[src/trunk]: src/sys/arch/powerpc/ibm4xx fix two bugs with wiring:

[chs <chs%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7b6c33d7beb6
branches:  trunk
changeset: 574496:7b6c33d7beb6
user:      chs <chs%NetBSD.org@localhost>
date:      Wed Mar 02 09:02:42 2005 +0000

description:
fix two bugs with wiring:
 (1) in pmap_enter_pv(), we would always mark the header entry wired, even if
     the new entry wasn't put there.  noticed by Juergen Hannken-Illjes.
 (2) in pmap_unwire(), we would never examine the header entry.
     noticed by me.

while I'm here, move the counter increment in the pmap_enter() path to be
next to the corresponding PV_WIRE() call so it's more obvious they match.

diffstat:

 sys/arch/powerpc/ibm4xx/pmap.c |  26 ++++++++++----------------
 1 files changed, 10 insertions(+), 16 deletions(-)

diffs (75 lines):

diff -r 57fea177d7e5 -r 7b6c33d7beb6 sys/arch/powerpc/ibm4xx/pmap.c
--- a/sys/arch/powerpc/ibm4xx/pmap.c    Wed Mar 02 08:14:26 2005 +0000
+++ b/sys/arch/powerpc/ibm4xx/pmap.c    Wed Mar 02 09:02:42 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.32 2005/02/25 07:09:58 simonb Exp $ */
+/*     $NetBSD: pmap.c,v 1.33 2005/03/02 09:02:42 chs Exp $    */
 
 /*
  * Copyright 2001 Wasabi Systems, Inc.
@@ -67,7 +67,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.32 2005/02/25 07:09:58 simonb Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.33 2005/03/02 09:02:42 chs Exp $");
 
 #include <sys/param.h>
 #include <sys/malloc.h>
@@ -728,9 +728,11 @@
                npv->pv_pm = pm;
                npv->pv_next = pv->pv_next;
                pv->pv_next = npv;
+               pv = npv;
        }
        if (wired) {
                PV_WIRE(pv);
+               pm->pm_stats.wired_count++;
        }
        splx(s);
        return (1);
@@ -869,16 +871,13 @@
        if ((prot & VM_PROT_EXECUTE) && (tte & TTE_I) == 0)
                __syncicache((void *)pa, PAGE_SIZE);
 
-       if (flags & PMAP_WIRED)
-               pm->pm_stats.wired_count++;
-
        return 0;
 }
 
 void
 pmap_unwire(struct pmap *pm, vaddr_t va)
 {
-       struct pv_entry *pv, *npv;
+       struct pv_entry *pv;
        paddr_t pa;
        int s;
 
@@ -890,21 +889,16 @@
        if (!pv)
                return;
 
-       /*
-        * If it is the first entry on the list, it is actually
-        * in the header and we must copy the following entry up
-        * to the header.  Otherwise we must search the list for
-        * the entry.  In either case we free the now unused entry.
-        */
        s = splvm();
-       for (npv = pv; (npv = pv->pv_next) != NULL; pv = npv) {
-               if (pm == npv->pv_pm && PV_CMPVA(va, npv)) {
-                       if (PV_ISWIRED(npv)) {
-                               PV_UNWIRE(npv);
+       while (pv != NULL) {
+               if (pm == pv->pv_pm && PV_CMPVA(va, pv)) {
+                       if (PV_ISWIRED(pv)) {
+                               PV_UNWIRE(pv);
                                pm->pm_stats.wired_count--;
                        }
                        break;
                }
+               pv = pv->pv_next;
        }
        splx(s);
 }