1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_IRQ_VECTORS_H
3 #define _ASM_X86_IRQ_VECTORS_H
5 #include <linux/threads.h>
7 * Linux IRQ vector layout.
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.
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
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
24 * 64-bit x86 has per CPU IDT tables, 32-bit has one shared IDT table.
26 * This file enumerates the exact layout of them:
29 /* This is used as an interrupt vector when programming the APIC. */
30 #define NMI_VECTOR 0x02
33 * IDT vectors usable for external interrupt sources start at 0x20.
34 * (0x80 is the syscall vector, 0x30-0x3f are for ISA)
36 #define FIRST_EXTERNAL_VECTOR 0x20
38 #define IA32_SYSCALL_VECTOR 0x80
41 * Vectors 0x30-0x3f are used for ISA interrupts.
42 * round up to the next 16-vector boundary
44 #define ISA_IRQ_VECTOR(irq) (((FIRST_EXTERNAL_VECTOR + 16) & ~15) + irq)
47 * Special IRQ vectors used by the SMP architecture, 0xf0-0xff
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.
54 #define SPURIOUS_APIC_VECTOR 0xff
58 #if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F)
59 # error SPURIOUS_APIC_VECTOR definition error
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
71 * Generic system vector for platform specific use
73 #define X86_PLATFORM_IPI_VECTOR 0xf7
78 #define IRQ_WORK_VECTOR 0xf6
80 /* 0xf5 - unused, was UV_BAU_MESSAGE */
81 #define DEFERRED_ERROR_VECTOR 0xf4
83 /* Vector on which hypervisor callbacks will be delivered */
84 #define HYPERVISOR_CALLBACK_VECTOR 0xf3
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
91 #define MANAGED_IRQ_SHUTDOWN_VECTOR 0xef
93 #if IS_ENABLED(CONFIG_HYPERV)
94 #define HYPERV_REENLIGHTENMENT_VECTOR 0xee
95 #define HYPERV_STIMER0_VECTOR 0xed
98 #define LOCAL_TIMER_VECTOR 0xec
100 #define NR_VECTORS 256
102 #ifdef CONFIG_X86_LOCAL_APIC
103 #define FIRST_SYSTEM_VECTOR LOCAL_TIMER_VECTOR
105 #define FIRST_SYSTEM_VECTOR NR_VECTORS
108 #define NR_EXTERNAL_VECTORS (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
109 #define NR_SYSTEM_VECTORS (NR_VECTORS - FIRST_SYSTEM_VECTOR)
112 * Size the maximum number of interrupts.
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.
118 * In other cases we size more conservatively, to not create too large
122 #define NR_IRQS_LEGACY 16
124 #define CPU_VECTOR_LIMIT (64 * NR_CPUS)
125 #define IO_APIC_VECTOR_LIMIT (32 * MAX_IO_APICS)
127 #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_PCI_MSI)
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)
137 #define NR_IRQS NR_IRQS_LEGACY
140 #endif /* _ASM_X86_IRQ_VECTORS_H */