[src/trunk]: src/sys/arch/arm/arm32 cleanup PVF_WRITE & pvh_attrs interaction.

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

details:   https://anonhg.NetBSD.org/src/rev/3aaec12b4591
branches:  trunk
changeset: 784562:3aaec12b4591
user:      matt <matt%NetBSD.org@localhost>
date:      Fri Feb 01 15:02:31 2013 +0000

description:
cleanup PVF_WRITE & pvh_attrs interaction.

diffstat:

 sys/arch/arm/arm32/pmap.c |  69 ++++++++++++++++++++++++++++++----------------
 1 files changed, 45 insertions(+), 24 deletions(-)

diffs (167 lines):

diff -r 6dd76d76a475 -r 3aaec12b4591 sys/arch/arm/arm32/pmap.c
--- a/sys/arch/arm/arm32/pmap.c Fri Feb 01 14:48:15 2013 +0000
+++ b/sys/arch/arm/arm32/pmap.c Fri Feb 01 15:02:31 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.250 2013/01/31 22:01:49 skrll Exp $ */
+/*     $NetBSD: pmap.c,v 1.251 2013/02/01 15:02:31 matt Exp $  */
 
 /*
  * Copyright 2003 Wasabi Systems, Inc.
@@ -212,7 +212,7 @@
 #include <arm/cpuconf.h>
 #include <arm/arm32/katelib.h>
 
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.250 2013/01/31 22:01:49 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.251 2013/02/01 15:02:31 matt Exp $");
 
 #ifdef PMAP_DEBUG
 
@@ -693,6 +693,12 @@
 }
 #endif /* PMAP_DEBUG */
 
+#ifdef PMAP_CACHE_VIPT
+#define PMAP_VALIDATE_MD_PAGE(md)      \
+       KASSERTMSG(arm_cache_prefer_mask == 0 || (((md)->pvh_attrs & PVF_WRITE) == 0) == ((md)->urw_mappings + (md)->krw_mappings == 0), \
+           "(md) %p: attrs=%#x urw=%u krw=%u", (md), \
+           (md)->pvh_attrs, (md)->urw_mappings, (md)->krw_mappings);
+#endif /* PMAP_CACHE_VIPT */
 /*
  * A bunch of routines to conditionally flush the caches/TLB depending
  * on whether the specified pmap actually needs to be flushed at any
@@ -890,6 +896,13 @@
 
 #ifdef PMAP_CACHE_VIPT
        /*
+        * Even though pmap_vac_me_harder will set PVF_WRITE for us,
+        * do it here as well to keep the mappings & KVF_WRITE consistent.
+        */
+       if (arm_cache_prefer_mask != 0 && (flags & PVF_WRITE) != 0) {
+               md->pvh_attrs |= PVF_WRITE;
+       }
+       /*
         * If this is an exec mapping and its the first exec mapping
         * for this page, make sure to sync the I-cache.
         */
@@ -1008,8 +1021,11 @@
         * mappings (ignoring KMPAGE), clear the WRITE flag and writeback
         * the contents to memory.
         */
-       if (md->krw_mappings + md->urw_mappings == 0)
-               md->pvh_attrs &= ~PVF_WRITE;
+       if (arm_cache_prefer_mask != 0) {
+               if (md->krw_mappings + md->urw_mappings == 0)
+                       md->pvh_attrs &= ~PVF_WRITE;
+               PMAP_VALIDATE_MD_PAGE(md);
+       }
        KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
 #endif /* PMAP_CACHE_VIPT */
 
@@ -1087,10 +1103,12 @@
                }
        }
 #ifdef PMAP_CACHE_VIPT
-       if (md->urw_mappings + md->krw_mappings == 0) {
-               md->pvh_attrs &= ~PVF_WRITE;
-       } else {
-               md->pvh_attrs |= PVF_WRITE;
+       if (arm_cache_prefer_mask != 0) {
+               if (md->urw_mappings + md->krw_mappings == 0) {
+                       md->pvh_attrs &= ~PVF_WRITE;
+               } else {
+                       md->pvh_attrs |= PVF_WRITE;
+               }
        }
        /*
         * We have two cases here: the first is from enter_pv (new exec
@@ -1847,7 +1865,7 @@
                 * Only check for a bad alias if we have writable mappings.
                 */
                tst_mask &= arm_cache_prefer_mask;
-               if (rw_mappings > 0 && arm_cache_prefer_mask) {
+               if (rw_mappings > 0) {
                        for (; pv && !bad_alias; pv = SLIST_NEXT(pv, pv_link)) {
                                /* if there's a bad alias, stop checking. */
                                if (tst_mask != (pv->pv_va & arm_cache_prefer_mask))
@@ -1903,7 +1921,7 @@
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
        } else if (!va) {
-               KASSERT(arm_cache_prefer_mask == 0 || pmap_is_page_colored_p(md));
+               KASSERT(pmap_is_page_colored_p(md));
                KASSERT(!(md->pvh_attrs & PVF_WRITE)
                    || (md->pvh_attrs & PVF_DIRTY));
                if (rw_mappings == 0) {
@@ -2227,10 +2245,12 @@
                                        md->uro_mappings++;
                                }
 #ifdef PMAP_CACHE_VIPT
-                               if (md->urw_mappings + md->krw_mappings == 0) {
-                                       md->pvh_attrs &= ~PVF_WRITE;
-                               } else {
-                                       KASSERT(md->pvh_attrs & PVF_WRITE);
+                               if (arm_cache_prefer_mask != 0) {
+                                       if (md->urw_mappings + md->krw_mappings == 0) {
+                                               md->pvh_attrs &= ~PVF_WRITE;
+                                       } else {
+                                               PMAP_VALIDATE_MD_PAGE(md);
+                                       }
                                }
                                if (want_syncicache)
                                        need_syncicache = true;
@@ -2564,7 +2584,7 @@
                if (PV_IS_EXEC_P(md->pvh_attrs))
                        PMAPCOUNT(exec_discarded_page_protect);
                md->pvh_attrs &= ~PVF_EXEC;
-               KASSERT((md->urw_mappings + md->krw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
+               PMAP_VALIDATE_MD_PAGE(md);
 #endif
                return;
        }
@@ -2663,9 +2683,11 @@
        md->pvh_attrs &= ~PVF_EXEC;
        KASSERT(md->urw_mappings == 0);
        KASSERT(md->uro_mappings == 0);
-       if (md->krw_mappings == 0)
-               md->pvh_attrs &= ~PVF_WRITE;
-       KASSERT((md->urw_mappings + md->krw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
+       if (arm_cache_prefer_mask != 0) {
+               if (md->krw_mappings == 0)
+                       md->pvh_attrs &= ~PVF_WRITE;
+               PMAP_VALIDATE_MD_PAGE(md);
+       }
 #endif
 
        if (flush) {
@@ -2809,8 +2831,7 @@
                /*
                 * This is to be a managed mapping.
                 */
-               if ((flags & VM_PROT_ALL) ||
-                   (md->pvh_attrs & PVF_REF)) {
+               if ((flags & VM_PROT_ALL) || (md->pvh_attrs & PVF_REF)) {
                        /*
                         * - The access type indicates that we don't need
                         *   to do referenced emulation.
@@ -3050,9 +3071,7 @@
                KASSERT(uvm_page_locked_p(pg));
 #endif
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
-               KASSERTMSG(arm_cache_prefer_mask == 0 || ((md->pvh_attrs & PVF_WRITE) == 0) == (md->urw_mappings + md->krw_mappings == 0),
-                   "pg %p: attrs=%#x urw=%u krw=%u", pg,
-                   md->pvh_attrs, md->urw_mappings, md->krw_mappings);
+               PMAP_VALIDATE_MD_PAGE(md);
        }
 #endif
 
@@ -3470,7 +3489,9 @@
                                        KASSERT(omd->kro_mappings == 0);
                                        omd->pvh_attrs &= ~PVF_KMPAGE;
 #ifdef PMAP_CACHE_VIPT
-                                       omd->pvh_attrs &= ~PVF_WRITE;
+                                       if (arm_cache_prefer_mask != 0) {
+                                               omd->pvh_attrs &= ~PVF_WRITE;
+                                       }
 #endif
                                        pmap_kmpages--;
 #ifdef PMAP_CACHE_VIPT