PCI: acpiphp: remove all functions in slot, even without ACPI _EJx
When we add a device with acpiphp, we enumerate all functions in the
slot with pci_scan_slot(), regardless of whether they have associated
ACPI methods such as _EJ0.
When removing the device, we previously removed only the functions
with those ACPI methods. This patch makes the remove symmetric with the
add: we remove all functions in the slot, whether they have associated
ACPI methods or not.
With qemu-kvm and SeaBIOS, we can build a multi-function device where
only function 0 has _EJ0 and _ADR (see bugzilla below). Removing and
re-adding that slot (including all functions of the device) works correctly
with Windows guests. This patch makes it also work in Linux guests.
[bhelgaas: restructure loop iteration, pull out of slot->funcs loop]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=43219
Signed-off-by: Amos Kong <kongjianjun@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index c8f9991..73af337 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -878,6 +878,24 @@
}
}
+/* return first device in slot, acquiring a reference on it */
+static struct pci_dev *dev_in_slot(struct acpiphp_slot *slot)
+{
+ struct pci_bus *bus = slot->bridge->pci_bus;
+ struct pci_dev *dev;
+ struct pci_dev *ret = NULL;
+
+ down_read(&pci_bus_sem);
+ list_for_each_entry(dev, &bus->devices, bus_list)
+ if (PCI_SLOT(dev->devfn) == slot->device) {
+ ret = pci_dev_get(dev);
+ break;
+ }
+ up_read(&pci_bus_sem);
+
+ return ret;
+}
+
/**
* disable_device - disable a slot
* @slot: ACPI PHP slot
@@ -902,18 +920,22 @@
(u32)1, NULL, NULL);
func->bridge = NULL;
}
+ }
- pdev = pci_get_slot(slot->bridge->pci_bus,
- PCI_DEVFN(slot->device, func->function));
- if (pdev) {
- pci_stop_bus_device(pdev);
- if (pdev->subordinate) {
- disable_bridges(pdev->subordinate);
- pci_disable_device(pdev);
- }
- __pci_remove_bus_device(pdev);
- pci_dev_put(pdev);
+ /*
+ * enable_device() enumerates all functions in this device via
+ * pci_scan_slot(), whether they have associated ACPI hotplug
+ * methods (_EJ0, etc.) or not. Therefore, we remove all functions
+ * here.
+ */
+ while ((pdev = dev_in_slot(slot))) {
+ pci_stop_bus_device(pdev);
+ if (pdev->subordinate) {
+ disable_bridges(pdev->subordinate);
+ pci_disable_device(pdev);
}
+ __pci_remove_bus_device(pdev);
+ pci_dev_put(pdev);
}
list_for_each_entry(func, &slot->funcs, sibling) {