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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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66db60eaf1
A long time ago I worked on a RHEL5 bug in which kdump hung during boot on a set of systems. The systems hung because they never received timer interrupts during calibrate_delay. These systems also all had Opteron processors on a hypertransport bus, bridged to a pci bus via an Nvidia MCP55 northbridge chip. After much wrangling I managed to learn from Nvidia that they have an undocumented register in some versions of that chip which control how legacy interrupts are send to the cpu complex when the ioapic isn't active. Nvidia defaults this register to only send legacy interrupts to the BSP, so if kdump happens to boot on an AP, we never get timer interrupts and boom. I had initially used this quirk as a workaround, with my intent being to move apic initalization to an earlier point in the boot process, so the setting of the register would be irrelevant. Given the work involved in doing that however, the fragile nature of the apic initalization code, and the fact that, over the 2 years since we found this bug, the MCP55 is the only chip which seems to have this issue, I've figure at this point its likely safer to just carry the quirk around. By setting the referenced bits in this hidden register, interrupts will be broadcast to all cpus when the ioapic isn't active on the above described systems. Acked-by: Simon Horman <horms@verge.net.au> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> |
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| .. | ||
| hotplug | ||
| pcie | ||
| .gitignore | ||
| access.c | ||
| bus.c | ||
| dmar.c | ||
| hotplug-pci.c | ||
| hotplug.c | ||
| htirq.c | ||
| intel-iommu.c | ||
| intr_remapping.c | ||
| intr_remapping.h | ||
| ioapic.c | ||
| iov.c | ||
| iova.c | ||
| irq.c | ||
| Kconfig | ||
| Makefile | ||
| msi.c | ||
| msi.h | ||
| pci-acpi.c | ||
| pci-driver.c | ||
| pci-label.c | ||
| pci-stub.c | ||
| pci-sysfs.c | ||
| pci.c | ||
| pci.h | ||
| probe.c | ||
| proc.c | ||
| quirks.c | ||
| remove.c | ||
| rom.c | ||
| search.c | ||
| setup-bus.c | ||
| setup-irq.c | ||
| setup-res.c | ||
| slot.c | ||
| syscall.c | ||
| vpd.c | ||