xref: /linux/arch/x86/kernel/idt.c (revision 636a7598f65938e1dbacafec74c2e3acdc66bd4d)
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 /* Task gate */
48 #define TSKG(_vector, _gdt)				\
49 	G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)
50 
51 /*
52  * Early traps running on the DEFAULT_STACK because the other interrupt
53  * stacks work only after cpu_init().
54  */
55 static const __initdata struct idt_data early_idts[] = {
56 	INTG(X86_TRAP_DB,		debug),
57 	SYSG(X86_TRAP_BP,		int3),
58 #ifdef CONFIG_X86_32
59 	INTG(X86_TRAP_PF,		page_fault),
60 #endif
61 };
62 
63 /*
64  * The default IDT entries which are set up in trap_init() before
65  * cpu_init() is invoked. Interrupt stacks cannot be used at that point and
66  * the traps which use them are reinitialized with IST after cpu_init() has
67  * set up TSS.
68  */
69 static const __initdata struct idt_data def_idts[] = {
70 	INTG(X86_TRAP_DE,		divide_error),
71 	INTG(X86_TRAP_NMI,		nmi),
72 	INTG(X86_TRAP_BR,		bounds),
73 	INTG(X86_TRAP_UD,		invalid_op),
74 	INTG(X86_TRAP_NM,		device_not_available),
75 	INTG(X86_TRAP_OLD_MF,		coprocessor_segment_overrun),
76 	INTG(X86_TRAP_TS,		invalid_TSS),
77 	INTG(X86_TRAP_NP,		segment_not_present),
78 	INTG(X86_TRAP_SS,		stack_segment),
79 	INTG(X86_TRAP_GP,		general_protection),
80 	INTG(X86_TRAP_SPURIOUS,		spurious_interrupt_bug),
81 	INTG(X86_TRAP_MF,		coprocessor_error),
82 	INTG(X86_TRAP_AC,		alignment_check),
83 	INTG(X86_TRAP_XF,		simd_coprocessor_error),
84 
85 #ifdef CONFIG_X86_32
86 	TSKG(X86_TRAP_DF,		GDT_ENTRY_DOUBLEFAULT_TSS),
87 #else
88 	INTG(X86_TRAP_DF,		double_fault),
89 #endif
90 	INTG(X86_TRAP_DB,		debug),
91 	INTG(X86_TRAP_NMI,		nmi),
92 	INTG(X86_TRAP_BP,		int3),
93 
94 #ifdef CONFIG_X86_MCE
95 	INTG(X86_TRAP_MC,		&machine_check),
96 #endif
97 
98 	SYSG(X86_TRAP_OF,		overflow),
99 #if defined(CONFIG_IA32_EMULATION)
100 	SYSG(IA32_SYSCALL_VECTOR,	entry_INT80_compat),
101 #elif defined(CONFIG_X86_32)
102 	SYSG(IA32_SYSCALL_VECTOR,	entry_INT80_32),
103 #endif
104 };
105 
106 /*
107  * The APIC and SMP idt entries
108  */
109 static const __initdata struct idt_data apic_idts[] = {
110 #ifdef CONFIG_SMP
111 	INTG(RESCHEDULE_VECTOR,		reschedule_interrupt),
112 	INTG(CALL_FUNCTION_VECTOR,	call_function_interrupt),
113 	INTG(CALL_FUNCTION_SINGLE_VECTOR, call_function_single_interrupt),
114 	INTG(IRQ_MOVE_CLEANUP_VECTOR,	irq_move_cleanup_interrupt),
115 	INTG(REBOOT_VECTOR,		reboot_interrupt),
116 #endif
117 
118 #ifdef CONFIG_X86_THERMAL_VECTOR
119 	INTG(THERMAL_APIC_VECTOR,	thermal_interrupt),
120 #endif
121 
122 #ifdef CONFIG_X86_MCE_THRESHOLD
123 	INTG(THRESHOLD_APIC_VECTOR,	threshold_interrupt),
124 #endif
125 
126 #ifdef CONFIG_X86_MCE_AMD
127 	INTG(DEFERRED_ERROR_VECTOR,	deferred_error_interrupt),
128 #endif
129 
130 #ifdef CONFIG_X86_LOCAL_APIC
131 	INTG(LOCAL_TIMER_VECTOR,	apic_timer_interrupt),
132 	INTG(X86_PLATFORM_IPI_VECTOR,	x86_platform_ipi),
133 # ifdef CONFIG_HAVE_KVM
134 	INTG(POSTED_INTR_VECTOR,	kvm_posted_intr_ipi),
135 	INTG(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi),
136 	INTG(POSTED_INTR_NESTED_VECTOR, kvm_posted_intr_nested_ipi),
137 # endif
138 # ifdef CONFIG_IRQ_WORK
139 	INTG(IRQ_WORK_VECTOR,		irq_work_interrupt),
140 # endif
141 	INTG(SPURIOUS_APIC_VECTOR,	spurious_interrupt),
142 	INTG(ERROR_APIC_VECTOR,		error_interrupt),
143 #endif
144 };
145 
146 #ifdef CONFIG_X86_64
147 /*
148  * Early traps running on the DEFAULT_STACK because the other interrupt
149  * stacks work only after cpu_init().
150  */
151 static const __initdata struct idt_data early_pf_idts[] = {
152 	INTG(X86_TRAP_PF,		page_fault),
153 };
154 
155 /*
156  * Override for the debug_idt. Same as the default, but with interrupt
157  * stack set to DEFAULT_STACK (0). Required for NMI trap handling.
158  */
159 static const __initdata struct idt_data dbg_idts[] = {
160 	INTG(X86_TRAP_DB,	debug),
161 	INTG(X86_TRAP_BP,	int3),
162 };
163 #endif
164 
165 /* Must be page-aligned because the real IDT is used in a fixmap. */
166 gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
167 
168 struct desc_ptr idt_descr __ro_after_init = {
169 	.size		= (IDT_ENTRIES * 2 * sizeof(unsigned long)) - 1,
170 	.address	= (unsigned long) idt_table,
171 };
172 
173 #ifdef CONFIG_X86_64
174 /* No need to be aligned, but done to keep all IDTs defined the same way. */
175 gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;
176 
177 /*
178  * The exceptions which use Interrupt stacks. They are setup after
179  * cpu_init() when the TSS has been initialized.
180  */
181 static const __initdata struct idt_data ist_idts[] = {
182 	ISTG(X86_TRAP_DB,	debug,		DEBUG_STACK),
183 	ISTG(X86_TRAP_NMI,	nmi,		NMI_STACK),
184 	ISTG(X86_TRAP_BP,	int3,		DEBUG_STACK),
185 	ISTG(X86_TRAP_DF,	double_fault,	DOUBLEFAULT_STACK),
186 #ifdef CONFIG_X86_MCE
187 	ISTG(X86_TRAP_MC,	&machine_check,	MCE_STACK),
188 #endif
189 };
190 
191 /*
192  * Override for the debug_idt. Same as the default, but with interrupt
193  * stack set to DEFAULT_STACK (0). Required for NMI trap handling.
194  */
195 const struct desc_ptr debug_idt_descr = {
196 	.size		= IDT_ENTRIES * 16 - 1,
197 	.address	= (unsigned long) debug_idt_table,
198 };
199 #endif
200 
201 static inline void idt_init_desc(gate_desc *gate, const struct idt_data *d)
202 {
203 	unsigned long addr = (unsigned long) d->addr;
204 
205 	gate->offset_low	= (u16) addr;
206 	gate->segment		= (u16) d->segment;
207 	gate->bits		= d->bits;
208 	gate->offset_middle	= (u16) (addr >> 16);
209 #ifdef CONFIG_X86_64
210 	gate->offset_high	= (u32) (addr >> 32);
211 	gate->reserved		= 0;
212 #endif
213 }
214 
215 static __init void
216 idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size)
217 {
218 	gate_desc desc;
219 
220 	for (; size > 0; t++, size--) {
221 		idt_init_desc(&desc, t);
222 		set_bit(t->vector, used_vectors);
223 		write_idt_entry(idt, t->vector, &desc);
224 	}
225 }
226 
227 /**
228  * idt_setup_early_traps - Initialize the idt table with early traps
229  *
230  * On X8664 these traps do not use interrupt stacks as they can't work
231  * before cpu_init() is invoked and sets up TSS. The IST variants are
232  * installed after that.
233  */
234 void __init idt_setup_early_traps(void)
235 {
236 	idt_setup_from_table(idt_table, early_idts, ARRAY_SIZE(early_idts));
237 	load_idt(&idt_descr);
238 }
239 
240 /**
241  * idt_setup_traps - Initialize the idt table with default traps
242  */
243 void __init idt_setup_traps(void)
244 {
245 	idt_setup_from_table(idt_table, def_idts, ARRAY_SIZE(def_idts));
246 }
247 
248 #ifdef CONFIG_X86_64
249 /**
250  * idt_setup_early_pf - Initialize the idt table with early pagefault handler
251  *
252  * On X8664 this does not use interrupt stacks as they can't work before
253  * cpu_init() is invoked and sets up TSS. The IST variant is installed
254  * after that.
255  *
256  * FIXME: Why is 32bit and 64bit installing the PF handler at different
257  * places in the early setup code?
258  */
259 void __init idt_setup_early_pf(void)
260 {
261 	idt_setup_from_table(idt_table, early_pf_idts,
262 			     ARRAY_SIZE(early_pf_idts));
263 }
264 
265 /**
266  * idt_setup_ist_traps - Initialize the idt table with traps using IST
267  */
268 void __init idt_setup_ist_traps(void)
269 {
270 	idt_setup_from_table(idt_table, ist_idts, ARRAY_SIZE(ist_idts));
271 }
272 
273 /**
274  * idt_setup_debugidt_traps - Initialize the debug idt table with debug traps
275  */
276 void __init idt_setup_debugidt_traps(void)
277 {
278 	memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
279 
280 	idt_setup_from_table(debug_idt_table, dbg_idts, ARRAY_SIZE(dbg_idts));
281 }
282 #endif
283 
284 /**
285  * idt_setup_apic_and_irq_gates - Setup APIC/SMP and normal interrupt gates
286  */
287 void __init idt_setup_apic_and_irq_gates(void)
288 {
289 	idt_setup_from_table(idt_table, apic_idts, ARRAY_SIZE(apic_idts));
290 }
291 
292 /**
293  * idt_setup_early_handler - Initializes the idt table with early handlers
294  */
295 void __init idt_setup_early_handler(void)
296 {
297 	int i;
298 
299 	for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
300 		set_intr_gate(i, early_idt_handler_array[i]);
301 #ifdef CONFIG_X86_32
302 	for ( ; i < NR_VECTORS; i++)
303 		set_intr_gate(i, early_ignore_irq);
304 #endif
305 	load_idt(&idt_descr);
306 }
307 
308 /**
309  * idt_invalidate - Invalidate interrupt descriptor table
310  * @addr:	The virtual address of the 'invalid' IDT
311  */
312 void idt_invalidate(void *addr)
313 {
314 	struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 };
315 
316 	load_idt(&idt);
317 }
318