Re: [PATCH] x86, HPET: mark HPET PCI BARs as IORESOURCE_PCI_FIXED

From: Bjorn Helgaas
Date: Fri Sep 24 2010 - 19:07:12 EST


Sorry Yinghai, I forgot to copy you on the initial post. Any
comments on this? If not, we should try to get it into linux-next
soon.

On Thursday, September 23, 2010 05:30:47 pm Bjorn Helgaas wrote:
>
> We often discover the HPET early, via the static ACPI HPET table, before
> enumerating PCI devices. If the HPET is implemented as a PCI function,
> we will discover it again during PCI device enumeration. We must make
> sure we never move the PCI function out from under the driver.
>
> Doing this for *any* PCI BAR that matches a previously discovered HPET
> should be more generic than the previous ATI-specific quirk.
>
> This is for a regression from 2.6.34, but the reporter has been unable
> to test it yet.
>
> Reference: https://bugzilla.kernel.org/show_bug.cgi?id=18482
> Reported-by: Simon Arlott <simon@xxxxxxxxxxx>
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx>
> ---
>
> arch/x86/kernel/quirks.c | 19 +++++++++++++++++++
> arch/x86/pci/fixup.c | 28 ----------------------------
> 2 files changed, 19 insertions(+), 28 deletions(-)
>
>
> diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
> index 939b9e9..8acd667 100644
> --- a/arch/x86/kernel/quirks.c
> +++ b/arch/x86/kernel/quirks.c
> @@ -507,6 +507,25 @@ static void force_disable_hpet_msi(struct pci_dev *unused)
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,
> force_disable_hpet_msi);
>
> +static void mark_pci_hpet_fixed(struct pci_dev *dev)
> +{
> + int i;
> +
> + if (!hpet_address)
> + return;
> +
> + for (i = 0; i < 6; i++) {
> + struct resource *res = &dev->resource[i];
> +
> + if (resource_type(res) == IORESOURCE_MEM &&
> + res->start == hpet_address) {
> + dev_info(&dev->dev, "BAR %d: %pR is an HPET we found earlier; making it immovable\n",
> + i, res);
> + res->flags |= IORESOURCE_PCI_FIXED;
> + }
> + }
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, mark_pci_hpet_fixed);
> #endif
>
> #if defined(CONFIG_PCI) && defined(CONFIG_NUMA)
> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
> index 6dd8955..08eba69 100644
> --- a/arch/x86/pci/fixup.c
> +++ b/arch/x86/pci/fixup.c
> @@ -493,31 +493,3 @@ static void __devinit pci_siemens_interrupt_controller(struct pci_dev *dev)
> }
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SIEMENS, 0x0015,
> pci_siemens_interrupt_controller);
> -
> -/*
> - * SB600: Disable BAR1 on device 14.0 to avoid HPET resources from
> - * confusing the PCI engine:
> - */
> -static void sb600_disable_hpet_bar(struct pci_dev *dev)
> -{
> - u8 val;
> -
> - /*
> - * The SB600 and SB700 both share the same device
> - * ID, but the PM register 0x55 does something different
> - * for the SB700, so make sure we are dealing with the
> - * SB600 before touching the bit:
> - */
> -
> - pci_read_config_byte(dev, 0x08, &val);
> -
> - if (val < 0x2F) {
> - outb(0x55, 0xCD6);
> - val = inb(0xCD7);
> -
> - /* Set bit 7 in PM register 0x55 */
> - outb(0x55, 0xCD6);
> - outb(val | 0x80, 0xCD7);
> - }
> -}
> -DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ATI, 0x4385, sb600_disable_hpet_bar);
>
>
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