From 6d659d7442e486afe80a6c29f4ca41b757a01e2b Mon Sep 17 00:00:00 2001
From: Keir Fraser <keir@xensource.com>
Date: Tue, 13 Nov 2007 17:28:44 +0000
Subject: [PATCH] Revert 16067:9f9f9b68cd08a03fc8cfad9f5ab702e50b6b6463.
 Signed-off-by: Keir Fraser <keir@xensource.com>

---
 xen/common/grant_table.c | 95 ++++++++++++----------------------------
 1 file changed, 29 insertions(+), 66 deletions(-)

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 948df08a5e..1bd49523c3 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -198,7 +198,6 @@ __gnttab_map_grant_ref(
     int            handle;
     unsigned long  frame = 0;
     int            rc = GNTST_okay;
-    int            is_iomem = 0;
     struct active_grant_entry *act;
     struct grant_mapping *mt;
     grant_entry_t *sha;
@@ -329,55 +328,34 @@ __gnttab_map_grant_ref(
 
     spin_unlock(&rd->grant_table->lock);
 
-    if ( op->flags & GNTMAP_host_map ) 
+    if ( unlikely(!mfn_valid(frame)) ||
+         unlikely(!((op->flags & GNTMAP_readonly) ?
+                    get_page(mfn_to_page(frame), rd) :
+                    get_page_and_type(mfn_to_page(frame), rd,
+                                      PGT_writable_page))) )
     {
-        /* Could be an iomem page for setting up permission */
-        if ( is_iomem_page(frame) )
-        {
-            is_iomem = 1;
-            if ( iomem_permit_access(ld, frame, frame) )
-            {
-                gdprintk(XENLOG_WARNING, 
-                         "Could not permit access to grant frame "
-                         "%lx as iomem\n", frame);
-                rc = GNTST_general_error;
-                goto undo_out;
-            }
-        }
-    } 
-
-    if ( !is_iomem ) 
+        if ( !rd->is_dying )
+            gdprintk(XENLOG_WARNING, "Could not pin grant frame %lx\n", frame);
+        rc = GNTST_general_error;
+        goto undo_out;
+    }
+        
+    if ( op->flags & GNTMAP_host_map )
     {
-        if ( unlikely(!mfn_valid(frame)) ||
-             unlikely(!((op->flags & GNTMAP_readonly) ?
-                        get_page(mfn_to_page(frame), rd) :
-                        get_page_and_type(mfn_to_page(frame), rd,
-                                          PGT_writable_page))))
+        rc = create_grant_host_mapping(op->host_addr, frame, op->flags);
+        if ( rc != GNTST_okay )
         {
-            if ( !rd->is_dying )
-                gdprintk(XENLOG_WARNING,
-                         "Could not pin grant frame %lx\n", frame);
-            rc = GNTST_general_error;
+            if ( !(op->flags & GNTMAP_readonly) )
+                put_page_type(mfn_to_page(frame));
+            put_page(mfn_to_page(frame));
             goto undo_out;
         }
-        
-        if ( op->flags & GNTMAP_host_map )
-        {
-            rc = create_grant_host_mapping(op->host_addr, frame, op->flags);
-            if ( rc != GNTST_okay )
-            {
-                if ( !(op->flags & GNTMAP_readonly) )
-                    put_page_type(mfn_to_page(frame));
-                put_page(mfn_to_page(frame));
-                goto undo_out;
-            }
 
-            if ( op->flags & GNTMAP_device_map )
-            {
-                (void)get_page(mfn_to_page(frame), rd);
-                if ( !(op->flags & GNTMAP_readonly) )
-                    get_page_type(mfn_to_page(frame), PGT_writable_page);
-            }
+        if ( op->flags & GNTMAP_device_map )
+        {
+            (void)get_page(mfn_to_page(frame), rd);
+            if ( !(op->flags & GNTMAP_readonly) )
+                get_page_type(mfn_to_page(frame), PGT_writable_page);
         }
     }
 
@@ -518,21 +496,12 @@ __gnttab_unmap_common(
         }
     }
 
-    if ( op->flags & GNTMAP_host_map )
+    if ( (op->host_addr != 0) && (op->flags & GNTMAP_host_map) )
     {
-        if ( (op->host_addr != 0) )
-        {
-            if ( (rc = replace_grant_host_mapping(op->host_addr,
-                                                  op->frame, op->new_addr, 
-                                                  op->flags)) < 0 )
-                goto unmap_out;
-        }
-        else if ( is_iomem_page(op->frame) &&
-                  iomem_access_permitted(ld, op->frame, op->frame) )
-        {
-            if ( (rc = iomem_deny_access(ld, op->frame, op->frame)) < 0 )
-                goto unmap_out;
-        }
+        if ( (rc = replace_grant_host_mapping(op->host_addr,
+                                              op->frame, op->new_addr, 
+                                              op->flags)) < 0 )
+            goto unmap_out;
 
         ASSERT(act->pin & (GNTPIN_hstw_mask | GNTPIN_hstr_mask));
         op->map->flags &= ~GNTMAP_host_map;
@@ -540,7 +509,7 @@ __gnttab_unmap_common(
             act->pin -= GNTPIN_hstr_inc;
         else
             act->pin -= GNTPIN_hstw_inc;
-    } 
+    }
 
     /* If just unmapped a writable mapping, mark as dirtied */
     if ( !(op->flags & GNTMAP_readonly) )
@@ -1592,7 +1561,6 @@ gnttab_release_mappings(
     struct domain        *rd;
     struct active_grant_entry *act;
     struct grant_entry   *sha;
-    int rc;
 
     BUG_ON(!d->is_dying);
 
@@ -1650,12 +1618,7 @@ gnttab_release_mappings(
             {
                 BUG_ON(!(act->pin & GNTPIN_hstw_mask));
                 act->pin -= GNTPIN_hstw_inc;
-
-                if ( is_iomem_page(act->frame) &&
-                     iomem_access_permitted(rd, act->frame, act->frame) )
-                    rc = iomem_deny_access(rd, act->frame, act->frame);
-                else 
-                    gnttab_release_put_page_and_type(mfn_to_page(act->frame));
+                gnttab_release_put_page_and_type(mfn_to_page(act->frame));
             }
 
             if ( (act->pin & (GNTPIN_devw_mask|GNTPIN_hstw_mask)) == 0 )
-- 
2.30.2