*/
#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
-#define ARCH_PFN_OFFSET virt_to_pfn(CONFIG_LINUX_RAM_BASE)
+/*
+ * When HIGHMEM is enabled we have holes in the memory map so we need
+ * pfn_valid() that takes into account the actual extents of the physical
+ * memory
+ */
+#ifdef CONFIG_HIGHMEM
+
+extern unsigned long arch_pfn_offset;
+#define ARCH_PFN_OFFSET arch_pfn_offset
+
+extern int pfn_valid(unsigned long pfn);
+#define pfn_valid pfn_valid
-#ifdef CONFIG_FLATMEM
+#else /* CONFIG_HIGHMEM */
+
+#define ARCH_PFN_OFFSET virt_to_pfn(CONFIG_LINUX_RAM_BASE)
#define pfn_valid(pfn) (((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
-#endif
+
+#endif /* CONFIG_HIGHMEM */
/*
* __pa, __va, virt_to_page (ALERT: deprecated, don't use them)