Messages in this thread | | | Subject | Re: [RESEND PATCH 3/3] x86/apic: Clean up the names of legacy irq mode setting related functions | From | Dou Liyang <> | Date | Fri, 19 Jan 2018 14:42:17 +0800 |
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Hi Baoquan,
At 01/05/2018 12:39 PM, Baoquan He wrote: [...] > /* > - * Not an __init, needed by kexec/kdump code. > - * For safety IO-APIC and Local APIC need be cleared before this. > + * In legacy irq mode, full DOS compatibility with the uniprocessor PC/AT is > + * provided by using the APICs in conjunction with standard 8259A-equivalent > + * programmable interrupt controllers (PICs). It's necessary to deliver legacy > + * interrupts even when APIC mode is not enabled. This is required by kexec/ > + * kdump before enter into the 2nd kernel. > */ > void switch_to_legacy_irq_mode(void) > { > if (!nr_legacy_irqs()) > return; > > - x86_io_apic_ops.disable(); > + ioapic_set_virtual_wire_mode(); > + > + if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config()) > + lapic_set_legacy_irq_mode(ioapic_i8259.pin != -1);
Seems these two function, ioapic/lapic_set_legacy_irq_mode should be exclusive.
But We do that because both the through-lapic and through-ioapic virtual wire mode need setup the APIC_SPIV_APIC_ENABLED which is only located in the lapic_set_legacy_irq_mode(). So we need call them both.
IMO, this cleanup may not make it clear. we can separate these two mode totally or just keep it like before.
Thanks, dou. > } > > #ifdef CONFIG_X86_32 > diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c > index 1151ccd72ce9..c30f0f273dbd 100644 > --- a/arch/x86/kernel/x86_init.c > +++ b/arch/x86/kernel/x86_init.c > @@ -148,5 +148,5 @@ void arch_restore_msi_irqs(struct pci_dev *dev) > > struct x86_io_apic_ops x86_io_apic_ops __ro_after_init = { > .read = native_io_apic_read, > - .disable = native_disable_io_apic, > + .disable = switch_to_legacy_irq_mode, > }; > diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c > index 49721b4e1975..751472ddf536 100644 > --- a/drivers/iommu/irq_remapping.c > +++ b/drivers/iommu/irq_remapping.c > @@ -37,7 +37,7 @@ static void irq_remapping_disable_io_apic(void) > * now. > */ > if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config()) > - disconnect_bsp_APIC(0); > + lapic_set_legacy_irq_mode(0); > } > > static void __init irq_remapping_modify_x86_ops(void) >
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