diff --git a/arch/arm/mach-ux500/mbox-db5500.c b/arch/arm/mach-ux500/mbox-db5500.c
index a4ffb9f4f4614366fae99d7af5f6e337d7110f9f..2b2d51caf9d8b9f4db2e62c1eaa7a596b3313546 100644
--- a/arch/arm/mach-ux500/mbox-db5500.c
+++ b/arch/arm/mach-ux500/mbox-db5500.c
@@ -416,8 +416,7 @@ struct mbox *mbox_setup(u8 mbox_id, mbox_recv_cb_t *mbox_cb, void *priv)
 	dev_dbg(&(mbox->pdev->dev),
 		"Resource name: %s start: 0x%X, end: 0x%X\n",
 		resource->name, resource->start, resource->end);
-	mbox->virtbase_peer =
-		ioremap(resource->start, resource->end - resource->start);
+	mbox->virtbase_peer = ioremap(resource->start, resource_size(resource));
 	if (!mbox->virtbase_peer) {
 		dev_err(&(mbox->pdev->dev), "Unable to ioremap peer mbox\n");
 		mbox = NULL;
@@ -440,8 +439,7 @@ struct mbox *mbox_setup(u8 mbox_id, mbox_recv_cb_t *mbox_cb, void *priv)
 	dev_dbg(&(mbox->pdev->dev),
 		"Resource name: %s start: 0x%X, end: 0x%X\n",
 		resource->name, resource->start, resource->end);
-	mbox->virtbase_local =
-		ioremap(resource->start, resource->end - resource->start);
+	mbox->virtbase_local = ioremap(resource->start, resource_size(resource));
 	if (!mbox->virtbase_local) {
 		dev_err(&(mbox->pdev->dev), "Unable to ioremap local mbox\n");
 		mbox = NULL;
diff --git a/arch/mips/rb532/gpio.c b/arch/mips/rb532/gpio.c
index 37de05d595e725ebdc59513181d3f43709ce1cb4..6c47dfeb7be326bf2dc4c5a7a1cbb1984b87efec 100644
--- a/arch/mips/rb532/gpio.c
+++ b/arch/mips/rb532/gpio.c
@@ -185,7 +185,7 @@ int __init rb532_gpio_init(void)
 	struct resource *r;
 
 	r = rb532_gpio_reg0_res;
-	rb532_gpio_chip->regbase = ioremap_nocache(r->start, r->end - r->start);
+	rb532_gpio_chip->regbase = ioremap_nocache(r->start, resource_size(r));
 
 	if (!rb532_gpio_chip->regbase) {
 		printk(KERN_ERR "rb532: cannot remap GPIO register 0\n");
diff --git a/drivers/video/msm/mddi.c b/drivers/video/msm/mddi.c
index b66d86ac7cea6d19a9ffa4b7fd5a0034ee702cc2..178b0720bd79a96d55e6d786fe8a183940263de2 100644
--- a/drivers/video/msm/mddi.c
+++ b/drivers/video/msm/mddi.c
@@ -679,7 +679,7 @@ static int __devinit mddi_probe(struct platform_device *pdev)
 		printk(KERN_ERR "mddi: no associated mem resource!\n");
 		return -ENOMEM;
 	}
-	mddi->base = ioremap(resource->start, resource->end - resource->start);
+	mddi->base = ioremap(resource->start, resource_size(resource));
 	if (!mddi->base) {
 		printk(KERN_ERR "mddi: failed to remap base!\n");
 		ret = -EINVAL;
diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c
index 3c5045a206ddbded9e82fbb9db41fa5fa50c178d..5064e831752128a41ee810dbb854af8ef1cadb40 100644
--- a/drivers/watchdog/bcm63xx_wdt.c
+++ b/drivers/watchdog/bcm63xx_wdt.c
@@ -248,7 +248,7 @@ static int __devinit bcm63xx_wdt_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	bcm63xx_wdt_device.regs = ioremap_nocache(r->start, r->end - r->start);
+	bcm63xx_wdt_device.regs = ioremap_nocache(r->start, resource_size(r));
 	if (!bcm63xx_wdt_device.regs) {
 		dev_err(&pdev->dev, "failed to remap I/O resources\n");
 		return -ENXIO;