diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8ea7c2c02cbf..c446e377acd3 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -128,6 +128,7 @@ config PPC
 	#
 	# Please keep this list sorted alphabetically.
 	#
+	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_SET_COHERENT_MASK
 	select ARCH_HAS_ELF_RANDOMIZE
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index e746becd9d6f..7f19fbd3ba55 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -29,12 +29,14 @@ extern struct pci_dev *isa_bridge_pcidev;
 
 #include <linux/device.h>
 #include <linux/compiler.h>
+#include <linux/mm.h>
 #include <asm/page.h>
 #include <asm/byteorder.h>
 #include <asm/synch.h>
 #include <asm/delay.h>
 #include <asm/mmu.h>
 #include <asm/ppc_asm.h>
+#include <asm/pgtable.h>
 
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>
@@ -804,6 +806,8 @@ extern void __iounmap_at(void *ea, unsigned long size);
  */
 static inline unsigned long virt_to_phys(volatile void * address)
 {
+	WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && !virt_addr_valid(address));
+
 	return __pa((unsigned long)address);
 }
 
@@ -827,7 +831,14 @@ static inline void * phys_to_virt(unsigned long address)
 /*
  * Change "struct page" to physical address.
  */
-#define page_to_phys(page)	((phys_addr_t)page_to_pfn(page) << PAGE_SHIFT)
+static inline phys_addr_t page_to_phys(struct page *page)
+{
+	unsigned long pfn = page_to_pfn(page);
+
+	WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && !pfn_valid(pfn));
+
+	return PFN_PHYS(pfn);
+}
 
 /*
  * 32 bits still uses virt_to_bus() for it's implementation of DMA
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 4fc77a99c9bf..d67215248d82 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -143,7 +143,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *call
 	 * Don't allow anybody to remap normal RAM that we're using.
 	 * mem_init() sets high_memory so only do the check after that.
 	 */
-	if (slab_is_available() && (p < virt_to_phys(high_memory)) &&
+	if (slab_is_available() && p <= virt_to_phys(high_memory - 1) &&
 	    page_is_ram(__phys_to_pfn(p))) {
 		printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
 		       (unsigned long long)p, __builtin_return_address(0));