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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
12struct 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 */
59static const __initconst 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 */
73static const __initconst 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
96#ifdef CONFIG_X86_MCE
97 INTG(X86_TRAP_MC, &machine_check),
98#endif
99
100 SYSG(X86_TRAP_OF, overflow),
101#if defined(CONFIG_IA32_EMULATION)
102 SYSG(IA32_SYSCALL_VECTOR, entry_INT80_compat),
103#elif defined(CONFIG_X86_32)
104 SYSG(IA32_SYSCALL_VECTOR, entry_INT80_32),
105#endif
106};
107
108/*
109 * The APIC and SMP idt entries
110 */
111static const __initconst struct idt_data apic_idts[] = {
112#ifdef CONFIG_SMP
113 INTG(RESCHEDULE_VECTOR, reschedule_interrupt),
114 INTG(CALL_FUNCTION_VECTOR, call_function_interrupt),
115 INTG(CALL_FUNCTION_SINGLE_VECTOR, call_function_single_interrupt),
116 INTG(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt),
117 INTG(REBOOT_VECTOR, reboot_interrupt),
118#endif
119
120#ifdef CONFIG_X86_THERMAL_VECTOR
121 INTG(THERMAL_APIC_VECTOR, thermal_interrupt),
122#endif
123
124#ifdef CONFIG_X86_MCE_THRESHOLD
125 INTG(THRESHOLD_APIC_VECTOR, threshold_interrupt),
126#endif
127
128#ifdef CONFIG_X86_MCE_AMD
129 INTG(DEFERRED_ERROR_VECTOR, deferred_error_interrupt),
130#endif
131
132#ifdef CONFIG_X86_LOCAL_APIC
133 INTG(LOCAL_TIMER_VECTOR, apic_timer_interrupt),
134 INTG(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi),
135# ifdef CONFIG_HAVE_KVM
136 INTG(POSTED_INTR_VECTOR, kvm_posted_intr_ipi),
137 INTG(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi),
138 INTG(POSTED_INTR_NESTED_VECTOR, kvm_posted_intr_nested_ipi),
139# endif
140# ifdef CONFIG_IRQ_WORK
141 INTG(IRQ_WORK_VECTOR, irq_work_interrupt),
142# endif
143#ifdef CONFIG_X86_UV
144 INTG(UV_BAU_MESSAGE, uv_bau_message_intr1),
145#endif
146 INTG(SPURIOUS_APIC_VECTOR, spurious_interrupt),
147 INTG(ERROR_APIC_VECTOR, error_interrupt),
148#endif
149};
150
151#ifdef CONFIG_X86_64
152/*
153 * Early traps running on the DEFAULT_STACK because the other interrupt
154 * stacks work only after cpu_init().
155 */
156static const __initconst struct idt_data early_pf_idts[] = {
157 INTG(X86_TRAP_PF, page_fault),
158};
159
160/*
161 * Override for the debug_idt. Same as the default, but with interrupt
162 * stack set to DEFAULT_STACK (0). Required for NMI trap handling.
163 */
164static const __initconst struct idt_data dbg_idts[] = {
165 INTG(X86_TRAP_DB, debug),
166};
167#endif
168
169/* Must be page-aligned because the real IDT is used in a fixmap. */
170gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
171
172struct 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. */
179gate_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 */
185static const __initconst struct idt_data ist_idts[] = {
186 ISTG(X86_TRAP_DB, debug, DEBUG_STACK),
187 ISTG(X86_TRAP_NMI, nmi, NMI_STACK),
188 ISTG(X86_TRAP_DF, double_fault, DOUBLEFAULT_STACK),
189#ifdef CONFIG_X86_MCE
190 ISTG(X86_TRAP_MC, &machine_check, MCE_STACK),
191#endif
192};
193
194/*
195 * Override for the debug_idt. Same as the default, but with interrupt
196 * stack set to DEFAULT_STACK (0). Required for NMI trap handling.
197 */
198const struct desc_ptr debug_idt_descr = {
199 .size = IDT_ENTRIES * 16 - 1,
200 .address = (unsigned long) debug_idt_table,
201};
202#endif
203
204static inline void idt_init_desc(gate_desc *gate, const struct idt_data *d)
205{
206 unsigned long addr = (unsigned long) d->addr;
207
208 gate->offset_low = (u16) addr;
209 gate->segment = (u16) d->segment;
210 gate->bits = d->bits;
211 gate->offset_middle = (u16) (addr >> 16);
212#ifdef CONFIG_X86_64
213 gate->offset_high = (u32) (addr >> 32);
214 gate->reserved = 0;
215#endif
216}
217
218static void
219idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size, bool sys)
220{
221 gate_desc desc;
222
223 for (; size > 0; t++, size--) {
224 idt_init_desc(&desc, t);
225 write_idt_entry(idt, t->vector, &desc);
226 if (sys)
227 set_bit(t->vector, system_vectors);
228 }
229}
230
231static void set_intr_gate(unsigned int n, const void *addr)
232{
233 struct idt_data data;
234
235 BUG_ON(n > 0xFF);
236
237 memset(&data, 0, sizeof(data));
238 data.vector = n;
239 data.addr = addr;
240 data.segment = __KERNEL_CS;
241 data.bits.type = GATE_INTERRUPT;
242 data.bits.p = 1;
243
244 idt_setup_from_table(idt_table, &data, 1, false);
245}
246
247/**
248 * idt_setup_early_traps - Initialize the idt table with early traps
249 *
250 * On X8664 these traps do not use interrupt stacks as they can't work
251 * before cpu_init() is invoked and sets up TSS. The IST variants are
252 * installed after that.
253 */
254void __init idt_setup_early_traps(void)
255{
256 idt_setup_from_table(idt_table, early_idts, ARRAY_SIZE(early_idts),
257 true);
258 load_idt(&idt_descr);
259}
260
261/**
262 * idt_setup_traps - Initialize the idt table with default traps
263 */
264void __init idt_setup_traps(void)
265{
266 idt_setup_from_table(idt_table, def_idts, ARRAY_SIZE(def_idts), true);
267}
268
269#ifdef CONFIG_X86_64
270/**
271 * idt_setup_early_pf - Initialize the idt table with early pagefault handler
272 *
273 * On X8664 this does not use interrupt stacks as they can't work before
274 * cpu_init() is invoked and sets up TSS. The IST variant is installed
275 * after that.
276 *
277 * FIXME: Why is 32bit and 64bit installing the PF handler at different
278 * places in the early setup code?
279 */
280void __init idt_setup_early_pf(void)
281{
282 idt_setup_from_table(idt_table, early_pf_idts,
283 ARRAY_SIZE(early_pf_idts), true);
284}
285
286/**
287 * idt_setup_ist_traps - Initialize the idt table with traps using IST
288 */
289void __init idt_setup_ist_traps(void)
290{
291 idt_setup_from_table(idt_table, ist_idts, ARRAY_SIZE(ist_idts), true);
292}
293
294/**
295 * idt_setup_debugidt_traps - Initialize the debug idt table with debug traps
296 */
297void __init idt_setup_debugidt_traps(void)
298{
299 memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
300
301 idt_setup_from_table(debug_idt_table, dbg_idts, ARRAY_SIZE(dbg_idts), false);
302}
303#endif
304
305/**
306 * idt_setup_apic_and_irq_gates - Setup APIC/SMP and normal interrupt gates
307 */
308void __init idt_setup_apic_and_irq_gates(void)
309{
310 int i = FIRST_EXTERNAL_VECTOR;
311 void *entry;
312
313 idt_setup_from_table(idt_table, apic_idts, ARRAY_SIZE(apic_idts), true);
314
315 for_each_clear_bit_from(i, system_vectors, FIRST_SYSTEM_VECTOR) {
316 entry = irq_entries_start + 8 * (i - FIRST_EXTERNAL_VECTOR);
317 set_intr_gate(i, entry);
318 }
319
320 for_each_clear_bit_from(i, system_vectors, NR_VECTORS) {
321#ifdef CONFIG_X86_LOCAL_APIC
322 set_bit(i, system_vectors);
323 set_intr_gate(i, spurious_interrupt);
324#else
325 entry = irq_entries_start + 8 * (i - FIRST_EXTERNAL_VECTOR);
326 set_intr_gate(i, entry);
327#endif
328 }
329}
330
331/**
332 * idt_setup_early_handler - Initializes the idt table with early handlers
333 */
334void __init idt_setup_early_handler(void)
335{
336 int i;
337
338 for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
339 set_intr_gate(i, early_idt_handler_array[i]);
340#ifdef CONFIG_X86_32
341 for ( ; i < NR_VECTORS; i++)
342 set_intr_gate(i, early_ignore_irq);
343#endif
344 load_idt(&idt_descr);
345}
346
347/**
348 * idt_invalidate - Invalidate interrupt descriptor table
349 * @addr: The virtual address of the 'invalid' IDT
350 */
351void idt_invalidate(void *addr)
352{
353 struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 };
354
355 load_idt(&idt);
356}
357
358void __init update_intr_gate(unsigned int n, const void *addr)
359{
360 if (WARN_ON_ONCE(!test_bit(n, system_vectors)))
361 return;
362 set_intr_gate(n, addr);
363}
364
365void alloc_intr_gate(unsigned int n, const void *addr)
366{
367 BUG_ON(n < FIRST_SYSTEM_VECTOR);
368 if (!test_and_set_bit(n, system_vectors))
369 set_intr_gate(n, addr);
370}