Changes in kernel/arch/ppc32/src/mm/pht.c [1dbc43f:1cab9972] in mainline

File:

• kernel/arch/ppc32/src/mm/pht.c (modified) (4 diffs)

kernel/arch/ppc32/src/mm/pht.c

@@ -49 +49 @@
  * @param access   Access mode that caused the fault.
  * @param istate   Pointer to interrupted state.
+ * @param pfrc     Pointer to variable where as_page_fault() return code
+ *                 will be stored.
  *
  * @return PTE on success, NULL otherwise.
@@ -54 +56 @@
  */
 static pte_t *find_mapping_and_check(as_t *as, uintptr_t badvaddr, int access,
-    istate_t *istate)
+    istate_t *istate, int *pfrc)
 {
         /*
@@ -66 +68 @@
                  */
                 return pte;
-        }
-        /*
-         * Mapping not found in page tables.
-         * Resort to higher-level page fault handler.
-         */
-        if (as_page_fault(badvaddr, access, istate) == AS_PF_OK) {
+        } else {
                 /*
-                 * The higher-level page fault handler succeeded,
-                 * The mapping ought to be in place.
+                 * Mapping not found in page tables.
+                 * Resort to higher-level page fault handler.
                  */
-                pte = page_mapping_find(as, badvaddr, true);
-                ASSERT((pte) && (pte->present));
-                return pte;
-        }
-
-        return NULL;
+                int rc = as_page_fault(badvaddr, access, istate);
+                switch (rc) {
+                case AS_PF_OK:
+                        /*
+                         * The higher-level page fault handler succeeded,
+                         * The mapping ought to be in place.
+                         */
+                        pte = page_mapping_find(as, badvaddr, true);
+                        ASSERT((pte) && (pte->present));
+                        *pfrc = 0;
+                        return pte;
+                case AS_PF_DEFER:
+                        *pfrc = rc;
+                        return NULL;
+                case AS_PF_FAULT:
+                        *pfrc = rc;
+                        return NULL;
+                default:
+                        panic("Unexpected rc (%d).", rc);
+                }
+        }
+}
+
+static void pht_refill_fail(uintptr_t badvaddr, istate_t *istate)
+{
+        fault_if_from_uspace(istate, "PHT Refill Exception on %p.",
+            (void *) badvaddr);
+        panic_memtrap(istate, PF_ACCESS_UNKNOWN, badvaddr,
+            "PHT Refill Exception.");
 }
 
@@ -182 +202 @@
                 badvaddr = istate->pc;
         
+        int pfrc;
         pte_t *pte = find_mapping_and_check(AS, badvaddr,
-            PF_ACCESS_READ /* FIXME */, istate);
-        
-        if (pte) {
-                /* Record access to PTE */
-                pte->accessed = 1;
-                pht_insert(badvaddr, pte);
-        }
+            PF_ACCESS_READ /* FIXME */, istate, &pfrc);
+        
+        if (!pte) {
+                switch (pfrc) {
+                case AS_PF_FAULT:
+                        pht_refill_fail(badvaddr, istate);
+                        return;
+                case AS_PF_DEFER:
+                        /*
+                         * The page fault came during copy_from_uspace()
+                         * or copy_to_uspace().
+                         */
+                        return;
+                default:
+                        panic("Unexpected pfrc (%d).", pfrc);
+                }
+        }
+        
+        /* Record access to PTE */
+        pte->accessed = 1;
+        pht_insert(badvaddr, pte);
 }