pds_core: implement pci reset handlers

Implement the callbacks for a nice PCI reset.  These get called
when a user is nice enough to use the sysfs PCI reset entry, e.g.
    echo 1 > /sys/bus/pci/devices/0000:2b:00.0/reset

Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: emusln

drivers/net/ethernet/amd/pds_core/core.c

@@ -515,18 +515,21 @@ void pdsc_stop(struct pdsc *pdsc)
 					   PDS_CORE_INTR_MASK_SET);
 }
 
-static void pdsc_fw_down(struct pdsc *pdsc)
+void pdsc_fw_down(struct pdsc *pdsc)
 {
 	union pds_core_notifyq_comp reset_event = {
 		.reset.ecode = cpu_to_le16(PDS_EVENT_RESET),
 		.reset.state = 0,
 	};
 
 	if (test_and_set_bit(PDSC_S_FW_DEAD, &pdsc->state)) {
-		dev_err(pdsc->dev, "%s: already happening\n", __func__);
+		dev_warn(pdsc->dev, "%s: already happening\n", __func__);
 		return;
 	}
 
+	if (pdsc->pdev->is_virtfn)
+		return;
+
 	/* Notify clients of fw_down */
 	if (pdsc->fw_reporter)
 		devlink_health_report(pdsc->fw_reporter, "FW down reported", pdsc);
@@ -536,7 +539,7 @@ static void pdsc_fw_down(struct pdsc *pdsc)
 	pdsc_teardown(pdsc, PDSC_TEARDOWN_RECOVERY);
 }
 
-static void pdsc_fw_up(struct pdsc *pdsc)
+void pdsc_fw_up(struct pdsc *pdsc)
 {
 	union pds_core_notifyq_comp reset_event = {
 		.reset.ecode = cpu_to_le16(PDS_EVENT_RESET),
@@ -549,6 +552,11 @@ static void pdsc_fw_up(struct pdsc *pdsc)
 		return;
 	}
 
+	if (pdsc->pdev->is_virtfn) {
+		clear_bit(PDSC_S_FW_DEAD, &pdsc->state);
+		return;
+	}
+
 	err = pdsc_setup(pdsc, PDSC_SETUP_RECOVERY);
 	if (err)
 		goto err_out;

drivers/net/ethernet/amd/pds_core/core.h

@@ -309,4 +309,8 @@ irqreturn_t pdsc_adminq_isr(int irq, void *data);
 
 int pdsc_firmware_update(struct pdsc *pdsc, const struct firmware *fw,
 			 struct netlink_ext_ack *extack);
+
+void pdsc_fw_down(struct pdsc *pdsc);
+void pdsc_fw_up(struct pdsc *pdsc);
+
 #endif /* _PDSC_H_ */

drivers/net/ethernet/amd/pds_core/main.c

@@ -445,12 +445,62 @@ static void pdsc_remove(struct pci_dev *pdev)
 	devlink_free(dl);
 }
 
+static void pdsc_reset_prepare(struct pci_dev *pdev)
+{
+	struct pdsc *pdsc = pci_get_drvdata(pdev);
+
+	pdsc_fw_down(pdsc);
+
+	pci_free_irq_vectors(pdev);
+	pdsc_unmap_bars(pdsc);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+}
+
+static void pdsc_reset_done(struct pci_dev *pdev)
+{
+	struct pdsc *pdsc = pci_get_drvdata(pdev);
+	struct device *dev = pdsc->dev;
+	int err;
+
+	err = pci_enable_device(pdev);
+	if (err) {
+		dev_err(dev, "Cannot enable PCI device: %pe\n", ERR_PTR(err));
+		return;
+	}
+	pci_set_master(pdev);
+
+	if (!pdev->is_virtfn) {
+		pcie_print_link_status(pdsc->pdev);
+
+		err = pci_request_regions(pdsc->pdev, PDS_CORE_DRV_NAME);
+		if (err) {
+			dev_err(pdsc->dev, "Cannot request PCI regions: %pe\n",
+				ERR_PTR(err));
+			return;
+		}
+
+		err = pdsc_map_bars(pdsc);
+		if (err)
+			return;
+	}
+
+	pdsc_fw_up(pdsc);
+}
+
+static const struct pci_error_handlers pdsc_err_handler = {
+	/* FLR handling */
+	.reset_prepare      = pdsc_reset_prepare,
+	.reset_done         = pdsc_reset_done,
+};
+
 static struct pci_driver pdsc_driver = {
 	.name = PDS_CORE_DRV_NAME,
 	.id_table = pdsc_id_table,
 	.probe = pdsc_probe,
 	.remove = pdsc_remove,
 	.sriov_configure = pdsc_sriov_configure,
+	.err_handler = &pdsc_err_handler,
 };
 
 void *pdsc_get_pf_struct(struct pci_dev *vf_pdev)