[PATCH v1 05/12] fpga: dfl: register dfl-pci device into fpgahph driver

[Tianfei Zhang <tianfei.zhang@intel.com>]

Add a registration of dfl-pci device into fpgahp driver by
fpgahp_register() API.

For Intel N3000 Card, FPGA devices like PFs/VFs and some ethernet
controllers are connected with a PCI switch, so the hotplug bridge
is the root hub of PCI device. This patch instances this hotplug
bridge as a hotplug controller.

Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/fpga/Kconfig   |  1 +
 drivers/fpga/dfl-pci.c | 77 ++++++++++++++++++++++++++++++++++++++----
 drivers/fpga/dfl.h     |  2 ++
 3 files changed, 74 insertions(+), 6 deletions(-)

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 6ce143dafd04..2188c5658e06 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -213,6 +213,7 @@ config FPGA_DFL_NIOS_INTEL_PAC_N3000
 config FPGA_DFL_PCI
 	tristate "FPGA DFL PCIe Device Driver"
 	depends on PCI && FPGA_DFL
+	depends on HOTPLUG_PCI_FPGA
 	help
 	  Select this option to enable PCIe driver for PCIe-based
 	  Field-Programmable Gate Array (FPGA) solutions which implement
diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
index 0914e7328b1a..0409cb30e563 100644
--- a/drivers/fpga/dfl-pci.c
+++ b/drivers/fpga/dfl-pci.c
@@ -23,6 +23,8 @@
 #include <linux/errno.h>
 #include <linux/aer.h>
 
+#include <linux/fpga/fpgahp_manager.h>
+
 #include "dfl.h"
 
 #define DRV_VERSION	"0.8"
@@ -40,6 +42,9 @@ struct cci_drvdata {
 	struct dfl_fpga_cdev *cdev;	/* container device */
 };
 
+static const struct fpgahp_manager_ops fpgahp_ops = {
+};
+
 static void __iomem *cci_pci_ioremap_bar0(struct pci_dev *pcidev)
 {
 	if (pcim_iomap_regions(pcidev, BIT(0), DRV_NAME))
@@ -118,6 +123,15 @@ static struct pci_device_id cci_pcie_id_tbl[] = {
 };
 MODULE_DEVICE_TABLE(pci, cci_pcie_id_tbl);
 
+/*
+ * List the FPGA cards which have some ethernet controllers connected to a PCI
+ * switch like PAC N3000, used to find hotplug bridge for fpgahp driver.
+ */
+static const struct pci_device_id has_pci_switch_devids[] = {
+	{ PCI_VDEVICE(INTEL, PCIE_DEVICE_ID_INTEL_PAC_N3000) },
+	{}
+};
+
 static int cci_init_drvdata(struct pci_dev *pcidev)
 {
 	struct cci_drvdata *drvdata;
@@ -306,12 +320,33 @@ static int find_dfls_by_default(struct pci_dev *pcidev,
 	return ret;
 }
 
+/*
+ * On N3000 Card, FPGA devices like PFs/VFs and some ethernet controllers
+ * are connected to a PCI switch, so the hotplug bridge on the root port of
+ * FPGA PF0 PCI device.
+ */
+static struct pci_dev *cci_find_hotplug_bridge(struct pci_dev *pcidev)
+{
+	struct pci_dev *hotplug_bridge;
+
+	if (!pci_match_id(has_pci_switch_devids, pcidev))
+		return pcidev;
+
+	hotplug_bridge = pcie_find_root_port(pcidev);
+	if (!hotplug_bridge)
+		return NULL;
+
+	return hotplug_bridge;
+}
+
 /* enumerate feature devices under pci device */
 static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
 {
 	struct cci_drvdata *drvdata = pci_get_drvdata(pcidev);
 	struct dfl_fpga_enum_info *info;
+	struct pci_dev *hotplug_bridge;
 	struct dfl_fpga_cdev *cdev;
+	struct fpgahp_manager *mgr;
 	int nvec, ret = 0;
 	int *irq_table;
 
@@ -346,23 +381,47 @@ static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
 	if (ret)
 		goto irq_free_exit;
 
+	/* register hotplug bridge of PF0 device into fpgahp driver */
+	if (dev_is_pf(&pcidev->dev)) {
+		hotplug_bridge = cci_find_hotplug_bridge(pcidev);
+		if (!hotplug_bridge) {
+			dev_err(&pcidev->dev, "Hotplug bridge not found\n");
+			ret = -ENODEV;
+			goto irq_free_exit;
+		}
+
+		mgr = fpgahp_register(hotplug_bridge, dev_name(&pcidev->dev),
+				      &fpgahp_ops, pcidev);
+		if (IS_ERR(mgr)) {
+			dev_err(&pcidev->dev, "Registering fpga hotplug failed\n");
+			ret = PTR_ERR(mgr);
+			goto irq_free_exit;
+		}
+	}
+
 	/* start enumeration with prepared enumeration information */
 	cdev = dfl_fpga_feature_devs_enumerate(info);
 	if (IS_ERR(cdev)) {
 		dev_err(&pcidev->dev, "Enumeration failure\n");
 		ret = PTR_ERR(cdev);
-		goto irq_free_exit;
+		goto free_register;
 	}
 
+	if (dev_is_pf(&pcidev->dev))
+		cdev->fpgahp_mgr = mgr;
+
 	drvdata->cdev = cdev;
 
-irq_free_exit:
-	if (ret)
-		cci_pci_free_irq(pcidev);
 enum_info_free_exit:
 	dfl_fpga_enum_info_free(info);
-
 	return ret;
+
+free_register:
+	if (dev_is_pf(&pcidev->dev))
+		fpgahp_unregister(mgr);
+irq_free_exit:
+	cci_pci_free_irq(pcidev);
+	goto enum_info_free_exit;
 }
 
 static
@@ -444,8 +503,13 @@ static int cci_pci_sriov_configure(struct pci_dev *pcidev, int num_vfs)
 
 static void cci_pci_remove(struct pci_dev *pcidev)
 {
-	if (dev_is_pf(&pcidev->dev))
+	struct cci_drvdata *drvdata = pci_get_drvdata(pcidev);
+	struct dfl_fpga_cdev *cdev = drvdata->cdev;
+
+	if (dev_is_pf(&pcidev->dev)) {
 		cci_pci_sriov_configure(pcidev, 0);
+		fpgahp_unregister(cdev->fpgahp_mgr);
+	}
 
 	cci_remove_feature_devs(pcidev);
 	pci_disable_pcie_error_reporting(pcidev);
@@ -464,3 +528,4 @@ module_pci_driver(cci_pci_driver);
 MODULE_DESCRIPTION("FPGA DFL PCIe Device Driver");
 MODULE_AUTHOR("Intel Corporation");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(FPGAHP);
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index 06cfcd5e84bb..898c05c269fb 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -469,6 +469,7 @@ void dfl_fpga_enum_info_free(struct dfl_fpga_enum_info *info);
  * @fme_dev: FME feature device under this container device.
  * @lock: mutex lock to protect the port device list.
  * @port_dev_list: list of all port feature devices under this container device.
+ * @fpgahp_mgr: fpga hotplug manager.
  * @released_port_num: released port number under this container device.
  */
 struct dfl_fpga_cdev {
@@ -477,6 +478,7 @@ struct dfl_fpga_cdev {
 	struct device *fme_dev;
 	struct mutex lock;
 	struct list_head port_dev_list;
+	struct fpgahp_manager *fpgahp_mgr;
 	int released_port_num;
 };
 
-- 
2.38.1