[v2,2/3] PCI: Remove PCIe Capability version checks

Commit c8b303d0206b28c4ff3aecada47108d1655ae00f upstream.  This is part
of the fix for https://bugzilla.kernel.org/show_bug.cgi?id=65211

Previously we relied on the PCIe r3.0, sec 7.8, spec language that says
"For Functions that do not implement the [Link, Slot, Root] registers,
these spaces must be hardwired to 0b," which means that for v2 PCIe
capabilities, we don't need to check the device type at all.

But it's simpler if we don't need to check the capability version at all,
and I think the spec is explicit enough about which registers are required
for which types that we can remove the version checks.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
CC: stable@vger.kernel.org	# v3.7+
---
 drivers/pci/access.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)


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On Tue, Nov 19, 2013 at 2:35 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> Commit c8b303d0206b28c4ff3aecada47108d1655ae00f upstream.  This is part
> of the fix for https://bugzilla.kernel.org/show_bug.cgi?id=65211
>
> Previously we relied on the PCIe r3.0, sec 7.8, spec language that says
> "For Functions that do not implement the [Link, Slot, Root] registers,
> these spaces must be hardwired to 0b," which means that for v2 PCIe
> capabilities, we don't need to check the device type at all.
>
> But it's simpler if we don't need to check the capability version at all,
> and I think the spec is explicit enough about which registers are required
> for which types that we can remove the version checks.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
> CC: stable@vger.kernel.org      # v3.7+
> ---
>  drivers/pci/access.c |    9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/access.c b/drivers/pci/access.c
> index e26c3bd9aca4..9a46fa9135d9 100644
> --- a/drivers/pci/access.c
> +++ b/drivers/pci/access.c
> @@ -484,8 +484,7 @@ static inline bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
>  {
>         int type = pci_pcie_type(dev);
>
> -       return pcie_cap_version(dev) > 1 ||
> -              type == PCI_EXP_TYPE_ENDPOINT ||
> +       return type == PCI_EXP_TYPE_ENDPOINT ||
>                type == PCI_EXP_TYPE_LEG_END ||
>                type == PCI_EXP_TYPE_ROOT_PORT ||
>                type == PCI_EXP_TYPE_UPSTREAM ||
> @@ -498,8 +497,7 @@ static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
>  {
>         int type = pci_pcie_type(dev);
>
> -       return pcie_cap_version(dev) > 1 ||
> -              type == PCI_EXP_TYPE_ROOT_PORT ||
> +       return type == PCI_EXP_TYPE_ROOT_PORT ||
>                (type == PCI_EXP_TYPE_DOWNSTREAM &&
>                 pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT);
>  }
> @@ -508,8 +506,7 @@ static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev)
>  {
>         int type = pci_pcie_type(dev);
>
> -       return pcie_cap_version(dev) > 1 ||
> -              type == PCI_EXP_TYPE_ROOT_PORT ||
> +       return type == PCI_EXP_TYPE_ROOT_PORT ||
>                type == PCI_EXP_TYPE_RC_EC;
>  }
>
>
> --

Acked-by: Myron Stowe <myron.stowe@redhat.com>

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