[Very RFC 08/46] powerpc/eeh: Calculate VF index rather than looking it up in pci_dn

[Oliver O'Halloran]

Find the VF index based on the BDFN of the device rather than using a cached
value in the pci_dn. This is probably slower than looking up the cached value
in the pci_dn, but it's done infrequently (only in the EEH recovery path) and
it's just arithmatic.

We need this here because the functions to remove a VF are slightly
different to those which remove a physical PCI device.

Signed-off-by: Oliver O'Halloran <ooh...@gmail.com>
---
 arch/powerpc/kernel/eeh_driver.c | 44 +++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index a1eaffe868de..1cdeed464aed 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -457,12 +457,35 @@ static enum pci_ers_result eeh_report_failure(struct 
eeh_dev *edev,
        return rc;
 }
 
+#ifdef CONFIG_PCI_IOV
+/* FIXME: this should probably go in drivers/pci/iov.c */
+static int eeh_find_vf_index(struct pci_dev *physfn, u16 vf_bdfn)
+{
+       u16 vf_bus, vf_devfn;
+       int i;
+
+       vf_bus = vf_bdfn >> 8;
+       vf_devfn = vf_bdfn & 0xff;
+
+       for (i = 0; i < pci_num_vf(physfn); i++) {
+               if (pci_iov_virtfn_bus(physfn, i) != vf_bus)
+                       continue;
+               if (pci_iov_virtfn_devfn(physfn, i) != vf_devfn)
+                       continue;
+               return i;
+       }
+
+       WARN_ON(1);
+       return -1;
+}
+
 static void *eeh_add_virt_device(struct eeh_dev *edev)
 {
-       struct pci_driver *driver;
        struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
+       struct pci_driver *driver;
+       int vf_index;
 
-       if (!(edev->physfn)) {
+       if (!edev->physfn) {
                eeh_edev_warn(edev, "Not for VF\n");
                return NULL;
        }
@@ -476,11 +499,18 @@ static void *eeh_add_virt_device(struct eeh_dev *edev)
                eeh_pcid_put(dev);
        }
 
-#ifdef CONFIG_PCI_IOV
-       pci_iov_add_virtfn(edev->physfn, eeh_dev_to_pdn(edev)->vf_index);
-#endif
+       vf_index = eeh_find_vf_index(edev->physfn, edev->bdfn);
+       pci_iov_add_virtfn(edev->physfn, vf_index);
+
        return NULL;
 }
+#else
+static void *eeh_add_virt_device(struct eeh_dev *edev)
+{
+       WARN_ON(1);
+       return NULL;
+}
+#endif
 
 static void eeh_rmv_device(struct eeh_dev *edev, void *userdata)
 {
@@ -521,9 +551,9 @@ static void eeh_rmv_device(struct eeh_dev *edev, void 
*userdata)
 
        if (edev->physfn) {
 #ifdef CONFIG_PCI_IOV
-               struct pci_dn *pdn = eeh_dev_to_pdn(edev);
+               int vf_index = eeh_find_vf_index(edev->physfn, edev->bdfn);
 
-               pci_iov_remove_virtfn(edev->physfn, pdn->vf_index);
+               pci_iov_remove_virtfn(edev->physfn, vf_index);
                edev->pdev = NULL;
 #endif
                if (rmv_data)
-- 
2.21.0