The HPET hardlockup detector requires that the HPET timer delivers the interrupt as NMI. When interrupt remapping is disabled, this can be done by programming the HPET MSI registers directly. With interrupt remapping, it is necessary to populate an entry in the interrupt remapping table.
In x86 there is not an IRQF_NMI flag that can be used to indicate the delivery mode when requesting an interrupt (via request_irq()). Thus, there is no way for the interrupt remapping driver to know and set the delivery mode. Hence, when allocating an interrupt, check if such interrupt belongs to the HPET hardlockup detector and fixup the delivery mode accordingly. Cc: Andi Kleen <andi.kl...@intel.com> Cc: Borislav Petkov <b...@suse.de> Cc: David Woodhouse <dw...@infradead.org> (supporter:INTEL IOMMU (VT-d)) Cc: "Ravi V. Shankar" <ravi.v.shan...@intel.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: Jacob Pan <jacob.jun....@intel.com> Cc: Lu Baolu <baolu...@linux.intel.com> (supporter:INTEL IOMMU (VT-d)) Cc: Stephane Eranian <eran...@google.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: iommu@lists.linux-foundation.org (open list:INTEL IOMMU (VT-d)) Cc: x...@kernel.org Reviewed-by: Ashok Raj <ashok....@intel.com> Signed-off-by: Ricardo Neri <ricardo.neri-calde...@linux.intel.com> --- Changes since v4: * Introduced this patch. Changes since v3: * N/A Changes since v2: * N/A Changes since v1: * N/A --- drivers/iommu/intel/irq_remapping.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c index daa5df53db59..b07c68ecac01 100644 --- a/drivers/iommu/intel/irq_remapping.c +++ b/drivers/iommu/intel/irq_remapping.c @@ -18,6 +18,7 @@ #include <asm/apic.h> #include <asm/smp.h> #include <asm/cpu.h> +#include <asm/hpet.h> #include <asm/irq_remapping.h> #include <asm/pci-direct.h> @@ -1376,6 +1377,14 @@ static int intel_irq_remapping_alloc(struct irq_domain *domain, irq_data->hwirq = (index << 16) + i; irq_data->chip_data = ird; irq_data->chip = &intel_ir_chip; + + /* + * If we find the HPET hardlockup detector irq, fixup the + * delivery mode. + */ + if (is_hpet_irq_hardlockup_detector(info)) + irq_cfg->delivery_mode = APIC_DELIVERY_MODE_NMI; + intel_irq_remapping_prepare_irte(ird, irq_cfg, info, index, i); irq_set_status_flags(virq + i, IRQ_MOVE_PCNTXT); } -- 2.17.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu