// SPDX-License-Identifier: GPL-2.0-only /* * Interrupt descriptor table related code */ #include #include #include #include #include struct idt_data { unsigned int vector; unsigned int segment; struct idt_bits bits; const void *addr; }; #define DPL0 0x0 #define DPL3 0x3 #define DEFAULT_STACK 0 #define G(_vector, _addr, _ist, _type, _dpl, _segment) \ { \ .vector = _vector, \ .bits.ist = _ist, \ .bits.type = _type, \ .bits.dpl = _dpl, \ .bits.p = 1, \ .addr = _addr, \ .segment = _segment, \ } /* Interrupt gate */ #define INTG(_vector, _addr) \ G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL0, __KERNEL_CS) /* System interrupt gate */ #define SYSG(_vector, _addr) \ G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL3, __KERNEL_CS) /* * Interrupt gate with interrupt stack. The _ist index is the index in * the tss.ist[] array, but for the descriptor it needs to start at 1. */ #define ISTG(_vector, _addr, _ist) \ G(_vector, _addr, _ist + 1, GATE_INTERRUPT, DPL0, __KERNEL_CS) /* Task gate */ #define TSKG(_vector, _gdt) \ G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3) static bool idt_setup_done __initdata; /* * Early traps running on the DEFAULT_STACK because the other interrupt * stacks work only after cpu_init(). */ static const __initconst struct idt_data early_idts[] = { INTG(X86_TRAP_DB, debug), SYSG(X86_TRAP_BP, int3), #ifdef CONFIG_X86_32 INTG(X86_TRAP_PF, page_fault), #endif }; /* * The default IDT entries which are set up in trap_init() before * cpu_init() is invoked. Interrupt stacks cannot be used at that point and * the traps which use them are reinitialized with IST after cpu_init() has * set up TSS. */ static const __initconst struct idt_data def_idts[] = { INTG(X86_TRAP_DE, asm_exc_divide_error), INTG(X86_TRAP_NMI, nmi), INTG(X86_TRAP_BR, asm_exc_bounds), INTG(X86_TRAP_UD, asm_exc_invalid_op), INTG(X86_TRAP_NM, asm_exc_device_not_available), INTG(X86_TRAP_OLD_MF, asm_exc_coproc_segment_overrun), INTG(X86_TRAP_TS, asm_exc_invalid_tss), INTG(X86_TRAP_NP, asm_exc_segment_not_present), INTG(X86_TRAP_SS, asm_exc_stack_segment), INTG(X86_TRAP_GP, general_protection), INTG(X86_TRAP_SPURIOUS, spurious_interrupt_bug), INTG(X86_TRAP_MF, coprocessor_error), INTG(X86_TRAP_AC, alignment_check), INTG(X86_TRAP_XF, simd_coprocessor_error), #ifdef CONFIG_X86_32 TSKG(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS), #else INTG(X86_TRAP_DF, double_fault), #endif INTG(X86_TRAP_DB, debug), #ifdef CONFIG_X86_MCE INTG(X86_TRAP_MC, machine_check), #endif SYSG(X86_TRAP_OF, asm_exc_overflow), #if defined(CONFIG_IA32_EMULATION) SYSG(IA32_SYSCALL_VECTOR, entry_INT80_compat), #elif defined(CONFIG_X86_32) SYSG(IA32_SYSCALL_VECTOR, entry_INT80_32), #endif }; /* * The APIC and SMP idt entries */ static const __initconst struct idt_data apic_idts[] = { #ifdef CONFIG_SMP INTG(RESCHEDULE_VECTOR, reschedule_interrupt), INTG(CALL_FUNCTION_VECTOR, call_function_interrupt), INTG(CALL_FUNCTION_SINGLE_VECTOR, call_function_single_interrupt), INTG(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt), INTG(REBOOT_VECTOR, reboot_interrupt), #endif #ifdef CONFIG_X86_THERMAL_VECTOR INTG(THERMAL_APIC_VECTOR, thermal_interrupt), #endif #ifdef CONFIG_X86_MCE_THRESHOLD INTG(THRESHOLD_APIC_VECTOR, threshold_interrupt), #endif #ifdef CONFIG_X86_MCE_AMD INTG(DEFERRED_ERROR_VECTOR, deferred_error_interrupt), #endif #ifdef CONFIG_X86_LOCAL_APIC INTG(LOCAL_TIMER_VECTOR, apic_timer_interrupt), INTG(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi), # ifdef CONFIG_HAVE_KVM INTG(POSTED_INTR_VECTOR, kvm_posted_intr_ipi), INTG(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi), INTG(POSTED_INTR_NESTED_VECTOR, kvm_posted_intr_nested_ipi), # endif # ifdef CONFIG_IRQ_WORK INTG(IRQ_WORK_VECTOR, irq_work_interrupt), # endif #ifdef CONFIG_X86_UV INTG(UV_BAU_MESSAGE, uv_bau_message_intr1), #endif INTG(SPURIOUS_APIC_VECTOR, spurious_interrupt), INTG(ERROR_APIC_VECTOR, error_interrupt), #endif }; #ifdef CONFIG_X86_64 /* * Early traps running on the DEFAULT_STACK because the other interrupt * stacks work only after cpu_init(). */ static const __initconst struct idt_data early_pf_idts[] = { INTG(X86_TRAP_PF, page_fault), }; /* * Override for the debug_idt. Same as the default, but with interrupt * stack set to DEFAULT_STACK (0). Required for NMI trap handling. */ static const __initconst struct idt_data dbg_idts[] = { INTG(X86_TRAP_DB, debug), }; #endif /* Must be page-aligned because the real IDT is used in a fixmap. */ gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss; struct desc_ptr idt_descr __ro_after_init = { .size = (IDT_ENTRIES * 2 * sizeof(unsigned long)) - 1, .address = (unsigned long) idt_table, }; #ifdef CONFIG_X86_64 /* No need to be aligned, but done to keep all IDTs defined the same way. */ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss; /* * The exceptions which use Interrupt stacks. They are setup after * cpu_init() when the TSS has been initialized. */ static const __initconst struct idt_data ist_idts[] = { ISTG(X86_TRAP_DB, debug, IST_INDEX_DB), ISTG(X86_TRAP_NMI, nmi, IST_INDEX_NMI), ISTG(X86_TRAP_DF, double_fault, IST_INDEX_DF), #ifdef CONFIG_X86_MCE ISTG(X86_TRAP_MC, machine_check, IST_INDEX_MCE), #endif }; /* * Override for the debug_idt. Same as the default, but with interrupt * stack set to DEFAULT_STACK (0). Required for NMI trap handling. */ const struct desc_ptr debug_idt_descr = { .size = IDT_ENTRIES * 16 - 1, .address = (unsigned long) debug_idt_table, }; #endif static inline void idt_init_desc(gate_desc *gate, const struct idt_data *d) { unsigned long addr = (unsigned long) d->addr; gate->offset_low = (u16) addr; gate->segment = (u16) d->segment; gate->bits = d->bits; gate->offset_middle = (u16) (addr >> 16); #ifdef CONFIG_X86_64 gate->offset_high = (u32) (addr >> 32); gate->reserved = 0; #endif } static void idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size, bool sys) { gate_desc desc; for (; size > 0; t++, size--) { idt_init_desc(&desc, t); write_idt_entry(idt, t->vector, &desc); if (sys) set_bit(t->vector, system_vectors); } } static void set_intr_gate(unsigned int n, const void *addr) { struct idt_data data; BUG_ON(n > 0xFF); memset(&data, 0, sizeof(data)); data.vector = n; data.addr = addr; data.segment = __KERNEL_CS; data.bits.type = GATE_INTERRUPT; data.bits.p = 1; idt_setup_from_table(idt_table, &data, 1, false); } /** * idt_setup_early_traps - Initialize the idt table with early traps * * On X8664 these traps do not use interrupt stacks as they can't work * before cpu_init() is invoked and sets up TSS. The IST variants are * installed after that. */ void __init idt_setup_early_traps(void) { idt_setup_from_table(idt_table, early_idts, ARRAY_SIZE(early_idts), true); load_idt(&idt_descr); } /** * idt_setup_traps - Initialize the idt table with default traps */ void __init idt_setup_traps(void) { idt_setup_from_table(idt_table, def_idts, ARRAY_SIZE(def_idts), true); } #ifdef CONFIG_X86_64 /** * idt_setup_early_pf - Initialize the idt table with early pagefault handler * * On X8664 this does not use interrupt stacks as they can't work before * cpu_init() is invoked and sets up TSS. The IST variant is installed * after that. * * FIXME: Why is 32bit and 64bit installing the PF handler at different * places in the early setup code? */ void __init idt_setup_early_pf(void) { idt_setup_from_table(idt_table, early_pf_idts, ARRAY_SIZE(early_pf_idts), true); } /** * idt_setup_ist_traps - Initialize the idt table with traps using IST */ void __init idt_setup_ist_traps(void) { idt_setup_from_table(idt_table, ist_idts, ARRAY_SIZE(ist_idts), true); } /** * idt_setup_debugidt_traps - Initialize the debug idt table with debug traps */ void __init idt_setup_debugidt_traps(void) { memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16); idt_setup_from_table(debug_idt_table, dbg_idts, ARRAY_SIZE(dbg_idts), false); } #endif /** * idt_setup_apic_and_irq_gates - Setup APIC/SMP and normal interrupt gates */ void __init idt_setup_apic_and_irq_gates(void) { int i = FIRST_EXTERNAL_VECTOR; void *entry; idt_setup_from_table(idt_table, apic_idts, ARRAY_SIZE(apic_idts), true); for_each_clear_bit_from(i, system_vectors, FIRST_SYSTEM_VECTOR) { entry = irq_entries_start + 8 * (i - FIRST_EXTERNAL_VECTOR); set_intr_gate(i, entry); } #ifdef CONFIG_X86_LOCAL_APIC for_each_clear_bit_from(i, system_vectors, NR_VECTORS) { /* * Don't set the non assigned system vectors in the * system_vectors bitmap. Otherwise they show up in * /proc/interrupts. */ entry = spurious_entries_start + 8 * (i - FIRST_SYSTEM_VECTOR); set_intr_gate(i, entry); } #endif idt_setup_done = true; } /** * idt_setup_early_handler - Initializes the idt table with early handlers */ void __init idt_setup_early_handler(void) { int i; for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) set_intr_gate(i, early_idt_handler_array[i]); #ifdef CONFIG_X86_32 for ( ; i < NR_VECTORS; i++) set_intr_gate(i, early_ignore_irq); #endif load_idt(&idt_descr); } /** * idt_invalidate - Invalidate interrupt descriptor table * @addr: The virtual address of the 'invalid' IDT */ void idt_invalidate(void *addr) { struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 }; load_idt(&idt); } void __init alloc_intr_gate(unsigned int n, const void *addr) { if (WARN_ON(n < FIRST_SYSTEM_VECTOR)) return; if (WARN_ON(idt_setup_done)) return; if (!WARN_ON(test_and_set_bit(n, system_vectors))) set_intr_gate(n, addr); }