memblock: add functions to convert allocated pointers between virt/phys

include/socks/memblock.h

@@ -301,6 +301,20 @@ extern int memblock_free(void *addr, size_t size);
 */
 extern int memblock_free_phys(phys_addr_t addr, size_t size);
 
+/* convert a virtual pointer returned by memblock
+   to a physical address.
+
+   @param p the pointer to convert.
+*/
+extern phys_addr_t memblock_virt_to_phys(void *p);
+
+/* convert a physical address returned by memblock
+   to a virtual pointer.
+
+   @param p the address to convert.
+*/
+extern void *memblock_phys_to_virt(phys_addr_t p);
+
 extern void __next_memory_region(memblock_iter_t *it, \
 		memblock_type_t *type_a, memblock_type_t *type_b,
 		phys_addr_t start, phys_addr_t end);

vm/memblock.c

@@ -404,3 +404,13 @@ void __next_memory_region(memblock_iter_t *it, memblock_type_t *type_a, memblock
 	/* ULLONG_MAX signals the end of the iteration */
 	it->__idx = ITER_END;
 }
+
+phys_addr_t memblock_virt_to_phys(void *p)
+{
+	return (phys_addr_t)p - memblock.m_voffset;
+}
+
+void *memblock_phys_to_virt(phys_addr_t p)
+{
+	return (void *)(p + memblock.m_voffset);
+}