diff options
| author | Amos Kong <kongjianjun@gmail.com> | 2012-05-23 10:20:35 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2012-06-13 16:38:10 -0600 |
| commit | ce29ca3ea40744f24c2b5d88431e8ac566d257cc (patch) | |
| tree | f5b56902875f1f9e4e9ea9baa0dfc35e22d54b05 | |
| parent | 638f293307b5787b69bf0a0bc915aed491efbec9 (diff) | |
| download | lwn-ce29ca3ea40744f24c2b5d88431e8ac566d257cc.tar.gz lwn-ce29ca3ea40744f24c2b5d88431e8ac566d257cc.zip | |
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>
| -rw-r--r-- | drivers/pci/hotplug/acpiphp_glue.c | 42 | ||||
| -rw-r--r-- | drivers/pci/search.c | 2 |
2 files changed, 34 insertions, 10 deletions
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index c8f999102765..73af3374e915 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -878,6 +878,24 @@ static void disable_bridges(struct pci_bus *bus) } } +/* 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 @@ static int disable_device(struct acpiphp_slot *slot) (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) { diff --git a/drivers/pci/search.c b/drivers/pci/search.c index 9d75dc8ca602..993d4a0a2469 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -15,6 +15,8 @@ #include "pci.h" DECLARE_RWSEM(pci_bus_sem); +EXPORT_SYMBOL_GPL(pci_bus_sem); + /* * find the upstream PCIe-to-PCI bridge of a PCI device * if the device is PCIE, return NULL |