linux-kernel - Re: [PATCH 4/5] x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 30h-3fh) Processors v3

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Date:   Sun, 7 May 2017 14:03:29 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Christian König <deathsimple@...afone.de>
Cc:     "linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
        Platform Driver <platform-driver-x86@...r.kernel.org>,
        Bjorn Helgaas <helgaas@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 4/5] x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models
 30h-3fh) Processors v3

On Thu, May 4, 2017 at 12:31 PM, Christian König
<deathsimple@...afone.de> wrote:
> From: Christian König <christian.koenig@....com>
>
> Most BIOS don't enable this because of compatibility reasons.
>
> Manually enable a 64bit BAR of 64GB size so that we have
> enough room for PCI devices.
>
> v2: style cleanups, increase size, add resource name, set correct flags,
>     print message that windows was added
> v3: add defines for all the magic numbers, style cleanups

FWIW:
Reviewed-by: Andy Shevchenko <andy.shevchenko@...il.com>

>
> Signed-off-by: Christian König <christian.koenig@....com>
> ---
>  arch/x86/pci/fixup.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 69 insertions(+)
>
> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
> index 6d52b94..1c36ed6 100644
> --- a/arch/x86/pci/fixup.c
> +++ b/arch/x86/pci/fixup.c
> @@ -571,3 +571,72 @@ 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);
> +
> +#define AMD_141b_MMIO_BASE(x)  (0x80 + (x) * 0x8)
> +#define AMD_141b_MMIO_BASE_RE_MASK             BIT(0)
> +#define AMD_141b_MMIO_BASE_WE_MASK             BIT(1)
> +#define AMD_141b_MMIO_BASE_MMIOBASE_MASK       GENMASK(31,8)
> +
> +#define AMD_141b_MMIO_LIMIT(x) (0x84 + (x) * 0x8)
> +#define AMD_141b_MMIO_LIMIT_MMIOLIMIT_MASK     GENMASK(31,8)
> +
> +#define AMD_141b_MMIO_HIGH(x)  (0x180 + (x) * 0x4)
> +#define AMD_141b_MMIO_HIGH_MMIOBASE_MASK       GENMASK(7,0)
> +#define AMD_141b_MMIO_HIGH_MMIOLIMIT_SHIFT     16
> +#define AMD_141b_MMIO_HIGH_MMIOLIMIT_MASK      GENMASK(23,16)
> +
> +static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
> +{
> +       struct resource *res, *conflict;
> +       u32 base, limit, high;
> +       unsigned i;
> +
> +       for (i = 0; i < 8; ++i) {
> +               pci_read_config_dword(dev, AMD_141b_MMIO_BASE(i), &base);
> +               pci_read_config_dword(dev, AMD_141b_MMIO_HIGH(i), &high);
> +
> +               /* Is this slot free? */
> +               if (!(base & (AMD_141b_MMIO_BASE_RE_MASK |
> +                             AMD_141b_MMIO_BASE_WE_MASK)))
> +                       break;
> +
> +               base >>= 8;
> +               base |= high << 24;
> +
> +               /* Abort if a slot already configures a 64bit BAR. */
> +               if (base > 0x10000)
> +                       return;
> +       }
> +       if (i == 8)
> +               return;
> +
> +       res = kzalloc(sizeof(*res), GFP_KERNEL);
> +       if (!res)
> +               return;
> +
> +       res->name = "PCI Bus 0000:00";
> +       res->flags = IORESOURCE_PREFETCH | IORESOURCE_MEM |
> +               IORESOURCE_MEM_64 | IORESOURCE_WINDOW;
> +       res->start = 0x100000000ull;
> +       res->end = 0xfd00000000ull - 1;
> +
> +       /* Just grab the free area behind system memory for this */
> +       while ((conflict = request_resource_conflict(&iomem_resource, res)))
> +               res->start = conflict->end + 1;
> +
> +       dev_info(&dev->dev, "adding root bus resource %pR\n", res);
> +
> +       base = ((res->start >> 8) & AMD_141b_MMIO_BASE_MMIOBASE_MASK) |
> +               AMD_141b_MMIO_BASE_RE_MASK | AMD_141b_MMIO_BASE_WE_MASK;
> +       limit = ((res->end + 1) >> 8) & AMD_141b_MMIO_LIMIT_MMIOLIMIT_MASK;
> +       high = ((res->start >> 40) & AMD_141b_MMIO_HIGH_MMIOBASE_MASK) |
> +               ((((res->end + 1) >> 40) << AMD_141b_MMIO_HIGH_MMIOLIMIT_SHIFT)
> +                & AMD_141b_MMIO_HIGH_MMIOLIMIT_MASK);
> +
> +       pci_write_config_dword(dev, AMD_141b_MMIO_HIGH(i), high);
> +       pci_write_config_dword(dev, AMD_141b_MMIO_LIMIT(i), limit);
> +       pci_write_config_dword(dev, AMD_141b_MMIO_BASE(i), base);
> +
> +       pci_bus_add_resource(dev->bus, res, 0);
> +}
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x141b, pci_amd_enable_64bit_bar);
> --
> 2.7.4
>



-- 
With Best Regards,
Andy Shevchenko