1 #ifndef _ASM_X86_IRQ_VECTORS_H
2 #define _ASM_X86_IRQ_VECTORS_H
5 * Linux IRQ vector layout.
7 * There are 256 IDT entries (per CPU - each entry is 8 bytes) which can
8 * be defined by Linux. They are used as a jump table by the CPU when a
9 * given vector is triggered - by a CPU-external, CPU-internal or
10 * software-triggered event.
12 * Linux sets the kernel code address each entry jumps to early during
13 * bootup, and never changes them. This is the general layout of the
16 * Vectors 0 ... 31 : system traps and exceptions - hardcoded events
17 * Vectors 32 ... 127 : device interrupts
18 * Vector 128 : legacy int80 syscall interface
19 * Vectors 129 ... 237 : device interrupts
20 * Vectors 238 ... 255 : special interrupts
22 * 64-bit x86 has per CPU IDT tables, 32-bit has one shared IDT table.
24 * This file enumerates the exact layout of them:
27 #define NMI_VECTOR 0x02
30 * IDT vectors usable for external interrupt sources start
33 #define FIRST_EXTERNAL_VECTOR 0x20
36 # define SYSCALL_VECTOR 0x80
37 # define IA32_SYSCALL_VECTOR 0x80
39 # define IA32_SYSCALL_VECTOR 0x80
43 * Reserve the lowest usable priority level 0x20 - 0x2f for triggering
44 * cleanup after irq migration.
46 #define IRQ_MOVE_CLEANUP_VECTOR FIRST_EXTERNAL_VECTOR
49 * Vectors 0x30-0x3f are used for ISA interrupts.
51 #define IRQ0_VECTOR (FIRST_EXTERNAL_VECTOR + 0x10)
53 #define IRQ1_VECTOR (IRQ0_VECTOR + 1)
54 #define IRQ2_VECTOR (IRQ0_VECTOR + 2)
55 #define IRQ3_VECTOR (IRQ0_VECTOR + 3)
56 #define IRQ4_VECTOR (IRQ0_VECTOR + 4)
57 #define IRQ5_VECTOR (IRQ0_VECTOR + 5)
58 #define IRQ6_VECTOR (IRQ0_VECTOR + 6)
59 #define IRQ7_VECTOR (IRQ0_VECTOR + 7)
60 #define IRQ8_VECTOR (IRQ0_VECTOR + 8)
61 #define IRQ9_VECTOR (IRQ0_VECTOR + 9)
62 #define IRQ10_VECTOR (IRQ0_VECTOR + 10)
63 #define IRQ11_VECTOR (IRQ0_VECTOR + 11)
64 #define IRQ12_VECTOR (IRQ0_VECTOR + 12)
65 #define IRQ13_VECTOR (IRQ0_VECTOR + 13)
66 #define IRQ14_VECTOR (IRQ0_VECTOR + 14)
67 #define IRQ15_VECTOR (IRQ0_VECTOR + 15)
70 * Special IRQ vectors used by the SMP architecture, 0xf0-0xff
72 * some of the following vectors are 'rare', they are merged
73 * into a single vector (CALL_FUNCTION_VECTOR) to save vector space.
74 * TLB, reschedule and local APIC vectors are performance-critical.
77 #define SPURIOUS_APIC_VECTOR 0xff
81 #if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F)
82 # error SPURIOUS_APIC_VECTOR definition error
85 #define ERROR_APIC_VECTOR 0xfe
86 #define RESCHEDULE_VECTOR 0xfd
87 #define CALL_FUNCTION_VECTOR 0xfc
88 #define CALL_FUNCTION_SINGLE_VECTOR 0xfb
89 #define THERMAL_APIC_VECTOR 0xfa
92 /* 0xf8 - 0xf9 : free */
94 # define THRESHOLD_APIC_VECTOR 0xf9
95 # define UV_BAU_MESSAGE 0xf8
98 /* f0-f7 used for spreading out TLB flushes: */
99 #define INVALIDATE_TLB_VECTOR_END 0xf7
100 #define INVALIDATE_TLB_VECTOR_START 0xf0
101 #define NUM_INVALIDATE_TLB_VECTORS 8
104 * Local APIC timer IRQ vector is on a different priority level,
105 * to work around the 'lost local interrupt if more than 2 IRQ
106 * sources per level' errata.
108 #define LOCAL_TIMER_VECTOR 0xef
111 * Generic system vector for platform specific use
113 #define GENERIC_INTERRUPT_VECTOR 0xed
116 * Performance monitoring pending work vector:
118 #define LOCAL_PENDING_VECTOR 0xec
121 * First APIC vector available to drivers: (vectors 0x30-0xee) we
122 * start at 0x31(0x41) to spread out vectors evenly between priority
123 * levels. (0x80 is the syscall vector)
125 #define FIRST_DEVICE_VECTOR (IRQ15_VECTOR + 2)
127 #define NR_VECTORS 256
131 #define FIRST_VM86_IRQ 3
132 #define LAST_VM86_IRQ 15
135 static inline int invalid_vm86_irq(int irq)
137 return irq < FIRST_VM86_IRQ || irq > LAST_VM86_IRQ;
142 * Size the maximum number of interrupts.
144 * If the irq_desc[] array has a sparse layout, we can size things
145 * generously - it scales up linearly with the maximum number of CPUs,
146 * and the maximum number of IO-APICs, whichever is higher.
148 * In other cases we size more conservatively, to not create too large
152 #define NR_IRQS_LEGACY 16
154 #define CPU_VECTOR_LIMIT ( 8 * NR_CPUS )
155 #define IO_APIC_VECTOR_LIMIT ( 32 * MAX_IO_APICS )
157 #ifdef CONFIG_X86_IO_APIC
158 # ifdef CONFIG_SPARSE_IRQ
160 (CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ? \
161 (NR_VECTORS + CPU_VECTOR_LIMIT) : \
162 (NR_VECTORS + IO_APIC_VECTOR_LIMIT))
164 # if NR_CPUS < MAX_IO_APICS
165 # define NR_IRQS (NR_VECTORS + 4*CPU_VECTOR_LIMIT)
167 # define NR_IRQS (NR_VECTORS + IO_APIC_VECTOR_LIMIT)
170 #else /* !CONFIG_X86_IO_APIC: */
171 # define NR_IRQS NR_IRQS_LEGACY
174 #endif /* _ASM_X86_IRQ_VECTORS_H */