xref: /openbmc/linux/arch/x86/include/asm/irq_vectors.h (revision 78c99ba1)
1 #ifndef _ASM_X86_IRQ_VECTORS_H
2 #define _ASM_X86_IRQ_VECTORS_H
3 
4 /*
5  * Linux IRQ vector layout.
6  *
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.
11  *
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
14  * IDT entries:
15  *
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
21  *
22  * 64-bit x86 has per CPU IDT tables, 32-bit has one shared IDT table.
23  *
24  * This file enumerates the exact layout of them:
25  */
26 
27 #define NMI_VECTOR			0x02
28 
29 /*
30  * IDT vectors usable for external interrupt sources start
31  * at 0x20:
32  */
33 #define FIRST_EXTERNAL_VECTOR		0x20
34 
35 #ifdef CONFIG_X86_32
36 # define SYSCALL_VECTOR			0x80
37 # define IA32_SYSCALL_VECTOR		0x80
38 #else
39 # define IA32_SYSCALL_VECTOR		0x80
40 #endif
41 
42 /*
43  * Reserve the lowest usable priority level 0x20 - 0x2f for triggering
44  * cleanup after irq migration.
45  */
46 #define IRQ_MOVE_CLEANUP_VECTOR		FIRST_EXTERNAL_VECTOR
47 
48 /*
49  * Vectors 0x30-0x3f are used for ISA interrupts.
50  */
51 #define IRQ0_VECTOR			(FIRST_EXTERNAL_VECTOR + 0x10)
52 
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)
68 
69 /*
70  * Special IRQ vectors used by the SMP architecture, 0xf0-0xff
71  *
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.
75  */
76 
77 #define SPURIOUS_APIC_VECTOR		0xff
78 /*
79  * Sanity check
80  */
81 #if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F)
82 # error SPURIOUS_APIC_VECTOR definition error
83 #endif
84 
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
90 
91 #ifdef CONFIG_X86_32
92 /* 0xf8 - 0xf9 : free */
93 #else
94 # define THRESHOLD_APIC_VECTOR		0xf9
95 # define UV_BAU_MESSAGE			0xf8
96 #endif
97 
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
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 /*
111  * Generic system vector for platform specific use
112  */
113 #define GENERIC_INTERRUPT_VECTOR	0xed
114 
115 /*
116  * Performance monitoring pending work vector:
117  */
118 #define LOCAL_PENDING_VECTOR		0xec
119 
120 /*
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)
124  */
125 #define FIRST_DEVICE_VECTOR		(IRQ15_VECTOR + 2)
126 
127 #define NR_VECTORS			 256
128 
129 #define FPU_IRQ				  13
130 
131 #define	FIRST_VM86_IRQ			   3
132 #define LAST_VM86_IRQ			  15
133 
134 #ifndef __ASSEMBLY__
135 static inline int invalid_vm86_irq(int irq)
136 {
137 	return irq < FIRST_VM86_IRQ || irq > LAST_VM86_IRQ;
138 }
139 #endif
140 
141 /*
142  * Size the maximum number of interrupts.
143  *
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.
147  *
148  * In other cases we size more conservatively, to not create too large
149  * static arrays.
150  */
151 
152 #define NR_IRQS_LEGACY			  16
153 
154 #define CPU_VECTOR_LIMIT		(  8 * NR_CPUS      )
155 #define IO_APIC_VECTOR_LIMIT		( 32 * MAX_IO_APICS )
156 
157 #ifdef CONFIG_X86_IO_APIC
158 # ifdef CONFIG_SPARSE_IRQ
159 #  define NR_IRQS					\
160 	(CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ?	\
161 		(NR_VECTORS + CPU_VECTOR_LIMIT)  :	\
162 		(NR_VECTORS + IO_APIC_VECTOR_LIMIT))
163 # else
164 #  if NR_CPUS < MAX_IO_APICS
165 #   define NR_IRQS 			(NR_VECTORS + 4*CPU_VECTOR_LIMIT)
166 #  else
167 #   define NR_IRQS			(NR_VECTORS + IO_APIC_VECTOR_LIMIT)
168 #  endif
169 # endif
170 #else /* !CONFIG_X86_IO_APIC: */
171 # define NR_IRQS			NR_IRQS_LEGACY
172 #endif
173 
174 #endif /* _ASM_X86_IRQ_VECTORS_H */
175