swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: ae83d0b416db002fe95601e7f97f64b59514d936 authored by Linus Torvalds on 19 April 2020, 21:35:30 UTC
Linux 5.7-rc2
Linux 5.7-rc2
Tip revision: ae83d0b
idt.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Interrupt descriptor table related code
*/
#include <linux/interrupt.h>
#include <asm/traps.h>
#include <asm/proto.h>
#include <asm/desc.h>
#include <asm/hw_irq.h>
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)
/*
* 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, divide_error),
INTG(X86_TRAP_NMI, nmi),
INTG(X86_TRAP_BR, bounds),
INTG(X86_TRAP_UD, invalid_op),
INTG(X86_TRAP_NM, device_not_available),
INTG(X86_TRAP_OLD_MF, coprocessor_segment_overrun),
INTG(X86_TRAP_TS, invalid_TSS),
INTG(X86_TRAP_NP, segment_not_present),
INTG(X86_TRAP_SS, 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, 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) {
set_bit(i, system_vectors);
entry = spurious_entries_start + 8 * (i - FIRST_SYSTEM_VECTOR);
set_intr_gate(i, entry);
}
#endif
}
/**
* 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 update_intr_gate(unsigned int n, const void *addr)
{
if (WARN_ON_ONCE(!test_bit(n, system_vectors)))
return;
set_intr_gate(n, addr);
}
void alloc_intr_gate(unsigned int n, const void *addr)
{
BUG_ON(n < FIRST_SYSTEM_VECTOR);
if (!test_and_set_bit(n, system_vectors))
set_intr_gate(n, addr);
}