Merge branch 'pci/endpoint/doorbell'

- Add RC-to-EP doorbell support using platform MSI controller (Frank Li)

- Check for MSI parent and mutability since we currently don't support
  mutable MSI controllers (Frank Li)

- Add pci_epf_align_inbound_addr() helper (Frank Li)

- Add a doorbell test (Frank Li)

* pci/endpoint/doorbell:
  selftests: pci_endpoint: Add doorbell test case
  misc: pci_endpoint_test: Add doorbell test case
  PCI: endpoint: pci-epf-test: Add doorbell test support
  PCI: endpoint: Add pci_epf_align_inbound_addr() helper for inbound address alignment
  PCI: endpoint: pci-ep-msi: Add checks for MSI parent and mutability
  PCI: endpoint: Add RC-to-EP doorbell support using platform MSI controller

3 files changed, 47 insertions, 0 deletions

diff --git a/include/linux/pci-ep-msi.h b/include/linux/pci-ep-msi.h
new file mode 100644
index 000000000000..7c5db90f9620
--- /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_PCI_ENDPOINT_MSI_DOORBELL
+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 -ENODATA;
+}
+
+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 749cee0bcf2c..2e85504ba2ba 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;
@@ -129,6 +130,16 @@ struct pci_epf_bar {
 };
 
 /**
+ * struct pci_epf_doorbell_msg - represents doorbell message
+ * @msg: MSI message
+ * @virq: IRQ number of this doorbell MSI message
+ */
+struct pci_epf_doorbell_msg {
+	struct msi_msg msg;
+	int virq;
+};
+
+/**
  * struct pci_epf - represents the PCI EPF device
  * @dev: the PCI EPF device
  * @name: the name of the PCI EPF device
@@ -155,6 +166,8 @@ 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;
@@ -185,6 +198,8 @@ 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;
 };
 
 /**
@@ -226,6 +241,9 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 			  enum pci_epc_interface_type type);
 void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
 			enum pci_epc_interface_type type);
+
+int pci_epf_align_inbound_addr(struct pci_epf *epf, enum pci_barno bar,
+			       u64 addr, dma_addr_t *base, size_t *off);
 int pci_epf_bind(struct pci_epf *epf);
 void pci_epf_unbind(struct pci_epf *epf);
 int pci_epf_add_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf);
diff --git a/include/uapi/linux/pcitest.h b/include/uapi/linux/pcitest.h
index d3aa8715a525..d6023a45a9d0 100644
--- a/include/uapi/linux/pcitest.h
+++ b/include/uapi/linux/pcitest.h
@@ -21,6 +21,7 @@
 #define PCITEST_SET_IRQTYPE	_IOW('P', 0x8, int)
 #define PCITEST_GET_IRQTYPE	_IO('P', 0x9)
 #define PCITEST_BARS		_IO('P', 0xa)
+#define PCITEST_DOORBELL	_IO('P', 0xb)
 #define PCITEST_CLEAR_IRQ	_IO('P', 0x10)
 
 #define PCITEST_IRQ_TYPE_UNDEFINED	-1