[src/trunk]: src/sys/arch/usermode/usermode Implement pmap_page_protect()

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

details:   https://anonhg.NetBSD.org/src/rev/bb0a0d5908df
branches:  trunk
changeset: 769026:bb0a0d5908df
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Tue Aug 30 11:31:57 2011 +0000

description:
Implement pmap_page_protect()

diffstat:

 sys/arch/usermode/usermode/pmap.c |  54 ++++++++++++++++++++++++++++++++++++--
 1 files changed, 50 insertions(+), 4 deletions(-)

diffs (77 lines):

diff -r db404c362132 -r bb0a0d5908df sys/arch/usermode/usermode/pmap.c
--- a/sys/arch/usermode/usermode/pmap.c Tue Aug 30 11:24:38 2011 +0000
+++ b/sys/arch/usermode/usermode/pmap.c Tue Aug 30 11:31:57 2011 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.43 2011/08/30 10:58:41 reinoud Exp $ */
+/* $NetBSD: pmap.c,v 1.44 2011/08/30 11:31:57 reinoud Exp $ */
 
 /*-
  * Copyright (c) 2011 Reinoud Zandijk <reinoud%NetBSD.org@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.43 2011/08/30 10:58:41 reinoud Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.44 2011/08/30 11:31:57 reinoud Exp $");
 
 #include "opt_memsize.h"
 #include "opt_kmempages.h"
@@ -825,10 +825,56 @@
 aprint_debug("pmap_copy_page not implemented\n");
 }
 
+/* change access permissions on a given physical page */
 void
-pmap_page_protect(struct vm_page *pg, vm_prot_t prot)
+pmap_page_protect(struct vm_page *page, vm_prot_t prot)
 {
-aprint_debug("pmap_page_protect not implemented\n");
+       intptr_t ppn;
+       struct pv_entry *pv, *npv;
+
+       ppn = atop(VM_PAGE_TO_PHYS(page));
+       aprint_debug("pmap_page_protect page %"PRIiPTR" to prot %d\n", ppn, prot);
+
+       if (prot == VM_PROT_NONE) {
+               /* visit all mappings */
+               npv = pv = &pv_table[ppn];
+               while (pv != NULL && pv->pv_pmap != NULL) {
+                       /* skip unmanaged entries */
+                       if (pv->pv_vflags & PV_UNMANAGED) {
+                               pv = pv->pv_next;
+                               continue;
+                       }
+
+                       /* if in an active pmap deactivate */
+                       if (pv->pv_pmap->pm_flags & PM_ACTIVE)
+                               pmap_page_deactivate(pv);
+
+                       /* if not on the head, remember our next */
+                       if (pv != &pv_table[ppn])
+                               npv = pv->pv_next;
+
+                       /* remove from pmap */
+                       pv->pv_pmap->pm_entries[pv->pv_lpn] = NULL;
+                       if (pv->pv_vflags & PV_WIRED)
+                               pv->pv_pmap->pm_stats.wired_count--;
+                       pv_release(pv->pv_pmap, ppn, pv->pv_lpn);
+
+                       pv = npv;
+               }
+       } else if (prot != VM_PROT_ALL) {
+               /* visit all mappings */
+               for (pv = &pv_table[ppn]; pv != NULL; pv = pv->pv_next) {
+                       /* if managed and in a pmap restrict access */
+                       if ((pv->pv_pmap != NULL) &&
+                           ((pv->pv_vflags & PV_UNMANAGED) == 0)) {
+                               pv->pv_prot &= prot;
+                               pv_update(pv);
+                               /* if in active pmap (re)activate page */
+                               if (pv->pv_pmap->pm_flags & PM_ACTIVE)
+                                       pmap_page_activate(pv);
+                       }
+               }
+       }
 }
 
 bool