arch/x86/include/asm/irq_vectors.h

   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 ... INVALIDATE_TLB_VECTOR_START-1 except 204 : device interrupts
  22  *  Vectors INVALIDATE_TLB_VECTOR_START ... 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 #define NMI_VECTOR                      0x02
  30 #define MCE_VECTOR                      0x12
  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  * We start allocating at 0x21 to spread out vectors evenly between
  39  * priority levels. (0x80 is the syscall vector)
  40  */
  41 #define VECTOR_OFFSET_START             1
  42
  43 /*
  44  * Reserve the lowest usable vector (and hence lowest priority)  0x20 for
  45  * triggering cleanup after irq migration. 0x21-0x2f will still be used
  46  * for device interrupts.
  47  */
  48 #define IRQ_MOVE_CLEANUP_VECTOR         FIRST_EXTERNAL_VECTOR
  49
  50 #define IA32_SYSCALL_VECTOR             0x80
  51
  52 /*
  53  * Vectors 0x30-0x3f are used for ISA interrupts.
  54  *   round up to the next 16-vector boundary
  55  */
  56 #define ISA_IRQ_VECTOR(irq)             (((FIRST_EXTERNAL_VECTOR + 16) & ~15) + irq)
  57
  58 /*
  59  * Special IRQ vectors used by the SMP architecture, 0xf0-0xff
  60  *
  61  *  some of the following vectors are 'rare', they are merged
  62  *  into a single vector (CALL_FUNCTION_VECTOR) to save vector space.
  63  *  TLB, reschedule and local APIC vectors are performance-critical.
  64  */
  65
  66 #define SPURIOUS_APIC_VECTOR            0xff
  67 /*
  68  * Sanity check
  69  */
  70 #if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F)
  71 # error SPURIOUS_APIC_VECTOR definition error
  72 #endif
  73
  74 #define ERROR_APIC_VECTOR               0xfe
  75 #define RESCHEDULE_VECTOR               0xfd
  76 #define CALL_FUNCTION_VECTOR            0xfc
  77 #define CALL_FUNCTION_SINGLE_VECTOR     0xfb
  78 #define THERMAL_APIC_VECTOR             0xfa
  79 #define THRESHOLD_APIC_VECTOR           0xf9
  80 #define REBOOT_VECTOR                   0xf8
  81
  82 /*
  83  * Generic system vector for platform specific use
  84  */
  85 #define X86_PLATFORM_IPI_VECTOR         0xf7
  86
  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 #define POSTED_INTR_WAKEUP_VECTOR       0xf1
 102 #define POSTED_INTR_NESTED_VECTOR       0xf0
 103 #endif
 104
 105 /*
 106  * Local APIC timer IRQ vector is on a different priority level,
 107  * to work around the 'lost local interrupt if more than 2 IRQ
 108  * sources per level' errata.
 109  */
 110 #define LOCAL_TIMER_VECTOR              0xef
 111
 112 #define NR_VECTORS                       256
 113
 114 #ifdef CONFIG_X86_LOCAL_APIC
 115 #define FIRST_SYSTEM_VECTOR             LOCAL_TIMER_VECTOR
 116 #else
 117 #define FIRST_SYSTEM_VECTOR             NR_VECTORS
 118 #endif
 119
 120 #define FPU_IRQ                           13
 121
 122 /*
 123  * Size the maximum number of interrupts.
 124  *
 125  * If the irq_desc[] array has a sparse layout, we can size things
 126  * generously - it scales up linearly with the maximum number of CPUs,
 127  * and the maximum number of IO-APICs, whichever is higher.
 128  *
 129  * In other cases we size more conservatively, to not create too large
 130  * static arrays.
 131  */
 132
 133 #define NR_IRQS_LEGACY                  16
 134
 135 #define CPU_VECTOR_LIMIT                (64 * NR_CPUS)
 136 #define IO_APIC_VECTOR_LIMIT            (32 * MAX_IO_APICS)
 137
 138 #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_PCI_MSI)
 139 #define NR_IRQS                                         \
 140         (CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ?      \
 141                 (NR_VECTORS + CPU_VECTOR_LIMIT)  :      \
 142                 (NR_VECTORS + IO_APIC_VECTOR_LIMIT))
 143 #elif defined(CONFIG_X86_IO_APIC)
 144 #define NR_IRQS                         (NR_VECTORS + IO_APIC_VECTOR_LIMIT)
 145 #elif defined(CONFIG_PCI_MSI)
 146 #define NR_IRQS                         (NR_VECTORS + CPU_VECTOR_LIMIT)
 147 #else
 148 #define NR_IRQS                         NR_IRQS_LEGACY
 149 #endif
 150
 151 #endif /* _ASM_X86_IRQ_VECTORS_H */