NetBSD/sys/uvm/uvm_amap_i.h

/*	$NetBSD: uvm_amap_i.h,v 1.3 1998/02/07 11:08:02 mrg Exp $	*/

/*
 * XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE!   
 *	   >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<<
 */
/*
 *
 * 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
 */

/*
 * inline functions [maybe]
 */

#if defined(UVM_AMAP_INLINE) || defined(UVM_AMAP)

/*
 * 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;
vm_offset_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_slotoff;

  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.
 */

AMAP_INLINE void amap_lookups(aref, offset, anons, npages)

struct vm_aref *aref;
vm_offset_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_slotoff;

  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");  

  bcopy(&amap->am_anon[slot], anons, 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.
 * => returns an "offset" which is meaningful to amap_unadd().
 */

AMAP_INLINE vm_offset_t amap_add(aref, offset, anon, replace)

struct vm_aref *aref;
vm_offset_t offset;
struct vm_anon *anon;
int replace;

{
  int slot;
  struct vm_amap *amap = aref->ar_amap;
  UVMHIST_FUNC("amap_add"); UVMHIST_CALLED(maphist);

  AMAP_B2SLOT(slot, offset);
  slot += aref->ar_slotoff;

  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(PMAP_PGARG(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);

  return(slot);

}

/*
 * amap_unadd: remove a page from an amap, given we know the slot #.
 *
 * => caller must lock amap
 */

AMAP_INLINE void amap_unadd(amap, slot)

struct vm_amap *amap;
vm_offset_t slot;

{
  int ptr;
  UVMHIST_FUNC("amap_unadd"); UVMHIST_CALLED(maphist);

  if (slot >= amap->am_nslot)
    panic("amap_add: 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)
 * => called at fork time to gain the child's reference
 */

AMAP_INLINE void amap_ref(entry, flags)

vm_map_entry_t entry;
int flags;
 
{  
  struct vm_amap *amap = entry->aref.ar_amap;
  UVMHIST_FUNC("amap_ref"); UVMHIST_CALLED(maphist);
  simple_lock(&amap->am_l);
  amap->am_ref++;
  if (flags & AMAP_SHARED)
    amap->am_flags |= AMAP_SHARED;
#ifdef VM_AMAP_PPREF
  if (amap->am_ppref == NULL && (flags & AMAP_REFALL) == 0 &&
      (entry->start - entry->end) / PAGE_SIZE != amap->am_nslot)
    amap_pp_establish(amap);
  if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
    if (flags & AMAP_REFALL)
      amap_pp_adjref(amap, 0, amap->am_nslot * PAGE_SIZE, 1);
    else
      amap_pp_adjref(amap, entry->aref.ar_slotoff, 
		     entry->end - entry->start, 1);
  }
#endif
  simple_unlock(&amap->am_l);
  UVMHIST_LOG(maphist,"<- done!  amap=0x%x", amap, 0, 0, 0);
}

/*
 * amap_unref: remove a reference to an amap
 *
 * => caller has already removed pmap mappings to amap.
 * => entry is no longer a part of a map, so it can't be changed and
 *	doesn't need to be locked.
 * => amap must be unlocked (we will lock it).
 */

AMAP_INLINE void amap_unref(entry, all)

vm_map_entry_t entry;
int all;

{
  struct vm_amap *amap = entry->aref.ar_amap;
  UVMHIST_FUNC("amap_unref"); UVMHIST_CALLED(maphist);

  /*
   * lock it
   */
  simple_lock(&amap->am_l);

  UVMHIST_LOG(maphist,"(entry=0x%x)  amap=0x%x  refs=%d, nused=%d",
	      entry, amap, amap->am_ref, amap->am_nused);

  /*
   * 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 VM_AMAP_PPREF
  if (amap->am_ppref == NULL && all == 0 &&
      (entry->start - entry->end) / PAGE_SIZE != amap->am_nslot)
    amap_pp_establish(amap);
  if (amap->am_ppref && amap->am_ppref != PPREF_NONE) {
    if (all)
      amap_pp_adjref(amap, 0, amap->am_nslot * PAGE_SIZE, -1);
    else
      amap_pp_adjref(amap, entry->aref.ar_slotoff, 
		     entry->end - entry->start, -1);
  }
#endif

  simple_unlock(&amap->am_l);

  UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
}

#endif /* defined(UVM_AMAP_INLINE) || defined(UVM_AMAP) */