diff --git a/drivers/pci/endpoint/Makefile b/drivers/pci/endpoint/Makefile
index 95b2fe47e3b06..c502ea7ef367c 100644
--- a/drivers/pci/endpoint/Makefile
+++ b/drivers/pci/endpoint/Makefile
@@ -6,3 +6,4 @@
 obj-$(CONFIG_PCI_ENDPOINT_CONFIGFS)	+= pci-ep-cfs.o
 obj-$(CONFIG_PCI_ENDPOINT)		+= pci-epc-core.o pci-epf-core.o\
 					   pci-epc-mem.o functions/
+obj-$(CONFIG_GENERIC_MSI_IRQ)		+= pci-ep-msi.o
diff --git a/drivers/pci/endpoint/pci-ep-msi.c b/drivers/pci/endpoint/pci-ep-msi.c
new file mode 100644
index 0000000000000..549b55b864d0e
--- /dev/null
+++ b/drivers/pci/endpoint/pci-ep-msi.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Endpoint *Controller* (EPC) MSI library
+ *
+ * Copyright (C) 2025 NXP
+ * Author: Frank Li <Frank.Li@nxp.com>
+ */
+
+#include <linux/device.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+#include <linux/pci-ep-cfs.h>
+#include <linux/pci-ep-msi.h>
+#include <linux/slab.h>
+
+static void pci_epf_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+	struct pci_epf *epf = to_pci_epf(desc->dev);
+
+	if (epf && epf->db_msg && desc->msi_index < epf->num_db)
+		memcpy(&epf->db_msg[desc->msi_index].msg, msg, sizeof(*msg));
+}
+
+int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
+{
+	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
+	struct irq_domain *dom;
+	void *msg;
+	u32 rid;
+	int ret;
+	int i;
+
+	rid = PCI_EPF_DEVID(epf->func_no, epf->vfunc_no);
+	dom = of_msi_map_get_device_domain(epc->dev.parent, rid, DOMAIN_BUS_PLATFORM_MSI);
+	if (!dom) {
+		dev_err(dev, "Can't find msi domain\n");
+		return -EINVAL;
+	}
+
+	dev_set_msi_domain(dev, dom);
+
+	msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	epf->num_db = num_db;
+	epf->db_msg = msg;
+
+	ret = platform_device_msi_init_and_alloc_irqs(&epf->dev, num_db, pci_epf_write_msi_msg);
+	if (ret) {
+		/*
+		 * The pcie_ep DT node has to specify 'msi-parent' for EP
+		 * doorbell support to work. Right now only GIC ITS is
+		 * supported. If you have GIC ITS and reached this print,
+		 * perhaps you are missing 'msi-map' in DT.
+		 */
+		dev_err(dev, "Failed to allocate MSI\n");
+		kfree(msg);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < num_db; i++)
+		epf->db_msg[i].virq = msi_get_virq(dev, i);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pci_epf_alloc_doorbell);
+
+void pci_epf_free_doorbell(struct pci_epf *epf)
+{
+	platform_device_msi_free_irqs_all(&epf->dev);
+
+	kfree(epf->db_msg);
+	epf->db_msg = NULL;
+	epf->num_db = 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_free_doorbell);
diff --git a/include/linux/pci-ep-msi.h b/include/linux/pci-ep-msi.h
new file mode 100644
index 0000000000000..6dfbe9353f0d8
--- /dev/null
+++ b/include/linux/pci-ep-msi.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * PCI Endpoint *Function* side MSI header file
+ *
+ * Copyright (C) 2024 NXP
+ * Author: Frank Li <Frank.Li@nxp.com>
+ */
+
+#ifndef __PCI_EP_MSI__
+#define __PCI_EP_MSI__
+
+struct pci_epf;
+
+#ifdef CONFIG_GENERIC_MSI_IRQ
+int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 nums);
+void pci_epf_free_doorbell(struct pci_epf *epf);
+#else
+static inline int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 nums)
+{
+	return -EINVAL;
+}
+
+static inline void pci_epf_free_doorbell(struct pci_epf *epf)
+{
+}
+#endif /* CONFIG_GENERIC_MSI_IRQ */
+
+#endif /* __PCI_EP_MSI__ */
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index d2790b8b29394..518bc4171285e 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -12,6 +12,7 @@
 #include <linux/configfs.h>
 #include <linux/device.h>
 #include <linux/mod_devicetable.h>
+#include <linux/msi.h>
 #include <linux/pci.h>
 
 struct pci_epf;
@@ -125,6 +126,17 @@ struct pci_epf_bar {
 	int		flags;
 };
 
+/**
+ * struct pci_epf_doorbell_msg - represents doorbell message
+ * @msi_msg: MSI message
+ * @virq: irq number of this doorbell MSI message
+ * @name: irq name for doorbell interrupt
+ */
+struct pci_epf_doorbell_msg {
+	struct msi_msg msg;
+	int virq;
+};
+
 /**
  * struct pci_epf - represents the PCI EPF device
  * @dev: the PCI EPF device
@@ -152,6 +164,8 @@ struct pci_epf_bar {
  * @vfunction_num_map: bitmap to manage virtual function number
  * @pci_vepf: list of virtual endpoint functions associated with this function
  * @event_ops: Callbacks for capturing the EPC events
+ * @db_msg: data for MSI from RC side
+ * @num_db: number of doorbells
  */
 struct pci_epf {
 	struct device		dev;
@@ -182,6 +196,8 @@ struct pci_epf {
 	unsigned long		vfunction_num_map;
 	struct list_head	pci_vepf;
 	const struct pci_epc_event_ops *event_ops;
+	struct pci_epf_doorbell_msg *db_msg;
+	u16 num_db;
 };
 
 /**
