diff --git a/arch/avr32/mach-at32ap/extint.c b/arch/avr32/mach-at32ap/extint.c
index fbc2aea..cfb298d 100644
--- a/arch/avr32/mach-at32ap/extint.c
+++ b/arch/avr32/mach-at32ap/extint.c
@@ -204,7 +204,7 @@
 	}
 
 	eic->first_irq = EIM_IRQ_BASE + 32 * pdev->id;
-	eic->regs = ioremap(regs->start, regs->end - regs->start + 1);
+	eic->regs = ioremap(regs->start, resource_size(regs));
 	if (!eic->regs) {
 		dev_dbg(&pdev->dev, "failed to map regs\n");
 		goto err_ioremap;
diff --git a/arch/avr32/mach-at32ap/hsmc.c b/arch/avr32/mach-at32ap/hsmc.c
index f7672d3..f66245e 100644
--- a/arch/avr32/mach-at32ap/hsmc.c
+++ b/arch/avr32/mach-at32ap/hsmc.c
@@ -245,7 +245,7 @@
 
 	hsmc->pclk = pclk;
 	hsmc->mck = mck;
-	hsmc->regs = ioremap(regs->start, regs->end - regs->start + 1);
+	hsmc->regs = ioremap(regs->start, resource_size(regs));
 	if (!hsmc->regs)
 		goto out_disable_clocks;
 
diff --git a/arch/avr32/mach-at32ap/intc.c b/arch/avr32/mach-at32ap/intc.c
index 3e36461..6c70043 100644
--- a/arch/avr32/mach-at32ap/intc.c
+++ b/arch/avr32/mach-at32ap/intc.c
@@ -107,7 +107,7 @@
 
 	clk_enable(pclk);
 
-	intc0.regs = ioremap(regs->start, regs->end - regs->start + 1);
+	intc0.regs = ioremap(regs->start, resource_size(regs));
 	if (!intc0.regs) {
 		printk(KERN_EMERG "intc: failed to map registers (0x%08lx)\n",
 		       (unsigned long)regs->start);
diff --git a/arch/avr32/mach-at32ap/pio.c b/arch/avr32/mach-at32ap/pio.c
index 2e0aa85..9b39dea 100644
--- a/arch/avr32/mach-at32ap/pio.c
+++ b/arch/avr32/mach-at32ap/pio.c
@@ -461,7 +461,7 @@
 		clk_enable(pio->clk);
 
 	pio->pdev = pdev;
-	pio->regs = ioremap(regs->start, regs->end - regs->start + 1);
+	pio->regs = ioremap(regs->start, resource_size(regs));
 
 	/* start with irqs disabled and acked */
 	pio_writel(pio, IDR, ~0UL);