irq_vectors.h

  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 */