powerpc/pseries: fix EEH recovery of some IOV devices

EEH recovery currently fails on pSeries for some IOV capable PCI
devices, if CONFIG_PCI_IOV is on and the hypervisor doesn't provide
certain device tree properties for the device. (Found on an IOV
capable device using the ipr driver.)

Recovery fails in pci_enable_resources() at the check on r->parent,
because r->flags is set and r->parent is not.  This state is due to
sriov_init() setting the start, end and flags members of the IOV BARs
but the parent not being set later in
pseries_pci_fixup_iov_resources(), because the
"ibm,open-sriov-vf-bar-info" property is missing.

Correct this by zeroing the resource flags for IOV BARs when they
can't be configured (this is the same method used by sriov_init() and
__pci_read_base()).

VFs cleared this way can't be enabled later, because that requires
another device tree property, "ibm,number-of-configurable-vfs" as well
as support for the RTAS function "ibm_map_pes". These are all part of
hypervisor support for IOV and it seems unlikely that a hypervisor
would ever partially, but not fully, support it. (None are currently
provided by QEMU/KVM.)

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Bryant G. Ly <bryantly@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index e14ccf3..9948ad1 100644 (file)
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -647,6 +647,15 @@ void of_pci_parse_iov_addrs(struct pci_dev *dev, const int *indexes)
        }
 }
 
+static void pseries_disable_sriov_resources(struct pci_dev *pdev)
+{
+       int i;
+
+       pci_warn(pdev, "No hypervisor support for SR-IOV on this device, IOV BARs disabled.\n");
+       for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
+               pdev->resource[i + PCI_IOV_RESOURCES].flags = 0;
+}
+
 static void pseries_pci_fixup_resources(struct pci_dev *pdev)
 {
        const int *indexes;
@@ -654,10 +663,10 @@ static void pseries_pci_fixup_resources(struct pci_dev *pdev)
 
        /*Firmware must support open sriov otherwise dont configure*/
        indexes = of_get_property(dn, "ibm,open-sriov-vf-bar-info", NULL);
-       if (!indexes)
-               return;
-       /* Assign the addresses from device tree*/
-       of_pci_set_vf_bar_size(pdev, indexes);
+       if (indexes)
+               of_pci_set_vf_bar_size(pdev, indexes);
+       else
+               pseries_disable_sriov_resources(pdev);
 }
 
 static void pseries_pci_fixup_iov_resources(struct pci_dev *pdev)
@@ -669,10 +678,10 @@ static void pseries_pci_fixup_iov_resources(struct pci_dev *pdev)
                return;
        /*Firmware must support open sriov otherwise dont configure*/
        indexes = of_get_property(dn, "ibm,open-sriov-vf-bar-info", NULL);
-       if (!indexes)
-               return;
-       /* Assign the addresses from device tree*/
-       of_pci_parse_iov_addrs(pdev, indexes);
+       if (indexes)
+               of_pci_parse_iov_addrs(pdev, indexes);
+       else
+               pseries_disable_sriov_resources(pdev);
 }
 
 static resource_size_t pseries_pci_iov_resource_alignment(struct pci_dev *pdev,