Re: [PATCH] PCI: Mark Haswell Power Control Unit as having non-compliant BARs

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Aug 31, 2016 at 10:50:09AM -0500, Bjorn Helgaas wrote:
> The Haswell Power Control Unit has a non-PCI register (CONFIG_TDP_NOMINAL)
> where BAR 0 is supposed to be.  This is erratum HSE43 in the spec update
> referenced below:
> 
>   The PCIe* Base Specification indicates that Configuration Space Headers
>   have a base address register at offset 0x10.  Due to this erratum, the
>   Power Control Unit's CONFIG_TDP_NOMINAL CSR (Bus 1; Device 30; Function
>   3; Offset 0x10) is located where a base register is expected.
> 
> Mark the PCU as having non-compliant BARs so we don't try to probe any of
> them.  There are no other BARs on this device.
> 
> Rename the quirk so it's not Broadwell-specific.
> 
> Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v3-spec-update.html
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=153881
> Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

I applied this with Myron's ack and Prarit's tested-by to for-linus
for v4.8.

> ---
>  arch/x86/pci/fixup.c |   20 +++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
> index 837ea36..6d52b94 100644
> --- a/arch/x86/pci/fixup.c
> +++ b/arch/x86/pci/fixup.c
> @@ -553,15 +553,21 @@ static void twinhead_reserve_killing_zone(struct pci_dev *dev)
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x27B9, twinhead_reserve_killing_zone);
>  
>  /*
> - * Broadwell EP Home Agent BARs erroneously return non-zero values when read.
> + * Device [8086:2fc0]
> + * Erratum HSE43
> + * CONFIG_TDP_NOMINAL CSR Implemented at Incorrect Offset
> + * http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v3-spec-update.html
>   *
> - * See http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v4-spec-update.html
> - * entry BDF2.
> + * Devices [8086:6f60,6fa0,6fc0]
> + * Erratum BDF2
> + * PCI BARs in the Home Agent Will Return Non-Zero Values During Enumeration
> + * http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v4-spec-update.html
>   */
> -static void pci_bdwep_bar(struct pci_dev *dev)
> +static void pci_invalid_bar(struct pci_dev *dev)
>  {
>  	dev->non_compliant_bars = 1;
>  }
> -DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_bdwep_bar);
> -DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_bdwep_bar);
> -DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_bdwep_bar);
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, pci_invalid_bar);
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_invalid_bar);
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_invalid_bar);
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_invalid_bar);
>