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 
acrn_detect(void)22 static u32 __init acrn_detect(void)
23 {
24 	return acrn_cpuid_base();
25 }
26 
acrn_init_platform(void)27 static 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 
acrn_x2apic_available(void)33 static bool acrn_x2apic_available(void)
34 {
35 	return boot_cpu_has(X86_FEATURE_X2APIC);
36 }
37 
38 static void (*acrn_intr_handler)(void);
39 
DEFINE_IDTENTRY_SYSVEC(sysvec_acrn_hv_callback)40 DEFINE_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 
acrn_setup_intr_handler(void (* handler)(void))60 void acrn_setup_intr_handler(void (*handler)(void))
61 {
62 	acrn_intr_handler = handler;
63 }
64 EXPORT_SYMBOL_GPL(acrn_setup_intr_handler);
65 
acrn_remove_intr_handler(void)66 void acrn_remove_intr_handler(void)
67 {
68 	acrn_intr_handler = NULL;
69 }
70 EXPORT_SYMBOL_GPL(acrn_remove_intr_handler);
71 
72 const __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