/* $OpenBSD: uvm_object.c,v 1.6 2010/05/01 13:13:10 oga 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/proc.h> /* XXX for atomic */ #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; RB_INIT(&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, off_t start, off_t end, struct pglist *pageq) { int i, npages, error; struct vm_page *pgs[FETCH_PAGECOUNT]; off_t offset = start, left; left = (end - start) >> PAGE_SHIFT; simple_lock(&uobj->vmobjlock); 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, VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL, PGO_ALLPAGES | PGO_SYNCIO); if (error) goto error; simple_lock(&uobj->vmobjlock); for (i = 0; i < npages; i++) { KASSERT(pgs[i] != NULL); KASSERT(!(pgs[i]->pg_flags & PG_RELEASED)); #if 0 /* * Loan break */ if (pgs[i]->loan_count) { while (pgs[i]->loan_count) { pg = uvm_loanbreak(pgs[i]); if (!pg) { simple_unlock(&uobj->vmobjlock); uvm_wait("uobjwirepg"); simple_lock(&uobj->vmobjlock); continue; } } pgs[i] = pg; } #endif 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 += npages << PAGE_SHIFT; } simple_unlock(&uobj->vmobjlock); 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, off_t start, off_t end) { struct vm_page *pg; off_t offset; simple_lock(&uobj->vmobjlock); 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(); simple_unlock(&uobj->vmobjlock); } #endif /* !SMALL_KERNEL */