Re: [PATCH] Detect mmconfig on nVidia MCP55

From: Yinghai Lu
Date: Mon Feb 09 2009 - 14:43:34 EST


Ed Swierk wrote:
> Detect and enable memory-mapped PCI configuration space on the nVidia
> MCP55 southbridge. Tested against 2.6.27.4 on an Arista Networks
> development board with one MCP55, Coreboot firmware, no ACPI.
>
> Signed-off-by: Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx>
>
> ---
>
> I've tried to incorporate the code style feedback from Ingo. I'm not
> sure whether this correctly handles boards with more than one MCP55, or
> with an AMD 10h--Yinghai?
>
> 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
> @@ -166,6 +166,36 @@ static const char __init *pci_mmcfg_amd_
> return "AMD Family 10h NB";
> }
>
> +static const char __init *pci_mmcfg_nvidia_mcp55(void)
> +{
> + u32 extcfg;
> + u64 base;
> + int end;
> + static const u32 extcfg_regnum = 0x90;
> + static const u32 extcfg_regsize = 4;
> + static const u32 extcfg_enable_mask = 0x80000000;
> + static const u32 extcfg_end_mask = 0x30000000;
> + static const int extcfg_end_shift = 28;
> + static const int extcfg_endbus[] = { 255, 127, 63, 31 };
> + static const u32 extcfg_base_mask = 0x00007fff;
> + static const int extcfg_base_lshift = 25;
> +
> + raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), extcfg_regnum, extcfg_regsize,
> + &extcfg);
1. mcp55 could one bus1
2. io55 could be on 0x40, 0x80, 0xc0

so it seems we could loop all 0-255 to find those HT in one function and add them one by one.

YH
> +
> + if (!(extcfg & extcfg_enable_mask))
> + return NULL;
> +
> + if (extend_mmcfg(1) == -1)
> + return NULL;
> +
> + base = (extcfg & extcfg_base_mask) << extcfg_base_lshift;
> + end = (extcfg & extcfg_end_mask) >> extcfg_end_shift;
> + fill_one_mmcfg(base, 0, 0, extcfg_endbus[end]);
> +
> + return "nVidia MCP55";
> +}
> +
> struct pci_mmcfg_hostbridge_probe {
> u32 bus;
> u32 devfn;
> @@ -183,6 +213,8 @@ 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 },
> };
>
> static int __init pci_mmcfg_check_hostbridge(void)
>

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