arch/x86/include/asm/irq_vectors.h

   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 #ifdef CONFIG_X86_32
  51 # define SYSCALL_VECTOR                 0x80
  52 #endif
  53
  54 /*
  55  * Vectors 0x30-0x3f are used for ISA interrupts.
  56  *   round up to the next 16-vector boundary
  57  */
  58 #define IRQ0_VECTOR                     ((FIRST_EXTERNAL_VECTOR + 16) & ~15)
  59
  60 #define IRQ1_VECTOR                     (IRQ0_VECTOR +  1)
  61 #define IRQ2_VECTOR                     (IRQ0_VECTOR +  2)
  62 #define IRQ3_VECTOR                     (IRQ0_VECTOR +  3)
  63 #define IRQ4_VECTOR                     (IRQ0_VECTOR +  4)
  64 #define IRQ5_VECTOR                     (IRQ0_VECTOR +  5)
  65 #define IRQ6_VECTOR                     (IRQ0_VECTOR +  6)
  66 #define IRQ7_VECTOR                     (IRQ0_VECTOR +  7)
  67 #define IRQ8_VECTOR                     (IRQ0_VECTOR +  8)
  68 #define IRQ9_VECTOR                     (IRQ0_VECTOR +  9)
  69 #define IRQ10_VECTOR                    (IRQ0_VECTOR + 10)
  70 #define IRQ11_VECTOR                    (IRQ0_VECTOR + 11)
  71 #define IRQ12_VECTOR                    (IRQ0_VECTOR + 12)
  72 #define IRQ13_VECTOR                    (IRQ0_VECTOR + 13)
  73 #define IRQ14_VECTOR                    (IRQ0_VECTOR + 14)
  74 #define IRQ15_VECTOR                    (IRQ0_VECTOR + 15)
  75
  76 /*
  77  * Special IRQ vectors used by the SMP architecture, 0xf0-0xff
  78  *
  79  *  some of the following vectors are 'rare', they are merged
  80  *  into a single vector (CALL_FUNCTION_VECTOR) to save vector space.
  81  *  TLB, reschedule and local APIC vectors are performance-critical.
  82  */
  83
  84 #define SPURIOUS_APIC_VECTOR            0xff
  85 /*
  86  * Sanity check
  87  */
  88 #if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F)
  89 # error SPURIOUS_APIC_VECTOR definition error
  90 #endif
  91
  92 #define ERROR_APIC_VECTOR               0xfe
  93 #define RESCHEDULE_VECTOR               0xfd
  94 #define CALL_FUNCTION_VECTOR            0xfc
  95 #define CALL_FUNCTION_SINGLE_VECTOR     0xfb
  96 #define THERMAL_APIC_VECTOR             0xfa
  97 #define THRESHOLD_APIC_VECTOR           0xf9
  98 #define REBOOT_VECTOR                   0xf8
  99
 100 /*
 101  * Generic system vector for platform specific use
 102  */
 103 #define X86_PLATFORM_IPI_VECTOR         0xf7
 104
 105 /* Vector for KVM to deliver posted interrupt IPI */
 106 #ifdef CONFIG_HAVE_KVM
 107 #define POSTED_INTR_VECTOR              0xf2
 108 #endif
 109
 110 /*
 111  * IRQ work vector:
 112  */
 113 #define IRQ_WORK_VECTOR                 0xf6
 114
 115 #define UV_BAU_MESSAGE                  0xf5
 116
 117 /* Vector on which hypervisor callbacks will be delivered */
 118 #define HYPERVISOR_CALLBACK_VECTOR      0xf3
 119
 120 /*
 121  * Local APIC timer IRQ vector is on a different priority level,
 122  * to work around the 'lost local interrupt if more than 2 IRQ
 123  * sources per level' errata.
 124  */
 125 #define LOCAL_TIMER_VECTOR              0xef
 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 IO_APIC_VECTOR_LIMIT            ( 32 * MAX_IO_APICS )
 155
 156 #ifdef CONFIG_X86_IO_APIC
 157 # define CPU_VECTOR_LIMIT               (64 * NR_CPUS)
 158 # define NR_IRQS                                        \
 159         (CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ?      \
 160                 (NR_VECTORS + CPU_VECTOR_LIMIT)  :      \
 161                 (NR_VECTORS + IO_APIC_VECTOR_LIMIT))
 162 #else /* !CONFIG_X86_IO_APIC: */
 163 # define NR_IRQS                        NR_IRQS_LEGACY
 164 #endif
 165
 166 #endif /* _ASM_X86_IRQ_VECTORS_H */