369 lines
9.4 KiB
C
369 lines
9.4 KiB
C
/*
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* Copyright (c) 1990 University of Utah.
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* the Systems Programming Group of the University of Utah Computer
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* Science Department.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)device_pager.c 8.1 (Berkeley) 6/11/93
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* $Id: device_pager.c,v 1.7 1995/03/11 22:25:00 davidg Exp $
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*/
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/*
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* Page to/from special files.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include <sys/mman.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <vm/vm.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_page.h>
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#include <vm/device_pager.h>
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struct pagerlst dev_pager_list; /* list of managed devices */
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struct pglist dev_pager_fakelist; /* list of available vm_page_t's */
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#ifdef DEBUG
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int dpagerdebug;
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#define DDB_FOLLOW 0x01
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#define DDB_INIT 0x02
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#define DDB_ALLOC 0x04
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#define DDB_FAIL 0x08
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#endif
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static vm_pager_t dev_pager_alloc __P((caddr_t, vm_size_t, vm_prot_t, vm_offset_t));
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static void dev_pager_dealloc __P((vm_pager_t));
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static int dev_pager_getpage __P((vm_pager_t, vm_page_t, boolean_t));
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static boolean_t dev_pager_haspage __P((vm_pager_t, vm_offset_t));
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static void dev_pager_init __P((void));
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static int dev_pager_putpage __P((vm_pager_t, vm_page_t, boolean_t));
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static vm_page_t dev_pager_getfake __P((vm_offset_t));
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static void dev_pager_putfake __P((vm_page_t));
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struct pagerops devicepagerops = {
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dev_pager_init,
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dev_pager_alloc,
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dev_pager_dealloc,
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dev_pager_getpage,
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0,
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dev_pager_putpage,
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0,
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dev_pager_haspage
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};
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static void
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dev_pager_init()
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{
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#ifdef DEBUG
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if (dpagerdebug & DDB_FOLLOW)
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printf("dev_pager_init()\n");
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#endif
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TAILQ_INIT(&dev_pager_list);
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TAILQ_INIT(&dev_pager_fakelist);
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}
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static vm_pager_t
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dev_pager_alloc(handle, size, prot, foff)
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caddr_t handle;
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vm_size_t size;
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vm_prot_t prot;
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vm_offset_t foff;
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{
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dev_t dev;
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vm_pager_t pager;
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int (*mapfunc) ();
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vm_object_t object;
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dev_pager_t devp;
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unsigned int npages, off;
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#ifdef DEBUG
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if (dpagerdebug & DDB_FOLLOW)
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printf("dev_pager_alloc(%x, %x, %x, %x)\n",
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handle, size, prot, foff);
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#endif
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#ifdef DIAGNOSTIC
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/*
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* Pageout to device, should never happen.
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*/
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if (handle == NULL)
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panic("dev_pager_alloc called");
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#endif
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/*
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* Make sure this device can be mapped.
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*/
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dev = (dev_t) (u_long) handle;
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mapfunc = cdevsw[major(dev)].d_mmap;
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if (mapfunc == NULL || mapfunc == enodev || mapfunc == nullop)
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return (NULL);
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/*
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* Offset should be page aligned.
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*/
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if (foff & (PAGE_SIZE - 1))
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return (NULL);
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/*
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* Check that the specified range of the device allows the desired
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* protection.
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*
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* XXX assumes VM_PROT_* == PROT_*
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*/
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npages = atop(round_page(size));
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for (off = foff; npages--; off += PAGE_SIZE)
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if ((*mapfunc) (dev, off, (int) prot) == -1)
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return (NULL);
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/*
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* Look up pager, creating as necessary.
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*/
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top:
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pager = vm_pager_lookup(&dev_pager_list, handle);
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if (pager == NULL) {
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/*
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* Allocate and initialize pager structs
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*/
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pager = (vm_pager_t) malloc(sizeof *pager, M_VMPAGER, M_WAITOK);
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if (pager == NULL)
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return (NULL);
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devp = (dev_pager_t) malloc(sizeof *devp, M_VMPGDATA, M_WAITOK);
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if (devp == NULL) {
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free((caddr_t) pager, M_VMPAGER);
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return (NULL);
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}
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pager->pg_handle = handle;
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pager->pg_ops = &devicepagerops;
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pager->pg_type = PG_DEVICE;
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pager->pg_data = (caddr_t) devp;
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TAILQ_INIT(&devp->devp_pglist);
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/*
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* Allocate object and associate it with the pager.
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*/
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object = devp->devp_object = vm_object_allocate(0);
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object->flags &= ~OBJ_INTERNAL;
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vm_object_enter(object, pager);
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object->pager = pager;
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/*
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* Finally, put it on the managed list so other can find it.
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* First we re-lookup in case someone else beat us to this
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* point (due to blocking in the various mallocs). If so, we
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* free everything and start over.
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*/
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if (vm_pager_lookup(&dev_pager_list, handle)) {
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free((caddr_t) devp, M_VMPGDATA);
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free((caddr_t) pager, M_VMPAGER);
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goto top;
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}
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TAILQ_INSERT_TAIL(&dev_pager_list, pager, pg_list);
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#ifdef DEBUG
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if (dpagerdebug & DDB_ALLOC) {
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printf("dev_pager_alloc: pager %x devp %x object %x\n",
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pager, devp, object);
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vm_object_print(object, FALSE);
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}
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#endif
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} else {
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/*
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* Gain a reference to the object.
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*/
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object = vm_object_lookup(pager);
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#ifdef DIAGNOSTIC
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devp = (dev_pager_t) pager->pg_data;
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if (object != devp->devp_object)
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panic("dev_pager_setup: bad object");
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#endif
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}
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return (pager);
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}
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static void
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dev_pager_dealloc(pager)
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vm_pager_t pager;
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{
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dev_pager_t devp;
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vm_object_t object;
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vm_page_t m;
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#ifdef DEBUG
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if (dpagerdebug & DDB_FOLLOW)
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printf("dev_pager_dealloc(%x)\n", pager);
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#endif
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TAILQ_REMOVE(&dev_pager_list, pager, pg_list);
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/*
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* Get the object. Note: cannot use vm_object_lookup since object has
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* already been removed from the hash chain.
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*/
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devp = (dev_pager_t) pager->pg_data;
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object = devp->devp_object;
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#ifdef DEBUG
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if (dpagerdebug & DDB_ALLOC)
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printf("dev_pager_dealloc: devp %x object %x\n", devp, object);
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#endif
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/*
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* Free up our fake pages.
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*/
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while ((m = devp->devp_pglist.tqh_first) != 0) {
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TAILQ_REMOVE(&devp->devp_pglist, m, pageq);
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dev_pager_putfake(m);
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}
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free((caddr_t) devp, M_VMPGDATA);
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free((caddr_t) pager, M_VMPAGER);
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}
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static int
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dev_pager_getpage(pager, m, sync)
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vm_pager_t pager;
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vm_page_t m;
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boolean_t sync;
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{
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register vm_object_t object;
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vm_offset_t offset, paddr;
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vm_page_t page;
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dev_t dev;
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int s;
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int (*mapfunc) (), prot;
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#ifdef DEBUG
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if (dpagerdebug & DDB_FOLLOW)
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printf("dev_pager_getpage(%x, %x)\n", pager, m);
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#endif
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object = m->object;
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dev = (dev_t) (u_long) pager->pg_handle;
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offset = m->offset + object->paging_offset;
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prot = PROT_READ; /* XXX should pass in? */
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mapfunc = cdevsw[major(dev)].d_mmap;
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if (mapfunc == NULL || mapfunc == enodev || mapfunc == nullop)
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panic("dev_pager_getpage: no map function");
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paddr = pmap_phys_address((*mapfunc) ((dev_t) dev, (int) offset, prot));
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#ifdef DIAGNOSTIC
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if (paddr == -1)
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panic("dev_pager_getpage: map function returns error");
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#endif
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/*
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* Replace the passed in page with our own fake page and free up the
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* original.
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*/
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page = dev_pager_getfake(paddr);
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TAILQ_INSERT_TAIL(&((dev_pager_t) pager->pg_data)->devp_pglist,
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page, pageq);
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vm_object_lock(object);
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vm_page_lock_queues();
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PAGE_WAKEUP(m);
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vm_page_free(m);
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vm_page_unlock_queues();
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s = splhigh();
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vm_page_insert(page, object, offset);
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splx(s);
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if (offset + PAGE_SIZE > object->size)
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object->size = offset + PAGE_SIZE; /* XXX anal */
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vm_object_unlock(object);
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return (VM_PAGER_OK);
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}
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static int
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dev_pager_putpage(pager, m, sync)
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vm_pager_t pager;
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vm_page_t m;
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boolean_t sync;
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{
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#ifdef DEBUG
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if (dpagerdebug & DDB_FOLLOW)
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printf("dev_pager_putpage(%x, %x)\n", pager, m);
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#endif
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if (pager == NULL)
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return 0;
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panic("dev_pager_putpage called");
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}
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static boolean_t
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dev_pager_haspage(pager, offset)
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vm_pager_t pager;
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vm_offset_t offset;
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{
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#ifdef DEBUG
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if (dpagerdebug & DDB_FOLLOW)
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printf("dev_pager_haspage(%x, %x)\n", pager, offset);
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#endif
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return (TRUE);
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}
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static vm_page_t
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dev_pager_getfake(paddr)
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vm_offset_t paddr;
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{
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vm_page_t m;
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int i;
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if (dev_pager_fakelist.tqh_first == NULL) {
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m = (vm_page_t) malloc(PAGE_SIZE * 2, M_VMPGDATA, M_WAITOK);
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for (i = (PAGE_SIZE * 2) / sizeof(*m); i > 0; i--) {
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TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq);
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m++;
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}
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}
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m = dev_pager_fakelist.tqh_first;
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TAILQ_REMOVE(&dev_pager_fakelist, m, pageq);
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m->flags = PG_BUSY | PG_FICTITIOUS;
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m->dirty = 0;
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m->valid = VM_PAGE_BITS_ALL;
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m->busy = 0;
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m->bmapped = 0;
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m->wire_count = 1;
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m->phys_addr = paddr;
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return (m);
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}
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static void
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dev_pager_putfake(m)
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vm_page_t m;
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{
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#ifdef DIAGNOSTIC
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if (!(m->flags & PG_FICTITIOUS))
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panic("dev_pager_putfake: bad page");
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#endif
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TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq);
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}
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