WebSVN – HelenOS-historic – Diff – //kernel/trunk/generic/src/mm/frame.c

 #include <align.h>
 spinlock_t zone_head_lock;       /**< this lock protects zone_head list */
 link_t zone_head;                /**< list of all zones in the system */
+/** Blacklist containing non-available areas of memory.
+ *
+ * This blacklist is used to exclude frames that cannot be allocated
+ * (e.g. kernel memory) from available memory map.
+ */
 region_t zone_blacklist[ZONE_BLACKLIST_SIZE];
 count_t zone_blacklist_count = 0;
 static struct buddy_system_operations  zone_buddy_system_operations = {
     .find_buddy = zone_buddy_find_buddy,
         goto loop;
+    }
     /* Allocate frames from zone buddy system */
-    cur = buddy_system_alloc(zone->buddy_system, order);
+    tmp = buddy_system_alloc(zone->buddy_system, order);
+    ASSERT(tmp);
+    /* Update zone information. */
+    zone->free_count -= (1 << order);
+    zone->busy_count += (1 << order);
-    /* frame will be actually a first frame of the block */
+    /* Frame will be actually a first frame of the block. */
-    frame = list_get_instance(cur, frame_t, buddy_link);
+    frame = list_get_instance(tmp, frame_t, buddy_link);
     /* get frame address */
     v = FRAME2ADDR(zone, frame);
-    if (flags & FRAME_KA)
-        v = PA2KA(v);
     spinlock_unlock(&zone->lock);
     spinlock_unlock(&zone_head_lock);
     interrupts_restore(ipl);
-    return v;
+    if (flags & FRAME_KA)
+        v = PA2KA(v);
+    return v;
+}
 /** Free a frame.
+ *
  * Find respective frame structrue for supplied addr.
     ASSERT(frame->refcount);
     if (!--frame->refcount) {
         buddy_system_free(zone->buddy_system, &frame->buddy_link);
+    }
+    /* Update zone information. */
+    zone->free_count += (1 << frame->buddy_order);
+    zone->busy_count -= (1 << frame->buddy_order);
     spinlock_unlock(&zone->lock);
     spinlock_unlock(&zone_head_lock);
     interrupts_restore(ipl);
+}
 /** Mark frame region not free.
+{
     spinlock_initialize(&zone_head_lock);
     list_initialize(&zone_head);
+}
+/** Create frame zones in region of available memory.
+ *
+ * Avoid any black listed areas of non-available memory.
+ * Assume that the black listed areas cannot overlap
+ * one another or cross available memory region boundaries.
+ *
+ * @param base Base address of available memory region.
+ * @param size Size of the region.
+ */
 void zone_create_in_region(__address base, size_t size) {
     int i;
     zone_t * z;
     __address s;
     size_t sz;
     zone_attach(z);
+}
 /** Create frame zone
+ *
  * Create new frame zone.
+ *
  * @param start Physical address of the first frame within the zone.
  * @param block Block for which buddy should be found
+ *
  * @return Buddy for given block if found
  */
 link_t * zone_buddy_find_buddy(buddy_system_t *b, link_t * block) {
-    frame_t * frame, * f;
+    frame_t * frame;
     zone_t * zone;
-    link_t * cur;
     count_t index;
     bool is_left, is_right;
     frame = list_get_instance(block, frame_t, buddy_link);
     zone = (zone_t *) b->data;
-    /*
-     * (FRAME_INDEX % 2^(ORDER+1)) == 0 ===> LEFT BUDDY
-     * (FRAME_INDEX % 2^(ORDER+1)) == 2^(ORDER) ===> RIGHT BUDDY
-     */
     is_left = IS_BUDDY_LEFT_BLOCK(zone, frame);
     is_right = !is_left;
     /*
      * test left buddy
             zone->frames[index].refcount == 0) {
             return &zone->frames[index].buddy_link;
+        }
+    }
     return NULL;
+}
 /** Buddy system bisect implementation
+ *
  * @param b Buddy system.

Subversion Repositories HelenOS-historic

(root)//kernel/trunk/generic/src/mm/frame.c – Rev 538 → 539