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 /* 39 * Reserve the lowest usable vector (and hence lowest priority) 0x20 for 40 * triggering cleanup after irq migration. 0x21-0x2f will still be used 41 * for device interrupts. 42 */ 43 #define IRQ_MOVE_CLEANUP_VECTOR FIRST_EXTERNAL_VECTOR 44 45 #define IA32_SYSCALL_VECTOR 0x80 46 47 /* 48 * Vectors 0x30-0x3f are used for ISA interrupts. 49 * round up to the next 16-vector boundary 50 */ 51 #define ISA_IRQ_VECTOR(irq) (((FIRST_EXTERNAL_VECTOR + 16) & ~15) + irq) 52 53 /* 54 * Special IRQ vectors used by the SMP architecture, 0xf0-0xff 55 * 56 * some of the following vectors are 'rare', they are merged 57 * into a single vector (CALL_FUNCTION_VECTOR) to save vector space. 58 * TLB, reschedule and local APIC vectors are performance-critical. 59 */ 60 61 #define SPURIOUS_APIC_VECTOR 0xff 62 /* 63 * Sanity check 64 */ 65 #if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F) 66 # error SPURIOUS_APIC_VECTOR definition error 67 #endif 68 69 #define ERROR_APIC_VECTOR 0xfe 70 #define RESCHEDULE_VECTOR 0xfd 71 #define CALL_FUNCTION_VECTOR 0xfc 72 #define CALL_FUNCTION_SINGLE_VECTOR 0xfb 73 #define THERMAL_APIC_VECTOR 0xfa 74 #define THRESHOLD_APIC_VECTOR 0xf9 75 #define REBOOT_VECTOR 0xf8 76 77 /* 78 * Generic system vector for platform specific use 79 */ 80 #define X86_PLATFORM_IPI_VECTOR 0xf7 81 82 /* 83 * IRQ work vector: 84 */ 85 #define IRQ_WORK_VECTOR 0xf6 86 87 /* 0xf5 - unused, was UV_BAU_MESSAGE */ 88 #define DEFERRED_ERROR_VECTOR 0xf4 89 90 /* Vector on which hypervisor callbacks will be delivered */ 91 #define HYPERVISOR_CALLBACK_VECTOR 0xf3 92 93 /* Vector for KVM to deliver posted interrupt IPI */ 94 #ifdef CONFIG_HAVE_KVM 95 #define POSTED_INTR_VECTOR 0xf2 96 #define POSTED_INTR_WAKEUP_VECTOR 0xf1 97 #define POSTED_INTR_NESTED_VECTOR 0xf0 98 #endif 99 100 #define MANAGED_IRQ_SHUTDOWN_VECTOR 0xef 101 102 #if IS_ENABLED(CONFIG_HYPERV) 103 #define HYPERV_REENLIGHTENMENT_VECTOR 0xee 104 #define HYPERV_STIMER0_VECTOR 0xed 105 #endif 106 107 #define LOCAL_TIMER_VECTOR 0xec 108 109 #define NR_VECTORS 256 110 111 #ifdef CONFIG_X86_LOCAL_APIC 112 #define FIRST_SYSTEM_VECTOR LOCAL_TIMER_VECTOR 113 #else 114 #define FIRST_SYSTEM_VECTOR NR_VECTORS 115 #endif 116 117 #define NR_EXTERNAL_VECTORS (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR) 118 #define NR_SYSTEM_VECTORS (NR_VECTORS - FIRST_SYSTEM_VECTOR) 119 120 /* 121 * Size the maximum number of interrupts. 122 * 123 * If the irq_desc[] array has a sparse layout, we can size things 124 * generously - it scales up linearly with the maximum number of CPUs, 125 * and the maximum number of IO-APICs, whichever is higher. 126 * 127 * In other cases we size more conservatively, to not create too large 128 * static arrays. 129 */ 130 131 #define NR_IRQS_LEGACY 16 132 133 #define CPU_VECTOR_LIMIT (64 * NR_CPUS) 134 #define IO_APIC_VECTOR_LIMIT (32 * MAX_IO_APICS) 135 136 #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_PCI_MSI) 137 #define NR_IRQS \ 138 (CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ? \ 139 (NR_VECTORS + CPU_VECTOR_LIMIT) : \ 140 (NR_VECTORS + IO_APIC_VECTOR_LIMIT)) 141 #elif defined(CONFIG_X86_IO_APIC) 142 #define NR_IRQS (NR_VECTORS + IO_APIC_VECTOR_LIMIT) 143 #elif defined(CONFIG_PCI_MSI) 144 #define NR_IRQS (NR_VECTORS + CPU_VECTOR_LIMIT) 145 #else 146 #define NR_IRQS NR_IRQS_LEGACY 147 #endif 148 149 #endif /* _ASM_X86_IRQ_VECTORS_H */ 150