Re: [PATCH] Detect mmconfig on nVidia MCP55

From: Yinghai Lu
Date: Wed Feb 04 2009 - 15:13:42 EST


On Wed, Feb 4, 2009 at 8:39 AM, Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx> wrote:
> Detect and enable memory-mapped PCI configuration space on the nVidia
> MCP55 southbridge even if the ACPI MCFG table is missing or wrong.
>
> Signed-off-by: Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx>
>
> ---
> Index: linux-2.6.27.4/arch/x86/pci/mmconfig-shared.c
> ===================================================================
> --- linux-2.6.27.4.orig/arch/x86/pci/mmconfig-shared.c
> +++ linux-2.6.27.4/arch/x86/pci/mmconfig-shared.c
> @@ -155,6 +155,26 @@ static const char __init *pci_mmcfg_amd_
> return "AMD Family 10h NB";
> }
>
> +static const char __init *pci_mmcfg_nvidia_mcp55(void)
> +{
> + u32 extcfg;
> +
> + raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0x90, 4, &extcfg);
> +
> + if (!(extcfg & 0x80000000))
> + return NULL;
> + pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
> + if (!pci_mmcfg_config)
> + return NULL;
> + pci_mmcfg_config[0].address = (extcfg & 0x00007fff) << 25;
> + pci_mmcfg_config[0].pci_segment = 0;
> + pci_mmcfg_config[0].start_bus_number = 0;
> + pci_mmcfg_config[0].end_bus_number = (1 << (8 - ((extcfg >> 28) & 3))) - 1;
> + pci_mmcfg_config_num = 1;
> +
> + return "nVidia MCP55";
> +}
> +
> struct pci_mmcfg_hostbridge_probe {
> u32 bus;
> u32 devfn;
> @@ -172,6 +192,8 @@ static struct pci_mmcfg_hostbridge_probe
> 0x1200, pci_mmcfg_amd_fam10h },
> { 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
> 0x1200, pci_mmcfg_amd_fam10h },
> + { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
> + 0x0369, pci_mmcfg_nvidia_mcp55 },

may break amd family 10h + mcp55 system. because some system have
setting in AMD cpu and mcp55
it will find setting in CPU nb, and your code will partially overwrite
those setting.

YH
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