From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Tue, 15 May 2018 11:07:06 +0200
Subject: PCI: Add support for unbinding the generic PCI host controller

Git-commit: 01fcb7f777a9f5d216a1ff41228f15656e50fb63
Patch-mainline: v4.18-rc1
References: fate#326572

Add support for unbinding the generic PCI host controller.  This is
particularly useful when working in virtual environments where the
controller may come and go, but possibly not only there.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 drivers/pci/host/pci-host-common.c  | 13 +++++++++++++
 drivers/pci/host/pci-host-generic.c |  1 +
 include/linux/pci-ecam.h            |  1 +
 3 files changed, 15 insertions(+)

diff --git a/drivers/pci/host/pci-host-common.c b/drivers/pci/host/pci-host-common.c
index 5d028f53fdcd..d8f10451f273 100644
--- a/drivers/pci/host/pci-host-common.c
+++ b/drivers/pci/host/pci-host-common.c
@@ -101,5 +101,18 @@ int pci_host_common_probe(struct platform_device *pdev,
 		return ret;
 	}
 
+	platform_set_drvdata(pdev, bridge->bus);
+	return 0;
+}
+
+int pci_host_common_remove(struct platform_device *pdev)
+{
+	struct pci_bus *bus = platform_get_drvdata(pdev);
+
+	pci_lock_rescan_remove();
+	pci_stop_root_bus(bus);
+	pci_remove_root_bus(bus);
+	pci_unlock_rescan_remove();
+
 	return 0;
 }
diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index 45319ee3b484..dea3ec7592a2 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -95,5 +95,6 @@ static struct platform_driver gen_pci_driver = {
 		.suppress_bind_attrs = true,
 	},
 	.probe = gen_pci_probe,
+	.remove = pci_host_common_remove,
 };
 builtin_platform_driver(gen_pci_driver);
diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
index baadad1aabbc..29efa09d686b 100644
--- a/include/linux/pci-ecam.h
+++ b/include/linux/pci-ecam.h
@@ -62,5 +62,6 @@ extern struct pci_ecam_ops xgene_v2_pcie_ecam_ops; /* APM X-Gene PCIe v2.x */
 /* for DT-based PCI controllers that support ECAM */
 int pci_host_common_probe(struct platform_device *pdev,
 			  struct pci_ecam_ops *ops);
+int pci_host_common_remove(struct platform_device *pdev);
 #endif
 #endif
-- 
2.11.0