Changes in kernel/genarch/src/mm/page_pt.c [235e6c7:c72dc15] in mainline

File:

• kernel/genarch/src/mm/page_pt.c (modified) (9 diffs)

kernel/genarch/src/mm/page_pt.c

@@ -39 +39 @@
 #include <mm/page.h>
 #include <mm/frame.h>
+#include <mm/km.h>
 #include <mm/as.h>
 #include <arch/mm/page.h>
@@ -75 +76 @@
         
         if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT) {
-                pte_t *newpt = (pte_t *) frame_alloc(PTL1_SIZE, FRAME_KA);
+                pte_t *newpt = (pte_t *) frame_alloc(PTL1_SIZE,
+                    FRAME_LOWMEM | FRAME_KA);
                 memsetb(newpt, FRAME_SIZE << PTL1_SIZE, 0);
                 SET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page), KA2PA(newpt));
-                SET_PTL1_FLAGS(ptl0, PTL0_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE);
+                SET_PTL1_FLAGS(ptl0, PTL0_INDEX(page),
+                    PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE |
+                    PAGE_WRITE);
         }
         
@@ -84 +88 @@
         
         if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT) {
-                pte_t *newpt = (pte_t *) frame_alloc(PTL2_SIZE, FRAME_KA);
+                pte_t *newpt = (pte_t *) frame_alloc(PTL2_SIZE,
+                    FRAME_LOWMEM | FRAME_KA);
                 memsetb(newpt, FRAME_SIZE << PTL2_SIZE, 0);
                 SET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page), KA2PA(newpt));
-                SET_PTL2_FLAGS(ptl1, PTL1_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE);
+                SET_PTL2_FLAGS(ptl1, PTL1_INDEX(page),
+                    PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE |
+                    PAGE_WRITE);
         }
         
@@ -93 +100 @@
         
         if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT) {
-                pte_t *newpt = (pte_t *) frame_alloc(PTL3_SIZE, FRAME_KA);
+                pte_t *newpt = (pte_t *) frame_alloc(PTL3_SIZE,
+                    FRAME_LOWMEM | FRAME_KA);
                 memsetb(newpt, FRAME_SIZE << PTL3_SIZE, 0);
                 SET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page), KA2PA(newpt));
-                SET_PTL3_FLAGS(ptl2, PTL2_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE);
+                SET_PTL3_FLAGS(ptl2, PTL2_INDEX(page),
+                    PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE |
+                    PAGE_WRITE);
         }
         
@@ -144 +154 @@
         
         /*
-         * Second, free all empty tables along the way from PTL3 down to PTL0.
-         *
+         * Second, free all empty tables along the way from PTL3 down to PTL0
+         * except those needed for sharing the kernel non-identity mappings.
          */
         
@@ -162 +172 @@
                 /*
                  * PTL3 is empty.
-                 * Release the frame and remove PTL3 pointer from preceding table.
-                 *
-                 */
-                frame_free(KA2PA((uintptr_t) ptl3));
+                 * Release the frame and remove PTL3 pointer from the parent
+                 * table.
+                 */
 #if (PTL2_ENTRIES != 0)
                 memsetb(&ptl2[PTL2_INDEX(page)], sizeof(pte_t), 0);
@@ -171 +180 @@
                 memsetb(&ptl1[PTL1_INDEX(page)], sizeof(pte_t), 0);
 #else
+                if (km_is_non_identity(page))
+                        return;
+
                 memsetb(&ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
 #endif
+                frame_free(KA2PA((uintptr_t) ptl3));
         } else {
                 /*
@@ -195 +208 @@
                 /*
                  * PTL2 is empty.
-                 * Release the frame and remove PTL2 pointer from preceding table.
-                 *
-                 */
-                frame_free(KA2PA((uintptr_t) ptl2));
+                 * Release the frame and remove PTL2 pointer from the parent
+                 * table.
+                 */
 #if (PTL1_ENTRIES != 0)
                 memsetb(&ptl1[PTL1_INDEX(page)], sizeof(pte_t), 0);
 #else
+                if (km_is_non_identity(page))
+                        return;
+
                 memsetb(&ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
 #endif
+                frame_free(KA2PA((uintptr_t) ptl2));
         } else {
                 /*
@@ -227 +243 @@
                 /*
                  * PTL1 is empty.
-                 * Release the frame and remove PTL1 pointer from preceding table.
-                 *
-                 */
+                 * Release the frame and remove PTL1 pointer from the parent
+                 * table.
+                 */
+                if (km_is_non_identity(page))
+                        return;
+
+                memsetb(&ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
                 frame_free(KA2PA((uintptr_t) ptl1));
-                memsetb(&ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
         }
 #endif /* PTL1_ENTRIES != 0 */