[src/trunk]: src/sys/arch/alpha/alpha Remove I-sync stuff from pmap_changebit...

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

details:   https://anonhg.NetBSD.org/src/rev/2ec15faa494b
branches:  trunk
changeset: 512777:2ec15faa494b
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Mon Jul 16 19:48:03 2001 +0000

description:
Remove I-sync stuff from pmap_changebit().  The AARM says that we
only have to sync the I-stream when the mapping is removed or chaged,
and since the I-stream is fetch-only, changing protection bits does
not constitute changing the mapping (the VA->PA translation is still
the same).

diffstat:

 sys/arch/alpha/alpha/pmap.c |  29 ++---------------------------
 1 files changed, 2 insertions(+), 27 deletions(-)

diffs (72 lines):

diff -r 41e43aa8252d -r 2ec15faa494b sys/arch/alpha/alpha/pmap.c
--- a/sys/arch/alpha/alpha/pmap.c       Mon Jul 16 18:59:33 2001 +0000
+++ b/sys/arch/alpha/alpha/pmap.c       Mon Jul 16 19:48:03 2001 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.183 2001/07/15 21:57:01 thorpej Exp $ */
+/* $NetBSD: pmap.c,v 1.184 2001/07/16 19:48:03 thorpej Exp $ */
 
 /*-
  * Copyright (c) 1998, 1999, 2000, 2001 The NetBSD Foundation, Inc.
@@ -154,7 +154,7 @@
 
 #include <sys/cdefs.h>                 /* RCS ID & Copyright macro defns */
 
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.183 2001/07/15 21:57:01 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.184 2001/07/16 19:48:03 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -2679,9 +2679,6 @@
  *     Note: we assume that the pv_head is already locked, and that
  *     the caller has acquired a PV->pmap mutex so that we can lock
  *     the pmaps as we encounter them.
- *
- *     XXX This routine could stand to have some I-stream
- *     XXX optimization done.
  */
 void
 pmap_changebit(struct vm_page *pg, u_long set, u_long mask, long cpu_id)
@@ -2690,7 +2687,6 @@
        pt_entry_t *pte, npte;
        vaddr_t va;
        boolean_t hadasm, isactive;
-       boolean_t needisync, needkisync = FALSE;
        PMAP_TLB_SHOOTDOWN_CPUSET_DECL
 
 #ifdef DEBUG
@@ -2721,25 +2717,7 @@
                if (*pte != npte) {
                        hadasm = (pmap_pte_asm(pte) != 0);
                        isactive = PMAP_ISACTIVE(pv->pv_pmap, cpu_id);
-                       /*
-                        * Determine what we need to do about the I-stream.
-                        * If PG_EXEC was set, we mark a user pmap as needing
-                        * an I-sync on the way out to userspace.  We always
-                        * need an immediate I-sync for the kernel pmap.
-                        */
-                       needisync = FALSE;
-                       if (pmap_pte_exec(pte)) {
-                               if (pv->pv_pmap == pmap_kernel())
-                                       needkisync = TRUE;
-                               else {
-                                       PMAP_SET_NEEDISYNC(pv->pv_pmap);
-                                       if (pv->pv_pmap->pm_cpus != 0)
-                                               needisync = TRUE;
-                               }
-                       }
                        PMAP_SET_PTE(pte, npte);
-                       if (needisync)
-                               PMAP_SYNC_ISTREAM_USER(pv->pv_pmap);
                        PMAP_INVALIDATE_TLB(pv->pv_pmap, va, hadasm, isactive,
                            cpu_id);
                        PMAP_TLB_SHOOTDOWN(pv->pv_pmap, va,
@@ -2749,9 +2727,6 @@
        }
 
        PMAP_TLB_SHOOTNOW();
-
-       if (needkisync)
-               PMAP_SYNC_ISTREAM_KERNEL();
 }
 
 /*