PCI/VFIO: use pcie_flags_reg instead of access PCI-E Capabilities Register

Currently, we use pcie_flags_reg to cache PCI-E Capabilities Register,
because PCI-E Capabilities Register bits are almost read-only. This patch
use pcie_caps_reg() instead of another access PCI-E Capabilities Register.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 1 insertions, 5 deletions

diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index 072fdacb6f96..0e83e8ead142 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -1037,13 +1037,9 @@ static int vfio_cap_len(struct vfio_pci_device *vdev, u8 cap, u8 pos)
                 return byte;
         case PCI_CAP_ID_EXP:
                 /* length based on version */
-                ret = pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &word);
-                if (ret)
-                        return pcibios_err_to_errno(ret);
-
                 vdev->extended_caps = true;
 
-                if ((word & PCI_EXP_FLAGS_VERS) == 1)
+                if ((pcie_caps_reg(pdev) & PCI_EXP_FLAGS_VERS) == 1)
                         return PCI_CAP_EXP_ENDPOINT_SIZEOF_V1;
                 else
                         return PCI_CAP_EXP_ENDPOINT_SIZEOF_V2;