Changeset ad12b5ea in mainline for kernel/generic/src/mm/frame.c

Timestamp:

2011-11-20T16:53:04Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

2686705

Parents:

a55ddc64

Message:

Factor out the amd64/ia32 code which calculates the bounds of
a zone after considering the low/hich memory split to a new
generic function frame_adjust_zone_bounds().

File:

• kernel/generic/src/mm/frame.c (modified) (1 diff)

kernel/generic/src/mm/frame.c

@@ -1264 +1264 @@
 }
 
+/** Adjust bounds of physical memory region according to low/high memory split.
+ *
+ * @param low[in]       If true, the adujstment is performed to make the region
+ *                      fit in the low memory. Otherwise the adjustment is
+ *                      performed to make the region fit in the high memory.
+ * @param basep[inout]  Pointer to a variable which contains the region's base
+ *                      address and which may receive the adjusted base address.
+ * @param sizep[inout]  Pointer to a variable which contains the region's size
+ *                      and which may receive the adjusted size.
+ * @retun               True if the region still exists even after the
+ *                      adjustment, false otherwise.
+ */
+bool frame_adjust_zone_bounds(bool low, uintptr_t *basep, size_t *sizep)
+{
+        uintptr_t limit = config.identity_size;
+
+        if (low) {
+                if (*basep > limit)
+                        return false;
+                if (*basep + *sizep > limit)
+                        *sizep = limit - *basep;
+        } else {
+                if (*basep + *sizep <= limit)
+                        return false;
+                if (*basep <= limit) {
+                        *sizep -= limit - *basep;
+                        *basep = limit;
+                }
+        }
+        return true;
+}
+
 /** Return total size of all zones.
  *