Re: [patch 5/5] x86: Set PCI config space size to extended for AMD Barcelona

dean gaudet
2007-09-03T16:48:24Z

it's so very unfortunate the PCI standard has no feature bit to indicate
the presence of ECS.

FWIW in my testing on a range of machines spanning 7 or 8 years i could
read config space reg 256... and get 0xffffffff when the device didn't
support ECS, and get valid data when the device did support ECS... granted
there may be some system out there which behaves really badly when you do
this.

perhaps someone could write a userspace program and test that concept on a
far wider range of machines.

-dean

On Mon, 3 Sep 2007, Robert Richter wrote:

> This patch sets the config space size for AMD Barcelona PCI devices to
> 4096.
>
> Signed-off-by: Robert Richter <robert.richter@amd.com>
>
> ---
> arch/i386/pci/fixup.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> Index: linux-2.6/arch/i386/pci/fixup.c
> ===================================================================
> --- linux-2.6.orig/arch/i386/pci/fixup.c
> +++ linux-2.6/arch/i386/pci/fixup.c
> @@ -8,6 +8,7 @@
> #include <linux/init.h>
> #include "pci.h"
>
> +#define PCI_CFG_SPACE_EXP_SIZE 4096
>
> static void __devinit pci_fixup_i450nx(struct pci_dev *d)
> {
> @@ -444,3 +445,16 @@ static void __devinit pci_siemens_interr
> }
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SIEMENS, 0x0015,
> pci_siemens_interrupt_controller);
> +
> +/*
> + * Extend size of PCI configuration space for AMD CPUs
> + */
> +static void __devinit pci_ext_cfg_space_access(struct pci_dev *dev)
> +{
> + dev->cfg_size = PCI_CFG_SPACE_EXP_SIZE;
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_FAM10H_HT, pci_ext_cfg_space_access);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_FAM10H_MAP, pci_ext_cfg_space_access);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_FAM10H_DRAM, pci_ext_cfg_space_access);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_FAM10H_MISC, pci_ext_cfg_space_access);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_FAM10H_LINK, pci_ext_cfg_space_access);
>
> --
> AMD Saxony, Dresden, Germany
> Operating System Research Center
> email: robert.richter@amd.com
>
>
>
> -
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