Changes in kernel/generic/src/mm/as.c [336db295:c964521] in mainline

File:

• kernel/generic/src/mm/as.c (modified) (23 diffs)

kernel/generic/src/mm/as.c

@@ -1 +1 @@
 /*
- * Copyright (c) 2001-2006 Jakub Jermar
+ * Copyright (c) 2010 Jakub Jermar
  * All rights reserved.
  *
@@ -75 +75 @@
 #include <config.h>
 #include <align.h>
-#include <arch/types.h>
+#include <typedefs.h>
 #include <syscall/copy.h>
 #include <arch/interrupt.h>
@@ -152 +152 @@
          * reference count never drops to zero.
          */
-        atomic_set(&AS_KERNEL->refcount, 1);
+        as_hold(AS_KERNEL);
 }
 
@@ -200 +200 @@
         DEADLOCK_PROBE_INIT(p_asidlock);
 
+        ASSERT(as != AS);
         ASSERT(atomic_get(&as->refcount) == 0);
         
         /*
-         * Since there is no reference to this area,
-         * it is safe not to lock its mutex.
+         * Since there is no reference to this address space, it is safe not to
+         * lock its mutex.
          */
 
@@ -225 +226 @@
         preemption_enable();    /* Interrupts disabled, enable preemption */
         if (as->asid != ASID_INVALID && as != AS_KERNEL) {
-                if (as != AS && as->cpu_refcount == 0)
+                if (as->cpu_refcount == 0)
                         list_remove(&as->inactive_as_with_asid_link);
                 asid_put(as->asid);
@@ -258 +259 @@
 
         slab_free(as_slab, as);
+}
+
+/** Hold a reference to an address space.
+ *
+ * Holding a reference to an address space prevents destruction of that address
+ * space.
+ *
+ * @param a             Address space to be held.
+ */
+void as_hold(as_t *as)
+{
+        atomic_inc(&as->refcount);
+}
+
+/** Release a reference to an address space.
+ *
+ * The last one to release a reference to an address space destroys the address
+ * space.
+ *
+ * @param a             Address space to be released.
+ */
+void as_release(as_t *as)
+{
+        if (atomic_predec(&as->refcount) == 0)
+                as_destroy(as);
 }
 
@@ -396 +422 @@
                  * No need to check for overlaps.
                  */
+
+                page_table_lock(as, false);
 
                 /*
@@ -460 +488 @@
                                         pte_t *pte;
                         
-                                        page_table_lock(as, false);
                                         pte = page_mapping_find(as, b +
                                             i * PAGE_SIZE);
@@ -473 +500 @@
                                         page_mapping_remove(as, b +
                                             i * PAGE_SIZE);
-                                        page_table_unlock(as, false);
                                 }
                         }
@@ -484 +510 @@
                 tlb_invalidate_pages(as->asid, area->base + pages * PAGE_SIZE,
                     area->pages - pages);
+
                 /*
                  * Invalidate software translation caches (e.g. TSB on sparc64).
@@ -490 +517 @@
                     pages * PAGE_SIZE, area->pages - pages);
                 tlb_shootdown_finalize();
+
+                page_table_unlock(as, false);
                 
         } else {
@@ -539 +568 @@
 
         base = area->base;
+
+        page_table_lock(as, false);
 
         /*
@@ -560 +591 @@
                         
                         for (j = 0; j < (size_t) node->value[i]; j++) {
-                                page_table_lock(as, false);
                                 pte = page_mapping_find(as, b + j * PAGE_SIZE);
                                 ASSERT(pte && PTE_VALID(pte) &&
@@ -570 +600 @@
                                 }
                                 page_mapping_remove(as, b + j * PAGE_SIZE);                             
-                                page_table_unlock(as, false);
                         }
                 }
@@ -580 +609 @@
 
         tlb_invalidate_pages(as->asid, area->base, area->pages);
+
         /*
          * Invalidate potential software translation caches (e.g. TSB on
@@ -586 +616 @@
         as_invalidate_translation_cache(as, area->base, area->pages);
         tlb_shootdown_finalize();
+
+        page_table_unlock(as, false);
         
         btree_destroy(&area->used_space);
@@ -784 +816 @@
 {
         as_area_t *area;
-        uintptr_t base;
         link_t *cur;
         ipl_t ipl;
@@ -813 +844 @@
                 return ENOTSUP;
         }
-
-        base = area->base;
 
         /*
@@ -834 +863 @@
         /* An array for storing frame numbers */
         old_frame = malloc(used_pages * sizeof(uintptr_t), 0);
+
+        page_table_lock(as, false);
 
         /*
@@ -858 +889 @@
                         
                         for (j = 0; j < (size_t) node->value[i]; j++) {
-                                page_table_lock(as, false);
                                 pte = page_mapping_find(as, b + j * PAGE_SIZE);
                                 ASSERT(pte && PTE_VALID(pte) &&
@@ -866 +896 @@
                                 /* Remove old mapping */
                                 page_mapping_remove(as, b + j * PAGE_SIZE);
-                                page_table_unlock(as, false);
                         }
                 }
@@ -883 +912 @@
         as_invalidate_translation_cache(as, area->base, area->pages);
         tlb_shootdown_finalize();
+
+        page_table_unlock(as, false);
 
         /*
@@ -952 +983 @@
         if (!THREAD)
                 return AS_PF_FAULT;
-                
-        ASSERT(AS);
-
+        
+        if (!AS)
+                return AS_PF_FAULT;
+        
         mutex_lock(&AS->lock);
-        area = find_area_and_lock(AS, page);    
+        area = find_area_and_lock(AS, page);
         if (!area) {
                 /*