[src/trunk]: src/sys/arch/sh5/sh5 As per TODO item #13, clear the Referenced ...

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

details:   https://anonhg.NetBSD.org/src/rev/fd6d99d21b61
branches:  trunk
changeset: 538543:fd6d99d21b61
user:      scw <scw%NetBSD.org@localhost>
date:      Tue Oct 22 13:10:28 2002 +0000

description:
As per TODO item #13, clear the Referenced bit in the PTE after purging
a mapping from the TLB/cache to prevent duplicate purges for pages
which were not touched since the last purge.

diffstat:

 sys/arch/sh5/sh5/pmap.c |  41 +++++++++++++++++++++++++++--------------
 1 files changed, 27 insertions(+), 14 deletions(-)

diffs (106 lines):

diff -r f23534e851ea -r fd6d99d21b61 sys/arch/sh5/sh5/pmap.c
--- a/sys/arch/sh5/sh5/pmap.c   Tue Oct 22 12:25:18 2002 +0000
+++ b/sys/arch/sh5/sh5/pmap.c   Tue Oct 22 13:10:28 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.20 2002/10/22 09:30:27 scw Exp $    */
+/*     $NetBSD: pmap.c,v 1.21 2002/10/22 13:10:28 scw Exp $    */
 
 /*
  * Copyright 2002 Wasabi Systems, Inc.
@@ -706,9 +706,16 @@
        pm = pvo->pvo_pmap;
        pteh = pt->pteh;
        ptel = pt->ptel;
-       pt->ptel = ptel & ~ptebit;
-
-       if (pm->pm_asid != PMAP_ASID_UNASSIGNED &&
+
+       /*
+        * Note:
+        * We clear the Referenced bit here so that subsequent calls to
+        * pmap_cache_sync_*() will only purge the cache for the page
+        * if it has been accessed between now and then.
+        */
+       pt->ptel = ptel & ~(ptebit | SH5_PTEL_R);
+
+       if ((ptel & SH5_PTEL_R) != 0 && pm->pm_asid != PMAP_ASID_UNASSIGNED &&
            pm->pm_asidgen == pmap_asid_generation) {
                /*
                 * The mapping may be cached in the TLB. Call cpu-specific
@@ -736,10 +743,12 @@
 {
        ptel_t ptel;
 
-       __cpu_tlbinv((pteh_t)PVO_VADDR(pvo) | SH5_PTEH_SH,
-           SH5_PTEH_EPN_MASK | SH5_PTEH_SH);
-
        ptel = pmap_kernel_ipt[idx];
+
+       if ((ptel & SH5_PTEL_R) != 0)
+               __cpu_tlbinv((pteh_t)PVO_VADDR(pvo) | SH5_PTEH_SH,
+                   SH5_PTEH_EPN_MASK | SH5_PTEH_SH);
+
        pmap_pteg_synch(ptel, pvo);
 
        /*
@@ -749,8 +758,11 @@
 
        /*
         * It's now safe to change the page table.
+        * We clear the Referenced bit here so that subsequent calls to
+        * pmap_cache_sync_*() will only purge the cache for the page
+        * if it has been accessed between now and then.
         */
-       pmap_kernel_ipt[idx] = ptel & ~ptebit;
+       pmap_kernel_ipt[idx] = ptel & ~(ptebit | SH5_PTEL_R);
 }
 
 /*
@@ -768,7 +780,7 @@
 pmap_pteg_set(volatile pte_t *pt, struct pvo_entry *pvo)
 {
 
-       pt->ptel = pvo->pvo_ptel;
+       pt->ptel = pvo->pvo_ptel & ~SH5_PTEL_R;
        pt->pteh = (pteh_t) PVO_VADDR(pvo);
        pt->vsid = pvo->pvo_pmap->pm_vsid;
 }
@@ -792,7 +804,7 @@
        pteh = pt->pteh;
        pt->pteh = 0;
 
-       if (pm->pm_asid != PMAP_ASID_UNASSIGNED &&
+       if ((ptel & SH5_PTEL_R) != 0 && pm->pm_asid != PMAP_ASID_UNASSIGNED &&
            pm->pm_asidgen == pmap_asid_generation) {
                /*
                 * The mapping may be in the TLB. Call cpu-specific
@@ -1579,8 +1591,9 @@
        oldptel = *ptel;
        *ptel = 0;
 
-       __cpu_tlbinv(((pteh_t)kva & SH5_PTEH_EPN_MASK) | SH5_PTEH_SH,
-           SH5_PTEH_EPN_MASK | SH5_PTEH_SH);
+       if ((oldptel & SH5_PTEL_R) != 0)
+               __cpu_tlbinv(((pteh_t)kva & SH5_PTEH_EPN_MASK) | SH5_PTEH_SH,
+                   SH5_PTEH_EPN_MASK | SH5_PTEH_SH);
 
        pmap_cache_sync_unmap(kva, oldptel);
 
@@ -1642,7 +1655,7 @@
                pvo->pvo_ptel |= new_mode;
 
                /* Re-insert it back into the page table */
-               pmap_kernel_ipt[idx] = pvo->pvo_ptel;
+               pmap_kernel_ipt[idx] = pvo->pvo_ptel & ~SH5_PTEL_R;
        }
 
        PMPRINTF(("pmap_change_cache_attr: done\n"));
@@ -1827,7 +1840,7 @@
                        PVO_PTEGIDX_SET(pvo, i);
                }
        } else {
-               pmap_kernel_ipt[idx] = ptel;
+               pmap_kernel_ipt[idx] = ptel & ~SH5_PTEL_R;
                PMPRINTF((
                    "pmap_pvo_enter: kva 0x%lx, ptel 0x%lx, kipt (idx %d)\n",
                    va, (u_long)ptel, idx));