PCI: hv: Fix wslot_to_devfn() to fix warnings on device removal

BugLink: http://bugs.launchpad.net/bugs/1672544
commit 60e2e2fbafdd1285ae1b4ad39ded41603e0c74d0 upstream.

The devfn of 00:02.0 is 0x10.  devfn_to_wslot(0x10) == 0x2, and
wslot_to_devfn(0x2) should be 0x10, while it's 0x2 in the current code.

Due to this, hv_eject_device_work() -> pci_get_domain_bus_and_slot()
returns NULL and pci_stop_and_remove_bus_device() is not called.

Later when the real device driver's .remove() is invoked by
hv_pci_remove() -> pci_stop_root_bus(), some warnings can be noticed
because the VM has lost the access to the underlying device at that
time.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
CC: K. Y. Srinivasan <kys@microsoft.com>
CC: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 3efcc7bdc5fb65b96e8bca3a2acd24f12da38773..cd114c6787be82effd6397534ce35132fee04bf7 100644 (file)
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -130,7 +130,8 @@ union pci_version {
  */
 union win_slot_encoding {
        struct {
-               u32     func:8;
+               u32     dev:5;
+               u32     func:3;
                u32     reserved:24;
        } bits;
        u32 slot;
@@ -485,7 +486,8 @@ static u32 devfn_to_wslot(int devfn)
        union win_slot_encoding wslot;
 
        wslot.slot = 0;
-       wslot.bits.func = PCI_SLOT(devfn) | (PCI_FUNC(devfn) << 5);
+       wslot.bits.dev = PCI_SLOT(devfn);
+       wslot.bits.func = PCI_FUNC(devfn);
 
        return wslot.slot;
 }
@@ -503,7 +505,7 @@ static int wslot_to_devfn(u32 wslot)
        union win_slot_encoding slot_no;
 
        slot_no.slot = wslot;
-       return PCI_DEVFN(0, slot_no.bits.func);
+       return PCI_DEVFN(slot_no.bits.dev, slot_no.bits.func);
 }
 
 /*