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2d1435b742
Install the system vector IRQ handlers for FRED even if FRED isn't fully enabled in hardware. This will allow KVM to use the FRED IRQ path even on non-FRED hardware, which in turn will eliminate a non-CFI indirect CALL (KVM currently invokes the IRQ handler via an IDT lookup on the vector). [sean: extract from diff, drop stub, write changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20250714103441.121251108@infradead.org
115 lines
3.1 KiB
C
115 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/linkage.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/ioport.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/timex.h>
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#include <linux/random.h>
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#include <linux/kprobes.h>
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#include <linux/init.h>
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#include <linux/kernel_stat.h>
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#include <linux/device.h>
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#include <linux/bitops.h>
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#include <linux/acpi.h>
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#include <linux/io.h>
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#include <linux/delay.h>
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#include <linux/pgtable.h>
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#include <linux/atomic.h>
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#include <asm/timer.h>
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#include <asm/hw_irq.h>
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#include <asm/desc.h>
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#include <asm/io_apic.h>
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#include <asm/acpi.h>
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#include <asm/apic.h>
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#include <asm/setup.h>
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#include <asm/i8259.h>
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#include <asm/traps.h>
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#include <asm/fred.h>
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#include <asm/prom.h>
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/*
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* ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
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* (these are usually mapped to vectors 0x30-0x3f)
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*/
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/*
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* The IO-APIC gives us many more interrupt sources. Most of these
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* are unused but an SMP system is supposed to have enough memory ...
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* sometimes (mostly wrt. hw bugs) we get corrupted vectors all
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* across the spectrum, so we really want to be prepared to get all
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* of these. Plus, more powerful systems might have more than 64
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* IO-APIC registers.
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*
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* (these are usually mapped into the 0x30-0xff vector range)
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*/
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DEFINE_PER_CPU(vector_irq_t, vector_irq) = {
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[0 ... NR_VECTORS - 1] = VECTOR_UNUSED,
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};
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void __init init_ISA_irqs(void)
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{
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struct irq_chip *chip = legacy_pic->chip;
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int i;
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/*
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* Try to set up the through-local-APIC virtual wire mode earlier.
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*
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* On some 32-bit UP machines, whose APIC has been disabled by BIOS
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* and then got re-enabled by "lapic", it hangs at boot time without this.
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*/
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init_bsp_APIC();
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legacy_pic->init(0);
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for (i = 0; i < nr_legacy_irqs(); i++) {
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irq_set_chip_and_handler(i, chip, handle_level_irq);
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irq_set_status_flags(i, IRQ_LEVEL);
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}
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}
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void __init init_IRQ(void)
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{
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int i;
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/*
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* On cpu 0, Assign ISA_IRQ_VECTOR(irq) to IRQ 0..15.
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* If these IRQ's are handled by legacy interrupt-controllers like PIC,
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* then this configuration will likely be static after the boot. If
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* these IRQs are handled by more modern controllers like IO-APIC,
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* then this vector space can be freed and re-used dynamically as the
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* irq's migrate etc.
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*/
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for (i = 0; i < nr_legacy_irqs(); i++)
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per_cpu(vector_irq, 0)[ISA_IRQ_VECTOR(i)] = irq_to_desc(i);
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BUG_ON(irq_init_percpu_irqstack(smp_processor_id()));
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x86_init.irqs.intr_init();
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}
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void __init native_init_IRQ(void)
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{
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/* Execute any quirks before the call gates are initialised: */
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x86_init.irqs.pre_vector_init();
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/* FRED's IRQ path may be used even if FRED isn't fully enabled. */
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if (IS_ENABLED(CONFIG_X86_FRED))
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fred_complete_exception_setup();
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if (!cpu_feature_enabled(X86_FEATURE_FRED))
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idt_setup_apic_and_irq_gates();
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lapic_assign_system_vectors();
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if (!acpi_ioapic && !of_ioapic && nr_legacy_irqs()) {
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/* IRQ2 is cascade interrupt to second interrupt controller */
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if (request_irq(2, no_action, IRQF_NO_THREAD, "cascade", NULL))
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pr_err("%s: request_irq() failed\n", "cascade");
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}
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}
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