diff --git a/drivers/ata/pata_octeon_cf.c b/drivers/ata/pata_octeon_cf.c
index e807cc3b6ab4..d6f69561dc86 100644
--- a/drivers/ata/pata_octeon_cf.c
+++ b/drivers/ata/pata_octeon_cf.c
@@ -841,7 +841,7 @@ static int __devinit octeon_cf_probe(struct platform_device *pdev)
 	ocd = pdev->dev.platform_data;
 
 	cs0 = devm_ioremap_nocache(&pdev->dev, res_cs0->start,
-				   res_cs0->end - res_cs0->start + 1);
+				   resource_size(res_cs0));
 
 	if (!cs0)
 		return -ENOMEM;
diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
index d8d743af3225..3f6ebc6c665a 100644
--- a/drivers/ata/pata_platform.c
+++ b/drivers/ata/pata_platform.c
@@ -151,14 +151,14 @@ int __devinit __pata_platform_probe(struct device *dev,
 	 */
 	if (mmio) {
 		ap->ioaddr.cmd_addr = devm_ioremap(dev, io_res->start,
-				io_res->end - io_res->start + 1);
+				resource_size(io_res));
 		ap->ioaddr.ctl_addr = devm_ioremap(dev, ctl_res->start,
-				ctl_res->end - ctl_res->start + 1);
+				resource_size(ctl_res));
 	} else {
 		ap->ioaddr.cmd_addr = devm_ioport_map(dev, io_res->start,
-				io_res->end - io_res->start + 1);
+				resource_size(io_res));
 		ap->ioaddr.ctl_addr = devm_ioport_map(dev, ctl_res->start,
-				ctl_res->end - ctl_res->start + 1);
+				resource_size(ctl_res));
 	}
 	if (!ap->ioaddr.cmd_addr || !ap->ioaddr.ctl_addr) {
 		dev_err(dev, "failed to map IO/CTL base\n");
diff --git a/drivers/ata/pata_rb532_cf.c b/drivers/ata/pata_rb532_cf.c
index 8e3cdef8a25f..45f1e10f917b 100644
--- a/drivers/ata/pata_rb532_cf.c
+++ b/drivers/ata/pata_rb532_cf.c
@@ -151,7 +151,7 @@ static __devinit int rb532_pata_driver_probe(struct platform_device *pdev)
 	info->irq = irq;
 
 	info->iobase = devm_ioremap_nocache(&pdev->dev, res->start,
-				res->end - res->start + 1);
+				resource_size(res));
 	if (!info->iobase)
 		return -ENOMEM;
 
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index c19417e02208..17f9ff9067a2 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -4013,7 +4013,7 @@ static int mv_platform_probe(struct platform_device *pdev)
 
 	host->iomap = NULL;
 	hpriv->base = devm_ioremap(&pdev->dev, res->start,
-				   res->end - res->start + 1);
+				   resource_size(res));
 	hpriv->base -= SATAHC0_REG_BASE;
 
 	/*