diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index 36fc7bfe9e11..d613653ed5b9 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -51,6 +51,8 @@
 #define H_VMALLOC_SIZE	(H_KERN_VIRT_SIZE >> 1)
 #define H_VMALLOC_END	(H_VMALLOC_START + H_VMALLOC_SIZE)
 
+#define H_KERN_IO_START	H_VMALLOC_END
+
 /*
  * Region IDs
  */
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index d1da415e283c..18a8580d3ddc 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -272,8 +272,10 @@ extern unsigned long __vmalloc_end;
 
 extern unsigned long __kernel_virt_start;
 extern unsigned long __kernel_virt_size;
+extern unsigned long __kernel_io_start;
 #define KERN_VIRT_START __kernel_virt_start
 #define KERN_VIRT_SIZE  __kernel_virt_size
+#define KERN_IO_START  __kernel_io_start
 extern struct page *vmemmap;
 extern unsigned long ioremap_bot;
 extern unsigned long pci_io_base;
@@ -298,7 +300,6 @@ extern unsigned long pci_io_base;
  *  PHB_IO_BASE = ISA_IO_BASE + 64K to ISA_IO_BASE + 2G, PHB IO spaces
  * IOREMAP_BASE = ISA_IO_BASE + 2G to VMALLOC_START + PGTABLE_RANGE
  */
-#define KERN_IO_START	(KERN_VIRT_START + (KERN_VIRT_SIZE >> 1))
 #define FULL_IO_SIZE	0x80000000ul
 #define  ISA_IO_BASE	(KERN_IO_START)
 #define  ISA_IO_END	(KERN_IO_START + 0x10000ul)
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index 544440b5aff3..1e5ba94e62ef 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -110,6 +110,8 @@
  */
 #define RADIX_VMEMMAP_BASE		(RADIX_VMALLOC_END)
 
+#define RADIX_KERN_IO_START	(RADIX_KERN_VIRT_START + (RADIX_KERN_VIRT_SIZE >> 1))
+
 #ifndef __ASSEMBLY__
 #define RADIX_PTE_TABLE_SIZE	(sizeof(pte_t) << RADIX_PTE_INDEX_SIZE)
 #define RADIX_PMD_TABLE_SIZE	(sizeof(pmd_t) << RADIX_PMD_INDEX_SIZE)
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 7419fc1854ad..a93137c358ea 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1019,6 +1019,7 @@ void __init hash__early_init_mmu(void)
 	__kernel_virt_size = H_KERN_VIRT_SIZE;
 	__vmalloc_start = H_VMALLOC_START;
 	__vmalloc_end = H_VMALLOC_END;
+	__kernel_io_start = H_KERN_IO_START;
 	vmemmap = (struct page *)H_VMEMMAP_BASE;
 	ioremap_bot = IOREMAP_BASE;
 
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 5d05245208ee..c1185c8ecb22 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -494,6 +494,7 @@ void __init radix__early_init_mmu(void)
 	__kernel_virt_size = RADIX_KERN_VIRT_SIZE;
 	__vmalloc_start = RADIX_VMALLOC_START;
 	__vmalloc_end = RADIX_VMALLOC_END;
+	__kernel_io_start = RADIX_KERN_IO_START;
 	vmemmap = (struct page *)RADIX_VMEMMAP_BASE;
 	ioremap_bot = IOREMAP_BASE;
 
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 0736e94c7615..ac0717a90ca6 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -104,6 +104,8 @@ unsigned long __vmalloc_start;
 EXPORT_SYMBOL(__vmalloc_start);
 unsigned long __vmalloc_end;
 EXPORT_SYMBOL(__vmalloc_end);
+unsigned long __kernel_io_start;
+EXPORT_SYMBOL(__kernel_io_start);
 struct page *vmemmap;
 EXPORT_SYMBOL(vmemmap);
 unsigned long __pte_frag_nr;