LXR linux/arch/x86/kernel/cpu/acrn.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * ACRN detection support
   4 *
   5 * Copyright (C) 2019 Intel Corporation. All rights reserved.
   6 *
   7 * Jason Chen CJ <jason.cj.chen@intel.com>
   8 * Zhao Yakui <yakui.zhao@intel.com>
   9 *
  10 */
  11
  12#include <linux/interrupt.h>
  13
  14#include <asm/acrn.h>
  15#include <asm/apic.h>
  16#include <asm/cpufeatures.h>
  17#include <asm/desc.h>
  18#include <asm/hypervisor.h>
  19#include <asm/idtentry.h>
  20#include <asm/irq_regs.h>
  21
  22static u32 __init acrn_detect(void)
  23{
  24        return acrn_cpuid_base();
  25}
  26
  27static void __init acrn_init_platform(void)
  28{
  29        /* Setup the IDT for ACRN hypervisor callback */
  30        alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_acrn_hv_callback);
  31}
  32
  33static bool acrn_x2apic_available(void)
  34{
  35        return boot_cpu_has(X86_FEATURE_X2APIC);
  36}
  37
  38static void (*acrn_intr_handler)(void);
  39
  40DEFINE_IDTENTRY_SYSVEC(sysvec_acrn_hv_callback)
  41{
  42        struct pt_regs *old_regs = set_irq_regs(regs);
  43
  44        /*
  45         * The hypervisor requires that the APIC EOI should be acked.
  46         * If the APIC EOI is not acked, the APIC ISR bit for the
  47         * HYPERVISOR_CALLBACK_VECTOR will not be cleared and then it
  48         * will block the interrupt whose vector is lower than
  49         * HYPERVISOR_CALLBACK_VECTOR.
  50         */
  51        ack_APIC_irq();
  52        inc_irq_stat(irq_hv_callback_count);
  53
  54        if (acrn_intr_handler)
  55                acrn_intr_handler();
  56
  57        set_irq_regs(old_regs);
  58}
  59
  60void acrn_setup_intr_handler(void (*handler)(void))
  61{
  62        acrn_intr_handler = handler;
  63}
  64EXPORT_SYMBOL_GPL(acrn_setup_intr_handler);
  65
  66void acrn_remove_intr_handler(void)
  67{
  68        acrn_intr_handler = NULL;
  69}
  70EXPORT_SYMBOL_GPL(acrn_remove_intr_handler);
  71
  72const __initconst struct hypervisor_x86 x86_hyper_acrn = {
  73        .name                   = "ACRN",
  74        .detect                 = acrn_detect,
  75        .type                   = X86_HYPER_ACRN,
  76        .init.init_platform     = acrn_init_platform,
  77        .init.x2apic_available  = acrn_x2apic_available,
  78};
  79