> -ben
>
>
>
> Neil Horman wrote:
> > Recently a kdump bug was discovered in which a system would hang inside
> > calibrate_delay during the booting of the kdump kernel. This was caused by the
> > fact that the jiffies counter was not being incremented during timer
> > calibration. The root cause of this problem was found to be a bios
> > misconfiguration of the hypertransport bus. On system affected by this hang,
> > the bios had assigned APIC ids which used extended apic bits (more than the
> > nominal 4 bit ids's), but failed to configure bit 17 of the hypertransport
> > transaction config register, which indicated that the mask for the destination
> > field of interrupt packets accross the ht bus (see section 3.3.9 of
> >
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.PDF).
> > If a crash occurs on a cpu with an APIC id that extends beyond 4 bits, it will
> > not recieve interrupts during the kdump kernel boot, and this hang will be the
> > result. The fix is to add this patch, whcih add an early pci quirk check, to
> > forcibly enable this bit in the httcfg register. This enables all cpus on a
> > system to receive interrupts, and allows kdump kernel bootup to procede
> > normally.
> >
> > Regards
> > Neil
> >
> >
> > Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> >
> >
> > early-quirks.c | 90 +++++++++++++++++++++++++++++++++++++++++++--------------
> > 1 file changed, 69 insertions(+), 21 deletions(-)
> >
> >
> > diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
> > index 88bb83e..c0d0c69 100644
> > --- a/arch/x86/kernel/early-quirks.c
> > +++ b/arch/x86/kernel/early-quirks.c
> > @@ -21,8 +21,36 @@
> > #include <asm/gart.h>
> > #endif
> >
> > -static void __init via_bugs(void)
> > +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)) {
> > + 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");
> > + printk(KERN_INFO "Note this is a bios bug, please contact your hw vendor\n");
> > + htcfg |= (1 << 17);
> > + write_pci_config(num, slot, func, 0x68, htcfg);
> > + }
> > + }
> > +
> > +
> > +}
> > +
> > +static void __init via_bugs(int num, int slot, int func)
> > +{
> > + static int fix_applied = 0;
> > +
> > + if (fix_applied++)
> > + return;
> > +
> > #ifdef CONFIG_GART_IOMMU
> > if ((end_pfn > MAX_DMA32_PFN || force_iommu) &&
> > !gart_iommu_aperture_allowed) {
> > @@ -44,8 +72,13 @@ static int __init nvidia_hpet_check(struct acpi_table_header *header)
> > #endif /* CONFIG_X86_IO_APIC */
> > #endif /* CONFIG_ACPI */
> >
> > -static void __init nvidia_bugs(void)
> > +static void __init nvidia_bugs(int num, int slot, int func)
> > {
> > + static int fix_applied = 0;
> > +
> > + if (fix_applied++)
> > + return;
> > +
> > #ifdef CONFIG_ACPI
> > #ifdef CONFIG_X86_IO_APIC
> > /*
> > @@ -72,8 +105,13 @@ static void __init nvidia_bugs(void)
> >
> > }
> >
> > -static void __init ati_bugs(void)
> > +static void __init ati_bugs(int num, int slot, int func)
> > {
> > + static int fix_applied = 0;
> > +
> > + if (fix_applied++)
> > + return;
> > +
> > #ifdef CONFIG_X86_IO_APIC
> > if (timer_over_8254 == 1) {
> > timer_over_8254 = 0;
> > @@ -84,14 +122,18 @@ static void __init ati_bugs(void)
> > }
> >
> > struct chipset {
> > - u16 vendor;
> > - void (*f)(void);
> > + u32 vendor;
> > + u32 device;
> > + u32 class;
> > + u32 class_mask;
> > + void (*f)(int num, int slot, int func);
> > };
> >
> > static struct chipset early_qrk[] __initdata = {
> > - { PCI_VENDOR_ID_NVIDIA, nvidia_bugs },
> > - { PCI_VENDOR_ID_VIA, via_bugs },
> > - { PCI_VENDOR_ID_ATI, ati_bugs },
> > + { PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, nvidia_bugs },
> > + { PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, via_bugs },
> > + { PCI_VENDOR_ID_ATI, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, ati_bugs },
> > + { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB, PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, fix_hypertransport_config },
> > {}
> > };
> >
> > @@ -106,27 +148,33 @@ void __init early_quirks(void)
> > for (num = 0; num < 32; num++) {
> > for (slot = 0; slot < 32; slot++) {
> > for (func = 0; func < 8; func++) {
> > - u32 class;
> > - u32 vendor;
> > + u16 class;
> > + u16 vendor;
> > + u16 device;
> > u8 type;
> > int i;
> > - class = read_pci_config(num,slot,func,
> > +
> > + class = read_pci_config_16(num,slot,func,
> > PCI_CLASS_REVISION);
> > - if (class == 0xffffffff)
> > + if (class == 0xffff)
> > break;
> >
> > - if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
> > - continue;
> > -
> > - vendor = read_pci_config(num, slot, func,
> > + vendor = read_pci_config_16(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;
> > + device = read_pci_config_16(num, slot, func,
> > + PCI_DEVICE_ID);
> > +
> > + for(i=0;early_qrk[i].f != NULL;i++) {
> > + if (((early_qrk[i].vendor == PCI_ANY_ID) ||
> > + (early_qrk[i].vendor == vendor)) &&
> > + ((early_qrk[i].device == PCI_ANY_ID) ||
> > + (early_qrk[i].device == device)) &&
> > + (!((early_qrk[i].class ^ class) &
> > + early_qrk[i].class_mask))) {
> > + early_qrk[i].f(num, slot, func);
> > }
> > + }
> >
> > type = read_pci_config_byte(num, slot, func,
> > PCI_HEADER_TYPE);
>
>
> --
> -ben
> -=-
>
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