Commit d3a78d8b authored by Long Li's avatar Long Li Committed by Bjorn Helgaas
Browse files

PCI: hv: Properly handle PCI bus remove 



hv_pci_devices_present() is called in hv_pci_remove() when we remove a PCI
device from the host, e.g., by disabling SR-IOV on a device.  In
hv_pci_remove(), the bus is already removed before the call, so we don't
need to rescan the bus in the workqueue scheduled from
hv_pci_devices_present().

By introducing bus state hv_pcibus_removed, we can avoid this situation.

Reported-by: default avatarXiaofeng Wang <xiaofwan@redhat.com>
Signed-off-by: default avatarLong Li <longli@microsoft.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
parent c1ae3cfa

drivers/pci/host/pci-hyperv.c

+17 −3
Original line number Diff line number Diff line
@@ -350,6 +350,7 @@ enum hv_pcibus_state { 
	hv_pcibus_init = 0,

	hv_pcibus_probed,

	hv_pcibus_installed,

	hv_pcibus_removed,

	hv_pcibus_maximum

};
@@ -1504,13 +1505,24 @@ static void pci_devices_present_work(struct work_struct *work) 
		put_pcichild(hpdev, hv_pcidev_ref_initial);

	}



	/* Tell the core to rescan bus because there may have been changes. */

	if (hbus->state == hv_pcibus_installed) {

	switch(hbus->state) {

	case hv_pcibus_installed:

		/*

		* Tell the core to rescan bus

		* because there may have been changes.

		*/

		pci_lock_rescan_remove();

		pci_scan_child_bus(hbus->pci_bus);

		pci_unlock_rescan_remove();

	} else {

		break;



	case hv_pcibus_init:

	case hv_pcibus_probed:

		survey_child_resources(hbus);

		break;



	default:

		break;

	}



	up(&hbus->enum_sem);
@@ -2185,6 +2197,7 @@ static int hv_pci_probe(struct hv_device *hdev, 
	hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);

	if (!hbus)

		return -ENOMEM;

	hbus->state = hv_pcibus_init;



	/*

	 * The PCI bus "domain" is what is called "segment" in ACPI and
@@ -2348,6 +2361,7 @@ static int hv_pci_remove(struct hv_device *hdev) 
		pci_stop_root_bus(hbus->pci_bus);

		pci_remove_root_bus(hbus->pci_bus);

		pci_unlock_rescan_remove();

		hbus->state = hv_pcibus_removed;

	}



	hv_pci_bus_exit(hdev);

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