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 ... FIRST_SYSTEM_VECTOR-1 : device interrupts
22 * Vectors FIRST_SYSTEM_VECTOR ... 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/* This is used as an interrupt vector when programming the APIC. */
30#define NMI_VECTOR 0x02
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#define IA32_SYSCALL_VECTOR 0x80
39
40/*
41 * Vectors 0x30-0x3f are used for ISA interrupts.
42 * round up to the next 16-vector boundary
43 */
44#define ISA_IRQ_VECTOR(irq) (((FIRST_EXTERNAL_VECTOR + 16) & ~15) + irq)
45
46/*
47 * Special IRQ vectors used by the SMP architecture, 0xf0-0xff
48 *
49 * some of the following vectors are 'rare', they are merged
50 * into a single vector (CALL_FUNCTION_VECTOR) to save vector space.
51 * TLB, reschedule and local APIC vectors are performance-critical.
52 */
53
54#define SPURIOUS_APIC_VECTOR 0xff
55/*
56 * Sanity check
57 */
58#if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F)
59# error SPURIOUS_APIC_VECTOR definition error
60#endif
61
62#define ERROR_APIC_VECTOR 0xfe
63#define RESCHEDULE_VECTOR 0xfd
64#define CALL_FUNCTION_VECTOR 0xfc
65#define CALL_FUNCTION_SINGLE_VECTOR 0xfb
66#define THERMAL_APIC_VECTOR 0xfa
67#define THRESHOLD_APIC_VECTOR 0xf9
68#define REBOOT_VECTOR 0xf8
69
70/*
71 * Generic system vector for platform specific use
72 */
73#define X86_PLATFORM_IPI_VECTOR 0xf7
74
75/*
76 * IRQ work vector:
77 */
78#define IRQ_WORK_VECTOR 0xf6
79
80/* 0xf5 - unused, was UV_BAU_MESSAGE */
81#define DEFERRED_ERROR_VECTOR 0xf4
82
83/* Vector on which hypervisor callbacks will be delivered */
84#define HYPERVISOR_CALLBACK_VECTOR 0xf3
85
86/* Vector for KVM to deliver posted interrupt IPI */
87#define POSTED_INTR_VECTOR 0xf2
88#define POSTED_INTR_WAKEUP_VECTOR 0xf1
89#define POSTED_INTR_NESTED_VECTOR 0xf0
90
91#define MANAGED_IRQ_SHUTDOWN_VECTOR 0xef
92
93#if IS_ENABLED(CONFIG_HYPERV)
94#define HYPERV_REENLIGHTENMENT_VECTOR 0xee
95#define HYPERV_STIMER0_VECTOR 0xed
96#endif
97
98#define LOCAL_TIMER_VECTOR 0xec
99
100/*
101 * Posted interrupt notification vector for all device MSIs delivered to
102 * the host kernel.
103 */
104#define POSTED_MSI_NOTIFICATION_VECTOR 0xeb
105
106#define NR_VECTORS 256
107
108#ifdef CONFIG_X86_LOCAL_APIC
109#define FIRST_SYSTEM_VECTOR POSTED_MSI_NOTIFICATION_VECTOR
110#else
111#define FIRST_SYSTEM_VECTOR NR_VECTORS
112#endif
113
114#define NR_EXTERNAL_VECTORS (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
115#define NR_SYSTEM_VECTORS (NR_VECTORS - FIRST_SYSTEM_VECTOR)
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

source code of linux/arch/x86/include/asm/irq_vectors.h