545 lines
13 KiB
C
545 lines
13 KiB
C
/* $NetBSD: uvm_device.c,v 1.22 2000/05/28 10:21:55 drochner Exp $ */
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/*
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*
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* Copyright (c) 1997 Charles D. Cranor and Washington University.
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* All rights reserved.
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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 Charles D. Cranor and
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* Washington University.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* from: Id: uvm_device.c,v 1.1.2.9 1998/02/06 05:11:47 chs Exp
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*/
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#include "opt_uvmhist.h"
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/*
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* uvm_device.c: the device pager.
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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/proc.h>
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#include <sys/malloc.h>
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#include <sys/vnode.h>
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#include <vm/vm.h>
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#include <vm/vm_page.h>
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#include <vm/vm_kern.h>
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#include <uvm/uvm.h>
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#include <uvm/uvm_device.h>
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/*
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* private global data structure
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*
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* we keep a list of active device objects in the system.
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*/
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LIST_HEAD(udv_list_struct, uvm_device);
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static struct udv_list_struct udv_list;
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static simple_lock_data_t udv_lock;
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/*
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* functions
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*/
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static void udv_init __P((void));
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static void udv_reference __P((struct uvm_object *));
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static void udv_detach __P((struct uvm_object *));
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static int udv_fault __P((struct uvm_faultinfo *, vaddr_t,
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vm_page_t *, int, int, vm_fault_t,
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vm_prot_t, int));
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static int udv_asyncget __P((struct uvm_object *, voff_t,
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int));
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static boolean_t udv_flush __P((struct uvm_object *, voff_t, voff_t,
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int));
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static int udv_put __P((struct uvm_object *, vm_page_t *,
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int, boolean_t));
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/*
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* master pager structure
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*/
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struct uvm_pagerops uvm_deviceops = {
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udv_init,
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udv_reference,
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udv_detach,
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udv_fault,
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udv_flush,
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NULL, /* no get function since we have udv_fault */
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udv_asyncget,
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udv_put,
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NULL, /* no cluster function */
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NULL, /* no put cluster function */
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NULL, /* no AIO-DONE function since no async i/o */
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NULL, /* no releasepg function since no normal pages */
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};
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/*
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* the ops!
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*/
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/*
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* udv_init
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*
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* init pager private data structures.
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*/
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void
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udv_init()
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{
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LIST_INIT(&udv_list);
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simple_lock_init(&udv_lock);
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}
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/*
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* udv_attach
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*
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* get a VM object that is associated with a device. allocate a new
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* one if needed.
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*
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* => caller must _not_ already be holding the lock on the uvm_object.
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* => in fact, nothing should be locked so that we can sleep here.
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*/
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struct uvm_object *
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udv_attach(arg, accessprot, off, size)
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void *arg;
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vm_prot_t accessprot;
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voff_t off; /* used only for access check */
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vsize_t size; /* used only for access check */
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{
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dev_t device = *((dev_t *) arg);
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struct uvm_device *udv, *lcv;
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int (*mapfn) __P((dev_t, int, int));
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UVMHIST_FUNC("udv_attach"); UVMHIST_CALLED(maphist);
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UVMHIST_LOG(maphist, "(device=0x%x)", device,0,0,0);
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/*
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* before we do anything, ensure this device supports mmap
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*/
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mapfn = cdevsw[major(device)].d_mmap;
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if (mapfn == NULL ||
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mapfn == (int (*) __P((dev_t, int, int))) enodev ||
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mapfn == (int (*) __P((dev_t, int, int))) nullop)
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return(NULL);
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/*
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* As long as the device d_mmap interface gets an "int"
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* offset, we have to watch out not to overflow its
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* numeric range. (assuming it will be interpreted as
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* "unsigned")
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*/
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if (((off + size - 1) & (u_int)-1) != off + size - 1)
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return (0);
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/*
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* Check that the specified range of the device allows the
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* desired protection.
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*
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* XXX assumes VM_PROT_* == PROT_*
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* XXX clobbers off and size, but nothing else here needs them.
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*/
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while (size != 0) {
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if ((*mapfn)(device, off, accessprot) == -1)
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return (NULL);
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off += PAGE_SIZE; size -= PAGE_SIZE;
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}
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/*
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* keep looping until we get it
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*/
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while (1) {
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/*
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* first, attempt to find it on the main list
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*/
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simple_lock(&udv_lock);
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for (lcv = udv_list.lh_first ; lcv != NULL ; lcv = lcv->u_list.le_next) {
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if (device == lcv->u_device)
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break;
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}
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/*
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* got it on main list. put a hold on it and unlock udv_lock.
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*/
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if (lcv) {
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/*
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* if someone else has a hold on it, sleep and start
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* over again.
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*/
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if (lcv->u_flags & UVM_DEVICE_HOLD) {
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lcv->u_flags |= UVM_DEVICE_WANTED;
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UVM_UNLOCK_AND_WAIT(lcv, &udv_lock, FALSE,
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"udv_attach",0);
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continue;
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}
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/* we are now holding it */
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lcv->u_flags |= UVM_DEVICE_HOLD;
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simple_unlock(&udv_lock);
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/*
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* bump reference count, unhold, return.
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*/
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simple_lock(&lcv->u_obj.vmobjlock);
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lcv->u_obj.uo_refs++;
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simple_unlock(&lcv->u_obj.vmobjlock);
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simple_lock(&udv_lock);
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if (lcv->u_flags & UVM_DEVICE_WANTED)
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wakeup(lcv);
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lcv->u_flags &= ~(UVM_DEVICE_WANTED|UVM_DEVICE_HOLD);
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simple_unlock(&udv_lock);
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return(&lcv->u_obj);
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}
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/*
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* did not find it on main list. need to malloc a new one.
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*/
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simple_unlock(&udv_lock);
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/* NOTE: we could sleep in the following malloc() */
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MALLOC(udv, struct uvm_device *, sizeof(*udv), M_TEMP, M_WAITOK);
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simple_lock(&udv_lock);
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/*
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* now we have to double check to make sure no one added it
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* to the list while we were sleeping...
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*/
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for (lcv = udv_list.lh_first ; lcv != NULL ;
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lcv = lcv->u_list.le_next) {
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if (device == lcv->u_device)
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break;
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}
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/*
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* did we lose a race to someone else? free our memory and retry.
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*/
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if (lcv) {
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simple_unlock(&udv_lock);
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FREE(udv, M_TEMP);
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continue;
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}
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/*
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* we have it! init the data structures, add to list
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* and return.
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*/
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simple_lock_init(&udv->u_obj.vmobjlock);
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udv->u_obj.pgops = &uvm_deviceops;
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TAILQ_INIT(&udv->u_obj.memq); /* not used, but be safe */
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udv->u_obj.uo_npages = 0;
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udv->u_obj.uo_refs = 1;
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udv->u_flags = 0;
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udv->u_device = device;
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LIST_INSERT_HEAD(&udv_list, udv, u_list);
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simple_unlock(&udv_lock);
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return(&udv->u_obj);
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} /* while(1) loop */
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/*NOTREACHED*/
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}
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/*
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* udv_reference
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*
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* add a reference to a VM object. Note that the reference count must
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* already be one (the passed in reference) so there is no chance of the
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* udv being released or locked out here.
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*
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* => caller must call with object unlocked.
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*/
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static void
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udv_reference(uobj)
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struct uvm_object *uobj;
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{
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UVMHIST_FUNC("udv_reference"); UVMHIST_CALLED(maphist);
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simple_lock(&uobj->vmobjlock);
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uobj->uo_refs++;
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UVMHIST_LOG(maphist, "<- done (uobj=0x%x, ref = %d)",
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uobj, uobj->uo_refs,0,0);
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simple_unlock(&uobj->vmobjlock);
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}
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/*
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* udv_detach
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*
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* remove a reference to a VM object.
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*
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* => caller must call with object unlocked and map locked.
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*/
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static void
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udv_detach(uobj)
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struct uvm_object *uobj;
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{
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struct uvm_device *udv = (struct uvm_device *) uobj;
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UVMHIST_FUNC("udv_detach"); UVMHIST_CALLED(maphist);
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/*
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* loop until done
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*/
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while (1) {
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simple_lock(&uobj->vmobjlock);
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if (uobj->uo_refs > 1) {
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uobj->uo_refs--; /* drop ref! */
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simple_unlock(&uobj->vmobjlock);
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UVMHIST_LOG(maphist," <- done, uobj=0x%x, ref=%d",
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uobj,uobj->uo_refs,0,0);
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return;
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}
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#ifdef DIAGNOSTIC
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if (uobj->uo_npages || uobj->memq.tqh_first)
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panic("udv_detach: pages in a device object?");
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#endif
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/*
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* now lock udv_lock
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*/
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simple_lock(&udv_lock);
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/*
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* is it being held? if so, wait until others are done.
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*/
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if (udv->u_flags & UVM_DEVICE_HOLD) {
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/*
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* want it
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*/
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udv->u_flags |= UVM_DEVICE_WANTED;
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simple_unlock(&uobj->vmobjlock);
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UVM_UNLOCK_AND_WAIT(udv, &udv_lock, FALSE, "udv_detach",0);
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continue;
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}
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/*
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* got it! nuke it now.
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*/
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LIST_REMOVE(udv, u_list);
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if (udv->u_flags & UVM_DEVICE_WANTED)
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wakeup(udv);
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FREE(udv, M_TEMP);
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break; /* DONE! */
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} /* while (1) loop */
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UVMHIST_LOG(maphist," <- done, freed uobj=0x%x", uobj,0,0,0);
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return;
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}
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/*
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* udv_flush
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*
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* flush pages out of a uvm object. a no-op for devices.
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*/
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static boolean_t udv_flush(uobj, start, stop, flags)
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struct uvm_object *uobj;
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voff_t start, stop;
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int flags;
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{
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return(TRUE);
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}
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/*
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* udv_fault: non-standard fault routine for device "pages"
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*
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* => rather than having a "get" function, we have a fault routine
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* since we don't return vm_pages we need full control over the
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* pmap_enter map in
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* => all the usual fault data structured are locked by the caller
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* (i.e. maps(read), amap (if any), uobj)
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* => on return, we unlock all fault data structures
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* => flags: PGO_ALLPAGES: get all of the pages
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* PGO_LOCKED: fault data structures are locked
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* XXX: currently PGO_LOCKED is always required ... consider removing
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* it as a flag
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* => NOTE: vaddr is the VA of pps[0] in ufi->entry, _NOT_ pps[centeridx]
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*/
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static int
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udv_fault(ufi, vaddr, pps, npages, centeridx, fault_type, access_type, flags)
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struct uvm_faultinfo *ufi;
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vaddr_t vaddr;
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vm_page_t *pps;
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int npages, centeridx, flags;
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vm_fault_t fault_type;
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vm_prot_t access_type;
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{
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struct vm_map_entry *entry = ufi->entry;
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struct uvm_object *uobj = entry->object.uvm_obj;
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struct uvm_device *udv = (struct uvm_device *)uobj;
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vaddr_t curr_va;
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int curr_offset;
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paddr_t paddr;
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int lcv, retval, mdpgno;
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dev_t device;
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int (*mapfn) __P((dev_t, int, int));
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vm_prot_t mapprot;
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UVMHIST_FUNC("udv_fault"); UVMHIST_CALLED(maphist);
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UVMHIST_LOG(maphist," flags=%d", flags,0,0,0);
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/*
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* XXX: !PGO_LOCKED calls are currently not allowed (or used)
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*/
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if ((flags & PGO_LOCKED) == 0)
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panic("udv_fault: !PGO_LOCKED fault");
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/*
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* we do not allow device mappings to be mapped copy-on-write
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* so we kill any attempt to do so here.
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*/
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if (UVM_ET_ISCOPYONWRITE(entry)) {
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UVMHIST_LOG(maphist, "<- failed -- COW entry (etype=0x%x)",
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entry->etype, 0,0,0);
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uvmfault_unlockall(ufi, ufi->entry->aref.ar_amap, uobj, NULL);
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return(VM_PAGER_ERROR);
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}
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/*
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* get device map function.
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*/
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device = udv->u_device;
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mapfn = cdevsw[major(device)].d_mmap;
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/*
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* now we must determine the offset in udv to use and the VA to
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* use for pmap_enter. note that we always use orig_map's pmap
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* for pmap_enter (even if we have a submap). since virtual
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* addresses in a submap must match the main map, this is ok.
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*/
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/* udv offset = (offset from start of entry) + entry's offset */
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curr_offset = (int)((vaddr - entry->start) + entry->offset);
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/* pmap va = vaddr (virtual address of pps[0]) */
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curr_va = vaddr;
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/*
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* loop over the page range entering in as needed
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*/
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retval = VM_PAGER_OK;
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for (lcv = 0 ; lcv < npages ; lcv++, curr_offset += PAGE_SIZE,
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curr_va += PAGE_SIZE) {
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if ((flags & PGO_ALLPAGES) == 0 && lcv != centeridx)
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continue;
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if (pps[lcv] == PGO_DONTCARE)
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continue;
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mdpgno = (*mapfn)(device, curr_offset, access_type);
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if (mdpgno == -1) {
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retval = VM_PAGER_ERROR;
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break;
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}
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paddr = pmap_phys_address(mdpgno);
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mapprot = ufi->entry->protection;
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UVMHIST_LOG(maphist,
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" MAPPING: device: pm=0x%x, va=0x%x, pa=0x%x, at=%d",
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ufi->orig_map->pmap, curr_va, (int)paddr, mapprot);
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if (pmap_enter(ufi->orig_map->pmap, curr_va, paddr,
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mapprot, PMAP_CANFAIL | mapprot) != KERN_SUCCESS) {
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/*
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* pmap_enter() didn't have the resource to
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* enter this mapping. Unlock everything,
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* wait for the pagedaemon to free up some
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* pages, and then tell uvm_fault() to start
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* the fault again.
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*
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* XXX Needs some rethinking for the PGO_ALLPAGES
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* XXX case.
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*/
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uvmfault_unlockall(ufi, ufi->entry->aref.ar_amap,
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uobj, NULL);
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uvm_wait("udv_fault");
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return (VM_PAGER_REFAULT);
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}
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}
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uvmfault_unlockall(ufi, ufi->entry->aref.ar_amap, uobj, NULL);
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return (retval);
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}
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/*
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* udv_asyncget: start async I/O to bring pages into ram
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*
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* => caller must lock object(???XXX: see if this is best)
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* => a no-op for devices
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*/
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static int
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udv_asyncget(uobj, offset, npages)
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struct uvm_object *uobj;
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voff_t offset;
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int npages;
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{
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return(KERN_SUCCESS);
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}
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/*
|
|
* udv_put: flush page data to backing store.
|
|
*
|
|
* => this function should never be called (since we never have any
|
|
* page structures to "put")
|
|
*/
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|
|
|
static int
|
|
udv_put(uobj, pps, npages, flags)
|
|
struct uvm_object *uobj;
|
|
struct vm_page **pps;
|
|
int npages, flags;
|
|
{
|
|
|
|
panic("udv_put: trying to page out to a device!");
|
|
}
|