PCI: set pci sriov page size before reading SRIOV BAR

For an SRIOV device, PCI_SRIOV_SYS_PGSIZE should be set before
the PCI_SRIOV_BAR are queried.  The sys pagesize defaults to 4k,
so this change is required on powerpc box with 64k base page size.
    
This is a regression caused due to moving SRIOV init to sriov_enable().
    
| commit afd24ece
| Author: Ram Pai <linuxram@us.ibm.com>
    
| PCI: delay configuration of SRIOV capability
| The SRIOV capability, namely page size and total_vfs of a device are
| configured during enumeration phase of the device.  This can potentially
| interfere with the PCI operations of the platform, if the IOV capability
| of the device is not enabled.
Signed-off-by: NVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Acked-by: NRam Pai <linuxram@us.ibm.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/iov.c

@@ -347,8 +347,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 			return rc;
 	}
 
-	pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
-
 	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
@@ -466,6 +464,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
 		return -EIO;
 
 	pgsz &= ~(pgsz - 1);
+	pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 
 	nres = 0;
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {