+/*
+ * Virtual to physical RAM address translation.
+ *
+ * In 29 bit mode, the physical offset of RAM from address 0 is visible in
+ * the kernel virtual address space, and thus we don't have to take
+ * this into account when translating. However in 32 bit mode this offset
+ * is not visible (it is part of the PMB mapping) and so needs to be
+ * added or subtracted as required.
+ */
+#ifdef CONFIG_32BIT
+#define __pa(x) ((unsigned long)(x)-PAGE_OFFSET+__MEMORY_START)
+#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET-__MEMORY_START))
+#else
+#define __pa(x) ((unsigned long)(x)-PAGE_OFFSET)
+#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
+#endif
+
+#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)