1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _ASM_X86_IRQ_VECTORS_H 3#define _ASM_X86_IRQ_VECTORS_H 4 5#include <linux/threads.h> 6/* 7 * Linux IRQ vector layout. 8 * 9 * There are 256 IDT entries (per CPU - each entry is 8 bytes) which can 10 * be defined by Linux. They are used as a jump table by the CPU when a 11 * given vector is triggered - by a CPU-external, CPU-internal or 12 * software-triggered event. 13 * 14 * Linux sets the kernel code address each entry jumps to early during 15 * bootup, and never changes them. This is the general layout of the 16 * IDT entries: 17 * 18 * Vectors 0 ... 31 : system traps and exceptions - hardcoded events 19 * Vectors 32 ... 127 : device interrupts 20 * Vector 128 : legacy int80 syscall interface 21 * Vectors 129 ... INVALIDATE_TLB_VECTOR_START-1 except 204 : device interrupts 22 * Vectors INVALIDATE_TLB_VECTOR_START ... 255 : special interrupts 23 * 24 * 64-bit x86 has per CPU IDT tables, 32-bit has one shared IDT table. 25 * 26 * This file enumerates the exact layout of them: 27 */ 28 29#define NMI_VECTOR 0x02 30#define MCE_VECTOR 0x12 31 32/* 33 * IDT vectors usable for external interrupt sources start at 0x20. 34 * (0x80 is the syscall vector, 0x30-0x3f are for ISA) 35 */ 36#define FIRST_EXTERNAL_VECTOR 0x20 37 38/* 39 * Reserve the lowest usable vector (and hence lowest priority) 0x20 for 40 * triggering cleanup after irq migration. 0x21-0x2f will still be used 41 * for device interrupts. 42 */ 43#define IRQ_MOVE_CLEANUP_VECTOR FIRST_EXTERNAL_VECTOR 44 45#define IA32_SYSCALL_VECTOR 0x80 46 47/* 48 * Vectors 0x30-0x3f are used for ISA interrupts. 49 * round up to the next 16-vector boundary 50 */ 51#define ISA_IRQ_VECTOR(irq) (((FIRST_EXTERNAL_VECTOR + 16) & ~15) + irq) 52 53/* 54 * Special IRQ vectors used by the SMP architecture, 0xf0-0xff 55 * 56 * some of the following vectors are 'rare', they are merged 57 * into a single vector (CALL_FUNCTION_VECTOR) to save vector space. 58 * TLB, reschedule and local APIC vectors are performance-critical. 59 */ 60 61#define SPURIOUS_APIC_VECTOR 0xff 62/* 63 * Sanity check 64 */ 65#if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F) 66# error SPURIOUS_APIC_VECTOR definition error 67#endif 68 69#define ERROR_APIC_VECTOR 0xfe 70#define RESCHEDULE_VECTOR 0xfd 71#define CALL_FUNCTION_VECTOR 0xfc 72#define CALL_FUNCTION_SINGLE_VECTOR 0xfb 73#define THERMAL_APIC_VECTOR 0xfa 74#define THRESHOLD_APIC_VECTOR 0xf9 75#define REBOOT_VECTOR 0xf8 76 77/* 78 * Generic system vector for platform specific use 79 */ 80#define X86_PLATFORM_IPI_VECTOR 0xf7 81 82/* 83 * IRQ work vector: 84 */ 85#define IRQ_WORK_VECTOR 0xf6 86 87#define UV_BAU_MESSAGE 0xf5 88#define DEFERRED_ERROR_VECTOR 0xf4 89 90/* Vector on which hypervisor callbacks will be delivered */ 91#define HYPERVISOR_CALLBACK_VECTOR 0xf3 92 93/* Vector for KVM to deliver posted interrupt IPI */ 94#ifdef CONFIG_HAVE_KVM 95#define POSTED_INTR_VECTOR 0xf2 96#define POSTED_INTR_WAKEUP_VECTOR 0xf1 97#define POSTED_INTR_NESTED_VECTOR 0xf0 98#endif 99 100#define MANAGED_IRQ_SHUTDOWN_VECTOR 0xef 101 102#if IS_ENABLED(CONFIG_HYPERV) 103#define HYPERV_REENLIGHTENMENT_VECTOR 0xee 104#define HYPERV_STIMER0_VECTOR 0xed 105#endif 106 107#define LOCAL_TIMER_VECTOR 0xec 108 109#define NR_VECTORS 256 110 111#ifdef CONFIG_X86_LOCAL_APIC 112#define FIRST_SYSTEM_VECTOR LOCAL_TIMER_VECTOR 113#else 114#define FIRST_SYSTEM_VECTOR NR_VECTORS 115#endif 116 117/* 118 * Size the maximum number of interrupts. 119 * 120 * If the irq_desc[] array has a sparse layout, we can size things 121 * generously - it scales up linearly with the maximum number of CPUs, 122 * and the maximum number of IO-APICs, whichever is higher. 123 * 124 * In other cases we size more conservatively, to not create too large 125 * static arrays. 126 */ 127 128#define NR_IRQS_LEGACY 16 129 130#define CPU_VECTOR_LIMIT (64 * NR_CPUS) 131#define IO_APIC_VECTOR_LIMIT (32 * MAX_IO_APICS) 132 133#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_PCI_MSI) 134#define NR_IRQS \ 135 (CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ? \ 136 (NR_VECTORS + CPU_VECTOR_LIMIT) : \ 137 (NR_VECTORS + IO_APIC_VECTOR_LIMIT)) 138#elif defined(CONFIG_X86_IO_APIC) 139#define NR_IRQS (NR_VECTORS + IO_APIC_VECTOR_LIMIT) 140#elif defined(CONFIG_PCI_MSI) 141#define NR_IRQS (NR_VECTORS + CPU_VECTOR_LIMIT) 142#else 143#define NR_IRQS NR_IRQS_LEGACY 144#endif 145 146#endif /* _ASM_X86_IRQ_VECTORS_H */ 147