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 /* 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