Revert "PCI/IOV: Use VF0 cached config space size for other VFs"

Revert 975bb8b4dc93 ("PCI/IOV: Use VF0 cached config space size for other
VFs"), which attempted to cache the config space size from the first VF to
re-use for subsequent VFs.

The cached value was determined prior to discovering the PCIe capability on
the VF, which resulted in the first VF reporting the correct config space
size (4K), as it has a special case through pci_cfg_space_size(), while all
the other VFs only reported 256 bytes.  As this was only a performance
optimization, we're better off without it.

Fixes: 975bb8b4dc93 ("PCI/IOV: Use VF0 cached config space size for other VFs")
Link: https://lore.kernel.org/r/156046663197.29869.3633634445109057665.stgit@gimli.home
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Hao Zheng <yinhe@linux.alibaba.com>

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 3aa115e..525fd3f 100644 (file)
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -132,8 +132,6 @@ static void pci_read_vf_config_common(struct pci_dev *virtfn)
                             &physfn->sriov->subsystem_vendor);
        pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
                             &physfn->sriov->subsystem_device);
-
-       physfn->sriov->cfg_size = pci_cfg_space_size(virtfn);
 }
 
 int pci_iov_add_virtfn(struct pci_dev *dev, int id)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9cb9938..3fc227e 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -293,7 +293,6 @@ struct pci_sriov {
        u16             driver_max_VFs; /* Max num VFs driver supports */
        struct pci_dev  *dev;           /* Lowest numbered PF */
        struct pci_dev  *self;          /* This PF */
-       u32             cfg_size;       /* VF config space size */
        u32             class;          /* VF device */
        u8              hdr_type;       /* VF header type */
        u16             subsystem_vendor; /* VF subsystem vendor */

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 0e8e2c1..a3a3c6b 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1555,29 +1555,12 @@ static int pci_cfg_space_size_ext(struct pci_dev *dev)
        return PCI_CFG_SPACE_EXP_SIZE;
 }
 
-#ifdef CONFIG_PCI_IOV
-static bool is_vf0(struct pci_dev *dev)
-{
-       if (pci_iov_virtfn_devfn(dev->physfn, 0) == dev->devfn &&
-           pci_iov_virtfn_bus(dev->physfn, 0) == dev->bus->number)
-               return true;
-
-       return false;
-}
-#endif
-
 int pci_cfg_space_size(struct pci_dev *dev)
 {
        int pos;
        u32 status;
        u16 class;
 
-#ifdef CONFIG_PCI_IOV
-       /* Read cached value for all VFs except for VF0 */
-       if (dev->is_virtfn && !is_vf0(dev))
-               return dev->physfn->sriov->cfg_size;
-#endif
-
        if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG)
                return PCI_CFG_SPACE_SIZE;