Changeset 2057572 in mainline for kernel/generic/src/mm/as.c

Timestamp:

2007-03-27T23:40:25Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

399ece9

Parents:

8d37a06

Message:

The Ultimate Solution To Illegal Virtual Aliases.
It is better to avoid them completely than to fight them.
Switch the sparc64 port to 16K pages. The TLBs and TSBs
continue to operate with 8K pages only. Page tables and
other generic parts operate with 16K pages.

Because the MMU doesn't support 16K directly, each 16K
page is emulated by a pair of 8K pages. With 16K pages,
illegal aliases cannot be created in 16K D-cache.

File:

• kernel/generic/src/mm/as.c (modified) (3 diffs)

kernel/generic/src/mm/as.c

@@ -614 +614 @@
  * or ENOMEM if there was a problem in allocating destination address space
  * area. ENOTSUP is returned if the address space area backend does not support
- * sharing or if the kernel detects an attempt to create an illegal address
- * alias.
+ * sharing.
  */
 int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
@@ -667 +666 @@
                 return EPERM;
         }
-
-#ifdef CONFIG_VIRT_IDX_DCACHE
-        if (!(dst_flags_mask & AS_AREA_EXEC)) {
-                if (PAGE_COLOR(src_area->base) != PAGE_COLOR(dst_base)) {
-                        /*
-                         * Refuse to create an illegal address alias.
-                         */
-                        mutex_unlock(&src_area->lock);
-                        mutex_unlock(&src_as->lock);
-                        interrupts_restore(ipl);
-                        return ENOTSUP;
-                }
-        }
-#endif /* CONFIG_VIRT_IDX_DCACHE */
 
         /*
@@ -902 +887 @@
                          * ASID.
                          */
-                         ASSERT(old_as->asid != ASID_INVALID);
-                         list_append(&old_as->inactive_as_with_asid_link,
-                             &inactive_as_with_asid_head);
+                        ASSERT(old_as->asid != ASID_INVALID);
+                        list_append(&old_as->inactive_as_with_asid_link,
+                            &inactive_as_with_asid_head);
                 }
                 mutex_unlock(&old_as->lock);