xref: /haiku/src/system/kernel/arch/x86/ioapic.cpp (revision ab4411e89a079bc0a40d901995f3418d998c51b3)
1 /*
2  * Copyright 2008-2011, Michael Lotz, mmlr@mlotz.ch.
3  * Distributed under the terms of the MIT License.
4  */
5 
6 #include <arch/x86/ioapic.h>
7 
8 #include <int.h>
9 #include <vm/vm.h>
10 
11 #include "irq_routing_table.h"
12 
13 #include <ACPI.h>
14 #include <AutoDeleter.h>
15 #include <safemode.h>
16 #include <string.h>
17 #include <stdio.h>
18 
19 #include <arch/x86/apic.h>
20 #include <arch/x86/arch_int.h>
21 #include <arch/x86/arch_smp.h>
22 #include <arch/x86/pic.h>
23 
24 // to gain access to the ACPICA types
25 #include "acpi.h"
26 
27 
28 //#define TRACE_IOAPIC
29 #ifdef TRACE_IOAPIC
30 #	define TRACE(...) dprintf(__VA_ARGS__)
31 #else
32 #	define TRACE(...) (void)0
33 #endif
34 
35 
36 // ACPI interrupt models
37 #define ACPI_INTERRUPT_MODEL_PIC	0
38 #define ACPI_INTERRUPT_MODEL_APIC	1
39 #define ACPI_INTERRUPT_MODEL_SAPIC	2
40 
41 
42 // Definitions for a 82093AA IO APIC controller
43 #define IO_APIC_ID							0x00
44 #define IO_APIC_VERSION						0x01
45 #define IO_APIC_ARBITRATION					0x02
46 #define IO_APIC_REDIRECTION_TABLE			0x10 // entry = base + 2 * index
47 
48 // Fields for the id register
49 #define IO_APIC_ID_SHIFT					24
50 #define IO_APIC_ID_MASK						0xff
51 
52 // Fields for the version register
53 #define IO_APIC_VERSION_SHIFT				0
54 #define IO_APIC_VERSION_MASK				0xff
55 #define IO_APIC_MAX_REDIRECTION_ENTRY_SHIFT	16
56 #define IO_APIC_MAX_REDIRECTION_ENTRY_MASK	0xff
57 
58 // Fields of each redirection table entry
59 #define IO_APIC_DESTINATION_FIELD_SHIFT		56
60 #define IO_APIC_DESTINATION_FIELD_MASK		0xff
61 #define IO_APIC_INTERRUPT_MASKED			(1 << 16)
62 #define IO_APIC_TRIGGER_MODE_EDGE			(0 << 16)
63 #define IO_APIC_TRIGGER_MODE_LEVEL			(1 << 15)
64 #define IO_APIC_TRIGGER_MODE_MASK			(1 << 15)
65 #define IO_APIC_REMOTE_IRR					(1 << 14)
66 #define IO_APIC_PIN_POLARITY_HIGH_ACTIVE	(0 << 13)
67 #define IO_APIC_PIN_POLARITY_LOW_ACTIVE		(1 << 13)
68 #define IO_APIC_PIN_POLARITY_MASK			(1 << 13)
69 #define IO_APIC_DELIVERY_STATUS_PENDING		(1 << 12)
70 #define IO_APIC_DESTINATION_MODE_PHYSICAL	(0 << 11)
71 #define IO_APIC_DESTINATION_MODE_LOGICAL	(1 << 11)
72 #define IO_APIC_DESTINATION_MODE_MASK		(1 << 11)
73 #define IO_APIC_DELIVERY_MODE_MASK			(7 << 8)
74 #define IO_APIC_DELIVERY_MODE_FIXED			(0 << 8)
75 #define IO_APIC_DELIVERY_MODE_LOWEST_PRIO	(1 << 8)
76 #define IO_APIC_DELIVERY_MODE_SMI			(2 << 8)
77 #define IO_APIC_DELIVERY_MODE_NMI			(4 << 8)
78 #define IO_APIC_DELIVERY_MODE_INIT			(5 << 8)
79 #define IO_APIC_DELIVERY_MODE_EXT_INT		(7 << 8)
80 #define IO_APIC_INTERRUPT_VECTOR_SHIFT		0
81 #define IO_APIC_INTERRUPT_VECTOR_MASK		0xff
82 
83 #define MAX_SUPPORTED_REDIRECTION_ENTRIES	64
84 #define ISA_INTERRUPT_COUNT					16
85 
86 
87 struct ioapic_registers {
88 	volatile uint32	io_register_select;
89 	uint32			reserved[3];
90 	volatile uint32	io_window_register;
91 };
92 
93 
94 struct ioapic {
95 	uint8				number;
96 	uint8				apic_id;
97 	uint32				version;
98 	uint8				max_redirection_entry;
99 	uint8				global_interrupt_base;
100 	uint8				global_interrupt_last;
101 	uint64				level_triggered_mask;
102 	uint64				nmi_mask;
103 
104 	area_id				register_area;
105 	ioapic_registers*	registers;
106 
107 	ioapic*				next;
108 };
109 
110 
111 static ioapic* sIOAPICs = NULL;
112 static int32 sSourceOverrides[ISA_INTERRUPT_COUNT];
113 
114 
115 // #pragma mark - I/O APIC
116 
117 
118 static void
119 print_ioapic(struct ioapic& ioapic)
120 {
121 	dprintf("io-apic %u has range %u-%u, %u entries, version 0x%08" B_PRIx32
122 		", apic-id %u\n", ioapic.number, ioapic.global_interrupt_base,
123 		ioapic.global_interrupt_last, ioapic.max_redirection_entry + 1,
124 		ioapic.version, ioapic.apic_id);
125 }
126 
127 
128 static inline struct ioapic*
129 find_ioapic(int32 gsi)
130 {
131 	if (gsi < 0)
132 		return NULL;
133 
134 	struct ioapic* current = sIOAPICs;
135 	while (current != NULL) {
136 		if (gsi >= current->global_interrupt_base
137 			&& gsi <= current->global_interrupt_last) {
138 			return current;
139 		}
140 
141 		current = current->next;
142 	}
143 
144 	return NULL;
145 }
146 
147 
148 static inline uint32
149 ioapic_read_32(struct ioapic& ioapic, uint8 registerSelect)
150 {
151 	ioapic.registers->io_register_select = registerSelect;
152 	return ioapic.registers->io_window_register;
153 }
154 
155 
156 static inline void
157 ioapic_write_32(struct ioapic& ioapic, uint8 registerSelect, uint32 value)
158 {
159 	ioapic.registers->io_register_select = registerSelect;
160 	ioapic.registers->io_window_register = value;
161 }
162 
163 
164 static inline uint64
165 ioapic_read_64(struct ioapic& ioapic, uint8 registerSelect)
166 {
167 	ioapic.registers->io_register_select = registerSelect + 1;
168 	uint64 result = ioapic.registers->io_window_register;
169 	result <<= 32;
170 	ioapic.registers->io_register_select = registerSelect;
171 	result |= ioapic.registers->io_window_register;
172 	return result;
173 }
174 
175 
176 static inline void
177 ioapic_write_64(struct ioapic& ioapic, uint8 registerSelect, uint64 value,
178 	bool maskFirst)
179 {
180 	ioapic.registers->io_register_select
181 		= registerSelect + (maskFirst ? 0 : 1);
182 	ioapic.registers->io_window_register
183 		= (uint32)(value >> (maskFirst ? 0 : 32));
184 	ioapic.registers->io_register_select
185 		= registerSelect + (maskFirst ? 1 : 0);
186 	ioapic.registers->io_window_register
187 		= (uint32)(value >> (maskFirst ? 32 : 0));
188 }
189 
190 
191 static void
192 ioapic_configure_pin(struct ioapic& ioapic, uint8 pin, uint8 vector,
193 	uint8 triggerPolarity, uint16 deliveryMode)
194 {
195 	uint64 entry = ioapic_read_64(ioapic, IO_APIC_REDIRECTION_TABLE + pin * 2);
196 	entry &= ~(IO_APIC_TRIGGER_MODE_MASK | IO_APIC_PIN_POLARITY_MASK
197 		| IO_APIC_INTERRUPT_VECTOR_MASK | IO_APIC_DELIVERY_MODE_MASK);
198 
199 	if (triggerPolarity & B_LEVEL_TRIGGERED) {
200 		entry |= IO_APIC_TRIGGER_MODE_LEVEL;
201 		ioapic.level_triggered_mask |= ((uint64)1 << pin);
202 	} else {
203 		entry |= IO_APIC_TRIGGER_MODE_EDGE;
204 		ioapic.level_triggered_mask &= ~((uint64)1 << pin);
205 	}
206 
207 	if (triggerPolarity & B_LOW_ACTIVE_POLARITY)
208 		entry |= IO_APIC_PIN_POLARITY_LOW_ACTIVE;
209 	else
210 		entry |= IO_APIC_PIN_POLARITY_HIGH_ACTIVE;
211 
212 	entry |= deliveryMode;
213 	entry |= (vector + ARCH_INTERRUPT_BASE) << IO_APIC_INTERRUPT_VECTOR_SHIFT;
214 	ioapic_write_64(ioapic, IO_APIC_REDIRECTION_TABLE + pin * 2, entry, true);
215 }
216 
217 
218 static bool
219 ioapic_is_spurious_interrupt(int32 gsi)
220 {
221 	// the spurious interrupt vector is initialized to the max value in smp
222 	return gsi == 0xff - ARCH_INTERRUPT_BASE;
223 }
224 
225 
226 static bool
227 ioapic_is_level_triggered_interrupt(int32 gsi)
228 {
229 	struct ioapic* ioapic = find_ioapic(gsi);
230 	if (ioapic == NULL)
231 		return false;
232 
233 	uint8 pin = gsi - ioapic->global_interrupt_base;
234 	return (ioapic->level_triggered_mask & ((uint64)1 << pin)) != 0;
235 }
236 
237 
238 static bool
239 ioapic_end_of_interrupt(int32 num)
240 {
241 	apic_end_of_interrupt();
242 	return true;
243 }
244 
245 
246 static void
247 ioapic_assign_interrupt_to_cpu(int32 gsi, int32 cpu)
248 {
249 	if (gsi < ISA_INTERRUPT_COUNT && sSourceOverrides[gsi] != 0)
250 		gsi = sSourceOverrides[gsi];
251 
252 	struct ioapic* ioapic = find_ioapic(gsi);
253 	if (ioapic == NULL)
254 		return;
255 
256 	uint32 apicid = x86_get_cpu_apic_id(cpu);
257 
258 	uint8 pin = gsi - ioapic->global_interrupt_base;
259 	TRACE("ioapic_assign_interrupt_to_cpu: gsi %ld (io-apic %u pin %u) to"
260 		" cpu %ld (apic_id %lu)\n", gsi, ioapic->number, pin, cpu, apicid);
261 
262 	uint64 entry = ioapic_read_64(*ioapic, IO_APIC_REDIRECTION_TABLE + pin * 2);
263 	entry &= ~(uint64(IO_APIC_DESTINATION_FIELD_MASK)
264 			<< IO_APIC_DESTINATION_FIELD_SHIFT);
265 	entry |= uint64(apicid) << IO_APIC_DESTINATION_FIELD_SHIFT;
266 	ioapic_write_64(*ioapic, IO_APIC_REDIRECTION_TABLE + pin * 2, entry, false);
267 }
268 
269 
270 static void
271 ioapic_enable_io_interrupt(int32 gsi)
272 {
273 	// If enabling an overriden source is attempted, enable the override entry
274 	// instead. An interrupt handler was installed at the override GSI to relay
275 	// interrupts to the overriden source.
276 	if (gsi < ISA_INTERRUPT_COUNT && sSourceOverrides[gsi] != 0)
277 		gsi = sSourceOverrides[gsi];
278 
279 	struct ioapic* ioapic = find_ioapic(gsi);
280 	if (ioapic == NULL)
281 		return;
282 
283 	x86_set_irq_source(gsi, IRQ_SOURCE_IOAPIC);
284 
285 	uint8 pin = gsi - ioapic->global_interrupt_base;
286 	TRACE("ioapic_enable_io_interrupt: gsi %ld -> io-apic %u pin %u\n",
287 		gsi, ioapic->number, pin);
288 
289 	uint64 entry = ioapic_read_64(*ioapic, IO_APIC_REDIRECTION_TABLE + pin * 2);
290 	entry &= ~IO_APIC_INTERRUPT_MASKED;
291 	ioapic_write_64(*ioapic, IO_APIC_REDIRECTION_TABLE + pin * 2, entry, false);
292 }
293 
294 
295 static void
296 ioapic_disable_io_interrupt(int32 gsi)
297 {
298 	struct ioapic* ioapic = find_ioapic(gsi);
299 	if (ioapic == NULL)
300 		return;
301 
302 	uint8 pin = gsi - ioapic->global_interrupt_base;
303 	TRACE("ioapic_disable_io_interrupt: gsi %ld -> io-apic %u pin %u\n",
304 		gsi, ioapic->number, pin);
305 
306 	uint64 entry = ioapic_read_64(*ioapic, IO_APIC_REDIRECTION_TABLE + pin * 2);
307 	entry |= IO_APIC_INTERRUPT_MASKED;
308 	ioapic_write_64(*ioapic, IO_APIC_REDIRECTION_TABLE + pin * 2, entry, true);
309 }
310 
311 
312 static void
313 ioapic_configure_io_interrupt(int32 gsi, uint32 config)
314 {
315 	struct ioapic* ioapic = find_ioapic(gsi);
316 	if (ioapic == NULL)
317 		return;
318 
319 	uint8 pin = gsi - ioapic->global_interrupt_base;
320 	TRACE("ioapic_configure_io_interrupt: gsi %ld -> io-apic %u pin %u; "
321 		"config 0x%08lx\n", gsi, ioapic->number, pin, config);
322 
323 	ioapic_configure_pin(*ioapic, pin, gsi, config,
324 		IO_APIC_DELIVERY_MODE_FIXED);
325 }
326 
327 
328 static status_t
329 ioapic_map_ioapic(struct ioapic& ioapic, phys_addr_t physicalAddress)
330 {
331 	ioapic.register_area = vm_map_physical_memory(B_SYSTEM_TEAM, "io-apic",
332 		(void**)&ioapic.registers, ioapic.registers != NULL ? B_EXACT_ADDRESS
333 		: B_ANY_KERNEL_ADDRESS, B_PAGE_SIZE, B_KERNEL_READ_AREA
334 		| B_KERNEL_WRITE_AREA, physicalAddress, ioapic.registers != NULL);
335 	if (ioapic.register_area < 0) {
336 		panic("mapping io-apic %u failed", ioapic.number);
337 		return ioapic.register_area;
338 	}
339 
340 	TRACE("mapped io-apic %u to %p\n", ioapic.number, ioapic.registers);
341 
342 	ioapic.version = ioapic_read_32(ioapic, IO_APIC_VERSION);
343 	if (ioapic.version == 0xffffffff) {
344 		dprintf("io-apic %u seems inaccessible, not using it\n",
345 			ioapic.number);
346 		vm_delete_area(B_SYSTEM_TEAM, ioapic.register_area, true);
347 		ioapic.register_area = -1;
348 		ioapic.registers = NULL;
349 		return B_ERROR;
350 	}
351 
352 	ioapic.max_redirection_entry
353 		= ((ioapic.version >> IO_APIC_MAX_REDIRECTION_ENTRY_SHIFT)
354 			& IO_APIC_MAX_REDIRECTION_ENTRY_MASK);
355 	if (ioapic.max_redirection_entry >= MAX_SUPPORTED_REDIRECTION_ENTRIES) {
356 		dprintf("io-apic %u entry count exceeds max supported, only using the "
357 			"first %u entries", ioapic.number,
358 			(uint8)MAX_SUPPORTED_REDIRECTION_ENTRIES);
359 		ioapic.max_redirection_entry = MAX_SUPPORTED_REDIRECTION_ENTRIES - 1;
360 	}
361 
362 	ioapic.global_interrupt_last
363 		= ioapic.global_interrupt_base + ioapic.max_redirection_entry;
364 
365 	ioapic.nmi_mask = 0;
366 
367 	return B_OK;
368 }
369 
370 
371 static status_t
372 ioapic_initialize_ioapic(struct ioapic& ioapic, uint8 targetAPIC)
373 {
374 	// program the APIC ID
375 	ioapic_write_32(ioapic, IO_APIC_ID, ioapic.apic_id << IO_APIC_ID_SHIFT);
376 
377 	// program the interrupt vectors of the io-apic
378 	ioapic.level_triggered_mask = 0;
379 	uint8 gsi = ioapic.global_interrupt_base;
380 	for (uint8 i = 0; i <= ioapic.max_redirection_entry; i++, gsi++) {
381 		// initialize everything to deliver to the boot CPU in physical mode
382 		// and masked until explicitly enabled through enable_io_interrupt()
383 		uint64 entry = ((uint64)targetAPIC << IO_APIC_DESTINATION_FIELD_SHIFT)
384 			| IO_APIC_INTERRUPT_MASKED | IO_APIC_DESTINATION_MODE_PHYSICAL
385 			| ((gsi + ARCH_INTERRUPT_BASE) << IO_APIC_INTERRUPT_VECTOR_SHIFT);
386 
387 		if (gsi == 0) {
388 			// make GSI 0 into an external interrupt
389 			entry |= IO_APIC_TRIGGER_MODE_EDGE
390 				| IO_APIC_PIN_POLARITY_HIGH_ACTIVE
391 				| IO_APIC_DELIVERY_MODE_EXT_INT;
392 		} else if (gsi < ISA_INTERRUPT_COUNT) {
393 			// identity map the legacy ISA interrupts
394 			entry |= IO_APIC_TRIGGER_MODE_EDGE
395 				| IO_APIC_PIN_POLARITY_HIGH_ACTIVE
396 				| IO_APIC_DELIVERY_MODE_FIXED;
397 		} else {
398 			// and the rest are PCI interrupts
399 			entry |= IO_APIC_TRIGGER_MODE_LEVEL
400 				| IO_APIC_PIN_POLARITY_LOW_ACTIVE
401 				| IO_APIC_DELIVERY_MODE_FIXED;
402 			ioapic.level_triggered_mask |= ((uint64)1 << i);
403 		}
404 
405 		ioapic_write_64(ioapic, IO_APIC_REDIRECTION_TABLE + 2 * i, entry, true);
406 	}
407 
408 	return B_OK;
409 }
410 
411 
412 static int32
413 ioapic_source_override_handler(void* data)
414 {
415 	int32 vector = (addr_t)data;
416 	bool levelTriggered = ioapic_is_level_triggered_interrupt(vector);
417 	return int_io_interrupt_handler(vector, levelTriggered);
418 }
419 
420 
421 static status_t
422 acpi_enumerate_ioapics(acpi_table_madt* madt)
423 {
424 	struct ioapic* lastIOAPIC = sIOAPICs;
425 
426 	acpi_subtable_header* apicEntry
427 		= (acpi_subtable_header*)((uint8*)madt + sizeof(acpi_table_madt));
428 	void* end = ((uint8*)madt + madt->Header.Length);
429 	while (apicEntry < end) {
430 		switch (apicEntry->Type) {
431 			case ACPI_MADT_TYPE_IO_APIC:
432 			{
433 				acpi_madt_io_apic* info = (acpi_madt_io_apic*)apicEntry;
434 				dprintf("found io-apic with address 0x%08" B_PRIx32 ", global "
435 					"interrupt base %" B_PRIu32 ", apic-id %u\n",
436 					(uint32)info->Address, (uint32)info->GlobalIrqBase,
437 					info->Id);
438 
439 				struct ioapic* ioapic
440 					= (struct ioapic*)malloc(sizeof(struct ioapic));
441 				if (ioapic == NULL) {
442 					dprintf("ran out of memory while allocating io-apic "
443 						"structure\n");
444 					return B_NO_MEMORY;
445 				}
446 
447 				ioapic->number
448 					= lastIOAPIC != NULL ? lastIOAPIC->number + 1 : 0;
449 				ioapic->apic_id = info->Id;
450 				ioapic->global_interrupt_base = info->GlobalIrqBase;
451 				ioapic->registers = NULL;
452 				ioapic->next = NULL;
453 
454 				dprintf("mapping io-apic %u at physical address %#" B_PRIx32
455 					"\n", ioapic->number, (uint32)info->Address);
456 				status_t status = ioapic_map_ioapic(*ioapic, info->Address);
457 				if (status != B_OK) {
458 					free(ioapic);
459 					break;
460 				}
461 
462 				print_ioapic(*ioapic);
463 
464 				if (lastIOAPIC == NULL)
465 					sIOAPICs = ioapic;
466 				else
467 					lastIOAPIC->next = ioapic;
468 
469 				lastIOAPIC = ioapic;
470 				break;
471 			}
472 
473 			case ACPI_MADT_TYPE_NMI_SOURCE:
474 			{
475 				acpi_madt_nmi_source* info
476 					= (acpi_madt_nmi_source*)apicEntry;
477 				dprintf("found nmi source global irq %" B_PRIu32 ", flags "
478 					"0x%04x\n", (uint32)info->GlobalIrq,
479 					(uint16)info->IntiFlags);
480 
481 				struct ioapic* ioapic = find_ioapic(info->GlobalIrq);
482 				if (ioapic == NULL) {
483 					dprintf("nmi source for gsi that is not mapped to any "
484 						" io-apic\n");
485 					break;
486 				}
487 
488 				uint8 pin = info->GlobalIrq - ioapic->global_interrupt_base;
489 				ioapic->nmi_mask |= (uint64)1 << pin;
490 				break;
491 			}
492 		}
493 
494 		apicEntry
495 			= (acpi_subtable_header*)((uint8*)apicEntry + apicEntry->Length);
496 	}
497 
498 	return B_OK;
499 }
500 
501 
502 static inline uint32
503 acpi_madt_convert_inti_flags(uint16 flags)
504 {
505 	uint32 config = 0;
506 	switch (flags & ACPI_MADT_POLARITY_MASK) {
507 		case ACPI_MADT_POLARITY_ACTIVE_LOW:
508 			config = B_LOW_ACTIVE_POLARITY;
509 			break;
510 		default:
511 			dprintf("invalid polarity in inti flags\n");
512 			// fall through and assume active high
513 		case ACPI_MADT_POLARITY_ACTIVE_HIGH:
514 		case ACPI_MADT_POLARITY_CONFORMS:
515 			config = B_HIGH_ACTIVE_POLARITY;
516 			break;
517 	}
518 
519 	switch (flags & ACPI_MADT_TRIGGER_MASK) {
520 		case ACPI_MADT_TRIGGER_LEVEL:
521 			config |= B_LEVEL_TRIGGERED;
522 			break;
523 		default:
524 			dprintf("invalid trigger mode in inti flags\n");
525 			// fall through and assume edge triggered
526 		case ACPI_MADT_TRIGGER_CONFORMS:
527 		case ACPI_MADT_TRIGGER_EDGE:
528 			config |= B_EDGE_TRIGGERED;
529 			break;
530 	}
531 
532 	return config;
533 }
534 
535 
536 static void
537 acpi_configure_source_overrides(acpi_table_madt* madt)
538 {
539 	acpi_subtable_header* apicEntry
540 		= (acpi_subtable_header*)((uint8*)madt + sizeof(acpi_table_madt));
541 	void* end = ((uint8*)madt + madt->Header.Length);
542 	while (apicEntry < end) {
543 		switch (apicEntry->Type) {
544 			case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
545 			{
546 				acpi_madt_interrupt_override* info
547 					= (acpi_madt_interrupt_override*)apicEntry;
548 				dprintf("found interrupt override for bus %u, source irq %u, "
549 					"global irq %" B_PRIu32 ", flags 0x%08" B_PRIx32 "\n",
550 					info->Bus, info->SourceIrq, (uint32)info->GlobalIrq,
551 					(uint32)info->IntiFlags);
552 
553 				if (info->SourceIrq >= ISA_INTERRUPT_COUNT) {
554 					dprintf("source override exceeds isa interrupt count\n");
555 					break;
556 				}
557 
558 				if (info->SourceIrq != info->GlobalIrq) {
559 					// we need a vector mapping
560 					install_io_interrupt_handler(info->GlobalIrq,
561 						&ioapic_source_override_handler,
562 						(void*)(addr_t)info->SourceIrq, B_NO_ENABLE_COUNTER);
563 
564 					sSourceOverrides[info->SourceIrq] = info->GlobalIrq;
565 				}
566 
567 				// configure non-standard polarity/trigger modes
568 				uint32 config = acpi_madt_convert_inti_flags(info->IntiFlags);
569 				ioapic_configure_io_interrupt(info->GlobalIrq, config);
570 				break;
571 			}
572 
573 			case ACPI_MADT_TYPE_NMI_SOURCE:
574 			{
575 				acpi_madt_nmi_source* info
576 					= (acpi_madt_nmi_source*)apicEntry;
577 				dprintf("found nmi source global irq %" B_PRIu32 ", flags "
578 					"0x%04x\n", (uint32)info->GlobalIrq,
579 					(uint16)info->IntiFlags);
580 
581 				struct ioapic* ioapic = find_ioapic(info->GlobalIrq);
582 				if (ioapic == NULL)
583 					break;
584 
585 				uint8 pin = info->GlobalIrq - ioapic->global_interrupt_base;
586 				uint32 config = acpi_madt_convert_inti_flags(info->IntiFlags);
587 				ioapic_configure_pin(*ioapic, pin, info->GlobalIrq, config,
588 					IO_APIC_DELIVERY_MODE_NMI);
589 				break;
590 			}
591 
592 #ifdef TRACE_IOAPIC
593 			case ACPI_MADT_TYPE_LOCAL_APIC:
594 			{
595 				// purely informational
596 				acpi_madt_local_apic* info = (acpi_madt_local_apic*)apicEntry;
597 				dprintf("found local apic with id %u, processor id %u, "
598 					"flags 0x%08lx\n", info->Id, info->ProcessorId,
599 					(uint32)info->LapicFlags);
600 				break;
601 			}
602 
603 			case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
604 			{
605 				// TODO: take these into account, but at apic.cpp
606 				acpi_madt_local_apic_nmi* info
607 					= (acpi_madt_local_apic_nmi*)apicEntry;
608 				dprintf("found local apic nmi source for processor %u, "
609 					"flags 0x%04x, local int %u\n", info->ProcessorId,
610 					(uint16)info->IntiFlags, info->Lint);
611 				break;
612 			}
613 
614 			case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
615 			{
616 				// TODO: take these into account, but at apic.cpp
617 				acpi_madt_local_apic_override* info
618 					= (acpi_madt_local_apic_override*)apicEntry;
619 				dprintf("found local apic override with address 0x%016llx\n",
620 					(uint64)info->Address);
621 				break;
622 			}
623 
624 			default:
625 				dprintf("found unhandled subtable of type %u length %u\n",
626 					apicEntry->Type, apicEntry->Length);
627 				break;
628 #endif
629 		}
630 
631 		apicEntry
632 			= (acpi_subtable_header*)((uint8*)apicEntry + apicEntry->Length);
633 	}
634 }
635 
636 
637 static status_t
638 acpi_set_interrupt_model(acpi_module_info* acpiModule, uint32 interruptModel)
639 {
640 	acpi_object_type model;
641 	model.object_type = ACPI_TYPE_INTEGER;
642 	model.integer.integer = interruptModel;
643 
644 	acpi_objects parameter;
645 	parameter.count = 1;
646 	parameter.pointer = &model;
647 
648 	dprintf("setting ACPI interrupt model to %s\n",
649 		interruptModel == 0 ? "PIC"
650 		: (interruptModel == 1 ? "APIC"
651 		: (interruptModel == 2 ? "SAPIC"
652 		: "unknown")));
653 
654 	return acpiModule->evaluate_method(NULL, "\\_PIC", &parameter, NULL);
655 }
656 
657 
658 bool
659 ioapic_is_interrupt_available(int32 gsi)
660 {
661 	struct ioapic* ioapic = find_ioapic(gsi);
662 	if (ioapic == NULL)
663 		return false;
664 
665 	uint8 pin = gsi - ioapic->global_interrupt_base;
666 	return (ioapic->nmi_mask & ((uint64)1 << pin)) == 0;
667 }
668 
669 
670 void
671 ioapic_init(kernel_args* args)
672 {
673 	static const interrupt_controller ioapicController = {
674 		"82093AA IOAPIC",
675 		&ioapic_enable_io_interrupt,
676 		&ioapic_disable_io_interrupt,
677 		&ioapic_configure_io_interrupt,
678 		&ioapic_is_spurious_interrupt,
679 		&ioapic_is_level_triggered_interrupt,
680 		&ioapic_end_of_interrupt,
681 		&ioapic_assign_interrupt_to_cpu,
682 	};
683 
684 	if (args->arch_args.apic == NULL)
685 		return;
686 
687 	if (args->arch_args.ioapic_phys == 0) {
688 		dprintf("no io-apics available, not using io-apics for interrupt "
689 			"routing\n");
690 		return;
691 	}
692 
693 	if (get_safemode_boolean(B_SAFEMODE_DISABLE_IOAPIC, false)) {
694 		dprintf("io-apics explicitly disabled, not using io-apics for "
695 			"interrupt routing\n");
696 		return;
697 	}
698 
699 	// load acpi module
700 	status_t status;
701 	acpi_module_info* acpiModule;
702 	status = get_module(B_ACPI_MODULE_NAME, (module_info**)&acpiModule);
703 	if (status != B_OK) {
704 		dprintf("acpi module not available, not configuring io-apics\n");
705 		return;
706 	}
707 	BPrivate::CObjectDeleter<const char, status_t>
708 		acpiModulePutter(B_ACPI_MODULE_NAME, put_module);
709 
710 	acpi_table_madt* madt = NULL;
711 	if (acpiModule->get_table(ACPI_SIG_MADT, 0, (void**)&madt) != B_OK) {
712 		dprintf("failed to get MADT from ACPI, not configuring io-apics\n");
713 		return;
714 	}
715 
716 	status = acpi_enumerate_ioapics(madt);
717 	if (status != B_OK) {
718 		// We don't treat this case as fatal just yet. If we are able to
719 		// route everything with the available IO-APICs we're fine, if not
720 		// we will fail at the routing preparation stage further down.
721 		dprintf("failed to enumerate all io-apics, working with what we got\n");
722 	}
723 
724 	// switch to the APIC interrupt model before retrieving the IRQ routing
725 	// table as it will return different settings depending on the model
726 	status = acpi_set_interrupt_model(acpiModule, ACPI_INTERRUPT_MODEL_APIC);
727 	if (status != B_OK) {
728 		dprintf("failed to put ACPI into APIC interrupt model, ignoring\n");
729 		// don't abort, as the _PIC method is optional and as long as there
730 		// aren't different routings based on it this is non-fatal
731 	}
732 
733 	IRQRoutingTable table;
734 	status = prepare_irq_routing(acpiModule, table,
735 		&ioapic_is_interrupt_available);
736 	if (status != B_OK) {
737 		dprintf("IRQ routing preparation failed, not configuring io-apics\n");
738 		acpi_set_interrupt_model(acpiModule, ACPI_INTERRUPT_MODEL_PIC);
739 			// revert to PIC interrupt model just in case
740 		return;
741 	}
742 
743 	// use the boot CPU as the target for all interrupts
744 	uint8 targetAPIC = args->arch_args.cpu_apic_id[0];
745 
746 	struct ioapic* current = sIOAPICs;
747 	while (current != NULL) {
748 		status = ioapic_initialize_ioapic(*current, targetAPIC);
749 		if (status != B_OK) {
750 			panic("failed to initialize io-apic %u", current->number);
751 			acpi_set_interrupt_model(acpiModule, ACPI_INTERRUPT_MODEL_PIC);
752 			return;
753 		}
754 
755 		current = current->next;
756 	}
757 
758 #ifdef TRACE_IOAPIC
759 	dprintf("trying interrupt routing:\n");
760 	print_irq_routing_table(table);
761 #endif
762 
763 	status = enable_irq_routing(acpiModule, table);
764 	if (status != B_OK) {
765 		panic("failed to enable IRQ routing");
766 		// if it failed early on it might still work in PIC mode
767 		acpi_set_interrupt_model(acpiModule, ACPI_INTERRUPT_MODEL_PIC);
768 		return;
769 	}
770 
771 	print_irq_routing_table(table);
772 
773 	// configure the source overrides, but let the PCI config below override it
774 	acpi_configure_source_overrides(madt);
775 
776 	// configure IO-APIC interrupts from PCI routing table
777 	for (int i = 0; i < table.Count(); i++) {
778 		irq_routing_entry& entry = table.ElementAt(i);
779 		ioapic_configure_io_interrupt(entry.irq,
780 			entry.polarity | entry.trigger_mode);
781 	}
782 
783 	// kill the local ints on the local APIC
784 	apic_disable_local_ints();
785 		// TODO: This uses the assumption that our init is running on the
786 		// boot CPU and only the boot CPU has the local ints configured
787 		// because it was running in legacy PIC mode. Possibly the other
788 		// local APICs of the other CPUs have them configured as well. It
789 		// shouldn't really harm, but should eventually be corrected.
790 
791 	// disable the legacy PIC
792 	uint16 legacyInterrupts;
793 	pic_disable(legacyInterrupts);
794 
795 	// enable previsouly enabled legacy interrupts
796 	for (uint8 i = 0; i < 16; i++) {
797 		if ((legacyInterrupts & (1 << i)) != 0)
798 			ioapic_enable_io_interrupt(i);
799 	}
800 
801 	// mark the interrupt vectors reserved so they aren't used for other stuff
802 	current = sIOAPICs;
803 	while (current != NULL) {
804 		reserve_io_interrupt_vectors(current->max_redirection_entry + 1,
805 			current->global_interrupt_base, INTERRUPT_TYPE_IRQ);
806 
807 		for (int32 i = 0; i < current->max_redirection_entry + 1; i++) {
808 			x86_set_irq_source(current->global_interrupt_base + i,
809 				IRQ_SOURCE_IOAPIC);
810 		}
811 
812 		current = current->next;
813 	}
814 
815 	// prefer the ioapic over the normal pic
816 	dprintf("using io-apics for interrupt routing\n");
817 	arch_int_set_interrupt_controller(ioapicController);
818 }
819