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 22 static u32 __init acrn_detect(void) 23 { 24 return acrn_cpuid_base(); 25 } 26 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 x86_platform.calibrate_tsc = acrn_get_tsc_khz; 33 x86_platform.calibrate_cpu = acrn_get_tsc_khz; 34 } 35 36 static bool acrn_x2apic_available(void) 37 { 38 return boot_cpu_has(X86_FEATURE_X2APIC); 39 } 40 41 static void (*acrn_intr_handler)(void); 42 43 DEFINE_IDTENTRY_SYSVEC(sysvec_acrn_hv_callback) 44 { 45 struct pt_regs *old_regs = set_irq_regs(regs); 46 47 /* 48 * The hypervisor requires that the APIC EOI should be acked. 49 * If the APIC EOI is not acked, the APIC ISR bit for the 50 * HYPERVISOR_CALLBACK_VECTOR will not be cleared and then it 51 * will block the interrupt whose vector is lower than 52 * HYPERVISOR_CALLBACK_VECTOR. 53 */ 54 apic_eoi(); 55 inc_irq_stat(irq_hv_callback_count); 56 57 if (acrn_intr_handler) 58 acrn_intr_handler(); 59 60 set_irq_regs(old_regs); 61 } 62 63 void acrn_setup_intr_handler(void (*handler)(void)) 64 { 65 acrn_intr_handler = handler; 66 } 67 EXPORT_SYMBOL_GPL(acrn_setup_intr_handler); 68 69 void acrn_remove_intr_handler(void) 70 { 71 acrn_intr_handler = NULL; 72 } 73 EXPORT_SYMBOL_GPL(acrn_remove_intr_handler); 74 75 const __initconst struct hypervisor_x86 x86_hyper_acrn = { 76 .name = "ACRN", 77 .detect = acrn_detect, 78 .type = X86_HYPER_ACRN, 79 .init.init_platform = acrn_init_platform, 80 .init.x2apic_available = acrn_x2apic_available, 81 }; 82