Changeset 87739fb in mainline for kernel/arch/arm32/include/mm/page_armv7.h

Timestamp:

2012-04-06T20:52:34Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

ea106a6

Parents:

708ec60

Message:

arm32,armv7,paging: Usermode mmio does not need special treatment.

Add some comments explaining memory access mode.

File:

• kernel/arch/arm32/include/mm/page_armv7.h (modified) (3 diffs)

kernel/arch/arm32/include/mm/page_armv7.h

@@ -265 +265 @@
                 p->should_be_zero_1 = 0;
                 p->domain = 0;
+                p->ns = 0;
         }
 }
@@ -293 +294 @@
         }
         
+        /* tex=0 buf=1 and cache=1 => normal memory
+         * tex=0 buf=1 and cache=0 => shareable device mmio
+         */
         p->cacheable = (flags & PAGE_CACHEABLE);
-        
-        /* even devices can use bufferable */
         p->bufferable = 1;
         p->tex = 0;
@@ -307 +309 @@
         /* default access permission: kernel only*/
         p->access_permission_0 = PTE_AP0_USER_NO_KERNEL_FULL;
-
+        
         if (flags & PAGE_USER) {
                 p->access_permission_0 = PTE_AP0_USER_FULL_KERNEL_FULL;
+                // TODO Fix kernel to use PAGE_WRITE flag properly and
+                // apply this for kernel pages as well.
                 if (!(flags & PAGE_WRITE))
                         p->access_permission_1 = PTE_AP1_RO;
-                if (!(flags & PAGE_CACHEABLE)) {
-                        p->tex = 0x2;
-                        p->bufferable = 0;
-                        p->cacheable = 0;
-                }
         }
 }