xref: /linux/arch/x86/include/asm/irq_vectors.h (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
1 #ifndef _ASM_X86_IRQ_VECTORS_H
2 #define _ASM_X86_IRQ_VECTORS_H
3 
4 #include <linux/threads.h>
5 /*
6  * Linux IRQ vector layout.
7  *
8  * There are 256 IDT entries (per CPU - each entry is 8 bytes) which can
9  * be defined by Linux. They are used as a jump table by the CPU when a
10  * given vector is triggered - by a CPU-external, CPU-internal or
11  * software-triggered event.
12  *
13  * Linux sets the kernel code address each entry jumps to early during
14  * bootup, and never changes them. This is the general layout of the
15  * IDT entries:
16  *
17  *  Vectors   0 ...  31 : system traps and exceptions - hardcoded events
18  *  Vectors  32 ... 127 : device interrupts
19  *  Vector  128         : legacy int80 syscall interface
20  *  Vectors 129 ... INVALIDATE_TLB_VECTOR_START-1 except 204 : device interrupts
21  *  Vectors INVALIDATE_TLB_VECTOR_START ... 255 : special interrupts
22  *
23  * 64-bit x86 has per CPU IDT tables, 32-bit has one shared IDT table.
24  *
25  * This file enumerates the exact layout of them:
26  */
27 
28 #define NMI_VECTOR			0x02
29 #define MCE_VECTOR			0x12
30 
31 /*
32  * IDT vectors usable for external interrupt sources start at 0x20.
33  * (0x80 is the syscall vector, 0x30-0x3f are for ISA)
34  */
35 #define FIRST_EXTERNAL_VECTOR		0x20
36 /*
37  * We start allocating at 0x21 to spread out vectors evenly between
38  * priority levels. (0x80 is the syscall vector)
39  */
40 #define VECTOR_OFFSET_START		1
41 
42 /*
43  * Reserve the lowest usable vector (and hence lowest priority)  0x20 for
44  * triggering cleanup after irq migration. 0x21-0x2f will still be used
45  * for device interrupts.
46  */
47 #define IRQ_MOVE_CLEANUP_VECTOR		FIRST_EXTERNAL_VECTOR
48 
49 #define IA32_SYSCALL_VECTOR		0x80
50 
51 /*
52  * Vectors 0x30-0x3f are used for ISA interrupts.
53  *   round up to the next 16-vector boundary
54  */
55 #define ISA_IRQ_VECTOR(irq)		(((FIRST_EXTERNAL_VECTOR + 16) & ~15) + irq)
56 
57 /*
58  * Special IRQ vectors used by the SMP architecture, 0xf0-0xff
59  *
60  *  some of the following vectors are 'rare', they are merged
61  *  into a single vector (CALL_FUNCTION_VECTOR) to save vector space.
62  *  TLB, reschedule and local APIC vectors are performance-critical.
63  */
64 
65 #define SPURIOUS_APIC_VECTOR		0xff
66 /*
67  * Sanity check
68  */
69 #if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F)
70 # error SPURIOUS_APIC_VECTOR definition error
71 #endif
72 
73 #define ERROR_APIC_VECTOR		0xfe
74 #define RESCHEDULE_VECTOR		0xfd
75 #define CALL_FUNCTION_VECTOR		0xfc
76 #define CALL_FUNCTION_SINGLE_VECTOR	0xfb
77 #define THERMAL_APIC_VECTOR		0xfa
78 #define THRESHOLD_APIC_VECTOR		0xf9
79 #define REBOOT_VECTOR			0xf8
80 
81 /*
82  * Generic system vector for platform specific use
83  */
84 #define X86_PLATFORM_IPI_VECTOR		0xf7
85 
86 #define POSTED_INTR_WAKEUP_VECTOR	0xf1
87 /*
88  * IRQ work vector:
89  */
90 #define IRQ_WORK_VECTOR			0xf6
91 
92 #define UV_BAU_MESSAGE			0xf5
93 #define DEFERRED_ERROR_VECTOR		0xf4
94 
95 /* Vector on which hypervisor callbacks will be delivered */
96 #define HYPERVISOR_CALLBACK_VECTOR	0xf3
97 
98 /* Vector for KVM to deliver posted interrupt IPI */
99 #ifdef CONFIG_HAVE_KVM
100 #define POSTED_INTR_VECTOR		0xf2
101 #endif
102 
103 /*
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.
107  */
108 #define LOCAL_TIMER_VECTOR		0xef
109 
110 #define NR_VECTORS			 256
111 
112 #ifdef CONFIG_X86_LOCAL_APIC
113 #define FIRST_SYSTEM_VECTOR		LOCAL_TIMER_VECTOR
114 #else
115 #define FIRST_SYSTEM_VECTOR		NR_VECTORS
116 #endif
117 
118 #define FPU_IRQ				  13
119 
120 #define	FIRST_VM86_IRQ			   3
121 #define LAST_VM86_IRQ			  15
122 
123 #ifndef __ASSEMBLY__
124 static inline int invalid_vm86_irq(int irq)
125 {
126 	return irq < FIRST_VM86_IRQ || irq > LAST_VM86_IRQ;
127 }
128 #endif
129 
130 /*
131  * Size the maximum number of interrupts.
132  *
133  * If the irq_desc[] array has a sparse layout, we can size things
134  * generously - it scales up linearly with the maximum number of CPUs,
135  * and the maximum number of IO-APICs, whichever is higher.
136  *
137  * In other cases we size more conservatively, to not create too large
138  * static arrays.
139  */
140 
141 #define NR_IRQS_LEGACY			16
142 
143 #define CPU_VECTOR_LIMIT		(64 * NR_CPUS)
144 #define IO_APIC_VECTOR_LIMIT		(32 * MAX_IO_APICS)
145 
146 #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_PCI_MSI)
147 #define NR_IRQS						\
148 	(CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ?	\
149 		(NR_VECTORS + CPU_VECTOR_LIMIT)  :	\
150 		(NR_VECTORS + IO_APIC_VECTOR_LIMIT))
151 #elif defined(CONFIG_X86_IO_APIC)
152 #define	NR_IRQS				(NR_VECTORS + IO_APIC_VECTOR_LIMIT)
153 #elif defined(CONFIG_PCI_MSI)
154 #define NR_IRQS				(NR_VECTORS + CPU_VECTOR_LIMIT)
155 #else
156 #define NR_IRQS				NR_IRQS_LEGACY
157 #endif
158 
159 #endif /* _ASM_X86_IRQ_VECTORS_H */
160