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};