[src/trunk]: src/sys/arch/arm/arm32 Since pmap_page_remove() is called from p...

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

details:   https://anonhg.NetBSD.org/src/rev/807f849c8e94
branches:  trunk
changeset: 580505:807f849c8e94
user:      scw <scw%NetBSD.org@localhost>
date:      Tue Apr 26 16:03:08 2005 +0000

description:
Since pmap_page_remove() is called from pmap_page_protect(), don't modify
the current pmap's pm_cstate if we have to flush the TLB, as callers of
pmap_page_protect() are not required to invoke pmap_update() afterwards.

Otherwise we can end up with a pm_cstate which is inconsistent with reality
in the TLB, which can lead to future TLB flushes being erroneously skipped.

diffstat:

 sys/arch/arm/arm32/pmap.c |  15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)

diffs (38 lines):

diff -r 011e70c9cf90 -r 807f849c8e94 sys/arch/arm/arm32/pmap.c
--- a/sys/arch/arm/arm32/pmap.c Tue Apr 26 13:02:06 2005 +0000
+++ b/sys/arch/arm/arm32/pmap.c Tue Apr 26 16:03:08 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.151 2005/04/01 11:59:23 yamt Exp $  */
+/*     $NetBSD: pmap.c,v 1.152 2005/04/26 16:03:08 scw Exp $   */
 
 /*
  * Copyright 2003 Wasabi Systems, Inc.
@@ -212,7 +212,7 @@
 #include <machine/param.h>
 #include <arm/arm32/katelib.h>
 
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.151 2005/04/01 11:59:23 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.152 2005/04/26 16:03:08 scw Exp $");
 
 #ifdef PMAP_DEBUG
 
@@ -1872,10 +1872,17 @@
        PMAP_HEAD_TO_MAP_UNLOCK();
 
        if (flush) {
+               /*
+                * Note: We can't use pmap_tlb_flush{I,}D() here since that
+                * would need a subsequent call to pmap_update() to ensure
+                * curpm->pm_cstate.cs_all is reset. Our callers are not
+                * required to do that (see pmap(9)), so we can't modify
+                * the current pmap's state.
+                */
                if (PV_BEEN_EXECD(flags))
-                       pmap_tlb_flushID(curpm);
+                       cpu_tlb_flushID();
                else
-                       pmap_tlb_flushD(curpm);
+                       cpu_tlb_flushD();
        }
        cpu_cpwait();
 }