Changeset 8f00329 in mainline for genarch/src/mm/page_pt.c

Timestamp:

2006-02-09T21:59:31Z (19 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

a3eeceb6

Parents:

bfb87df

Message:

Add page_mapping_remove().

File:

• genarch/src/mm/page_pt.c (modified) (2 diffs)

genarch/src/mm/page_pt.c

@@ -39 +39 @@
 
 static void pt_mapping_insert(as_t *as, __address page, __address frame, int flags);
+static void pt_mapping_remove(as_t *as, __address page);
 static pte_t *pt_mapping_find(as_t *as, __address page);
 
 page_mapping_operations_t pt_mapping_operations = {
         .mapping_insert = pt_mapping_insert,
+        .mapping_remove = pt_mapping_remove,
         .mapping_find = pt_mapping_find
 };
@@ -96 +98 @@
 }
 
+/** Remove mapping of page from hierarchical page tables.
+ *
+ * Remove any mapping of 'page' within address space 'as'.
+ * TLB shootdown should follow in order to make effects of
+ * this call visible.
+ *
+ * The address space must be locked and interrupts must be disabled.
+ *
+ * @param as Address space to wich page belongs.
+ * @param page Virtual address of the page to be demapped.
+ */
+void pt_mapping_remove(as_t *as, __address page)
+{
+        pte_t *ptl0, *ptl1, *ptl2, *ptl3;
+
+        ptl0 = (pte_t *) PA2KA((__address) as->page_table);
+
+        if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT)
+                return;
+
+        ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page)));
+
+        if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT)
+                return;
+
+        ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page)));
+
+        if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT)
+                return;
+
+        ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page)));
+
+        /* Destroy the mapping. Setting to PAGE_NOT_PRESENT is not sufficient. */
+        memsetb((__address) &ptl3[PTL3_INDEX(page)], sizeof(pte_t), 0);
+}
+
 /** Find mapping for virtual page in hierarchical page tables.
  *