diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index e25c11e727fe..b3162715ed78 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -95,7 +95,7 @@ static int __init dt_scan_depth1_nodes(unsigned long node,
  * __acpi_map_table() will be called before page_init(), so early_ioremap()
  * or early_memremap() should be called here to for ACPI table mapping.
  */
-char *__init __acpi_map_table(unsigned long phys, unsigned long size)
+void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
 {
 	if (!size)
 		return NULL;
@@ -103,7 +103,7 @@ char *__init __acpi_map_table(unsigned long phys, unsigned long size)
 	return early_memremap(phys, size);
 }
 
-void __init __acpi_unmap_table(char *map, unsigned long size)
+void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
 {
 	if (!map || !size)
 		return;
diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 7508c306aa9e..1d29b2f8726b 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -159,12 +159,12 @@ int acpi_request_vector(u32 int_type)
 	return vector;
 }
 
-char *__init __acpi_map_table(unsigned long phys_addr, unsigned long size)
+void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
 {
-	return __va(phys_addr);
+	return __va(phys);
 }
 
-void __init __acpi_unmap_table(char *map, unsigned long size)
+void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
 {
 }
 
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 27f0240773b3..666dcc3e14e1 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -118,7 +118,7 @@ static u32 isa_irq_to_gsi[NR_IRQS_LEGACY] __read_mostly = {
  * This is just a simple wrapper around early_ioremap(),
  * with sanity checks for phys == 0 and size == 0.
  */
-char *__init __acpi_map_table(unsigned long phys, unsigned long size)
+void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
 {
 
 	if (!phys || !size)
@@ -127,7 +127,7 @@ char *__init __acpi_map_table(unsigned long phys, unsigned long size)
 	return early_ioremap(phys, size);
 }
 
-void __init __acpi_unmap_table(char *map, unsigned long size)
+void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
 {
 	if (!map || !size)
 		return;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index c749eef1daa1..7443af1d16e7 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -228,8 +228,8 @@ struct acpi_subtable_proc {
 	int count;
 };
 
-char * __acpi_map_table (unsigned long phys_addr, unsigned long size);
-void __acpi_unmap_table(char *map, unsigned long size);
+void __iomem *__acpi_map_table(unsigned long phys, unsigned long size);
+void __acpi_unmap_table(void __iomem *map, unsigned long size);
 int early_acpi_boot_init(void);
 int acpi_boot_init (void);
 void acpi_boot_table_init (void);