Re: [PATCH] kexec: force x86_64 arches to boot kdump kernels on boot cpu

Neil Horman
2007-12-10T15:44:26Z

On Fri, Dec 07, 2007 at 12:58:32PM -0500, Neil Horman wrote:
>
> Ok, New patch attached. It preforms the same function as previously described,
> but is more restricted in its application. As Yinghai pointed out, the
> broadcast mask bit (bit 17 in the htcfg register) should only be enabled, if the
> extened apic id bit (bit 18 in the same register) is also set. So this patch
> now check for that bit to be turned on first. Also, this patch now adds an
> independent quirk check for all AMD hypertransport host controllers, since its
> possible for this misconfiguration to be present in systems other than nvidias.
> The net effect of these changes is, that its now applicable to all AMD systems
> containing hypertransport busses, and is only activated if extended apic ids are
> in use, meaning that this quirk guarantees that all processors in a system are
> elligible to receive interrupts from the ioapic, even if their apicid extends
> beyond the nominal 4 bit limitation. Tested successfully by me.
>
> Thanks & Regards
> Neil
>
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
>
>
> early-quirks.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 76 insertions(+), 7 deletions(-)
>
>
>
> diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
> index 88bb83e..d5a7b30 100644
> --- a/arch/x86/kernel/early-quirks.c
> +++ b/arch/x86/kernel/early-quirks.c
> @@ -44,6 +44,50 @@ static int __init nvidia_hpet_check(struct acpi_table_header *header)
> #endif /* CONFIG_X86_IO_APIC */
> #endif /* CONFIG_ACPI */
>
> +static void __init fix_hypertransport_config(int num, int slot, int func)
> +{
> + u32 htcfg;
> + /*
> + *we found a hypertransport bus
> + *make sure that are broadcasting
> + *interrupts to all cpus on the ht bus
> + *if we're using extended apic ids
> + */
> + htcfg = read_pci_config(num, slot, func, 0x68);
> + if ((htcfg & (1 << 18)) == 1) {
> + printk(KERN_INFO "Detected use of extended apic ids on hypertransport bus\n");
> + if ((htcfg & (1 << 17)) == 0) {
> + printk(KERN_INFO "Enabling hypertransport extended apic interrupt broadcast\n");
> + htcfg |= (1 << 17);
> + write_pci_config(num, slot, func, 0x68, htcfg);
> + }
> + }
> +
> +}
> +
> +static void __init check_hypertransport_config()
> +{
> + int num, slot, func;
> + u32 device, vendor;
> + func = 0;
> + for (num = 0; num < 32; num++) {
> + for (slot = 0; slot < 32; slot++) {
> + vendor = read_pci_config(num,slot,func,
> + PCI_VENDOR_ID);
> + device = read_pci_config(num,slot,func,
> + PCI_DEVICE_ID);
> + vendor &= 0x0000ffff;
> + device >>= 16;
> + if ((vendor == PCI_VENDOR_ID_AMD) &&
> + (device == PCI_DEVICE_ID_AMD_K8_NB))
> + fix_hypertransport_config(num,slot,func);
> + }
> + }
> +
> + return;
> +
> +}
> +
> static void __init nvidia_bugs(void)
> {
> #ifdef CONFIG_ACPI
> @@ -83,6 +127,12 @@ static void __init ati_bugs(void)
> #endif
> }
>
> +static void __init amd_host_bugs(void)
> +{
> + printk(KERN_CRIT "IN AMD_HOST_BUGS\n");
> + check_hypertransport_config();
> +}
> +
> struct chipset {
> u16 vendor;
> void (*f)(void);
> @@ -95,9 +145,16 @@ static struct chipset early_qrk[] __initdata = {
> {}
> };
>
> +static struct chipset early_host_qrk[] __initdata = {
> + { PCI_VENDOR_ID_AMD, amd_host_bugs},
> + {}
> +};
> +
> void __init early_quirks(void)
> {
> int num, slot, func;
> + u8 found_bridge = 0;
> + u8 found_host = 0;
>
> if (!early_pci_allowed())
> return;
> @@ -115,18 +172,30 @@ void __init early_quirks(void)
> if (class == 0xffffffff)
> break;
>
> - if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
> + class >>= 16;
> + if ((class != PCI_CLASS_BRIDGE_PCI) &&
> + (class != PCI_CLASS_BRIDGE_HOST))
> continue;
>
> vendor = read_pci_config(num, slot, func,
> PCI_VENDOR_ID);
> vendor &= 0xffff;
> -
> - for (i = 0; early_qrk[i].f; i++)
> - if (early_qrk[i].vendor == vendor) {
> - early_qrk[i].f();
> - return;
> - }
> + if ((class == PCI_CLASS_BRIDGE_PCI) && (!found_bridge)) {
> + for (i = 0; early_qrk[i].f; i++)
> + if (early_qrk[i].vendor == vendor) {
> + early_qrk[i].f();
> + found_bridge = 1;;
> + }
> + } else if (!found_host) {
> + for (i = 0; early_host_qrk[i].f; i++)
> + if (early_host_qrk[i].vendor == vendor) {
> + early_host_qrk[i].f();
> + found_host = 1;
> + }
> + }
> +
> + if (found_bridge && found_host)
> + return;
>
> type = read_pci_config_byte(num, slot, func,
> PCI_HEADER_TYPE);
>
> _______________________________________________
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> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

Sorry to reply to myself, but do we have consensus on this patch? I'd like to
figure out its disposition if possible.

Thanks & Regards
Neil