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/* $OpenBSD: uvm_object.c,v 1.15 2019/11/29 22:10:04 beck Exp $ */
/*
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Mindaugas Rasiukevicius.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* uvm_object.c: operate with memory objects
*
*/
#include <sys/param.h>
#include <sys/mman.h>
#include <sys/atomic.h>
#include <uvm/uvm.h>
/* We will fetch this page count per step */
#define FETCH_PAGECOUNT 16
/*
* uvm_objinit: initialise a uvm object.
*/
void
uvm_objinit(struct uvm_object *uobj, struct uvm_pagerops *pgops, int refs)
{
uobj->pgops = pgops;
RBT_INIT(uvm_objtree, &uobj->memt);
uobj->uo_npages = 0;
uobj->uo_refs = refs;
}
#ifndef SMALL_KERNEL
/*
* uvm_objwire: wire the pages of entire uobj
*
* => caller must pass page-aligned start and end values
* => if the caller passes in a pageq pointer, we'll return a list of
* wired pages.
*/
int
uvm_objwire(struct uvm_object *uobj, voff_t start, voff_t end,
struct pglist *pageq)
{
int i, npages, left, error;
struct vm_page *pgs[FETCH_PAGECOUNT];
voff_t offset = start;
left = (end - start) >> PAGE_SHIFT;
while (left) {
npages = MIN(FETCH_PAGECOUNT, left);
/* Get the pages */
memset(pgs, 0, sizeof(pgs));
error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0,
PROT_READ | PROT_WRITE, MADV_SEQUENTIAL,
PGO_ALLPAGES | PGO_SYNCIO);
if (error)
goto error;
for (i = 0; i < npages; i++) {
KASSERT(pgs[i] != NULL);
KASSERT(!(pgs[i]->pg_flags & PG_RELEASED));
if (pgs[i]->pg_flags & PQ_AOBJ) {
atomic_clearbits_int(&pgs[i]->pg_flags,
PG_CLEAN);
uao_dropswap(uobj, i);
}
}
/* Wire the pages */
uvm_lock_pageq();
for (i = 0; i < npages; i++) {
uvm_pagewire(pgs[i]);
if (pageq != NULL)
TAILQ_INSERT_TAIL(pageq, pgs[i], pageq);
}
uvm_unlock_pageq();
/* Unbusy the pages */
uvm_page_unbusy(pgs, npages);
left -= npages;
offset += (voff_t)npages << PAGE_SHIFT;
}
return 0;
error:
/* Unwire the pages which have been wired */
uvm_objunwire(uobj, start, offset);
return error;
}
/*
* uobj_unwirepages: unwire the pages of entire uobj
*
* => caller must pass page-aligned start and end values
*/
void
uvm_objunwire(struct uvm_object *uobj, voff_t start, voff_t end)
{
struct vm_page *pg;
off_t offset;
uvm_lock_pageq();
for (offset = start; offset < end; offset += PAGE_SIZE) {
pg = uvm_pagelookup(uobj, offset);
KASSERT(pg != NULL);
KASSERT(!(pg->pg_flags & PG_RELEASED));
uvm_pageunwire(pg);
}
uvm_unlock_pageq();
}
#endif /* !SMALL_KERNEL */
/*
* uvm_objfree: free all pages in a uvm object, used by the buffer
* cache to free all pages attached to a buffer.
*/
void
uvm_objfree(struct uvm_object *uobj)
{
struct vm_page *pg;
struct pglist pgl;
TAILQ_INIT(&pgl);
/*
* Extract from rb tree in offset order. The phys addresses
* usually increase in that order, which is better for
* uvm_pmr_freepageq.
*/
RBT_FOREACH(pg, uvm_objtree, &uobj->memt) {
/*
* clear PG_TABLED so we don't do work to remove
* this pg from the uobj we are throwing away
*/
atomic_clearbits_int(&pg->pg_flags, PG_TABLED);
uvm_pageclean(pg);
TAILQ_INSERT_TAIL(&pgl, pg, pageq);
}
uvm_pmr_freepageq(&pgl);
}
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