diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index e5f2377..a4baa0d 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -246,29 +246,38 @@ static int dw_pcie_ep_map_addr(struct pci_epc *epc, u8 func_no,
 
 static int dw_pcie_ep_get_msi(struct pci_epc *epc, u8 func_no)
 {
-	int val;
 	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	u32 val, reg;
+
+	if (!ep->msi_cap)
+		return 0;
 
-	val = dw_pcie_readw_dbi(pci, MSI_MESSAGE_CONTROL);
-	if (!(val & MSI_CAP_MSI_EN_MASK))
+	reg = ep->msi_cap + PCI_MSI_FLAGS;
+	val = dw_pcie_readw_dbi(pci, reg);
+	if (!(val & PCI_MSI_FLAGS_ENABLE))
 		return -EINVAL;
 
-	val = (val & MSI_CAP_MME_MASK) >> MSI_CAP_MME_SHIFT;
+	val = (val & PCI_MSI_FLAGS_QSIZE) >> 4;
+
 	return val;
 }
 
-static int dw_pcie_ep_set_msi(struct pci_epc *epc, u8 func_no, u8 encode_int)
+static int dw_pcie_ep_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts)
 {
-	int val;
 	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	u32 val, reg;
 
-	val = dw_pcie_readw_dbi(pci, MSI_MESSAGE_CONTROL);
-	val &= ~MSI_CAP_MMC_MASK;
-	val |= (encode_int << MSI_CAP_MMC_SHIFT) & MSI_CAP_MMC_MASK;
+	if (!ep->msi_cap)
+		return 0;
+
+	reg = ep->msi_cap + PCI_MSI_FLAGS;
+	val = dw_pcie_readw_dbi(pci, reg);
+	val &= ~PCI_MSI_FLAGS_QMASK;
+	val |= (interrupts << 1) & PCI_MSI_FLAGS_QMASK;
 	dw_pcie_dbi_ro_wr_en(pci);
-	dw_pcie_writew_dbi(pci, MSI_MESSAGE_CONTROL, val);
+	dw_pcie_writew_dbi(pci, reg, val);
 	dw_pcie_dbi_ro_wr_dis(pci);
 
 	return 0;
@@ -367,21 +376,29 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 	struct pci_epc *epc = ep->epc;
 	u16 msg_ctrl, msg_data;
-	u32 msg_addr_lower, msg_addr_upper;
+	u32 msg_addr_lower, msg_addr_upper, reg;
 	u64 msg_addr;
 	bool has_upper;
 	int ret;
 
+	if (!ep->msi_cap)
+		return 0;
+
 	/* Raise MSI per the PCI Local Bus Specification Revision 3.0, 6.8.1. */
-	msg_ctrl = dw_pcie_readw_dbi(pci, MSI_MESSAGE_CONTROL);
+	reg = ep->msi_cap + PCI_MSI_FLAGS;
+	msg_ctrl = dw_pcie_readw_dbi(pci, reg);
 	has_upper = !!(msg_ctrl & PCI_MSI_FLAGS_64BIT);
-	msg_addr_lower = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_L32);
+	reg = ep->msi_cap + PCI_MSI_ADDRESS_LO;
+	msg_addr_lower = dw_pcie_readl_dbi(pci, reg);
 	if (has_upper) {
-		msg_addr_upper = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_U32);
-		msg_data = dw_pcie_readw_dbi(pci, MSI_MESSAGE_DATA_64);
+		reg = ep->msi_cap + PCI_MSI_ADDRESS_HI;
+		msg_addr_upper = dw_pcie_readl_dbi(pci, reg);
+		reg = ep->msi_cap + PCI_MSI_DATA_64;
+		msg_data = dw_pcie_readw_dbi(pci, reg);
 	} else {
 		msg_addr_upper = 0;
-		msg_data = dw_pcie_readw_dbi(pci, MSI_MESSAGE_DATA_32);
+		reg = ep->msi_cap + PCI_MSI_DATA_32;
+		msg_data = dw_pcie_readw_dbi(pci, reg);
 	}
 	msg_addr = ((u64) msg_addr_upper) << 32 | msg_addr_lower;
 	ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys, msg_addr,
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index b22c5bb..a0ab12f 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -96,17 +96,6 @@
 #define PCIE_GET_ATU_INB_UNR_REG_OFFSET(region)				\
 			((0x3 << 20) | ((region) << 9) | (0x1 << 8))
 
-#define MSI_MESSAGE_CONTROL		0x52
-#define MSI_CAP_MMC_SHIFT		1
-#define MSI_CAP_MMC_MASK		(7 << MSI_CAP_MMC_SHIFT)
-#define MSI_CAP_MME_SHIFT		4
-#define MSI_CAP_MSI_EN_MASK		0x1
-#define MSI_CAP_MME_MASK		(7 << MSI_CAP_MME_SHIFT)
-#define MSI_MESSAGE_ADDR_L32		0x54
-#define MSI_MESSAGE_ADDR_U32		0x58
-#define MSI_MESSAGE_DATA_32		0x58
-#define MSI_MESSAGE_DATA_64		0x5C
-
 #define MAX_MSI_IRQS			256
 #define MAX_MSI_IRQS_PER_CTRL		32
 #define MAX_MSI_CTRLS			(MAX_MSI_IRQS / MAX_MSI_IRQS_PER_CTRL)
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index a23aa75..b18a8b07 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -201,7 +201,8 @@ int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts)
 	u8 encode_int;
 	unsigned long flags;
 
-	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
+	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
+	    interrupts > 32)
 		return -EINVAL;
 
 	if (!epc->ops->set_msi)
