FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_amap_i.h

     /*      $NetBSD: uvm_amap_i.h,v 1.20 2002/12/20 18:21:13 atatat Exp $   */
     
     /*
      *
      * Copyright (c) 1997 Charles D. Cranor and Washington University.
      * All rights reserved.
      *
      * 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. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by Charles D. Cranor and
     *      Washington University.
     * 4. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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: Id: uvm_amap_i.h,v 1.1.2.4 1998/01/05 18:12:57 chuck Exp
     */
    
    /*
     * uvm_amap_i.h
     */
    
    /*
     * if inlines are enabled always pull in these functions, otherwise
     * pull them in only once (when we are compiling uvm_amap.c).
     */
    #if defined(UVM_AMAP_INLINE) || defined(UVM_AMAP_C)
    #ifndef _UVM_UVM_AMAP_I_H_
    #define _UVM_UVM_AMAP_I_H_
    
    /*
     * amap_lookup: look up a page in an amap
     *
     * => amap should be locked by caller.
     */
    AMAP_INLINE struct vm_anon *
    amap_lookup(aref, offset)
            struct vm_aref *aref;
            vaddr_t offset;
    {
            int slot;
            struct vm_amap *amap = aref->ar_amap;
            UVMHIST_FUNC("amap_lookup"); UVMHIST_CALLED(maphist);
    
            AMAP_B2SLOT(slot, offset);
            slot += aref->ar_pageoff;
    
            if (slot >= amap->am_nslot)
                    panic("amap_lookup: offset out of range");
    
            UVMHIST_LOG(maphist, "<- done (amap=0x%x, offset=0x%x, result=0x%x)",
                amap, offset, amap->am_anon[slot], 0);
            return(amap->am_anon[slot]);
    }
    
    /*
     * amap_lookups: look up a range of pages in an amap
     *
     * => amap should be locked by caller.
     * => XXXCDC: this interface is biased toward array-based amaps.  fix.
     */
    AMAP_INLINE void
    amap_lookups(aref, offset, anons, npages)
            struct vm_aref *aref;
            vaddr_t offset;
            struct vm_anon **anons;
            int npages;
    {
            int slot;
            struct vm_amap *amap = aref->ar_amap;
            UVMHIST_FUNC("amap_lookups"); UVMHIST_CALLED(maphist);
    
            AMAP_B2SLOT(slot, offset);
            slot += aref->ar_pageoff;
    
            UVMHIST_LOG(maphist, "  slot=%d, npages=%d, nslot=%d", slot, npages,
                    amap->am_nslot, 0);
    
            if ((slot + (npages - 1)) >= amap->am_nslot)
                    panic("amap_lookups: offset out of range");
    
           memcpy(anons, &amap->am_anon[slot], npages * sizeof(struct vm_anon *));
   
           UVMHIST_LOG(maphist, "<- done", 0, 0, 0, 0);
           return;
   }
   
   /*
    * amap_add: add (or replace) a page to an amap
    *
    * => caller must lock amap.
    * => if (replace) caller must lock anon because we might have to call
    *      pmap_page_protect on the anon's page.
    */
   AMAP_INLINE void
   amap_add(aref, offset, anon, replace)
           struct vm_aref *aref;
           vaddr_t offset;
           struct vm_anon *anon;
           boolean_t replace;
   {
           int slot;
           struct vm_amap *amap = aref->ar_amap;
           UVMHIST_FUNC("amap_add"); UVMHIST_CALLED(maphist);
   
           AMAP_B2SLOT(slot, offset);
           slot += aref->ar_pageoff;
   
           if (slot >= amap->am_nslot)
                   panic("amap_add: offset out of range");
   
           if (replace) {
   
                   if (amap->am_anon[slot] == NULL)
                           panic("amap_add: replacing null anon");
                   if (amap->am_anon[slot]->u.an_page != NULL &&
                       (amap->am_flags & AMAP_SHARED) != 0) {
                           pmap_page_protect(amap->am_anon[slot]->u.an_page,
                               VM_PROT_NONE);
                           /*
                            * XXX: suppose page is supposed to be wired somewhere?
                            */
                   }
           } else {   /* !replace */
                   if (amap->am_anon[slot] != NULL)
                           panic("amap_add: slot in use");
   
                   amap->am_bckptr[slot] = amap->am_nused;
                   amap->am_slots[amap->am_nused] = slot;
                   amap->am_nused++;
           }
           amap->am_anon[slot] = anon;
           UVMHIST_LOG(maphist,
               "<- done (amap=0x%x, offset=0x%x, anon=0x%x, rep=%d)",
               amap, offset, anon, replace);
   }
   
   /*
    * amap_unadd: remove a page from an amap
    *
    * => caller must lock amap
    */
   AMAP_INLINE void
   amap_unadd(aref, offset)
           struct vm_aref *aref;
           vaddr_t offset;
   {
           int ptr, slot;
           struct vm_amap *amap = aref->ar_amap;
           UVMHIST_FUNC("amap_unadd"); UVMHIST_CALLED(maphist);
   
           AMAP_B2SLOT(slot, offset);
           slot += aref->ar_pageoff;
   
           if (slot >= amap->am_nslot)
                   panic("amap_unadd: offset out of range");
   
           if (amap->am_anon[slot] == NULL)
                   panic("amap_unadd: nothing there");
   
           amap->am_anon[slot] = NULL;
           ptr = amap->am_bckptr[slot];
   
           if (ptr != (amap->am_nused - 1)) {      /* swap to keep slots contig? */
                   amap->am_slots[ptr] = amap->am_slots[amap->am_nused - 1];
                   amap->am_bckptr[amap->am_slots[ptr]] = ptr;     /* back link */
           }
           amap->am_nused--;
           UVMHIST_LOG(maphist, "<- done (amap=0x%x, slot=0x%x)", amap, slot,0, 0);
   }
   
   /*
    * amap_ref: gain a reference to an amap
    *
    * => amap must not be locked (we will lock)
    * => "offset" and "len" are in units of pages
    * => called at fork time to gain the child's reference
    */
   AMAP_INLINE void
   amap_ref(amap, offset, len, flags)
           struct vm_amap *amap;
           vaddr_t offset;
           vsize_t len;
           int flags;
   {
           UVMHIST_FUNC("amap_ref"); UVMHIST_CALLED(maphist);
   
           amap_lock(amap);
           if (flags & AMAP_SHARED)
                   amap->am_flags |= AMAP_SHARED;
   #ifdef UVM_AMAP_PPREF
           if (amap->am_ppref == NULL && (flags & AMAP_REFALL) == 0 &&
               len != amap->am_nslot)
                   amap_pp_establish(amap, offset);
   #endif
           amap->am_ref++;
   #ifdef UVM_AMAP_PPREF
           if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
                   if (flags & AMAP_REFALL)
                           amap_pp_adjref(amap, 0, amap->am_nslot, 1);
                   else
                           amap_pp_adjref(amap, offset, len, 1);
           }
   #endif
           amap_unlock(amap);
           UVMHIST_LOG(maphist,"<- done!  amap=0x%x", amap, 0, 0, 0);
   }
   
   /*
    * amap_unref: remove a reference to an amap
    *
    * => caller must remove all pmap-level references to this amap before
    *      dropping the reference
    * => called from uvm_unmap_detach [only]  ... note that entry is no
    *      longer part of a map and thus has no need for locking
    * => amap must be unlocked (we will lock it).
    */
   AMAP_INLINE void
   amap_unref(amap, offset, len, all)
           struct vm_amap *amap;
           vaddr_t offset;
           vsize_t len;
           boolean_t all;
   {
           UVMHIST_FUNC("amap_unref"); UVMHIST_CALLED(maphist);
   
           /*
            * lock it
            */
           amap_lock(amap);
           UVMHIST_LOG(maphist,"  amap=0x%x  refs=%d, nused=%d",
               amap, amap->am_ref, amap->am_nused, 0);
   
           /*
            * if we are the last reference, free the amap and return.
            */
   
           if (amap->am_ref == 1) {
                   amap_wipeout(amap);     /* drops final ref and frees */
                   UVMHIST_LOG(maphist,"<- done (was last ref)!", 0, 0, 0, 0);
                   return;                 /* no need to unlock */
           }
   
           /*
            * otherwise just drop the reference count(s)
            */
   
           amap->am_ref--;
           if (amap->am_ref == 1 && (amap->am_flags & AMAP_SHARED) != 0)
                   amap->am_flags &= ~AMAP_SHARED; /* clear shared flag */
   #ifdef UVM_AMAP_PPREF
           if (amap->am_ppref == NULL && all == 0 && len != amap->am_nslot)
                   amap_pp_establish(amap, offset);
           if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
                   if (all)
                           amap_pp_adjref(amap, 0, amap->am_nslot, -1);
                   else
                           amap_pp_adjref(amap, offset, len, -1);
           }
   #endif
           amap_unlock(amap);
   
           UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
   }
   
   #endif /* _UVM_UVM_AMAP_I_H_ */
   
   #endif /* defined(UVM_AMAP_INLINE) || defined(UVM_AMAP_C) */
   

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