diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4df73da11adc..7dedfe56c3f3 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1493,6 +1493,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 		forcesac
 		soft
 		pt		[x86, IA-64]
+		nobypass	[PPC/POWERNV]
+			Disable IOMMU bypass, using IOMMU for PCI devices.
 
 
 	io7=		[HW] IO7 for Marvel based alpha systems
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 4f1e43c05e84..85b473823fda 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -75,6 +75,28 @@ static void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
 #define pe_info(pe, fmt, ...)					\
 	pe_level_printk(pe, KERN_INFO, fmt, ##__VA_ARGS__)
 
+static bool pnv_iommu_bypass_disabled __read_mostly;
+
+static int __init iommu_setup(char *str)
+{
+	if (!str)
+		return -EINVAL;
+
+	while (*str) {
+		if (!strncmp(str, "nobypass", 8)) {
+			pnv_iommu_bypass_disabled = true;
+			pr_info("PowerNV: IOMMU bypass window disabled.\n");
+			break;
+		}
+		str += strcspn(str, ",");
+		if (*str == ',')
+			str++;
+	}
+
+	return 0;
+}
+early_param("iommu", iommu_setup);
+
 /*
  * stdcix is only supposed to be used in hypervisor real mode as per
  * the architecture spec
@@ -1351,7 +1373,9 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 		pnv_ioda_setup_bus_dma(pe, pe->pbus, true);
 
 	/* Also create a bypass window */
-	pnv_pci_ioda2_setup_bypass_pe(phb, pe);
+	if (!pnv_iommu_bypass_disabled)
+		pnv_pci_ioda2_setup_bypass_pe(phb, pe);
+
 	return;
 fail:
 	if (pe->tce32_seg >= 0)