arch/x86/kernel/idt.c

   1 /*
   2  * Interrupt descriptor table related code
   3  *
   4  * This file is licensed under the GPL V2
   5  */
   6 #include <linux/interrupt.h>
   7
   8 #include <asm/traps.h>
   9 #include <asm/proto.h>
  10 #include <asm/desc.h>
  11
  12 struct idt_data {
  13         unsigned int    vector;
  14         unsigned int    segment;
  15         struct idt_bits bits;
  16         const void      *addr;
  17 };
  18
  19 #define DPL0            0x0
  20 #define DPL3            0x3
  21
  22 #define DEFAULT_STACK   0
  23
  24 #define G(_vector, _addr, _ist, _type, _dpl, _segment)  \
  25         {                                               \
  26                 .vector         = _vector,              \
  27                 .bits.ist       = _ist,                 \
  28                 .bits.type      = _type,                \
  29                 .bits.dpl       = _dpl,                 \
  30                 .bits.p         = 1,                    \
  31                 .addr           = _addr,                \
  32                 .segment        = _segment,             \
  33         }
  34
  35 /* Interrupt gate */
  36 #define INTG(_vector, _addr)                            \
  37         G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL0, __KERNEL_CS)
  38
  39 /* System interrupt gate */
  40 #define SYSG(_vector, _addr)                            \
  41         G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL3, __KERNEL_CS)
  42
  43 /* Interrupt gate with interrupt stack */
  44 #define ISTG(_vector, _addr, _ist)                      \
  45         G(_vector, _addr, _ist, GATE_INTERRUPT, DPL0, __KERNEL_CS)
  46
  47 /* System interrupt gate with interrupt stack */
  48 #define SISTG(_vector, _addr, _ist)                     \
  49         G(_vector, _addr, _ist, GATE_INTERRUPT, DPL3, __KERNEL_CS)
  50
  51 /* Task gate */
  52 #define TSKG(_vector, _gdt)                             \
  53         G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)
  54
  55 /*
  56  * Early traps running on the DEFAULT_STACK because the other interrupt
  57  * stacks work only after cpu_init().
  58  */
  59 static const __initdata struct idt_data early_idts[] = {
  60         INTG(X86_TRAP_DB,               debug),
  61         SYSG(X86_TRAP_BP,               int3),
  62 #ifdef CONFIG_X86_32
  63         INTG(X86_TRAP_PF,               page_fault),
  64 #endif
  65 };
  66
  67 /*
  68  * The default IDT entries which are set up in trap_init() before
  69  * cpu_init() is invoked. Interrupt stacks cannot be used at that point and
  70  * the traps which use them are reinitialized with IST after cpu_init() has
  71  * set up TSS.
  72  */
  73 static const __initdata struct idt_data def_idts[] = {
  74         INTG(X86_TRAP_DE,               divide_error),
  75         INTG(X86_TRAP_NMI,              nmi),
  76         INTG(X86_TRAP_BR,               bounds),
  77         INTG(X86_TRAP_UD,               invalid_op),
  78         INTG(X86_TRAP_NM,               device_not_available),
  79         INTG(X86_TRAP_OLD_MF,           coprocessor_segment_overrun),
  80         INTG(X86_TRAP_TS,               invalid_TSS),
  81         INTG(X86_TRAP_NP,               segment_not_present),
  82         INTG(X86_TRAP_SS,               stack_segment),
  83         INTG(X86_TRAP_GP,               general_protection),
  84         INTG(X86_TRAP_SPURIOUS,         spurious_interrupt_bug),
  85         INTG(X86_TRAP_MF,               coprocessor_error),
  86         INTG(X86_TRAP_AC,               alignment_check),
  87         INTG(X86_TRAP_XF,               simd_coprocessor_error),
  88
  89 #ifdef CONFIG_X86_32
  90         TSKG(X86_TRAP_DF,               GDT_ENTRY_DOUBLEFAULT_TSS),
  91 #else
  92         INTG(X86_TRAP_DF,               double_fault),
  93 #endif
  94         INTG(X86_TRAP_DB,               debug),
  95         INTG(X86_TRAP_NMI,              nmi),
  96         INTG(X86_TRAP_BP,               int3),
  97
  98 #ifdef CONFIG_X86_MCE
  99         INTG(X86_TRAP_MC,               &machine_check),
 100 #endif
 101
 102         SYSG(X86_TRAP_OF,               overflow),
 103 #if defined(CONFIG_IA32_EMULATION)
 104         SYSG(IA32_SYSCALL_VECTOR,       entry_INT80_compat),
 105 #elif defined(CONFIG_X86_32)
 106         SYSG(IA32_SYSCALL_VECTOR,       entry_INT80_32),
 107 #endif
 108 };
 109
 110 /*
 111  * The APIC and SMP idt entries
 112  */
 113 static const __initdata struct idt_data apic_idts[] = {
 114 #ifdef CONFIG_SMP
 115         INTG(RESCHEDULE_VECTOR,         reschedule_interrupt),
 116         INTG(CALL_FUNCTION_VECTOR,      call_function_interrupt),
 117         INTG(CALL_FUNCTION_SINGLE_VECTOR, call_function_single_interrupt),
 118         INTG(IRQ_MOVE_CLEANUP_VECTOR,   irq_move_cleanup_interrupt),
 119         INTG(REBOOT_VECTOR,             reboot_interrupt),
 120 #endif
 121
 122 #ifdef CONFIG_X86_THERMAL_VECTOR
 123         INTG(THERMAL_APIC_VECTOR,       thermal_interrupt),
 124 #endif
 125
 126 #ifdef CONFIG_X86_MCE_THRESHOLD
 127         INTG(THRESHOLD_APIC_VECTOR,     threshold_interrupt),
 128 #endif
 129
 130 #ifdef CONFIG_X86_MCE_AMD
 131         INTG(DEFERRED_ERROR_VECTOR,     deferred_error_interrupt),
 132 #endif
 133
 134 #ifdef CONFIG_X86_LOCAL_APIC
 135         INTG(LOCAL_TIMER_VECTOR,        apic_timer_interrupt),
 136         INTG(X86_PLATFORM_IPI_VECTOR,   x86_platform_ipi),
 137 # ifdef CONFIG_HAVE_KVM
 138         INTG(POSTED_INTR_VECTOR,        kvm_posted_intr_ipi),
 139         INTG(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi),
 140         INTG(POSTED_INTR_NESTED_VECTOR, kvm_posted_intr_nested_ipi),
 141 # endif
 142 # ifdef CONFIG_IRQ_WORK
 143         INTG(IRQ_WORK_VECTOR,           irq_work_interrupt),
 144 # endif
 145         INTG(SPURIOUS_APIC_VECTOR,      spurious_interrupt),
 146         INTG(ERROR_APIC_VECTOR,         error_interrupt),
 147 #endif
 148 };
 149
 150 #ifdef CONFIG_X86_64
 151 /*
 152  * Early traps running on the DEFAULT_STACK because the other interrupt
 153  * stacks work only after cpu_init().
 154  */
 155 static const __initdata struct idt_data early_pf_idts[] = {
 156         INTG(X86_TRAP_PF,               page_fault),
 157 };
 158
 159 /*
 160  * Override for the debug_idt. Same as the default, but with interrupt
 161  * stack set to DEFAULT_STACK (0). Required for NMI trap handling.
 162  */
 163 static const __initdata struct idt_data dbg_idts[] = {
 164         INTG(X86_TRAP_DB,       debug),
 165         INTG(X86_TRAP_BP,       int3),
 166 };
 167 #endif
 168
 169 /* Must be page-aligned because the real IDT is used in a fixmap. */
 170 gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
 171
 172 struct desc_ptr idt_descr __ro_after_init = {
 173         .size           = (IDT_ENTRIES * 2 * sizeof(unsigned long)) - 1,
 174         .address        = (unsigned long) idt_table,
 175 };
 176
 177 #ifdef CONFIG_X86_64
 178 /* No need to be aligned, but done to keep all IDTs defined the same way. */
 179 gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;
 180
 181 /*
 182  * The exceptions which use Interrupt stacks. They are setup after
 183  * cpu_init() when the TSS has been initialized.
 184  */
 185 static const __initdata struct idt_data ist_idts[] = {
 186         ISTG(X86_TRAP_DB,       debug,          DEBUG_STACK),
 187         ISTG(X86_TRAP_NMI,      nmi,            NMI_STACK),
 188         SISTG(X86_TRAP_BP,      int3,           DEBUG_STACK),
 189         ISTG(X86_TRAP_DF,       double_fault,   DOUBLEFAULT_STACK),
 190 #ifdef CONFIG_X86_MCE
 191         ISTG(X86_TRAP_MC,       &machine_check, MCE_STACK),
 192 #endif
 193 };
 194
 195 /*
 196  * Override for the debug_idt. Same as the default, but with interrupt
 197  * stack set to DEFAULT_STACK (0). Required for NMI trap handling.
 198  */
 199 const struct desc_ptr debug_idt_descr = {
 200         .size           = IDT_ENTRIES * 16 - 1,
 201         .address        = (unsigned long) debug_idt_table,
 202 };
 203 #endif
 204
 205 static inline void idt_init_desc(gate_desc *gate, const struct idt_data *d)
 206 {
 207         unsigned long addr = (unsigned long) d->addr;
 208
 209         gate->offset_low        = (u16) addr;
 210         gate->segment           = (u16) d->segment;
 211         gate->bits              = d->bits;
 212         gate->offset_middle     = (u16) (addr >> 16);
 213 #ifdef CONFIG_X86_64
 214         gate->offset_high       = (u32) (addr >> 32);
 215         gate->reserved          = 0;
 216 #endif
 217 }
 218
 219 static void
 220 idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size, bool sys)
 221 {
 222         gate_desc desc;
 223
 224         for (; size > 0; t++, size--) {
 225                 idt_init_desc(&desc, t);
 226                 write_idt_entry(idt, t->vector, &desc);
 227                 if (sys)
 228                         set_bit(t->vector, used_vectors);
 229         }
 230 }
 231
 232 static void set_intr_gate(unsigned int n, const void *addr)
 233 {
 234         struct idt_data data;
 235
 236         BUG_ON(n > 0xFF);
 237
 238         memset(&data, 0, sizeof(data));
 239         data.vector     = n;
 240         data.addr       = addr;
 241         data.segment    = __KERNEL_CS;
 242         data.bits.type  = GATE_INTERRUPT;
 243         data.bits.p     = 1;
 244
 245         idt_setup_from_table(idt_table, &data, 1, false);
 246 }
 247
 248 /**
 249  * idt_setup_early_traps - Initialize the idt table with early traps
 250  *
 251  * On X8664 these traps do not use interrupt stacks as they can't work
 252  * before cpu_init() is invoked and sets up TSS. The IST variants are
 253  * installed after that.
 254  */
 255 void __init idt_setup_early_traps(void)
 256 {
 257         idt_setup_from_table(idt_table, early_idts, ARRAY_SIZE(early_idts),
 258                              true);
 259         load_idt(&idt_descr);
 260 }
 261
 262 /**
 263  * idt_setup_traps - Initialize the idt table with default traps
 264  */
 265 void __init idt_setup_traps(void)
 266 {
 267         idt_setup_from_table(idt_table, def_idts, ARRAY_SIZE(def_idts), true);
 268 }
 269
 270 #ifdef CONFIG_X86_64
 271 /**
 272  * idt_setup_early_pf - Initialize the idt table with early pagefault handler
 273  *
 274  * On X8664 this does not use interrupt stacks as they can't work before
 275  * cpu_init() is invoked and sets up TSS. The IST variant is installed
 276  * after that.
 277  *
 278  * FIXME: Why is 32bit and 64bit installing the PF handler at different
 279  * places in the early setup code?
 280  */
 281 void __init idt_setup_early_pf(void)
 282 {
 283         idt_setup_from_table(idt_table, early_pf_idts,
 284                              ARRAY_SIZE(early_pf_idts), true);
 285 }
 286
 287 /**
 288  * idt_setup_ist_traps - Initialize the idt table with traps using IST
 289  */
 290 void __init idt_setup_ist_traps(void)
 291 {
 292         idt_setup_from_table(idt_table, ist_idts, ARRAY_SIZE(ist_idts), true);
 293 }
 294
 295 /**
 296  * idt_setup_debugidt_traps - Initialize the debug idt table with debug traps
 297  */
 298 void __init idt_setup_debugidt_traps(void)
 299 {
 300         memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
 301
 302         idt_setup_from_table(debug_idt_table, dbg_idts, ARRAY_SIZE(dbg_idts), false);
 303 }
 304 #endif
 305
 306 /**
 307  * idt_setup_apic_and_irq_gates - Setup APIC/SMP and normal interrupt gates
 308  */
 309 void __init idt_setup_apic_and_irq_gates(void)
 310 {
 311         int i = FIRST_EXTERNAL_VECTOR;
 312         void *entry;
 313
 314         idt_setup_from_table(idt_table, apic_idts, ARRAY_SIZE(apic_idts), true);
 315
 316         for_each_clear_bit_from(i, used_vectors, FIRST_SYSTEM_VECTOR) {
 317                 entry = irq_entries_start + 8 * (i - FIRST_EXTERNAL_VECTOR);
 318                 set_intr_gate(i, entry);
 319         }
 320
 321         for_each_clear_bit_from(i, used_vectors, NR_VECTORS) {
 322 #ifdef CONFIG_X86_LOCAL_APIC
 323                 set_bit(i, used_vectors);
 324                 set_intr_gate(i, spurious_interrupt);
 325 #else
 326                 entry = irq_entries_start + 8 * (i - FIRST_EXTERNAL_VECTOR);
 327                 set_intr_gate(i, entry);
 328 #endif
 329         }
 330 }
 331
 332 /**
 333  * idt_setup_early_handler - Initializes the idt table with early handlers
 334  */
 335 void __init idt_setup_early_handler(void)
 336 {
 337         int i;
 338
 339         for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
 340                 set_intr_gate(i, early_idt_handler_array[i]);
 341 #ifdef CONFIG_X86_32
 342         for ( ; i < NR_VECTORS; i++)
 343                 set_intr_gate(i, early_ignore_irq);
 344 #endif
 345         load_idt(&idt_descr);
 346 }
 347
 348 /**
 349  * idt_invalidate - Invalidate interrupt descriptor table
 350  * @addr:       The virtual address of the 'invalid' IDT
 351  */
 352 void idt_invalidate(void *addr)
 353 {
 354         struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 };
 355
 356         load_idt(&idt);
 357 }
 358
 359 void __init update_intr_gate(unsigned int n, const void *addr)
 360 {
 361         if (WARN_ON_ONCE(!test_bit(n, used_vectors)))
 362                 return;
 363         set_intr_gate(n, addr);
 364 }
 365
 366 void alloc_intr_gate(unsigned int n, const void *addr)
 367 {
 368         BUG_ON(n < FIRST_SYSTEM_VECTOR);
 369         if (!test_and_set_bit(n, used_vectors))
 370                 set_intr_gate(n, addr);
 371 }