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 ... LOCAL_TIMER_VECTOR-1
22 *  Vectors LOCAL_TIMER_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#define NR_VECTORS			 256
101
102#ifdef CONFIG_X86_LOCAL_APIC
103#define FIRST_SYSTEM_VECTOR		LOCAL_TIMER_VECTOR
104#else
105#define FIRST_SYSTEM_VECTOR		NR_VECTORS
106#endif
107
108#define NR_EXTERNAL_VECTORS		(FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
109#define NR_SYSTEM_VECTORS		(NR_VECTORS - FIRST_SYSTEM_VECTOR)
110
111/*
112 * Size the maximum number of interrupts.
113 *
114 * If the irq_desc[] array has a sparse layout, we can size things
115 * generously - it scales up linearly with the maximum number of CPUs,
116 * and the maximum number of IO-APICs, whichever is higher.
117 *
118 * In other cases we size more conservatively, to not create too large
119 * static arrays.
120 */
121
122#define NR_IRQS_LEGACY			16
123
124#define CPU_VECTOR_LIMIT		(64 * NR_CPUS)
125#define IO_APIC_VECTOR_LIMIT		(32 * MAX_IO_APICS)
126
127#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_PCI_MSI)
128#define NR_IRQS						\
129	(CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ?	\
130		(NR_VECTORS + CPU_VECTOR_LIMIT)  :	\
131		(NR_VECTORS + IO_APIC_VECTOR_LIMIT))
132#elif defined(CONFIG_X86_IO_APIC)
133#define	NR_IRQS				(NR_VECTORS + IO_APIC_VECTOR_LIMIT)
134#elif defined(CONFIG_PCI_MSI)
135#define NR_IRQS				(NR_VECTORS + CPU_VECTOR_LIMIT)
136#else
137#define NR_IRQS				NR_IRQS_LEGACY
138#endif
139
140#endif /* _ASM_X86_IRQ_VECTORS_H */
141