lib/bootmem: Add method to walk OS POV memory tables

Add method to walk memory tables from OS point of view.
The tables don't change when modifiying bootmem entries and doesn't contain
bootmem specific tags.

Change-Id: Iee332a9821d12a7d9a684063b77b0502febd8d7d
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/25747
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/bootmem.h

@@ -70,6 +70,17 @@ void bootmem_dump_ranges(void);
 
 typedef bool (*range_action_t)(const struct range_entry *r, void *arg);
 
+/**
+ * Walk memory tables from OS point of view and call the provided function,
+ * for every region. The caller has to return false to break out of the loop any
+ * time, or return true to continue.
+ *
+ * @param action The function to call for each memory range.
+ * @param arg Pointer passed to function @action. Set to NULL if unused.
+ * @return true if the function 'action' returned false.
+ */
+bool bootmem_walk_os_mem(range_action_t action, void *arg);
+
 /**
  * Walk memory tables and call the provided function, for every region.
  * The caller has to return false to break out of the loop any time, or