define VM_OBJECT_ASSERT_REFERENCE(object)                              \
        KASSERT((object)->reference_count != 0,                         \
            ("vm_object %p is not referenced", object))
 
struct vnode;
 
/*
 *      The object must be locked or thread private.
 */
static __inline void
vm_object_set_flag(vm_object_t object, u_short bits)
{
 
        object->flags |= bits;
}
 
/*
 *      Conditionally set the object's color, which (1) enables the allocation
 *      of physical memory reservations for anonymous objects and larger-than-
 *      superpage-sized named objects and (2) determines the first page offset
 *      within the object at which a reservation may be allocated.  In other
 *      words, the color determines the alignment of the object with respect
 *      to the largest superpage boundary.  When mapping named objects, like
 *      files or POSIX shared memory objects, the color should be set to zero
 *      before a virtual address is selected for the mapping.  In contrast,
 *      for anonymous objects, the color may be set after the virtual address
 *      is selected.
 *
 *      The object must be locked.
 */
static __inline void
vm_object_color(vm_object_t object, u_short color)
{
 
        if ((object->flags & OBJ_COLORED) == 0) {
                object->pg_color = color;
                object->flags |= OBJ_COLORED;
        }
}
 
static __inline bool
vm_object_reserv(vm_object_t object)
{
 
        if (object != NULL &&
            (object->flags & (OBJ_COLORED | OBJ_FICTITIOUS)) == OBJ_COLORED) {
                return (true);
        }
        return (false);
}
 
void vm_object_clear_flag(vm_object_t object, u_short bits);
void vm_object_pip_add(vm_object_t object, short i);
void vm_object_pip_wakeup(vm_object_t object);
void vm_object_pip_wakeupn(vm_object_t object, short i);
void vm_object_pip_wait(vm_object_t object, const char *waitid);
void vm_object_pip_wait_unlocked(vm_object_t object, const char *waitid);
 
void vm_object_busy(vm_object_t object);
void vm_object_unbusy(vm_object_t object);
void vm_object_busy_wait(vm_object_t object, const char *wmesg);
 
static inline bool
vm_object_busied(vm_object_t object)
{
 
        return (blockcount_read(&object->busy) != 0);
}
#define VM_OBJECT_ASSERT_BUSY(object)   MPASS(vm_object_busied((object)))
 
void umtx_shm_object_init(vm_object_t object);
void umtx_shm_object_terminated(vm_object_t object);
extern int umtx_shm_vnobj_persistent;
 
vm_object_t vm_object_allocate (objtype_t, vm_pindex_t);
vm_object_t vm_object_allocate_anon(vm_pindex_t, vm_object_t, struct ucred *,
   vm_size_t);
vm_object_t vm_object_allocate_dyn(objtype_t, vm_pindex_t, u_short);
boolean_t vm_object_coalesce(vm_object_t, vm_ooffset_t, vm_size_t, vm_size_t,
   boolean_t);
void vm_object_collapse (vm_object_t);
void vm_object_deallocate (vm_object_t);
void vm_object_destroy (vm_object_t);
void vm_object_terminate (vm_object_t);
void vm_object_set_writeable_dirty (vm_object_t);
void vm_object_set_writeable_dirty_(vm_object_t object);
bool vm_object_mightbedirty(vm_object_t object);
bool vm_object_mightbedirty_(vm_object_t object);
void vm_object_init (void);
int  vm_object_kvme_type(vm_object_t object, struct vnode **vpp);
void vm_object_madvise(vm_object_t, vm_pindex_t, vm_pindex_t, int);
boolean_t vm_object_page_clean(vm_object_t object, vm_ooffset_t start,
    vm_ooffset_t end, int flags);
void vm_object_page_noreuse(vm_object_t object, vm_pindex_t start,
    vm_pindex_t end);
void vm_object_page_remove(vm_object_t object, vm_pindex_t start,
    vm_pindex_t end, int options);
boolean_t vm_object_populate(vm_object_t, vm_pindex_t, vm_pindex_t);
void vm_object_print(long addr, boolean_t have_addr, long count, char *modif);
void vm_object_reference (vm_object_t);
void vm_object_reference_locked(vm_object_t);
int  vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr);
void vm_object_shadow(vm_object_t *, vm_ooffset_t *, vm_size_t, struct ucred *,
    bool);
void vm_object_split(vm_map_entry_t);
boolean_t vm_object_sync(vm_object_t, vm_ooffset_t, vm_size_t, boolean_t,
    boolean_t);
void vm_object_unwire(vm_object_t object, vm_ooffset_t offset,
    vm_size_t length, uint8_t queue);
struct vnode *vm_object_vnode(vm_object_t object);
bool vm_object_is_active(vm_object_t obj);
#endif                          /* _KERNEL */
 
#endif                          /* _VM_OBJECT_ */