1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* Intel IO-APIC support for multi-Pentium hosts.
4	*
5	* Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
6	*
7	* Many thanks to Stig Venaas for trying out countless experimental
8	* patches and reporting/debugging problems patiently!
9	*
10	* (c) 1999, Multiple IO-APIC support, developed by
11	* Ken-ichi Yaku <yaku@css1.kbnes.nec.co.jp> and
12	* Hidemi Kishimoto <kisimoto@css1.kbnes.nec.co.jp>,
13	* further tested and cleaned up by Zach Brown <zab@redhat.com>
14	* and Ingo Molnar <mingo@redhat.com>
15	*
16	* Fixes
17	* Maciej W. Rozycki : Bits for genuine 82489DX APICs;
18	* thanks to Eric Gilmore
19	* and Rolf G. Tews
20	* for testing these extensively
21	* Paul Diefenbaugh : Added full ACPI support
22	*
23	* Historical information which is worth to be preserved:
24	*
25	* - SiS APIC rmw bug:
26	*
27	* We used to have a workaround for a bug in SiS chips which
28	* required to rewrite the index register for a read-modify-write
29	* operation as the chip lost the index information which was
30	* setup for the read already. We cache the data now, so that
31	* workaround has been removed.
32	*/
33
34	#include <linux/mm.h>
35	#include <linux/interrupt.h>
36	#include <linux/irq.h>
37	#include <linux/init.h>
38	#include <linux/delay.h>
39	#include <linux/sched.h>
40	#include <linux/pci.h>
41	#include <linux/mc146818rtc.h>
42	#include <linux/compiler.h>
43	#include <linux/acpi.h>
44	#include <linux/export.h>
45	#include <linux/syscore_ops.h>
46	#include <linux/freezer.h>
47	#include <linux/kthread.h>
48	#include <linux/jiffies.h> /* time_after() */
49	#include <linux/slab.h>
50	#include <linux/memblock.h>
51	#include <linux/msi.h>
52
53	#include <asm/irqdomain.h>
54	#include <asm/io.h>
55	#include <asm/smp.h>
56	#include <asm/cpu.h>
57	#include <asm/desc.h>
58	#include <asm/proto.h>
59	#include <asm/acpi.h>
60	#include <asm/dma.h>
61	#include <asm/timer.h>
62	#include <asm/time.h>
63	#include <asm/i8259.h>
64	#include <asm/setup.h>
65	#include <asm/irq_remapping.h>
66	#include <asm/hw_irq.h>
67	#include <asm/apic.h>
68	#include <asm/pgtable.h>
69	#include <asm/x86_init.h>
70
71	#define for_each_ioapic(idx) \
72	for ((idx) = 0; (idx) < nr_ioapics; (idx)++)
73	#define for_each_ioapic_reverse(idx) \
74	for ((idx) = nr_ioapics - 1; (idx) >= 0; (idx)--)
75	#define for_each_pin(idx, pin) \
76	for ((pin) = 0; (pin) < ioapics[(idx)].nr_registers; (pin)++)
77	#define for_each_ioapic_pin(idx, pin) \
78	for_each_ioapic((idx)) \
79	for_each_pin((idx), (pin))
80	#define for_each_irq_pin(entry, head) \
81	list_for_each_entry(entry, &head, list)
82
83	static DEFINE_RAW_SPINLOCK(ioapic_lock);
84	static DEFINE_MUTEX(ioapic_mutex);
85	static unsigned int ioapic_dynirq_base;
86	static int ioapic_initialized;
87
88	struct irq_pin_list {
89	struct list_head list;
90	int apic, pin;
91	};
92
93	struct mp_chip_data {
94	struct list_head irq_2_pin;
95	struct IO_APIC_route_entry entry;
96	bool is_level;
97	bool active_low;
98	bool isa_irq;
99	u32 count;
100	};
101
102	struct mp_ioapic_gsi {
103	u32 gsi_base;
104	u32 gsi_end;
105	};
106
107	static struct ioapic {
108	/*
109	* # of IRQ routing registers
110	*/
111	int nr_registers;
112	/*
113	* Saved state during suspend/resume, or while enabling intr-remap.
114	*/
115	struct IO_APIC_route_entry *saved_registers;
116	/* I/O APIC config */
117	struct mpc_ioapic mp_config;
118	/* IO APIC gsi routing info */
119	struct mp_ioapic_gsi gsi_config;
120	struct ioapic_domain_cfg irqdomain_cfg;
121	struct irq_domain *irqdomain;
122	struct resource *iomem_res;
123	} ioapics[MAX_IO_APICS];
124
125	#define mpc_ioapic_ver(ioapic_idx) ioapics[ioapic_idx].mp_config.apicver
126
127	int mpc_ioapic_id(int ioapic_idx)
128	{
129	return ioapics[ioapic_idx].mp_config.apicid;
130	}
131
132	unsigned int mpc_ioapic_addr(int ioapic_idx)
133	{
134	return ioapics[ioapic_idx].mp_config.apicaddr;
135	}
136
137	static inline struct mp_ioapic_gsi *mp_ioapic_gsi_routing(int ioapic_idx)
138	{
139	return &ioapics[ioapic_idx].gsi_config;
140	}
141
142	static inline int mp_ioapic_pin_count(int ioapic)
143	{
144	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic_idx: ioapic);
145
146	return gsi_cfg->gsi_end - gsi_cfg->gsi_base + 1;
147	}
148
149	static inline u32 mp_pin_to_gsi(int ioapic, int pin)
150	{
151	return mp_ioapic_gsi_routing(ioapic_idx: ioapic)->gsi_base + pin;
152	}
153
154	static inline bool mp_is_legacy_irq(int irq)
155	{
156	return irq >= 0 && irq < nr_legacy_irqs();
157	}
158
159	static inline struct irq_domain *mp_ioapic_irqdomain(int ioapic)
160	{
161	return ioapics[ioapic].irqdomain;
162	}
163
164	int nr_ioapics;
165
166	/* The one past the highest gsi number used */
167	u32 gsi_top;
168
169	/* MP IRQ source entries */
170	struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
171
172	/* # of MP IRQ source entries */
173	int mp_irq_entries;
174
175	#ifdef CONFIG_EISA
176	int mp_bus_id_to_type[MAX_MP_BUSSES];
177	#endif
178
179	DECLARE_BITMAP(mp_bus_not_pci, MAX_MP_BUSSES);
180
181	bool ioapic_is_disabled __ro_after_init;
182
183	/**
184	* disable_ioapic_support() - disables ioapic support at runtime
185	*/
186	void disable_ioapic_support(void)
187	{
188	#ifdef CONFIG_PCI
189	noioapicquirk = 1;
190	noioapicreroute = -1;
191	#endif
192	ioapic_is_disabled = true;
193	}
194
195	static int __init parse_noapic(char *str)
196	{
197	/* disable IO-APIC */
198	disable_ioapic_support();
199	return 0;
200	}
201	early_param("noapic", parse_noapic);
202
203	/* Will be called in mpparse/ACPI codes for saving IRQ info */
204	void mp_save_irq(struct mpc_intsrc *m)
205	{
206	int i;
207
208	apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
209	" IRQ %02x, APIC ID %x, APIC INT %02x\n",
210	m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbus,
211	m->srcbusirq, m->dstapic, m->dstirq);
212
213	for (i = 0; i < mp_irq_entries; i++) {
214	if (!memcmp(p: &mp_irqs[i], q: m, size: sizeof(*m)))
215	return;
216	}
217
218	memcpy(&mp_irqs[mp_irq_entries], m, sizeof(*m));
219	if (++mp_irq_entries == MAX_IRQ_SOURCES)
220	panic(fmt: "Max # of irq sources exceeded!!\n");
221	}
222
223	static void alloc_ioapic_saved_registers(int idx)
224	{
225	size_t size;
226
227	if (ioapics[idx].saved_registers)
228	return;
229
230	size = sizeof(struct IO_APIC_route_entry) * ioapics[idx].nr_registers;
231	ioapics[idx].saved_registers = kzalloc(size, GFP_KERNEL);
232	if (!ioapics[idx].saved_registers)
233	pr_err("IOAPIC %d: suspend/resume impossible!\n", idx);
234	}
235
236	static void free_ioapic_saved_registers(int idx)
237	{
238	kfree(objp: ioapics[idx].saved_registers);
239	ioapics[idx].saved_registers = NULL;
240	}
241
242	int __init arch_early_ioapic_init(void)
243	{
244	int i;
245
246	if (!nr_legacy_irqs())
247	io_apic_irqs = ~0UL;
248
249	for_each_ioapic(i)
250	alloc_ioapic_saved_registers(idx: i);
251
252	return 0;
253	}
254
255	struct io_apic {
256	unsigned int index;
257	unsigned int unused[3];
258	unsigned int data;
259	unsigned int unused2[11];
260	unsigned int eoi;
261	};
262
263	static __attribute_const__ struct io_apic __iomem *io_apic_base(int idx)
264	{
265	return (void __iomem *) __fix_to_virt(FIX_IO_APIC_BASE_0 + idx)
266	+ (mpc_ioapic_addr(ioapic_idx: idx) & ~PAGE_MASK);
267	}
268
269	static inline void io_apic_eoi(unsigned int apic, unsigned int vector)
270	{
271	struct io_apic __iomem *io_apic = io_apic_base(idx: apic);
272	writel(val: vector, addr: &io_apic->eoi);
273	}
274
275	unsigned int native_io_apic_read(unsigned int apic, unsigned int reg)
276	{
277	struct io_apic __iomem *io_apic = io_apic_base(idx: apic);
278	writel(val: reg, addr: &io_apic->index);
279	return readl(addr: &io_apic->data);
280	}
281
282	static void io_apic_write(unsigned int apic, unsigned int reg,
283	unsigned int value)
284	{
285	struct io_apic __iomem *io_apic = io_apic_base(idx: apic);
286
287	writel(val: reg, addr: &io_apic->index);
288	writel(val: value, addr: &io_apic->data);
289	}
290
291	static struct IO_APIC_route_entry __ioapic_read_entry(int apic, int pin)
292	{
293	struct IO_APIC_route_entry entry;
294
295	entry.w1 = io_apic_read(apic, reg: 0x10 + 2 * pin);
296	entry.w2 = io_apic_read(apic, reg: 0x11 + 2 * pin);
297
298	return entry;
299	}
300
301	static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
302	{
303	struct IO_APIC_route_entry entry;
304	unsigned long flags;
305
306	raw_spin_lock_irqsave(&ioapic_lock, flags);
307	entry = __ioapic_read_entry(apic, pin);
308	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
309
310	return entry;
311	}
312
313	/*
314	* When we write a new IO APIC routing entry, we need to write the high
315	* word first! If the mask bit in the low word is clear, we will enable
316	* the interrupt, and we need to make sure the entry is fully populated
317	* before that happens.
318	*/
319	static void __ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
320	{
321	io_apic_write(apic, reg: 0x11 + 2*pin, value: e.w2);
322	io_apic_write(apic, reg: 0x10 + 2*pin, value: e.w1);
323	}
324
325	static void ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
326	{
327	unsigned long flags;
328
329	raw_spin_lock_irqsave(&ioapic_lock, flags);
330	__ioapic_write_entry(apic, pin, e);
331	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
332	}
333
334	/*
335	* When we mask an IO APIC routing entry, we need to write the low
336	* word first, in order to set the mask bit before we change the
337	* high bits!
338	*/
339	static void ioapic_mask_entry(int apic, int pin)
340	{
341	struct IO_APIC_route_entry e = { .masked = true };
342	unsigned long flags;
343
344	raw_spin_lock_irqsave(&ioapic_lock, flags);
345	io_apic_write(apic, reg: 0x10 + 2*pin, value: e.w1);
346	io_apic_write(apic, reg: 0x11 + 2*pin, value: e.w2);
347	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
348	}
349
350	/*
351	* The common case is 1:1 IRQ<->pin mappings. Sometimes there are
352	* shared ISA-space IRQs, so we have to support them. We are super
353	* fast in the common case, and fast for shared ISA-space IRQs.
354	*/
355	static int __add_pin_to_irq_node(struct mp_chip_data *data,
356	int node, int apic, int pin)
357	{
358	struct irq_pin_list *entry;
359
360	/* don't allow duplicates */
361	for_each_irq_pin(entry, data->irq_2_pin)
362	if (entry->apic == apic && entry->pin == pin)
363	return 0;
364
365	entry = kzalloc_node(size: sizeof(struct irq_pin_list), GFP_ATOMIC, node);
366	if (!entry) {
367	pr_err("can not alloc irq_pin_list (%d,%d,%d)\n",
368	node, apic, pin);
369	return -ENOMEM;
370	}
371	entry->apic = apic;
372	entry->pin = pin;
373	list_add_tail(new: &entry->list, head: &data->irq_2_pin);
374
375	return 0;
376	}
377
378	static void __remove_pin_from_irq(struct mp_chip_data *data, int apic, int pin)
379	{
380	struct irq_pin_list *tmp, *entry;
381
382	list_for_each_entry_safe(entry, tmp, &data->irq_2_pin, list)
383	if (entry->apic == apic && entry->pin == pin) {
384	list_del(entry: &entry->list);
385	kfree(objp: entry);
386	return;
387	}
388	}
389
390	static void add_pin_to_irq_node(struct mp_chip_data *data,
391	int node, int apic, int pin)
392	{
393	if (__add_pin_to_irq_node(data, node, apic, pin))
394	panic(fmt: "IO-APIC: failed to add irq-pin. Can not proceed\n");
395	}
396
397	/*
398	* Reroute an IRQ to a different pin.
399	*/
400	static void __init replace_pin_at_irq_node(struct mp_chip_data *data, int node,
401	int oldapic, int oldpin,
402	int newapic, int newpin)
403	{
404	struct irq_pin_list *entry;
405
406	for_each_irq_pin(entry, data->irq_2_pin) {
407	if (entry->apic == oldapic && entry->pin == oldpin) {
408	entry->apic = newapic;
409	entry->pin = newpin;
410	/* every one is different, right? */
411	return;
412	}
413	}
414
415	/* old apic/pin didn't exist, so just add new ones */
416	add_pin_to_irq_node(data, node, apic: newapic, pin: newpin);
417	}
418
419	static void io_apic_modify_irq(struct mp_chip_data *data, bool masked,
420	void (*final)(struct irq_pin_list *entry))
421	{
422	struct irq_pin_list *entry;
423
424	data->entry.masked = masked;
425
426	for_each_irq_pin(entry, data->irq_2_pin) {
427	io_apic_write(apic: entry->apic, reg: 0x10 + 2 * entry->pin, value: data->entry.w1);
428	if (final)
429	final(entry);
430	}
431	}
432
433	static void io_apic_sync(struct irq_pin_list *entry)
434	{
435	/*
436	* Synchronize the IO-APIC and the CPU by doing
437	* a dummy read from the IO-APIC
438	*/
439	struct io_apic __iomem *io_apic;
440
441	io_apic = io_apic_base(idx: entry->apic);
442	readl(addr: &io_apic->data);
443	}
444
445	static void mask_ioapic_irq(struct irq_data *irq_data)
446	{
447	struct mp_chip_data *data = irq_data->chip_data;
448	unsigned long flags;
449
450	raw_spin_lock_irqsave(&ioapic_lock, flags);
451	io_apic_modify_irq(data, masked: true, final: &io_apic_sync);
452	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
453	}
454
455	static void __unmask_ioapic(struct mp_chip_data *data)
456	{
457	io_apic_modify_irq(data, masked: false, NULL);
458	}
459
460	static void unmask_ioapic_irq(struct irq_data *irq_data)
461	{
462	struct mp_chip_data *data = irq_data->chip_data;
463	unsigned long flags;
464
465	raw_spin_lock_irqsave(&ioapic_lock, flags);
466	__unmask_ioapic(data);
467	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
468	}
469
470	/*
471	* IO-APIC versions below 0x20 don't support EOI register.
472	* For the record, here is the information about various versions:
473	* 0Xh 82489DX
474	* 1Xh I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant
475	* 2Xh I/O(x)APIC which is PCI 2.2 Compliant
476	* 30h-FFh Reserved
477	*
478	* Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic
479	* version as 0x2. This is an error with documentation and these ICH chips
480	* use io-apic's of version 0x20.
481	*
482	* For IO-APIC's with EOI register, we use that to do an explicit EOI.
483	* Otherwise, we simulate the EOI message manually by changing the trigger
484	* mode to edge and then back to level, with RTE being masked during this.
485	*/
486	static void __eoi_ioapic_pin(int apic, int pin, int vector)
487	{
488	if (mpc_ioapic_ver(apic) >= 0x20) {
489	io_apic_eoi(apic, vector);
490	} else {
491	struct IO_APIC_route_entry entry, entry1;
492
493	entry = entry1 = __ioapic_read_entry(apic, pin);
494
495	/*
496	* Mask the entry and change the trigger mode to edge.
497	*/
498	entry1.masked = true;
499	entry1.is_level = false;
500
501	__ioapic_write_entry(apic, pin, e: entry1);
502
503	/*
504	* Restore the previous level triggered entry.
505	*/
506	__ioapic_write_entry(apic, pin, e: entry);
507	}
508	}
509
510	static void eoi_ioapic_pin(int vector, struct mp_chip_data *data)
511	{
512	unsigned long flags;
513	struct irq_pin_list *entry;
514
515	raw_spin_lock_irqsave(&ioapic_lock, flags);
516	for_each_irq_pin(entry, data->irq_2_pin)
517	__eoi_ioapic_pin(apic: entry->apic, pin: entry->pin, vector);
518	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
519	}
520
521	static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
522	{
523	struct IO_APIC_route_entry entry;
524
525	/* Check delivery_mode to be sure we're not clearing an SMI pin */
526	entry = ioapic_read_entry(apic, pin);
527	if (entry.delivery_mode == APIC_DELIVERY_MODE_SMI)
528	return;
529
530	/*
531	* Make sure the entry is masked and re-read the contents to check
532	* if it is a level triggered pin and if the remote-IRR is set.
533	*/
534	if (!entry.masked) {
535	entry.masked = true;
536	ioapic_write_entry(apic, pin, e: entry);
537	entry = ioapic_read_entry(apic, pin);
538	}
539
540	if (entry.irr) {
541	unsigned long flags;
542
543	/*
544	* Make sure the trigger mode is set to level. Explicit EOI
545	* doesn't clear the remote-IRR if the trigger mode is not
546	* set to level.
547	*/
548	if (!entry.is_level) {
549	entry.is_level = true;
550	ioapic_write_entry(apic, pin, e: entry);
551	}
552	raw_spin_lock_irqsave(&ioapic_lock, flags);
553	__eoi_ioapic_pin(apic, pin, vector: entry.vector);
554	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
555	}
556
557	/*
558	* Clear the rest of the bits in the IO-APIC RTE except for the mask
559	* bit.
560	*/
561	ioapic_mask_entry(apic, pin);
562	entry = ioapic_read_entry(apic, pin);
563	if (entry.irr)
564	pr_err("Unable to reset IRR for apic: %d, pin :%d\n",
565	mpc_ioapic_id(apic), pin);
566	}
567
568	void clear_IO_APIC (void)
569	{
570	int apic, pin;
571
572	for_each_ioapic_pin(apic, pin)
573	clear_IO_APIC_pin(apic, pin);
574	}
575
576	#ifdef CONFIG_X86_32
577	/*
578	* support for broken MP BIOSs, enables hand-redirection of PIRQ0-7 to
579	* specific CPU-side IRQs.
580	*/
581
582	#define MAX_PIRQS 8
583	static int pirq_entries[MAX_PIRQS] = {
584	[0 ... MAX_PIRQS - 1] = -1
585	};
586
587	static int __init ioapic_pirq_setup(char *str)
588	{
589	int i, max;
590	int ints[MAX_PIRQS+1];
591
592	get_options(str, ARRAY_SIZE(ints), ints);
593
594	apic_printk(APIC_VERBOSE, KERN_INFO
595	"PIRQ redirection, working around broken MP-BIOS.\n");
596	max = MAX_PIRQS;
597	if (ints[0] < MAX_PIRQS)
598	max = ints[0];
599
600	for (i = 0; i < max; i++) {
601	apic_printk(APIC_VERBOSE, KERN_DEBUG
602	"... PIRQ%d -> IRQ %d\n", i, ints[i+1]);
603	/*
604	* PIRQs are mapped upside down, usually.
605	*/
606	pirq_entries[MAX_PIRQS-i-1] = ints[i+1];
607	}
608	return 1;
609	}
610
611	__setup("pirq=", ioapic_pirq_setup);
612	#endif /* CONFIG_X86_32 */
613
614	/*
615	* Saves all the IO-APIC RTE's
616	*/
617	int save_ioapic_entries(void)
618	{
619	int apic, pin;
620	int err = 0;
621
622	for_each_ioapic(apic) {
623	if (!ioapics[apic].saved_registers) {
624	err = -ENOMEM;
625	continue;
626	}
627
628	for_each_pin(apic, pin)
629	ioapics[apic].saved_registers[pin] =
630	ioapic_read_entry(apic, pin);
631	}
632
633	return err;
634	}
635
636	/*
637	* Mask all IO APIC entries.
638	*/
639	void mask_ioapic_entries(void)
640	{
641	int apic, pin;
642
643	for_each_ioapic(apic) {
644	if (!ioapics[apic].saved_registers)
645	continue;
646
647	for_each_pin(apic, pin) {
648	struct IO_APIC_route_entry entry;
649
650	entry = ioapics[apic].saved_registers[pin];
651	if (!entry.masked) {
652	entry.masked = true;
653	ioapic_write_entry(apic, pin, e: entry);
654	}
655	}
656	}
657	}
658
659	/*
660	* Restore IO APIC entries which was saved in the ioapic structure.
661	*/
662	int restore_ioapic_entries(void)
663	{
664	int apic, pin;
665
666	for_each_ioapic(apic) {
667	if (!ioapics[apic].saved_registers)
668	continue;
669
670	for_each_pin(apic, pin)
671	ioapic_write_entry(apic, pin,
672	e: ioapics[apic].saved_registers[pin]);
673	}
674	return 0;
675	}
676
677	/*
678	* Find the IRQ entry number of a certain pin.
679	*/
680	static int find_irq_entry(int ioapic_idx, int pin, int type)
681	{
682	int i;
683
684	for (i = 0; i < mp_irq_entries; i++)
685	if (mp_irqs[i].irqtype == type &&
686	(mp_irqs[i].dstapic == mpc_ioapic_id(ioapic_idx) ||
687	mp_irqs[i].dstapic == MP_APIC_ALL) &&
688	mp_irqs[i].dstirq == pin)
689	return i;
690
691	return -1;
692	}
693
694	/*
695	* Find the pin to which IRQ[irq] (ISA) is connected
696	*/
697	static int __init find_isa_irq_pin(int irq, int type)
698	{
699	int i;
700
701	for (i = 0; i < mp_irq_entries; i++) {
702	int lbus = mp_irqs[i].srcbus;
703
704	if (test_bit(lbus, mp_bus_not_pci) &&
705	(mp_irqs[i].irqtype == type) &&
706	(mp_irqs[i].srcbusirq == irq))
707
708	return mp_irqs[i].dstirq;
709	}
710	return -1;
711	}
712
713	static int __init find_isa_irq_apic(int irq, int type)
714	{
715	int i;
716
717	for (i = 0; i < mp_irq_entries; i++) {
718	int lbus = mp_irqs[i].srcbus;
719
720	if (test_bit(lbus, mp_bus_not_pci) &&
721	(mp_irqs[i].irqtype == type) &&
722	(mp_irqs[i].srcbusirq == irq))
723	break;
724	}
725
726	if (i < mp_irq_entries) {
727	int ioapic_idx;
728
729	for_each_ioapic(ioapic_idx)
730	if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic)
731	return ioapic_idx;
732	}
733
734	return -1;
735	}
736
737	static bool irq_active_low(int idx)
738	{
739	int bus = mp_irqs[idx].srcbus;
740
741	/*
742	* Determine IRQ line polarity (high active or low active):
743	*/
744	switch (mp_irqs[idx].irqflag & MP_IRQPOL_MASK) {
745	case MP_IRQPOL_DEFAULT:
746	/*
747	* Conforms to spec, ie. bus-type dependent polarity. PCI
748	* defaults to low active. [E]ISA defaults to high active.
749	*/
750	return !test_bit(bus, mp_bus_not_pci);
751	case MP_IRQPOL_ACTIVE_HIGH:
752	return false;
753	case MP_IRQPOL_RESERVED:
754	pr_warn("IOAPIC: Invalid polarity: 2, defaulting to low\n");
755	fallthrough;
756	case MP_IRQPOL_ACTIVE_LOW:
757	default: /* Pointless default required due to do gcc stupidity */
758	return true;
759	}
760	}
761
762	#ifdef CONFIG_EISA
763	/*
764	* EISA Edge/Level control register, ELCR
765	*/
766	static bool EISA_ELCR(unsigned int irq)
767	{
768	if (irq < nr_legacy_irqs()) {
769	unsigned int port = PIC_ELCR1 + (irq >> 3);
770	return (inb(port) >> (irq & 7)) & 1;
771	}
772	apic_printk(APIC_VERBOSE, KERN_INFO
773	"Broken MPtable reports ISA irq %d\n", irq);
774	return false;
775	}
776
777	/*
778	* EISA interrupts are always active high and can be edge or level
779	* triggered depending on the ELCR value. If an interrupt is listed as
780	* EISA conforming in the MP table, that means its trigger type must be
781	* read in from the ELCR.
782	*/
783	static bool eisa_irq_is_level(int idx, int bus, bool level)
784	{
785	switch (mp_bus_id_to_type[bus]) {
786	case MP_BUS_PCI:
787	case MP_BUS_ISA:
788	return level;
789	case MP_BUS_EISA:
790	return EISA_ELCR(irq: mp_irqs[idx].srcbusirq);
791	}
792	pr_warn("IOAPIC: Invalid srcbus: %d defaulting to level\n", bus);
793	return true;
794	}
795	#else
796	static inline int eisa_irq_is_level(int idx, int bus, bool level)
797	{
798	return level;
799	}
800	#endif
801
802	static bool irq_is_level(int idx)
803	{
804	int bus = mp_irqs[idx].srcbus;
805	bool level;
806
807	/*
808	* Determine IRQ trigger mode (edge or level sensitive):
809	*/
810	switch (mp_irqs[idx].irqflag & MP_IRQTRIG_MASK) {
811	case MP_IRQTRIG_DEFAULT:
812	/*
813	* Conforms to spec, ie. bus-type dependent trigger
814	* mode. PCI defaults to level, ISA to edge.
815	*/
816	level = !test_bit(bus, mp_bus_not_pci);
817	/* Take EISA into account */
818	return eisa_irq_is_level(idx, bus, level);
819	case MP_IRQTRIG_EDGE:
820	return false;
821	case MP_IRQTRIG_RESERVED:
822	pr_warn("IOAPIC: Invalid trigger mode 2 defaulting to level\n");
823	fallthrough;
824	case MP_IRQTRIG_LEVEL:
825	default: /* Pointless default required due to do gcc stupidity */
826	return true;
827	}
828	}
829
830	static int __acpi_get_override_irq(u32 gsi, bool *trigger, bool *polarity)
831	{
832	int ioapic, pin, idx;
833
834	if (ioapic_is_disabled)
835	return -1;
836
837	ioapic = mp_find_ioapic(gsi);
838	if (ioapic < 0)
839	return -1;
840
841	pin = mp_find_ioapic_pin(ioapic, gsi);
842	if (pin < 0)
843	return -1;
844
845	idx = find_irq_entry(ioapic_idx: ioapic, pin, type: mp_INT);
846	if (idx < 0)
847	return -1;
848
849	*trigger = irq_is_level(idx);
850	*polarity = irq_active_low(idx);
851	return 0;
852	}
853
854	#ifdef CONFIG_ACPI
855	int acpi_get_override_irq(u32 gsi, int *is_level, int *active_low)
856	{
857	*is_level = *active_low = 0;
858	return __acpi_get_override_irq(gsi, trigger: (bool *)is_level,
859	polarity: (bool *)active_low);
860	}
861	#endif
862
863	void ioapic_set_alloc_attr(struct irq_alloc_info *info, int node,
864	int trigger, int polarity)
865	{
866	init_irq_alloc_info(info, NULL);
867	info->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
868	info->ioapic.node = node;
869	info->ioapic.is_level = trigger;
870	info->ioapic.active_low = polarity;
871	info->ioapic.valid = 1;
872	}
873
874	static void ioapic_copy_alloc_attr(struct irq_alloc_info *dst,
875	struct irq_alloc_info *src,
876	u32 gsi, int ioapic_idx, int pin)
877	{
878	bool level, pol_low;
879
880	copy_irq_alloc_info(dst, src);
881	dst->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
882	dst->devid = mpc_ioapic_id(ioapic_idx);
883	dst->ioapic.pin = pin;
884	dst->ioapic.valid = 1;
885	if (src && src->ioapic.valid) {
886	dst->ioapic.node = src->ioapic.node;
887	dst->ioapic.is_level = src->ioapic.is_level;
888	dst->ioapic.active_low = src->ioapic.active_low;
889	} else {
890	dst->ioapic.node = NUMA_NO_NODE;
891	if (__acpi_get_override_irq(gsi, trigger: &level, polarity: &pol_low) >= 0) {
892	dst->ioapic.is_level = level;
893	dst->ioapic.active_low = pol_low;
894	} else {
895	/*
896	* PCI interrupts are always active low level
897	* triggered.
898	*/
899	dst->ioapic.is_level = true;
900	dst->ioapic.active_low = true;
901	}
902	}
903	}
904
905	static int ioapic_alloc_attr_node(struct irq_alloc_info *info)
906	{
907	return (info && info->ioapic.valid) ? info->ioapic.node : NUMA_NO_NODE;
908	}
909
910	static void mp_register_handler(unsigned int irq, bool level)
911	{
912	irq_flow_handler_t hdl;
913	bool fasteoi;
914
915	if (level) {
916	irq_set_status_flags(irq, set: IRQ_LEVEL);
917	fasteoi = true;
918	} else {
919	irq_clear_status_flags(irq, clr: IRQ_LEVEL);
920	fasteoi = false;
921	}
922
923	hdl = fasteoi ? handle_fasteoi_irq : handle_edge_irq;
924	__irq_set_handler(irq, handle: hdl, is_chained: 0, name: fasteoi ? "fasteoi" : "edge");
925	}
926
927	static bool mp_check_pin_attr(int irq, struct irq_alloc_info *info)
928	{
929	struct mp_chip_data *data = irq_get_chip_data(irq);
930
931	/*
932	* setup_IO_APIC_irqs() programs all legacy IRQs with default trigger
933	* and polarity attributes. So allow the first user to reprogram the
934	* pin with real trigger and polarity attributes.
935	*/
936	if (irq < nr_legacy_irqs() && data->count == 1) {
937	if (info->ioapic.is_level != data->is_level)
938	mp_register_handler(irq, level: info->ioapic.is_level);
939	data->entry.is_level = data->is_level = info->ioapic.is_level;
940	data->entry.active_low = data->active_low = info->ioapic.active_low;
941	}
942
943	return data->is_level == info->ioapic.is_level &&
944	data->active_low == info->ioapic.active_low;
945	}
946
947	static int alloc_irq_from_domain(struct irq_domain *domain, int ioapic, u32 gsi,
948	struct irq_alloc_info *info)
949	{
950	bool legacy = false;
951	int irq = -1;
952	int type = ioapics[ioapic].irqdomain_cfg.type;
953
954	switch (type) {
955	case IOAPIC_DOMAIN_LEGACY:
956	/*
957	* Dynamically allocate IRQ number for non-ISA IRQs in the first
958	* 16 GSIs on some weird platforms.
959	*/
960	if (!ioapic_initialized || gsi >= nr_legacy_irqs())
961	irq = gsi;
962	legacy = mp_is_legacy_irq(irq);
963	break;
964	case IOAPIC_DOMAIN_STRICT:
965	irq = gsi;
966	break;
967	case IOAPIC_DOMAIN_DYNAMIC:
968	break;
969	default:
970	WARN(1, "ioapic: unknown irqdomain type %d\n", type);
971	return -1;
972	}
973
974	return __irq_domain_alloc_irqs(domain, irq_base: irq, nr_irqs: 1,
975	node: ioapic_alloc_attr_node(info),
976	arg: info, realloc: legacy, NULL);
977	}
978
979	/*
980	* Need special handling for ISA IRQs because there may be multiple IOAPIC pins
981	* sharing the same ISA IRQ number and irqdomain only supports 1:1 mapping
982	* between IOAPIC pin and IRQ number. A typical IOAPIC has 24 pins, pin 0-15 are
983	* used for legacy IRQs and pin 16-23 are used for PCI IRQs (PIRQ A-H).
984	* When ACPI is disabled, only legacy IRQ numbers (IRQ0-15) are available, and
985	* some BIOSes may use MP Interrupt Source records to override IRQ numbers for
986	* PIRQs instead of reprogramming the interrupt routing logic. Thus there may be
987	* multiple pins sharing the same legacy IRQ number when ACPI is disabled.
988	*/
989	static int alloc_isa_irq_from_domain(struct irq_domain *domain,
990	int irq, int ioapic, int pin,
991	struct irq_alloc_info *info)
992	{
993	struct mp_chip_data *data;
994	struct irq_data *irq_data = irq_get_irq_data(irq);
995	int node = ioapic_alloc_attr_node(info);
996
997	/*
998	* Legacy ISA IRQ has already been allocated, just add pin to
999	* the pin list associated with this IRQ and program the IOAPIC
1000	* entry. The IOAPIC entry
1001	*/
1002	if (irq_data && irq_data->parent_data) {
1003	if (!mp_check_pin_attr(irq, info))
1004	return -EBUSY;
1005	if (__add_pin_to_irq_node(data: irq_data->chip_data, node, apic: ioapic,
1006	pin: info->ioapic.pin))
1007	return -ENOMEM;
1008	} else {
1009	info->flags |= X86_IRQ_ALLOC_LEGACY;
1010	irq = __irq_domain_alloc_irqs(domain, irq_base: irq, nr_irqs: 1, node, arg: info, realloc: true,
1011	NULL);
1012	if (irq >= 0) {
1013	irq_data = irq_domain_get_irq_data(domain, virq: irq);
1014	data = irq_data->chip_data;
1015	data->isa_irq = true;
1016	}
1017	}
1018
1019	return irq;
1020	}
1021
1022	static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin,
1023	unsigned int flags, struct irq_alloc_info *info)
1024	{
1025	int irq;
1026	bool legacy = false;
1027	struct irq_alloc_info tmp;
1028	struct mp_chip_data *data;
1029	struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
1030
1031	if (!domain)
1032	return -ENOSYS;
1033
1034	if (idx >= 0 && test_bit(mp_irqs[idx].srcbus, mp_bus_not_pci)) {
1035	irq = mp_irqs[idx].srcbusirq;
1036	legacy = mp_is_legacy_irq(irq);
1037	/*
1038	* IRQ2 is unusable for historical reasons on systems which
1039	* have a legacy PIC. See the comment vs. IRQ2 further down.
1040	*
1041	* If this gets removed at some point then the related code
1042	* in lapic_assign_system_vectors() needs to be adjusted as
1043	* well.
1044	*/
1045	if (legacy && irq == PIC_CASCADE_IR)
1046	return -EINVAL;
1047	}
1048
1049	mutex_lock(&ioapic_mutex);
1050	if (!(flags & IOAPIC_MAP_ALLOC)) {
1051	if (!legacy) {
1052	irq = irq_find_mapping(domain, hwirq: pin);
1053	if (irq == 0)
1054	irq = -ENOENT;
1055	}
1056	} else {
1057	ioapic_copy_alloc_attr(dst: &tmp, src: info, gsi, ioapic_idx: ioapic, pin);
1058	if (legacy)
1059	irq = alloc_isa_irq_from_domain(domain, irq,
1060	ioapic, pin, info: &tmp);
1061	else if ((irq = irq_find_mapping(domain, hwirq: pin)) == 0)
1062	irq = alloc_irq_from_domain(domain, ioapic, gsi, info: &tmp);
1063	else if (!mp_check_pin_attr(irq, info: &tmp))
1064	irq = -EBUSY;
1065	if (irq >= 0) {
1066	data = irq_get_chip_data(irq);
1067	data->count++;
1068	}
1069	}
1070	mutex_unlock(lock: &ioapic_mutex);
1071
1072	return irq;
1073	}
1074
1075	static int pin_2_irq(int idx, int ioapic, int pin, unsigned int flags)
1076	{
1077	u32 gsi = mp_pin_to_gsi(ioapic, pin);
1078
1079	/*
1080	* Debugging check, we are in big trouble if this message pops up!
1081	*/
1082	if (mp_irqs[idx].dstirq != pin)
1083	pr_err("broken BIOS or MPTABLE parser, ayiee!!\n");
1084
1085	#ifdef CONFIG_X86_32
1086	/*
1087	* PCI IRQ command line redirection. Yes, limits are hardcoded.
1088	*/
1089	if ((pin >= 16) && (pin <= 23)) {
1090	if (pirq_entries[pin-16] != -1) {
1091	if (!pirq_entries[pin-16]) {
1092	apic_printk(APIC_VERBOSE, KERN_DEBUG
1093	"disabling PIRQ%d\n", pin-16);
1094	} else {
1095	int irq = pirq_entries[pin-16];
1096	apic_printk(APIC_VERBOSE, KERN_DEBUG
1097	"using PIRQ%d -> IRQ %d\n",
1098	pin-16, irq);
1099	return irq;
1100	}
1101	}
1102	}
1103	#endif
1104
1105	return mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, NULL);
1106	}
1107
1108	int mp_map_gsi_to_irq(u32 gsi, unsigned int flags, struct irq_alloc_info *info)
1109	{
1110	int ioapic, pin, idx;
1111
1112	ioapic = mp_find_ioapic(gsi);
1113	if (ioapic < 0)
1114	return -ENODEV;
1115
1116	pin = mp_find_ioapic_pin(ioapic, gsi);
1117	idx = find_irq_entry(ioapic_idx: ioapic, pin, type: mp_INT);
1118	if ((flags & IOAPIC_MAP_CHECK) && idx < 0)
1119	return -ENODEV;
1120
1121	return mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, info);
1122	}
1123
1124	void mp_unmap_irq(int irq)
1125	{
1126	struct irq_data *irq_data = irq_get_irq_data(irq);
1127	struct mp_chip_data *data;
1128
1129	if (!irq_data || !irq_data->domain)
1130	return;
1131
1132	data = irq_data->chip_data;
1133	if (!data || data->isa_irq)
1134	return;
1135
1136	mutex_lock(&ioapic_mutex);
1137	if (--data->count == 0)
1138	irq_domain_free_irqs(virq: irq, nr_irqs: 1);
1139	mutex_unlock(lock: &ioapic_mutex);
1140	}
1141
1142	/*
1143	* Find a specific PCI IRQ entry.
1144	* Not an __init, possibly needed by modules
1145	*/
1146	int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin)
1147	{
1148	int irq, i, best_ioapic = -1, best_idx = -1;
1149
1150	apic_printk(APIC_DEBUG,
1151	"querying PCI -> IRQ mapping bus:%d, slot:%d, pin:%d.\n",
1152	bus, slot, pin);
1153	if (test_bit(bus, mp_bus_not_pci)) {
1154	apic_printk(APIC_VERBOSE,
1155	"PCI BIOS passed nonexistent PCI bus %d!\n", bus);
1156	return -1;
1157	}
1158
1159	for (i = 0; i < mp_irq_entries; i++) {
1160	int lbus = mp_irqs[i].srcbus;
1161	int ioapic_idx, found = 0;
1162
1163	if (bus != lbus || mp_irqs[i].irqtype != mp_INT ||
1164	slot != ((mp_irqs[i].srcbusirq >> 2) & 0x1f))
1165	continue;
1166
1167	for_each_ioapic(ioapic_idx)
1168	if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic ||
1169	mp_irqs[i].dstapic == MP_APIC_ALL) {
1170	found = 1;
1171	break;
1172	}
1173	if (!found)
1174	continue;
1175
1176	/* Skip ISA IRQs */
1177	irq = pin_2_irq(idx: i, ioapic: ioapic_idx, pin: mp_irqs[i].dstirq, flags: 0);
1178	if (irq > 0 && !IO_APIC_IRQ(irq))
1179	continue;
1180
1181	if (pin == (mp_irqs[i].srcbusirq & 3)) {
1182	best_idx = i;
1183	best_ioapic = ioapic_idx;
1184	goto out;
1185	}
1186
1187	/*
1188	* Use the first all-but-pin matching entry as a
1189	* best-guess fuzzy result for broken mptables.
1190	*/
1191	if (best_idx < 0) {
1192	best_idx = i;
1193	best_ioapic = ioapic_idx;
1194	}
1195	}
1196	if (best_idx < 0)
1197	return -1;
1198
1199	out:
1200	return pin_2_irq(idx: best_idx, ioapic: best_ioapic, pin: mp_irqs[best_idx].dstirq,
1201	IOAPIC_MAP_ALLOC);
1202	}
1203	EXPORT_SYMBOL(IO_APIC_get_PCI_irq_vector);
1204
1205	static struct irq_chip ioapic_chip, ioapic_ir_chip;
1206
1207	static void __init setup_IO_APIC_irqs(void)
1208	{
1209	unsigned int ioapic, pin;
1210	int idx;
1211
1212	apic_printk(APIC_VERBOSE, KERN_DEBUG "init IO_APIC IRQs\n");
1213
1214	for_each_ioapic_pin(ioapic, pin) {
1215	idx = find_irq_entry(ioapic_idx: ioapic, pin, type: mp_INT);
1216	if (idx < 0)
1217	apic_printk(APIC_VERBOSE,
1218	KERN_DEBUG " apic %d pin %d not connected\n",
1219	mpc_ioapic_id(ioapic), pin);
1220	else
1221	pin_2_irq(idx, ioapic, pin,
1222	flags: ioapic ? 0 : IOAPIC_MAP_ALLOC);
1223	}
1224	}
1225
1226	void ioapic_zap_locks(void)
1227	{
1228	raw_spin_lock_init(&ioapic_lock);
1229	}
1230
1231	static void io_apic_print_entries(unsigned int apic, unsigned int nr_entries)
1232	{
1233	struct IO_APIC_route_entry entry;
1234	char buf[256];
1235	int i;
1236
1237	printk(KERN_DEBUG "IOAPIC %d:\n", apic);
1238	for (i = 0; i <= nr_entries; i++) {
1239	entry = ioapic_read_entry(apic, pin: i);
1240	snprintf(buf, size: sizeof(buf),
1241	fmt: " pin%02x, %s, %s, %s, V(%02X), IRR(%1d), S(%1d)",
1242	i,
1243	entry.masked ? "disabled" : "enabled ",
1244	entry.is_level ? "level" : "edge ",
1245	entry.active_low ? "low " : "high",
1246	entry.vector, entry.irr, entry.delivery_status);
1247	if (entry.ir_format) {
1248	printk(KERN_DEBUG "%s, remapped, I(%04X), Z(%X)\n",
1249	buf,
1250	(entry.ir_index_15 << 15) | entry.ir_index_0_14,
1251	entry.ir_zero);
1252	} else {
1253	printk(KERN_DEBUG "%s, %s, D(%02X%02X), M(%1d)\n", buf,
1254	entry.dest_mode_logical ? "logical " : "physical",
1255	entry.virt_destid_8_14, entry.destid_0_7,
1256	entry.delivery_mode);
1257	}
1258	}
1259	}
1260
1261	static void __init print_IO_APIC(int ioapic_idx)
1262	{
1263	union IO_APIC_reg_00 reg_00;
1264	union IO_APIC_reg_01 reg_01;
1265	union IO_APIC_reg_02 reg_02;
1266	union IO_APIC_reg_03 reg_03;
1267	unsigned long flags;
1268
1269	raw_spin_lock_irqsave(&ioapic_lock, flags);
1270	reg_00.raw = io_apic_read(apic: ioapic_idx, reg: 0);
1271	reg_01.raw = io_apic_read(apic: ioapic_idx, reg: 1);
1272	if (reg_01.bits.version >= 0x10)
1273	reg_02.raw = io_apic_read(apic: ioapic_idx, reg: 2);
1274	if (reg_01.bits.version >= 0x20)
1275	reg_03.raw = io_apic_read(apic: ioapic_idx, reg: 3);
1276	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1277
1278	printk(KERN_DEBUG "IO APIC #%d......\n", mpc_ioapic_id(ioapic_idx));
1279	printk(KERN_DEBUG ".... register #00: %08X\n", reg_00.raw);
1280	printk(KERN_DEBUG "....... : physical APIC id: %02X\n", reg_00.bits.ID);
1281	printk(KERN_DEBUG "....... : Delivery Type: %X\n", reg_00.bits.delivery_type);
1282	printk(KERN_DEBUG "....... : LTS : %X\n", reg_00.bits.LTS);
1283
1284	printk(KERN_DEBUG ".... register #01: %08X\n", *(int *)&reg_01);
1285	printk(KERN_DEBUG "....... : max redirection entries: %02X\n",
1286	reg_01.bits.entries);
1287
1288	printk(KERN_DEBUG "....... : PRQ implemented: %X\n", reg_01.bits.PRQ);
1289	printk(KERN_DEBUG "....... : IO APIC version: %02X\n",
1290	reg_01.bits.version);
1291
1292	/*
1293	* Some Intel chipsets with IO APIC VERSION of 0x1? don't have reg_02,
1294	* but the value of reg_02 is read as the previous read register
1295	* value, so ignore it if reg_02 == reg_01.
1296	*/
1297	if (reg_01.bits.version >= 0x10 && reg_02.raw != reg_01.raw) {
1298	printk(KERN_DEBUG ".... register #02: %08X\n", reg_02.raw);
1299	printk(KERN_DEBUG "....... : arbitration: %02X\n", reg_02.bits.arbitration);
1300	}
1301
1302	/*
1303	* Some Intel chipsets with IO APIC VERSION of 0x2? don't have reg_02
1304	* or reg_03, but the value of reg_0[23] is read as the previous read
1305	* register value, so ignore it if reg_03 == reg_0[12].
1306	*/
1307	if (reg_01.bits.version >= 0x20 && reg_03.raw != reg_02.raw &&
1308	reg_03.raw != reg_01.raw) {
1309	printk(KERN_DEBUG ".... register #03: %08X\n", reg_03.raw);
1310	printk(KERN_DEBUG "....... : Boot DT : %X\n", reg_03.bits.boot_DT);
1311	}
1312
1313	printk(KERN_DEBUG ".... IRQ redirection table:\n");
1314	io_apic_print_entries(apic: ioapic_idx, nr_entries: reg_01.bits.entries);
1315	}
1316
1317	void __init print_IO_APICs(void)
1318	{
1319	int ioapic_idx;
1320	unsigned int irq;
1321
1322	printk(KERN_DEBUG "number of MP IRQ sources: %d.\n", mp_irq_entries);
1323	for_each_ioapic(ioapic_idx)
1324	printk(KERN_DEBUG "number of IO-APIC #%d registers: %d.\n",
1325	mpc_ioapic_id(ioapic_idx),
1326	ioapics[ioapic_idx].nr_registers);
1327
1328	/*
1329	* We are a bit conservative about what we expect. We have to
1330	* know about every hardware change ASAP.
1331	*/
1332	printk(KERN_INFO "testing the IO APIC.......................\n");
1333
1334	for_each_ioapic(ioapic_idx)
1335	print_IO_APIC(ioapic_idx);
1336
1337	printk(KERN_DEBUG "IRQ to pin mappings:\n");
1338	for_each_active_irq(irq) {
1339	struct irq_pin_list *entry;
1340	struct irq_chip *chip;
1341	struct mp_chip_data *data;
1342
1343	chip = irq_get_chip(irq);
1344	if (chip != &ioapic_chip && chip != &ioapic_ir_chip)
1345	continue;
1346	data = irq_get_chip_data(irq);
1347	if (!data)
1348	continue;
1349	if (list_empty(head: &data->irq_2_pin))
1350	continue;
1351
1352	printk(KERN_DEBUG "IRQ%d ", irq);
1353	for_each_irq_pin(entry, data->irq_2_pin)
1354	pr_cont("-> %d:%d", entry->apic, entry->pin);
1355	pr_cont("\n");
1356	}
1357
1358	printk(KERN_INFO ".................................... done.\n");
1359	}
1360
1361	/* Where if anywhere is the i8259 connect in external int mode */
1362	static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
1363
1364	void __init enable_IO_APIC(void)
1365	{
1366	int i8259_apic, i8259_pin;
1367	int apic, pin;
1368
1369	if (ioapic_is_disabled)
1370	nr_ioapics = 0;
1371
1372	if (!nr_legacy_irqs() || !nr_ioapics)
1373	return;
1374
1375	for_each_ioapic_pin(apic, pin) {
1376	/* See if any of the pins is in ExtINT mode */
1377	struct IO_APIC_route_entry entry = ioapic_read_entry(apic, pin);
1378
1379	/* If the interrupt line is enabled and in ExtInt mode
1380	* I have found the pin where the i8259 is connected.
1381	*/
1382	if (!entry.masked &&
1383	entry.delivery_mode == APIC_DELIVERY_MODE_EXTINT) {
1384	ioapic_i8259.apic = apic;
1385	ioapic_i8259.pin = pin;
1386	goto found_i8259;
1387	}
1388	}
1389	found_i8259:
1390	/* Look to see what if the MP table has reported the ExtINT */
1391	/* If we could not find the appropriate pin by looking at the ioapic
1392	* the i8259 probably is not connected the ioapic but give the
1393	* mptable a chance anyway.
1394	*/
1395	i8259_pin = find_isa_irq_pin(irq: 0, type: mp_ExtINT);
1396	i8259_apic = find_isa_irq_apic(irq: 0, type: mp_ExtINT);
1397	/* Trust the MP table if nothing is setup in the hardware */
1398	if ((ioapic_i8259.pin == -1) && (i8259_pin >= 0)) {
1399	printk(KERN_WARNING "ExtINT not setup in hardware but reported by MP table\n");
1400	ioapic_i8259.pin = i8259_pin;
1401	ioapic_i8259.apic = i8259_apic;
1402	}
1403	/* Complain if the MP table and the hardware disagree */
1404	if (((ioapic_i8259.apic != i8259_apic) || (ioapic_i8259.pin != i8259_pin)) &&
1405	(i8259_pin >= 0) && (ioapic_i8259.pin >= 0))
1406	{
1407	printk(KERN_WARNING "ExtINT in hardware and MP table differ\n");
1408	}
1409
1410	/*
1411	* Do not trust the IO-APIC being empty at bootup
1412	*/
1413	clear_IO_APIC();
1414	}
1415
1416	void native_restore_boot_irq_mode(void)
1417	{
1418	/*
1419	* If the i8259 is routed through an IOAPIC
1420	* Put that IOAPIC in virtual wire mode
1421	* so legacy interrupts can be delivered.
1422	*/
1423	if (ioapic_i8259.pin != -1) {
1424	struct IO_APIC_route_entry entry;
1425	u32 apic_id = read_apic_id();
1426
1427	memset(&entry, 0, sizeof(entry));
1428	entry.masked = false;
1429	entry.is_level = false;
1430	entry.active_low = false;
1431	entry.dest_mode_logical = false;
1432	entry.delivery_mode = APIC_DELIVERY_MODE_EXTINT;
1433	entry.destid_0_7 = apic_id & 0xFF;
1434	entry.virt_destid_8_14 = apic_id >> 8;
1435
1436	/*
1437	* Add it to the IO-APIC irq-routing table:
1438	*/
1439	ioapic_write_entry(apic: ioapic_i8259.apic, pin: ioapic_i8259.pin, e: entry);
1440	}
1441
1442	if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
1443	disconnect_bsp_APIC(virt_wire_setup: ioapic_i8259.pin != -1);
1444	}
1445
1446	void restore_boot_irq_mode(void)
1447	{
1448	if (!nr_legacy_irqs())
1449	return;
1450
1451	x86_apic_ops.restore();
1452	}
1453
1454	#ifdef CONFIG_X86_32
1455	/*
1456	* function to set the IO-APIC physical IDs based on the
1457	* values stored in the MPC table.
1458	*
1459	* by Matt Domsch <Matt_Domsch@dell.com> Tue Dec 21 12:25:05 CST 1999
1460	*/
1461	void __init setup_ioapic_ids_from_mpc_nocheck(void)
1462	{
1463	union IO_APIC_reg_00 reg_00;
1464	physid_mask_t phys_id_present_map;
1465	int ioapic_idx;
1466	int i;
1467	unsigned char old_id;
1468	unsigned long flags;
1469
1470	/*
1471	* This is broken; anything with a real cpu count has to
1472	* circumvent this idiocy regardless.
1473	*/
1474	apic->ioapic_phys_id_map(&phys_cpu_present_map, &phys_id_present_map);
1475
1476	/*
1477	* Set the IOAPIC ID to the value stored in the MPC table.
1478	*/
1479	for_each_ioapic(ioapic_idx) {
1480	/* Read the register 0 value */
1481	raw_spin_lock_irqsave(&ioapic_lock, flags);
1482	reg_00.raw = io_apic_read(ioapic_idx, 0);
1483	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1484
1485	old_id = mpc_ioapic_id(ioapic_idx);
1486
1487	if (mpc_ioapic_id(ioapic_idx) >= get_physical_broadcast()) {
1488	printk(KERN_ERR "BIOS bug, IO-APIC#%d ID is %d in the MPC table!...\n",
1489	ioapic_idx, mpc_ioapic_id(ioapic_idx));
1490	printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
1491	reg_00.bits.ID);
1492	ioapics[ioapic_idx].mp_config.apicid = reg_00.bits.ID;
1493	}
1494
1495	/*
1496	* Sanity check, is the ID really free? Every APIC in a
1497	* system must have a unique ID or we get lots of nice
1498	* 'stuck on smp_invalidate_needed IPI wait' messages.
1499	*/
1500	if (apic->check_apicid_used(&phys_id_present_map,
1501	mpc_ioapic_id(ioapic_idx))) {
1502	printk(KERN_ERR "BIOS bug, IO-APIC#%d ID %d is already used!...\n",
1503	ioapic_idx, mpc_ioapic_id(ioapic_idx));
1504	for (i = 0; i < get_physical_broadcast(); i++)
1505	if (!physid_isset(i, phys_id_present_map))
1506	break;
1507	if (i >= get_physical_broadcast())
1508	panic("Max APIC ID exceeded!\n");
1509	printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
1510	i);
1511	physid_set(i, phys_id_present_map);
1512	ioapics[ioapic_idx].mp_config.apicid = i;
1513	} else {
1514	apic_printk(APIC_VERBOSE, "Setting %d in the phys_id_present_map\n",
1515	mpc_ioapic_id(ioapic_idx));
1516	physid_set(mpc_ioapic_id(ioapic_idx), phys_id_present_map);
1517	}
1518
1519	/*
1520	* We need to adjust the IRQ routing table
1521	* if the ID changed.
1522	*/
1523	if (old_id != mpc_ioapic_id(ioapic_idx))
1524	for (i = 0; i < mp_irq_entries; i++)
1525	if (mp_irqs[i].dstapic == old_id)
1526	mp_irqs[i].dstapic
1527	= mpc_ioapic_id(ioapic_idx);
1528
1529	/*
1530	* Update the ID register according to the right value
1531	* from the MPC table if they are different.
1532	*/
1533	if (mpc_ioapic_id(ioapic_idx) == reg_00.bits.ID)
1534	continue;
1535
1536	apic_printk(APIC_VERBOSE, KERN_INFO
1537	"...changing IO-APIC physical APIC ID to %d ...",
1538	mpc_ioapic_id(ioapic_idx));
1539
1540	reg_00.bits.ID = mpc_ioapic_id(ioapic_idx);
1541	raw_spin_lock_irqsave(&ioapic_lock, flags);
1542	io_apic_write(ioapic_idx, 0, reg_00.raw);
1543	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1544
1545	/*
1546	* Sanity check
1547	*/
1548	raw_spin_lock_irqsave(&ioapic_lock, flags);
1549	reg_00.raw = io_apic_read(ioapic_idx, 0);
1550	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1551	if (reg_00.bits.ID != mpc_ioapic_id(ioapic_idx))
1552	pr_cont("could not set ID!\n");
1553	else
1554	apic_printk(APIC_VERBOSE, " ok.\n");
1555	}
1556	}
1557
1558	void __init setup_ioapic_ids_from_mpc(void)
1559	{
1560
1561	if (acpi_ioapic)
1562	return;
1563	/*
1564	* Don't check I/O APIC IDs for xAPIC systems. They have
1565	* no meaning without the serial APIC bus.
1566	*/
1567	if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
1568	|| APIC_XAPIC(boot_cpu_apic_version))
1569	return;
1570	setup_ioapic_ids_from_mpc_nocheck();
1571	}
1572	#endif
1573
1574	int no_timer_check __initdata;
1575
1576	static int __init notimercheck(char *s)
1577	{
1578	no_timer_check = 1;
1579	return 1;
1580	}
1581	__setup("no_timer_check", notimercheck);
1582
1583	static void __init delay_with_tsc(void)
1584	{
1585	unsigned long long start, now;
1586	unsigned long end = jiffies + 4;
1587
1588	start = rdtsc();
1589
1590	/*
1591	* We don't know the TSC frequency yet, but waiting for
1592	* 40000000000/HZ TSC cycles is safe:
1593	* 4 GHz == 10 jiffies
1594	* 1 GHz == 40 jiffies
1595	*/
1596	do {
1597	rep_nop();
1598	now = rdtsc();
1599	} while ((now - start) < 40000000000ULL / HZ &&
1600	time_before_eq(jiffies, end));
1601	}
1602
1603	static void __init delay_without_tsc(void)
1604	{
1605	unsigned long end = jiffies + 4;
1606	int band = 1;
1607
1608	/*
1609	* We don't know any frequency yet, but waiting for
1610	* 40940000000/HZ cycles is safe:
1611	* 4 GHz == 10 jiffies
1612	* 1 GHz == 40 jiffies
1613	* 1 << 1 + 1 << 2 +...+ 1 << 11 = 4094
1614	*/
1615	do {
1616	__delay(loops: ((1U << band++) * 10000000UL) / HZ);
1617	} while (band < 12 && time_before_eq(jiffies, end));
1618	}
1619
1620	/*
1621	* There is a nasty bug in some older SMP boards, their mptable lies
1622	* about the timer IRQ. We do the following to work around the situation:
1623	*
1624	* - timer IRQ defaults to IO-APIC IRQ
1625	* - if this function detects that timer IRQs are defunct, then we fall
1626	* back to ISA timer IRQs
1627	*/
1628	static int __init timer_irq_works(void)
1629	{
1630	unsigned long t1 = jiffies;
1631
1632	if (no_timer_check)
1633	return 1;
1634
1635	local_irq_enable();
1636	if (boot_cpu_has(X86_FEATURE_TSC))
1637	delay_with_tsc();
1638	else
1639	delay_without_tsc();
1640
1641	/*
1642	* Expect a few ticks at least, to be sure some possible
1643	* glue logic does not lock up after one or two first
1644	* ticks in a non-ExtINT mode. Also the local APIC
1645	* might have cached one ExtINT interrupt. Finally, at
1646	* least one tick may be lost due to delays.
1647	*/
1648
1649	local_irq_disable();
1650
1651	/* Did jiffies advance? */
1652	return time_after(jiffies, t1 + 4);
1653	}
1654
1655	/*
1656	* In the SMP+IOAPIC case it might happen that there are an unspecified
1657	* number of pending IRQ events unhandled. These cases are very rare,
1658	* so we 'resend' these IRQs via IPIs, to the same CPU. It's much
1659	* better to do it this way as thus we do not have to be aware of
1660	* 'pending' interrupts in the IRQ path, except at this point.
1661	*/
1662	/*
1663	* Edge triggered needs to resend any interrupt
1664	* that was delayed but this is now handled in the device
1665	* independent code.
1666	*/
1667
1668	/*
1669	* Starting up a edge-triggered IO-APIC interrupt is
1670	* nasty - we need to make sure that we get the edge.
1671	* If it is already asserted for some reason, we need
1672	* return 1 to indicate that is was pending.
1673	*
1674	* This is not complete - we should be able to fake
1675	* an edge even if it isn't on the 8259A...
1676	*/
1677	static unsigned int startup_ioapic_irq(struct irq_data *data)
1678	{
1679	int was_pending = 0, irq = data->irq;
1680	unsigned long flags;
1681
1682	raw_spin_lock_irqsave(&ioapic_lock, flags);
1683	if (irq < nr_legacy_irqs()) {
1684	legacy_pic->mask(irq);
1685	if (legacy_pic->irq_pending(irq))
1686	was_pending = 1;
1687	}
1688	__unmask_ioapic(data: data->chip_data);
1689	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1690
1691	return was_pending;
1692	}
1693
1694	atomic_t irq_mis_count;
1695
1696	#ifdef CONFIG_GENERIC_PENDING_IRQ
1697	static bool io_apic_level_ack_pending(struct mp_chip_data *data)
1698	{
1699	struct irq_pin_list *entry;
1700	unsigned long flags;
1701
1702	raw_spin_lock_irqsave(&ioapic_lock, flags);
1703	for_each_irq_pin(entry, data->irq_2_pin) {
1704	struct IO_APIC_route_entry e;
1705	int pin;
1706
1707	pin = entry->pin;
1708	e.w1 = io_apic_read(apic: entry->apic, reg: 0x10 + pin*2);
1709	/* Is the remote IRR bit set? */
1710	if (e.irr) {
1711	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1712	return true;
1713	}
1714	}
1715	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1716
1717	return false;
1718	}
1719
1720	static inline bool ioapic_prepare_move(struct irq_data *data)
1721	{
1722	/* If we are moving the IRQ we need to mask it */
1723	if (unlikely(irqd_is_setaffinity_pending(data))) {
1724	if (!irqd_irq_masked(d: data))
1725	mask_ioapic_irq(irq_data: data);
1726	return true;
1727	}
1728	return false;
1729	}
1730
1731	static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
1732	{
1733	if (unlikely(moveit)) {
1734	/* Only migrate the irq if the ack has been received.
1735	*
1736	* On rare occasions the broadcast level triggered ack gets
1737	* delayed going to ioapics, and if we reprogram the
1738	* vector while Remote IRR is still set the irq will never
1739	* fire again.
1740	*
1741	* To prevent this scenario we read the Remote IRR bit
1742	* of the ioapic. This has two effects.
1743	* - On any sane system the read of the ioapic will
1744	* flush writes (and acks) going to the ioapic from
1745	* this cpu.
1746	* - We get to see if the ACK has actually been delivered.
1747	*
1748	* Based on failed experiments of reprogramming the
1749	* ioapic entry from outside of irq context starting
1750	* with masking the ioapic entry and then polling until
1751	* Remote IRR was clear before reprogramming the
1752	* ioapic I don't trust the Remote IRR bit to be
1753	* completely accurate.
1754	*
1755	* However there appears to be no other way to plug
1756	* this race, so if the Remote IRR bit is not
1757	* accurate and is causing problems then it is a hardware bug
1758	* and you can go talk to the chipset vendor about it.
1759	*/
1760	if (!io_apic_level_ack_pending(data: data->chip_data))
1761	irq_move_masked_irq(data);
1762	/* If the IRQ is masked in the core, leave it: */
1763	if (!irqd_irq_masked(d: data))
1764	unmask_ioapic_irq(irq_data: data);
1765	}
1766	}
1767	#else
1768	static inline bool ioapic_prepare_move(struct irq_data *data)
1769	{
1770	return false;
1771	}
1772	static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
1773	{
1774	}
1775	#endif
1776
1777	static void ioapic_ack_level(struct irq_data *irq_data)
1778	{
1779	struct irq_cfg *cfg = irqd_cfg(irq_data);
1780	unsigned long v;
1781	bool moveit;
1782	int i;
1783
1784	irq_complete_move(cfg);
1785	moveit = ioapic_prepare_move(data: irq_data);
1786
1787	/*
1788	* It appears there is an erratum which affects at least version 0x11
1789	* of I/O APIC (that's the 82093AA and cores integrated into various
1790	* chipsets). Under certain conditions a level-triggered interrupt is
1791	* erroneously delivered as edge-triggered one but the respective IRR
1792	* bit gets set nevertheless. As a result the I/O unit expects an EOI
1793	* message but it will never arrive and further interrupts are blocked
1794	* from the source. The exact reason is so far unknown, but the
1795	* phenomenon was observed when two consecutive interrupt requests
1796	* from a given source get delivered to the same CPU and the source is
1797	* temporarily disabled in between.
1798	*
1799	* A workaround is to simulate an EOI message manually. We achieve it
1800	* by setting the trigger mode to edge and then to level when the edge
1801	* trigger mode gets detected in the TMR of a local APIC for a
1802	* level-triggered interrupt. We mask the source for the time of the
1803	* operation to prevent an edge-triggered interrupt escaping meanwhile.
1804	* The idea is from Manfred Spraul. --macro
1805	*
1806	* Also in the case when cpu goes offline, fixup_irqs() will forward
1807	* any unhandled interrupt on the offlined cpu to the new cpu
1808	* destination that is handling the corresponding interrupt. This
1809	* interrupt forwarding is done via IPI's. Hence, in this case also
1810	* level-triggered io-apic interrupt will be seen as an edge
1811	* interrupt in the IRR. And we can't rely on the cpu's EOI
1812	* to be broadcasted to the IO-APIC's which will clear the remoteIRR
1813	* corresponding to the level-triggered interrupt. Hence on IO-APIC's
1814	* supporting EOI register, we do an explicit EOI to clear the
1815	* remote IRR and on IO-APIC's which don't have an EOI register,
1816	* we use the above logic (mask+edge followed by unmask+level) from
1817	* Manfred Spraul to clear the remote IRR.
1818	*/
1819	i = cfg->vector;
1820	v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1));
1821
1822	/*
1823	* We must acknowledge the irq before we move it or the acknowledge will
1824	* not propagate properly.
1825	*/
1826	apic_eoi();
1827
1828	/*
1829	* Tail end of clearing remote IRR bit (either by delivering the EOI
1830	* message via io-apic EOI register write or simulating it using
1831	* mask+edge followed by unmask+level logic) manually when the
1832	* level triggered interrupt is seen as the edge triggered interrupt
1833	* at the cpu.
1834	*/
1835	if (!(v & (1 << (i & 0x1f)))) {
1836	atomic_inc(v: &irq_mis_count);
1837	eoi_ioapic_pin(vector: cfg->vector, data: irq_data->chip_data);
1838	}
1839
1840	ioapic_finish_move(data: irq_data, moveit);
1841	}
1842
1843	static void ioapic_ir_ack_level(struct irq_data *irq_data)
1844	{
1845	struct mp_chip_data *data = irq_data->chip_data;
1846
1847	/*
1848	* Intr-remapping uses pin number as the virtual vector
1849	* in the RTE. Actual vector is programmed in
1850	* intr-remapping table entry. Hence for the io-apic
1851	* EOI we use the pin number.
1852	*/
1853	apic_ack_irq(data: irq_data);
1854	eoi_ioapic_pin(vector: data->entry.vector, data);
1855	}
1856
1857	/*
1858	* The I/OAPIC is just a device for generating MSI messages from legacy
1859	* interrupt pins. Various fields of the RTE translate into bits of the
1860	* resulting MSI which had a historical meaning.
1861	*
1862	* With interrupt remapping, many of those bits have different meanings
1863	* in the underlying MSI, but the way that the I/OAPIC transforms them
1864	* from its RTE to the MSI message is the same. This function allows
1865	* the parent IRQ domain to compose the MSI message, then takes the
1866	* relevant bits to put them in the appropriate places in the RTE in
1867	* order to generate that message when the IRQ happens.
1868	*
1869	* The setup here relies on a preconfigured route entry (is_level,
1870	* active_low, masked) because the parent domain is merely composing the
1871	* generic message routing information which is used for the MSI.
1872	*/
1873	static void ioapic_setup_msg_from_msi(struct irq_data *irq_data,
1874	struct IO_APIC_route_entry *entry)
1875	{
1876	struct msi_msg msg;
1877
1878	/* Let the parent domain compose the MSI message */
1879	irq_chip_compose_msi_msg(data: irq_data, msg: &msg);
1880
1881	/*
1882	* - Real vector
1883	* - DMAR/IR: 8bit subhandle (ioapic.pin)
1884	* - AMD/IR: 8bit IRTE index
1885	*/
1886	entry->vector = msg.arch_data.vector;
1887	/* Delivery mode (for DMAR/IR all 0) */
1888	entry->delivery_mode = msg.arch_data.delivery_mode;
1889	/* Destination mode or DMAR/IR index bit 15 */
1890	entry->dest_mode_logical = msg.arch_addr_lo.dest_mode_logical;
1891	/* DMAR/IR: 1, 0 for all other modes */
1892	entry->ir_format = msg.arch_addr_lo.dmar_format;
1893	/*
1894	* - DMAR/IR: index bit 0-14.
1895	*
1896	* - Virt: If the host supports x2apic without a virtualized IR
1897	* unit then bit 0-6 of dmar_index_0_14 are providing bit
1898	* 8-14 of the destination id.
1899	*
1900	* All other modes have bit 0-6 of dmar_index_0_14 cleared and the
1901	* topmost 8 bits are destination id bit 0-7 (entry::destid_0_7).
1902	*/
1903	entry->ir_index_0_14 = msg.arch_addr_lo.dmar_index_0_14;
1904	}
1905
1906	static void ioapic_configure_entry(struct irq_data *irqd)
1907	{
1908	struct mp_chip_data *mpd = irqd->chip_data;
1909	struct irq_pin_list *entry;
1910
1911	ioapic_setup_msg_from_msi(irq_data: irqd, entry: &mpd->entry);
1912
1913	for_each_irq_pin(entry, mpd->irq_2_pin)
1914	__ioapic_write_entry(apic: entry->apic, pin: entry->pin, e: mpd->entry);
1915	}
1916
1917	static int ioapic_set_affinity(struct irq_data *irq_data,
1918	const struct cpumask *mask, bool force)
1919	{
1920	struct irq_data *parent = irq_data->parent_data;
1921	unsigned long flags;
1922	int ret;
1923
1924	ret = parent->chip->irq_set_affinity(parent, mask, force);
1925	raw_spin_lock_irqsave(&ioapic_lock, flags);
1926	if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE)
1927	ioapic_configure_entry(irqd: irq_data);
1928	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1929
1930	return ret;
1931	}
1932
1933	/*
1934	* Interrupt shutdown masks the ioapic pin, but the interrupt might already
1935	* be in flight, but not yet serviced by the target CPU. That means
1936	* __synchronize_hardirq() would return and claim that everything is calmed
1937	* down. So free_irq() would proceed and deactivate the interrupt and free
1938	* resources.
1939	*
1940	* Once the target CPU comes around to service it it will find a cleared
1941	* vector and complain. While the spurious interrupt is harmless, the full
1942	* release of resources might prevent the interrupt from being acknowledged
1943	* which keeps the hardware in a weird state.
1944	*
1945	* Verify that the corresponding Remote-IRR bits are clear.
1946	*/
1947	static int ioapic_irq_get_chip_state(struct irq_data *irqd,
1948	enum irqchip_irq_state which,
1949	bool *state)
1950	{
1951	struct mp_chip_data *mcd = irqd->chip_data;
1952	struct IO_APIC_route_entry rentry;
1953	struct irq_pin_list *p;
1954
1955	if (which != IRQCHIP_STATE_ACTIVE)
1956	return -EINVAL;
1957
1958	*state = false;
1959	raw_spin_lock(&ioapic_lock);
1960	for_each_irq_pin(p, mcd->irq_2_pin) {
1961	rentry = __ioapic_read_entry(apic: p->apic, pin: p->pin);
1962	/*
1963	* The remote IRR is only valid in level trigger mode. It's
1964	* meaning is undefined for edge triggered interrupts and
1965	* irrelevant because the IO-APIC treats them as fire and
1966	* forget.
1967	*/
1968	if (rentry.irr && rentry.is_level) {
1969	*state = true;
1970	break;
1971	}
1972	}
1973	raw_spin_unlock(&ioapic_lock);
1974	return 0;
1975	}
1976
1977	static struct irq_chip ioapic_chip __read_mostly = {
1978	.name = "IO-APIC",
1979	.irq_startup = startup_ioapic_irq,
1980	.irq_mask = mask_ioapic_irq,
1981	.irq_unmask = unmask_ioapic_irq,
1982	.irq_ack = irq_chip_ack_parent,
1983	.irq_eoi = ioapic_ack_level,
1984	.irq_set_affinity = ioapic_set_affinity,
1985	.irq_retrigger = irq_chip_retrigger_hierarchy,
1986	.irq_get_irqchip_state = ioapic_irq_get_chip_state,
1987	.flags = IRQCHIP_SKIP_SET_WAKE |
1988	IRQCHIP_AFFINITY_PRE_STARTUP,
1989	};
1990
1991	static struct irq_chip ioapic_ir_chip __read_mostly = {
1992	.name = "IR-IO-APIC",
1993	.irq_startup = startup_ioapic_irq,
1994	.irq_mask = mask_ioapic_irq,
1995	.irq_unmask = unmask_ioapic_irq,
1996	.irq_ack = irq_chip_ack_parent,
1997	.irq_eoi = ioapic_ir_ack_level,
1998	.irq_set_affinity = ioapic_set_affinity,
1999	.irq_retrigger = irq_chip_retrigger_hierarchy,
2000	.irq_get_irqchip_state = ioapic_irq_get_chip_state,
2001	.flags = IRQCHIP_SKIP_SET_WAKE |
2002	IRQCHIP_AFFINITY_PRE_STARTUP,
2003	};
2004
2005	static inline void init_IO_APIC_traps(void)
2006	{
2007	struct irq_cfg *cfg;
2008	unsigned int irq;
2009
2010	for_each_active_irq(irq) {
2011	cfg = irq_cfg(irq);
2012	if (IO_APIC_IRQ(irq) && cfg && !cfg->vector) {
2013	/*
2014	* Hmm.. We don't have an entry for this,
2015	* so default to an old-fashioned 8259
2016	* interrupt if we can..
2017	*/
2018	if (irq < nr_legacy_irqs())
2019	legacy_pic->make_irq(irq);
2020	else
2021	/* Strange. Oh, well.. */
2022	irq_set_chip(irq, chip: &no_irq_chip);
2023	}
2024	}
2025	}
2026
2027	/*
2028	* The local APIC irq-chip implementation:
2029	*/
2030
2031	static void mask_lapic_irq(struct irq_data *data)
2032	{
2033	unsigned long v;
2034
2035	v = apic_read(APIC_LVT0);
2036	apic_write(APIC_LVT0, val: v | APIC_LVT_MASKED);
2037	}
2038
2039	static void unmask_lapic_irq(struct irq_data *data)
2040	{
2041	unsigned long v;
2042
2043	v = apic_read(APIC_LVT0);
2044	apic_write(APIC_LVT0, val: v & ~APIC_LVT_MASKED);
2045	}
2046
2047	static void ack_lapic_irq(struct irq_data *data)
2048	{
2049	apic_eoi();
2050	}
2051
2052	static struct irq_chip lapic_chip __read_mostly = {
2053	.name = "local-APIC",
2054	.irq_mask = mask_lapic_irq,
2055	.irq_unmask = unmask_lapic_irq,
2056	.irq_ack = ack_lapic_irq,
2057	};
2058
2059	static void lapic_register_intr(int irq)
2060	{
2061	irq_clear_status_flags(irq, clr: IRQ_LEVEL);
2062	irq_set_chip_and_handler_name(irq, chip: &lapic_chip, handle: handle_edge_irq,
2063	name: "edge");
2064	}
2065
2066	/*
2067	* This looks a bit hackish but it's about the only one way of sending
2068	* a few INTA cycles to 8259As and any associated glue logic. ICR does
2069	* not support the ExtINT mode, unfortunately. We need to send these
2070	* cycles as some i82489DX-based boards have glue logic that keeps the
2071	* 8259A interrupt line asserted until INTA. --macro
2072	*/
2073	static inline void __init unlock_ExtINT_logic(void)
2074	{
2075	int apic, pin, i;
2076	struct IO_APIC_route_entry entry0, entry1;
2077	unsigned char save_control, save_freq_select;
2078	u32 apic_id;
2079
2080	pin = find_isa_irq_pin(irq: 8, type: mp_INT);
2081	if (pin == -1) {
2082	WARN_ON_ONCE(1);
2083	return;
2084	}
2085	apic = find_isa_irq_apic(irq: 8, type: mp_INT);
2086	if (apic == -1) {
2087	WARN_ON_ONCE(1);
2088	return;
2089	}
2090
2091	entry0 = ioapic_read_entry(apic, pin);
2092	clear_IO_APIC_pin(apic, pin);
2093
2094	apic_id = read_apic_id();
2095	memset(&entry1, 0, sizeof(entry1));
2096
2097	entry1.dest_mode_logical = true;
2098	entry1.masked = false;
2099	entry1.destid_0_7 = apic_id & 0xFF;
2100	entry1.virt_destid_8_14 = apic_id >> 8;
2101	entry1.delivery_mode = APIC_DELIVERY_MODE_EXTINT;
2102	entry1.active_low = entry0.active_low;
2103	entry1.is_level = false;
2104	entry1.vector = 0;
2105
2106	ioapic_write_entry(apic, pin, e: entry1);
2107
2108	save_control = CMOS_READ(RTC_CONTROL);
2109	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
2110	CMOS_WRITE((save_freq_select & ~RTC_RATE_SELECT) | 0x6,
2111	RTC_FREQ_SELECT);
2112	CMOS_WRITE(save_control | RTC_PIE, RTC_CONTROL);
2113
2114	i = 100;
2115	while (i-- > 0) {
2116	mdelay(10);
2117	if ((CMOS_READ(RTC_INTR_FLAGS) & RTC_PF) == RTC_PF)
2118	i -= 10;
2119	}
2120
2121	CMOS_WRITE(save_control, RTC_CONTROL);
2122	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
2123	clear_IO_APIC_pin(apic, pin);
2124
2125	ioapic_write_entry(apic, pin, e: entry0);
2126	}
2127
2128	static int disable_timer_pin_1 __initdata;
2129	/* Actually the next is obsolete, but keep it for paranoid reasons -AK */
2130	static int __init disable_timer_pin_setup(char *arg)
2131	{
2132	disable_timer_pin_1 = 1;
2133	return 0;
2134	}
2135	early_param("disable_timer_pin_1", disable_timer_pin_setup);
2136
2137	static int mp_alloc_timer_irq(int ioapic, int pin)
2138	{
2139	int irq = -1;
2140	struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
2141
2142	if (domain) {
2143	struct irq_alloc_info info;
2144
2145	ioapic_set_alloc_attr(info: &info, NUMA_NO_NODE, trigger: 0, polarity: 0);
2146	info.devid = mpc_ioapic_id(ioapic_idx: ioapic);
2147	info.ioapic.pin = pin;
2148	mutex_lock(&ioapic_mutex);
2149	irq = alloc_isa_irq_from_domain(domain, irq: 0, ioapic, pin, info: &info);
2150	mutex_unlock(lock: &ioapic_mutex);
2151	}
2152
2153	return irq;
2154	}
2155
2156	/*
2157	* This code may look a bit paranoid, but it's supposed to cooperate with
2158	* a wide range of boards and BIOS bugs. Fortunately only the timer IRQ
2159	* is so screwy. Thanks to Brian Perkins for testing/hacking this beast
2160	* fanatically on his truly buggy board.
2161	*
2162	* FIXME: really need to revamp this for all platforms.
2163	*/
2164	static inline void __init check_timer(void)
2165	{
2166	struct irq_data *irq_data = irq_get_irq_data(irq: 0);
2167	struct mp_chip_data *data = irq_data->chip_data;
2168	struct irq_cfg *cfg = irqd_cfg(irq_data);
2169	int node = cpu_to_node(cpu: 0);
2170	int apic1, pin1, apic2, pin2;
2171	int no_pin1 = 0;
2172
2173	if (!global_clock_event)
2174	return;
2175
2176	local_irq_disable();
2177
2178	/*
2179	* get/set the timer IRQ vector:
2180	*/
2181	legacy_pic->mask(0);
2182
2183	/*
2184	* As IRQ0 is to be enabled in the 8259A, the virtual
2185	* wire has to be disabled in the local APIC. Also
2186	* timer interrupts need to be acknowledged manually in
2187	* the 8259A for the i82489DX when using the NMI
2188	* watchdog as that APIC treats NMIs as level-triggered.
2189	* The AEOI mode will finish them in the 8259A
2190	* automatically.
2191	*/
2192	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
2193	legacy_pic->init(1);
2194
2195	pin1 = find_isa_irq_pin(irq: 0, type: mp_INT);
2196	apic1 = find_isa_irq_apic(irq: 0, type: mp_INT);
2197	pin2 = ioapic_i8259.pin;
2198	apic2 = ioapic_i8259.apic;
2199
2200	apic_printk(APIC_QUIET, KERN_INFO "..TIMER: vector=0x%02X "
2201	"apic1=%d pin1=%d apic2=%d pin2=%d\n",
2202	cfg->vector, apic1, pin1, apic2, pin2);
2203
2204	/*
2205	* Some BIOS writers are clueless and report the ExtINTA
2206	* I/O APIC input from the cascaded 8259A as the timer
2207	* interrupt input. So just in case, if only one pin
2208	* was found above, try it both directly and through the
2209	* 8259A.
2210	*/
2211	if (pin1 == -1) {
2212	panic_if_irq_remap(msg: "BIOS bug: timer not connected to IO-APIC");
2213	pin1 = pin2;
2214	apic1 = apic2;
2215	no_pin1 = 1;
2216	} else if (pin2 == -1) {
2217	pin2 = pin1;
2218	apic2 = apic1;
2219	}
2220
2221	if (pin1 != -1) {
2222	/* Ok, does IRQ0 through the IOAPIC work? */
2223	if (no_pin1) {
2224	mp_alloc_timer_irq(ioapic: apic1, pin: pin1);
2225	} else {
2226	/*
2227	* for edge trigger, it's already unmasked,
2228	* so only need to unmask if it is level-trigger
2229	* do we really have level trigger timer?
2230	*/
2231	int idx = find_irq_entry(ioapic_idx: apic1, pin: pin1, type: mp_INT);
2232
2233	if (idx != -1 && irq_is_level(idx))
2234	unmask_ioapic_irq(irq_data: irq_get_irq_data(irq: 0));
2235	}
2236	irq_domain_deactivate_irq(irq_data);
2237	irq_domain_activate_irq(irq_data, early: false);
2238	if (timer_irq_works()) {
2239	if (disable_timer_pin_1 > 0)
2240	clear_IO_APIC_pin(apic: 0, pin: pin1);
2241	goto out;
2242	}
2243	panic_if_irq_remap(msg: "timer doesn't work through Interrupt-remapped IO-APIC");
2244	clear_IO_APIC_pin(apic: apic1, pin: pin1);
2245	if (!no_pin1)
2246	apic_printk(APIC_QUIET, KERN_ERR "..MP-BIOS bug: "
2247	"8254 timer not connected to IO-APIC\n");
2248
2249	apic_printk(APIC_QUIET, KERN_INFO "...trying to set up timer "
2250	"(IRQ0) through the 8259A ...\n");
2251	apic_printk(APIC_QUIET, KERN_INFO
2252	"..... (found apic %d pin %d) ...\n", apic2, pin2);
2253	/*
2254	* legacy devices should be connected to IO APIC #0
2255	*/
2256	replace_pin_at_irq_node(data, node, oldapic: apic1, oldpin: pin1, newapic: apic2, newpin: pin2);
2257	irq_domain_deactivate_irq(irq_data);
2258	irq_domain_activate_irq(irq_data, early: false);
2259	legacy_pic->unmask(0);
2260	if (timer_irq_works()) {
2261	apic_printk(APIC_QUIET, KERN_INFO "....... works.\n");
2262	goto out;
2263	}
2264	/*
2265	* Cleanup, just in case ...
2266	*/
2267	legacy_pic->mask(0);
2268	clear_IO_APIC_pin(apic: apic2, pin: pin2);
2269	apic_printk(APIC_QUIET, KERN_INFO "....... failed.\n");
2270	}
2271
2272	apic_printk(APIC_QUIET, KERN_INFO
2273	"...trying to set up timer as Virtual Wire IRQ...\n");
2274
2275	lapic_register_intr(irq: 0);
2276	apic_write(APIC_LVT0, APIC_DM_FIXED | cfg->vector); /* Fixed mode */
2277	legacy_pic->unmask(0);
2278
2279	if (timer_irq_works()) {
2280	apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
2281	goto out;
2282	}
2283	legacy_pic->mask(0);
2284	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | cfg->vector);
2285	apic_printk(APIC_QUIET, KERN_INFO "..... failed.\n");
2286
2287	apic_printk(APIC_QUIET, KERN_INFO
2288	"...trying to set up timer as ExtINT IRQ...\n");
2289
2290	legacy_pic->init(0);
2291	legacy_pic->make_irq(0);
2292	apic_write(APIC_LVT0, APIC_DM_EXTINT);
2293	legacy_pic->unmask(0);
2294
2295	unlock_ExtINT_logic();
2296
2297	if (timer_irq_works()) {
2298	apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
2299	goto out;
2300	}
2301	apic_printk(APIC_QUIET, KERN_INFO "..... failed :(.\n");
2302	if (apic_is_x2apic_enabled())
2303	apic_printk(APIC_QUIET, KERN_INFO
2304	"Perhaps problem with the pre-enabled x2apic mode\n"
2305	"Try booting with x2apic and interrupt-remapping disabled in the bios.\n");
2306	panic(fmt: "IO-APIC + timer doesn't work! Boot with apic=debug and send a "
2307	"report. Then try booting with the 'noapic' option.\n");
2308	out:
2309	local_irq_enable();
2310	}
2311
2312	/*
2313	* Traditionally ISA IRQ2 is the cascade IRQ, and is not available
2314	* to devices. However there may be an I/O APIC pin available for
2315	* this interrupt regardless. The pin may be left unconnected, but
2316	* typically it will be reused as an ExtINT cascade interrupt for
2317	* the master 8259A. In the MPS case such a pin will normally be
2318	* reported as an ExtINT interrupt in the MP table. With ACPI
2319	* there is no provision for ExtINT interrupts, and in the absence
2320	* of an override it would be treated as an ordinary ISA I/O APIC
2321	* interrupt, that is edge-triggered and unmasked by default. We
2322	* used to do this, but it caused problems on some systems because
2323	* of the NMI watchdog and sometimes IRQ0 of the 8254 timer using
2324	* the same ExtINT cascade interrupt to drive the local APIC of the
2325	* bootstrap processor. Therefore we refrain from routing IRQ2 to
2326	* the I/O APIC in all cases now. No actual device should request
2327	* it anyway. --macro
2328	*/
2329	#define PIC_IRQS (1UL << PIC_CASCADE_IR)
2330
2331	static int mp_irqdomain_create(int ioapic)
2332	{
2333	struct irq_domain *parent;
2334	int hwirqs = mp_ioapic_pin_count(ioapic);
2335	struct ioapic *ip = &ioapics[ioapic];
2336	struct ioapic_domain_cfg *cfg = &ip->irqdomain_cfg;
2337	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic_idx: ioapic);
2338	struct fwnode_handle *fn;
2339	struct irq_fwspec fwspec;
2340
2341	if (cfg->type == IOAPIC_DOMAIN_INVALID)
2342	return 0;
2343
2344	/* Handle device tree enumerated APICs proper */
2345	if (cfg->dev) {
2346	fn = of_node_to_fwnode(node: cfg->dev);
2347	} else {
2348	fn = irq_domain_alloc_named_id_fwnode(name: "IO-APIC", id: mpc_ioapic_id(ioapic_idx: ioapic));
2349	if (!fn)
2350	return -ENOMEM;
2351	}
2352
2353	fwspec.fwnode = fn;
2354	fwspec.param_count = 1;
2355	fwspec.param[0] = mpc_ioapic_id(ioapic_idx: ioapic);
2356
2357	parent = irq_find_matching_fwspec(fwspec: &fwspec, bus_token: DOMAIN_BUS_ANY);
2358	if (!parent) {
2359	if (!cfg->dev)
2360	irq_domain_free_fwnode(fwnode: fn);
2361	return -ENODEV;
2362	}
2363
2364	ip->irqdomain = irq_domain_create_hierarchy(parent, flags: 0, size: hwirqs, fwnode: fn, ops: cfg->ops,
2365	host_data: (void *)(long)ioapic);
2366	if (!ip->irqdomain) {
2367	/* Release fw handle if it was allocated above */
2368	if (!cfg->dev)
2369	irq_domain_free_fwnode(fwnode: fn);
2370	return -ENOMEM;
2371	}
2372
2373	if (cfg->type == IOAPIC_DOMAIN_LEGACY ||
2374	cfg->type == IOAPIC_DOMAIN_STRICT)
2375	ioapic_dynirq_base = max(ioapic_dynirq_base,
2376	gsi_cfg->gsi_end + 1);
2377
2378	return 0;
2379	}
2380
2381	static void ioapic_destroy_irqdomain(int idx)
2382	{
2383	struct ioapic_domain_cfg *cfg = &ioapics[idx].irqdomain_cfg;
2384	struct fwnode_handle *fn = ioapics[idx].irqdomain->fwnode;
2385
2386	if (ioapics[idx].irqdomain) {
2387	irq_domain_remove(host: ioapics[idx].irqdomain);
2388	if (!cfg->dev)
2389	irq_domain_free_fwnode(fwnode: fn);
2390	ioapics[idx].irqdomain = NULL;
2391	}
2392	}
2393
2394	void __init setup_IO_APIC(void)
2395	{
2396	int ioapic;
2397
2398	if (ioapic_is_disabled || !nr_ioapics)
2399	return;
2400
2401	io_apic_irqs = nr_legacy_irqs() ? ~PIC_IRQS : ~0UL;
2402
2403	apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
2404	for_each_ioapic(ioapic)
2405	BUG_ON(mp_irqdomain_create(ioapic));
2406
2407	/*
2408	* Set up IO-APIC IRQ routing.
2409	*/
2410	x86_init.mpparse.setup_ioapic_ids();
2411
2412	sync_Arb_IDs();
2413	setup_IO_APIC_irqs();
2414	init_IO_APIC_traps();
2415	if (nr_legacy_irqs())
2416	check_timer();
2417
2418	ioapic_initialized = 1;
2419	}
2420
2421	static void resume_ioapic_id(int ioapic_idx)
2422	{
2423	unsigned long flags;
2424	union IO_APIC_reg_00 reg_00;
2425
2426	raw_spin_lock_irqsave(&ioapic_lock, flags);
2427	reg_00.raw = io_apic_read(apic: ioapic_idx, reg: 0);
2428	if (reg_00.bits.ID != mpc_ioapic_id(ioapic_idx)) {
2429	reg_00.bits.ID = mpc_ioapic_id(ioapic_idx);
2430	io_apic_write(apic: ioapic_idx, reg: 0, value: reg_00.raw);
2431	}
2432	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2433	}
2434
2435	static void ioapic_resume(void)
2436	{
2437	int ioapic_idx;
2438
2439	for_each_ioapic_reverse(ioapic_idx)
2440	resume_ioapic_id(ioapic_idx);
2441
2442	restore_ioapic_entries();
2443	}
2444
2445	static struct syscore_ops ioapic_syscore_ops = {
2446	.suspend = save_ioapic_entries,
2447	.resume = ioapic_resume,
2448	};
2449
2450	static int __init ioapic_init_ops(void)
2451	{
2452	register_syscore_ops(ops: &ioapic_syscore_ops);
2453
2454	return 0;
2455	}
2456
2457	device_initcall(ioapic_init_ops);
2458
2459	static int io_apic_get_redir_entries(int ioapic)
2460	{
2461	union IO_APIC_reg_01 reg_01;
2462	unsigned long flags;
2463
2464	raw_spin_lock_irqsave(&ioapic_lock, flags);
2465	reg_01.raw = io_apic_read(apic: ioapic, reg: 1);
2466	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2467
2468	/* The register returns the maximum index redir index
2469	* supported, which is one less than the total number of redir
2470	* entries.
2471	*/
2472	return reg_01.bits.entries + 1;
2473	}
2474
2475	unsigned int arch_dynirq_lower_bound(unsigned int from)
2476	{
2477	unsigned int ret;
2478
2479	/*
2480	* dmar_alloc_hwirq() may be called before setup_IO_APIC(), so use
2481	* gsi_top if ioapic_dynirq_base hasn't been initialized yet.
2482	*/
2483	ret = ioapic_dynirq_base ? : gsi_top;
2484
2485	/*
2486	* For DT enabled machines ioapic_dynirq_base is irrelevant and
2487	* always 0. gsi_top can be 0 if there is no IO/APIC registered.
2488	* 0 is an invalid interrupt number for dynamic allocations. Return
2489	* @from instead.
2490	*/
2491	return ret ? : from;
2492	}
2493
2494	#ifdef CONFIG_X86_32
2495	static int io_apic_get_unique_id(int ioapic, int apic_id)
2496	{
2497	union IO_APIC_reg_00 reg_00;
2498	static physid_mask_t apic_id_map = PHYSID_MASK_NONE;
2499	physid_mask_t tmp;
2500	unsigned long flags;
2501	int i = 0;
2502
2503	/*
2504	* The P4 platform supports up to 256 APIC IDs on two separate APIC
2505	* buses (one for LAPICs, one for IOAPICs), where predecessors only
2506	* supports up to 16 on one shared APIC bus.
2507	*
2508	* TBD: Expand LAPIC/IOAPIC support on P4-class systems to take full
2509	* advantage of new APIC bus architecture.
2510	*/
2511
2512	if (physids_empty(apic_id_map))
2513	apic->ioapic_phys_id_map(&phys_cpu_present_map, &apic_id_map);
2514
2515	raw_spin_lock_irqsave(&ioapic_lock, flags);
2516	reg_00.raw = io_apic_read(ioapic, 0);
2517	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2518
2519	if (apic_id >= get_physical_broadcast()) {
2520	printk(KERN_WARNING "IOAPIC[%d]: Invalid apic_id %d, trying "
2521	"%d\n", ioapic, apic_id, reg_00.bits.ID);
2522	apic_id = reg_00.bits.ID;
2523	}
2524
2525	/*
2526	* Every APIC in a system must have a unique ID or we get lots of nice
2527	* 'stuck on smp_invalidate_needed IPI wait' messages.
2528	*/
2529	if (apic->check_apicid_used(&apic_id_map, apic_id)) {
2530
2531	for (i = 0; i < get_physical_broadcast(); i++) {
2532	if (!apic->check_apicid_used(&apic_id_map, i))
2533	break;
2534	}
2535
2536	if (i == get_physical_broadcast())
2537	panic("Max apic_id exceeded!\n");
2538
2539	printk(KERN_WARNING "IOAPIC[%d]: apic_id %d already used, "
2540	"trying %d\n", ioapic, apic_id, i);
2541
2542	apic_id = i;
2543	}
2544
2545	physid_set_mask_of_physid(apic_id, &tmp);
2546	physids_or(apic_id_map, apic_id_map, tmp);
2547
2548	if (reg_00.bits.ID != apic_id) {
2549	reg_00.bits.ID = apic_id;
2550
2551	raw_spin_lock_irqsave(&ioapic_lock, flags);
2552	io_apic_write(ioapic, 0, reg_00.raw);
2553	reg_00.raw = io_apic_read(ioapic, 0);
2554	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2555
2556	/* Sanity check */
2557	if (reg_00.bits.ID != apic_id) {
2558	pr_err("IOAPIC[%d]: Unable to change apic_id!\n",
2559	ioapic);
2560	return -1;
2561	}
2562	}
2563
2564	apic_printk(APIC_VERBOSE, KERN_INFO
2565	"IOAPIC[%d]: Assigned apic_id %d\n", ioapic, apic_id);
2566
2567	return apic_id;
2568	}
2569
2570	static u8 io_apic_unique_id(int idx, u8 id)
2571	{
2572	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
2573	!APIC_XAPIC(boot_cpu_apic_version))
2574	return io_apic_get_unique_id(idx, id);
2575	else
2576	return id;
2577	}
2578	#else
2579	static u8 io_apic_unique_id(int idx, u8 id)
2580	{
2581	union IO_APIC_reg_00 reg_00;
2582	DECLARE_BITMAP(used, 256);
2583	unsigned long flags;
2584	u8 new_id;
2585	int i;
2586
2587	bitmap_zero(dst: used, nbits: 256);
2588	for_each_ioapic(i)
2589	__set_bit(mpc_ioapic_id(i), used);
2590
2591	/* Hand out the requested id if available */
2592	if (!test_bit(id, used))
2593	return id;
2594
2595	/*
2596	* Read the current id from the ioapic and keep it if
2597	* available.
2598	*/
2599	raw_spin_lock_irqsave(&ioapic_lock, flags);
2600	reg_00.raw = io_apic_read(apic: idx, reg: 0);
2601	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2602	new_id = reg_00.bits.ID;
2603	if (!test_bit(new_id, used)) {
2604	apic_printk(APIC_VERBOSE, KERN_INFO
2605	"IOAPIC[%d]: Using reg apic_id %d instead of %d\n",
2606	idx, new_id, id);
2607	return new_id;
2608	}
2609
2610	/*
2611	* Get the next free id and write it to the ioapic.
2612	*/
2613	new_id = find_first_zero_bit(addr: used, size: 256);
2614	reg_00.bits.ID = new_id;
2615	raw_spin_lock_irqsave(&ioapic_lock, flags);
2616	io_apic_write(apic: idx, reg: 0, value: reg_00.raw);
2617	reg_00.raw = io_apic_read(apic: idx, reg: 0);
2618	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2619	/* Sanity check */
2620	BUG_ON(reg_00.bits.ID != new_id);
2621
2622	return new_id;
2623	}
2624	#endif
2625
2626	static int io_apic_get_version(int ioapic)
2627	{
2628	union IO_APIC_reg_01 reg_01;
2629	unsigned long flags;
2630
2631	raw_spin_lock_irqsave(&ioapic_lock, flags);
2632	reg_01.raw = io_apic_read(apic: ioapic, reg: 1);
2633	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2634
2635	return reg_01.bits.version;
2636	}
2637
2638	/*
2639	* This function updates target affinity of IOAPIC interrupts to include
2640	* the CPUs which came online during SMP bringup.
2641	*/
2642	#define IOAPIC_RESOURCE_NAME_SIZE 11
2643
2644	static struct resource *ioapic_resources;
2645
2646	static struct resource * __init ioapic_setup_resources(void)
2647	{
2648	unsigned long n;
2649	struct resource *res;
2650	char *mem;
2651	int i;
2652
2653	if (nr_ioapics == 0)
2654	return NULL;
2655
2656	n = IOAPIC_RESOURCE_NAME_SIZE + sizeof(struct resource);
2657	n *= nr_ioapics;
2658
2659	mem = memblock_alloc(size: n, SMP_CACHE_BYTES);
2660	if (!mem)
2661	panic(fmt: "%s: Failed to allocate %lu bytes\n", __func__, n);
2662	res = (void *)mem;
2663
2664	mem += sizeof(struct resource) * nr_ioapics;
2665
2666	for_each_ioapic(i) {
2667	res[i].name = mem;
2668	res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
2669	snprintf(buf: mem, IOAPIC_RESOURCE_NAME_SIZE, fmt: "IOAPIC %u", i);
2670	mem += IOAPIC_RESOURCE_NAME_SIZE;
2671	ioapics[i].iomem_res = &res[i];
2672	}
2673
2674	ioapic_resources = res;
2675
2676	return res;
2677	}
2678
2679	static void io_apic_set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
2680	{
2681	pgprot_t flags = FIXMAP_PAGE_NOCACHE;
2682
2683	/*
2684	* Ensure fixmaps for IO-APIC MMIO respect memory encryption pgprot
2685	* bits, just like normal ioremap():
2686	*/
2687	if (cc_platform_has(attr: CC_ATTR_GUEST_MEM_ENCRYPT)) {
2688	if (x86_platform.hyper.is_private_mmio(phys))
2689	flags = pgprot_encrypted(flags);
2690	else
2691	flags = pgprot_decrypted(flags);
2692	}
2693
2694	__set_fixmap(idx, phys, flags);
2695	}
2696
2697	void __init io_apic_init_mappings(void)
2698	{
2699	unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
2700	struct resource *ioapic_res;
2701	int i;
2702
2703	ioapic_res = ioapic_setup_resources();
2704	for_each_ioapic(i) {
2705	if (smp_found_config) {
2706	ioapic_phys = mpc_ioapic_addr(ioapic_idx: i);
2707	#ifdef CONFIG_X86_32
2708	if (!ioapic_phys) {
2709	printk(KERN_ERR
2710	"WARNING: bogus zero IO-APIC "
2711	"address found in MPTABLE, "
2712	"disabling IO/APIC support!\n");
2713	smp_found_config = 0;
2714	ioapic_is_disabled = true;
2715	goto fake_ioapic_page;
2716	}
2717	#endif
2718	} else {
2719	#ifdef CONFIG_X86_32
2720	fake_ioapic_page:
2721	#endif
2722	ioapic_phys = (unsigned long)memblock_alloc(PAGE_SIZE,
2723	PAGE_SIZE);
2724	if (!ioapic_phys)
2725	panic(fmt: "%s: Failed to allocate %lu bytes align=0x%lx\n",
2726	__func__, PAGE_SIZE, PAGE_SIZE);
2727	ioapic_phys = __pa(ioapic_phys);
2728	}
2729	io_apic_set_fixmap(idx, phys: ioapic_phys);
2730	apic_printk(APIC_VERBOSE, "mapped IOAPIC to %08lx (%08lx)\n",
2731	__fix_to_virt(idx) + (ioapic_phys & ~PAGE_MASK),
2732	ioapic_phys);
2733	idx++;
2734
2735	ioapic_res->start = ioapic_phys;
2736	ioapic_res->end = ioapic_phys + IO_APIC_SLOT_SIZE - 1;
2737	ioapic_res++;
2738	}
2739	}
2740
2741	void __init ioapic_insert_resources(void)
2742	{
2743	int i;
2744	struct resource *r = ioapic_resources;
2745
2746	if (!r) {
2747	if (nr_ioapics > 0)
2748	printk(KERN_ERR
2749	"IO APIC resources couldn't be allocated.\n");
2750	return;
2751	}
2752
2753	for_each_ioapic(i) {
2754	insert_resource(parent: &iomem_resource, new: r);
2755	r++;
2756	}
2757	}
2758
2759	int mp_find_ioapic(u32 gsi)
2760	{
2761	int i;
2762
2763	if (nr_ioapics == 0)
2764	return -1;
2765
2766	/* Find the IOAPIC that manages this GSI. */
2767	for_each_ioapic(i) {
2768	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic_idx: i);
2769	if (gsi >= gsi_cfg->gsi_base && gsi <= gsi_cfg->gsi_end)
2770	return i;
2771	}
2772
2773	printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
2774	return -1;
2775	}
2776
2777	int mp_find_ioapic_pin(int ioapic, u32 gsi)
2778	{
2779	struct mp_ioapic_gsi *gsi_cfg;
2780
2781	if (WARN_ON(ioapic < 0))
2782	return -1;
2783
2784	gsi_cfg = mp_ioapic_gsi_routing(ioapic_idx: ioapic);
2785	if (WARN_ON(gsi > gsi_cfg->gsi_end))
2786	return -1;
2787
2788	return gsi - gsi_cfg->gsi_base;
2789	}
2790
2791	static int bad_ioapic_register(int idx)
2792	{
2793	union IO_APIC_reg_00 reg_00;
2794	union IO_APIC_reg_01 reg_01;
2795	union IO_APIC_reg_02 reg_02;
2796
2797	reg_00.raw = io_apic_read(apic: idx, reg: 0);
2798	reg_01.raw = io_apic_read(apic: idx, reg: 1);
2799	reg_02.raw = io_apic_read(apic: idx, reg: 2);
2800
2801	if (reg_00.raw == -1 && reg_01.raw == -1 && reg_02.raw == -1) {
2802	pr_warn("I/O APIC 0x%x registers return all ones, skipping!\n",
2803	mpc_ioapic_addr(idx));
2804	return 1;
2805	}
2806
2807	return 0;
2808	}
2809
2810	static int find_free_ioapic_entry(void)
2811	{
2812	int idx;
2813
2814	for (idx = 0; idx < MAX_IO_APICS; idx++)
2815	if (ioapics[idx].nr_registers == 0)
2816	return idx;
2817
2818	return MAX_IO_APICS;
2819	}
2820
2821	/**
2822	* mp_register_ioapic - Register an IOAPIC device
2823	* @id: hardware IOAPIC ID
2824	* @address: physical address of IOAPIC register area
2825	* @gsi_base: base of GSI associated with the IOAPIC
2826	* @cfg: configuration information for the IOAPIC
2827	*/
2828	int mp_register_ioapic(int id, u32 address, u32 gsi_base,
2829	struct ioapic_domain_cfg *cfg)
2830	{
2831	bool hotplug = !!ioapic_initialized;
2832	struct mp_ioapic_gsi *gsi_cfg;
2833	int idx, ioapic, entries;
2834	u32 gsi_end;
2835
2836	if (!address) {
2837	pr_warn("Bogus (zero) I/O APIC address found, skipping!\n");
2838	return -EINVAL;
2839	}
2840	for_each_ioapic(ioapic)
2841	if (ioapics[ioapic].mp_config.apicaddr == address) {
2842	pr_warn("address 0x%x conflicts with IOAPIC%d\n",
2843	address, ioapic);
2844	return -EEXIST;
2845	}
2846
2847	idx = find_free_ioapic_entry();
2848	if (idx >= MAX_IO_APICS) {
2849	pr_warn("Max # of I/O APICs (%d) exceeded (found %d), skipping\n",
2850	MAX_IO_APICS, idx);
2851	return -ENOSPC;
2852	}
2853
2854	ioapics[idx].mp_config.type = MP_IOAPIC;
2855	ioapics[idx].mp_config.flags = MPC_APIC_USABLE;
2856	ioapics[idx].mp_config.apicaddr = address;
2857
2858	io_apic_set_fixmap(idx: FIX_IO_APIC_BASE_0 + idx, phys: address);
2859	if (bad_ioapic_register(idx)) {
2860	clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2861	return -ENODEV;
2862	}
2863
2864	ioapics[idx].mp_config.apicid = io_apic_unique_id(idx, id);
2865	ioapics[idx].mp_config.apicver = io_apic_get_version(ioapic: idx);
2866
2867	/*
2868	* Build basic GSI lookup table to facilitate gsi->io_apic lookups
2869	* and to prevent reprogramming of IOAPIC pins (PCI GSIs).
2870	*/
2871	entries = io_apic_get_redir_entries(ioapic: idx);
2872	gsi_end = gsi_base + entries - 1;
2873	for_each_ioapic(ioapic) {
2874	gsi_cfg = mp_ioapic_gsi_routing(ioapic_idx: ioapic);
2875	if ((gsi_base >= gsi_cfg->gsi_base &&
2876	gsi_base <= gsi_cfg->gsi_end) ||
2877	(gsi_end >= gsi_cfg->gsi_base &&
2878	gsi_end <= gsi_cfg->gsi_end)) {
2879	pr_warn("GSI range [%u-%u] for new IOAPIC conflicts with GSI[%u-%u]\n",
2880	gsi_base, gsi_end,
2881	gsi_cfg->gsi_base, gsi_cfg->gsi_end);
2882	clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2883	return -ENOSPC;
2884	}
2885	}
2886	gsi_cfg = mp_ioapic_gsi_routing(ioapic_idx: idx);
2887	gsi_cfg->gsi_base = gsi_base;
2888	gsi_cfg->gsi_end = gsi_end;
2889
2890	ioapics[idx].irqdomain = NULL;
2891	ioapics[idx].irqdomain_cfg = *cfg;
2892
2893	/*
2894	* If mp_register_ioapic() is called during early boot stage when
2895	* walking ACPI/DT tables, it's too early to create irqdomain,
2896	* we are still using bootmem allocator. So delay it to setup_IO_APIC().
2897	*/
2898	if (hotplug) {
2899	if (mp_irqdomain_create(ioapic: idx)) {
2900	clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2901	return -ENOMEM;
2902	}
2903	alloc_ioapic_saved_registers(idx);
2904	}
2905
2906	if (gsi_cfg->gsi_end >= gsi_top)
2907	gsi_top = gsi_cfg->gsi_end + 1;
2908	if (nr_ioapics <= idx)
2909	nr_ioapics = idx + 1;
2910
2911	/* Set nr_registers to mark entry present */
2912	ioapics[idx].nr_registers = entries;
2913
2914	pr_info("IOAPIC[%d]: apic_id %d, version %d, address 0x%x, GSI %d-%d\n",
2915	idx, mpc_ioapic_id(idx),
2916	mpc_ioapic_ver(idx), mpc_ioapic_addr(idx),
2917	gsi_cfg->gsi_base, gsi_cfg->gsi_end);
2918
2919	return 0;
2920	}
2921
2922	int mp_unregister_ioapic(u32 gsi_base)
2923	{
2924	int ioapic, pin;
2925	int found = 0;
2926
2927	for_each_ioapic(ioapic)
2928	if (ioapics[ioapic].gsi_config.gsi_base == gsi_base) {
2929	found = 1;
2930	break;
2931	}
2932	if (!found) {
2933	pr_warn("can't find IOAPIC for GSI %d\n", gsi_base);
2934	return -ENODEV;
2935	}
2936
2937	for_each_pin(ioapic, pin) {
2938	u32 gsi = mp_pin_to_gsi(ioapic, pin);
2939	int irq = mp_map_gsi_to_irq(gsi, flags: 0, NULL);
2940	struct mp_chip_data *data;
2941
2942	if (irq >= 0) {
2943	data = irq_get_chip_data(irq);
2944	if (data && data->count) {
2945	pr_warn("pin%d on IOAPIC%d is still in use.\n",
2946	pin, ioapic);
2947	return -EBUSY;
2948	}
2949	}
2950	}
2951
2952	/* Mark entry not present */
2953	ioapics[ioapic].nr_registers = 0;
2954	ioapic_destroy_irqdomain(idx: ioapic);
2955	free_ioapic_saved_registers(idx: ioapic);
2956	if (ioapics[ioapic].iomem_res)
2957	release_resource(new: ioapics[ioapic].iomem_res);
2958	clear_fixmap(FIX_IO_APIC_BASE_0 + ioapic);
2959	memset(&ioapics[ioapic], 0, sizeof(ioapics[ioapic]));
2960
2961	return 0;
2962	}
2963
2964	int mp_ioapic_registered(u32 gsi_base)
2965	{
2966	int ioapic;
2967
2968	for_each_ioapic(ioapic)
2969	if (ioapics[ioapic].gsi_config.gsi_base == gsi_base)
2970	return 1;
2971
2972	return 0;
2973	}
2974
2975	static void mp_irqdomain_get_attr(u32 gsi, struct mp_chip_data *data,
2976	struct irq_alloc_info *info)
2977	{
2978	if (info && info->ioapic.valid) {
2979	data->is_level = info->ioapic.is_level;
2980	data->active_low = info->ioapic.active_low;
2981	} else if (__acpi_get_override_irq(gsi, trigger: &data->is_level,
2982	polarity: &data->active_low) < 0) {
2983	/* PCI interrupts are always active low level triggered. */
2984	data->is_level = true;
2985	data->active_low = true;
2986	}
2987	}
2988
2989	/*
2990	* Configure the I/O-APIC specific fields in the routing entry.
2991	*
2992	* This is important to setup the I/O-APIC specific bits (is_level,
2993	* active_low, masked) because the underlying parent domain will only
2994	* provide the routing information and is oblivious of the I/O-APIC
2995	* specific bits.
2996	*
2997	* The entry is just preconfigured at this point and not written into the
2998	* RTE. This happens later during activation which will fill in the actual
2999	* routing information.
3000	*/
3001	static void mp_preconfigure_entry(struct mp_chip_data *data)
3002	{
3003	struct IO_APIC_route_entry *entry = &data->entry;
3004
3005	memset(entry, 0, sizeof(*entry));
3006	entry->is_level = data->is_level;
3007	entry->active_low = data->active_low;
3008	/*
3009	* Mask level triggered irqs. Edge triggered irqs are masked
3010	* by the irq core code in case they fire.
3011	*/
3012	entry->masked = data->is_level;
3013	}
3014
3015	int mp_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
3016	unsigned int nr_irqs, void *arg)
3017	{
3018	struct irq_alloc_info *info = arg;
3019	struct mp_chip_data *data;
3020	struct irq_data *irq_data;
3021	int ret, ioapic, pin;
3022	unsigned long flags;
3023
3024	if (!info || nr_irqs > 1)
3025	return -EINVAL;
3026	irq_data = irq_domain_get_irq_data(domain, virq);
3027	if (!irq_data)
3028	return -EINVAL;
3029
3030	ioapic = mp_irqdomain_ioapic_idx(domain);
3031	pin = info->ioapic.pin;
3032	if (irq_find_mapping(domain, hwirq: (irq_hw_number_t)pin) > 0)
3033	return -EEXIST;
3034
3035	data = kzalloc(size: sizeof(*data), GFP_KERNEL);
3036	if (!data)
3037	return -ENOMEM;
3038
3039	ret = irq_domain_alloc_irqs_parent(domain, irq_base: virq, nr_irqs, arg: info);
3040	if (ret < 0) {
3041	kfree(objp: data);
3042	return ret;
3043	}
3044
3045	INIT_LIST_HEAD(list: &data->irq_2_pin);
3046	irq_data->hwirq = info->ioapic.pin;
3047	irq_data->chip = (domain->parent == x86_vector_domain) ?
3048	&ioapic_chip : &ioapic_ir_chip;
3049	irq_data->chip_data = data;
3050	mp_irqdomain_get_attr(gsi: mp_pin_to_gsi(ioapic, pin), data, info);
3051
3052	add_pin_to_irq_node(data, node: ioapic_alloc_attr_node(info), apic: ioapic, pin);
3053
3054	mp_preconfigure_entry(data);
3055	mp_register_handler(irq: virq, level: data->is_level);
3056
3057	local_irq_save(flags);
3058	if (virq < nr_legacy_irqs())
3059	legacy_pic->mask(virq);
3060	local_irq_restore(flags);
3061
3062	apic_printk(APIC_VERBOSE, KERN_DEBUG
3063	"IOAPIC[%d]: Preconfigured routing entry (%d-%d -> IRQ %d Level:%i ActiveLow:%i)\n",
3064	ioapic, mpc_ioapic_id(ioapic), pin, virq,
3065	data->is_level, data->active_low);
3066	return 0;
3067	}
3068
3069	void mp_irqdomain_free(struct irq_domain *domain, unsigned int virq,
3070	unsigned int nr_irqs)
3071	{
3072	struct irq_data *irq_data;
3073	struct mp_chip_data *data;
3074
3075	BUG_ON(nr_irqs != 1);
3076	irq_data = irq_domain_get_irq_data(domain, virq);
3077	if (irq_data && irq_data->chip_data) {
3078	data = irq_data->chip_data;
3079	__remove_pin_from_irq(data, apic: mp_irqdomain_ioapic_idx(domain),
3080	pin: (int)irq_data->hwirq);
3081	WARN_ON(!list_empty(&data->irq_2_pin));
3082	kfree(objp: irq_data->chip_data);
3083	}
3084	irq_domain_free_irqs_top(domain, virq, nr_irqs);
3085	}
3086
3087	int mp_irqdomain_activate(struct irq_domain *domain,
3088	struct irq_data *irq_data, bool reserve)
3089	{
3090	unsigned long flags;
3091
3092	raw_spin_lock_irqsave(&ioapic_lock, flags);
3093	ioapic_configure_entry(irqd: irq_data);
3094	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
3095	return 0;
3096	}
3097
3098	void mp_irqdomain_deactivate(struct irq_domain *domain,
3099	struct irq_data *irq_data)
3100	{
3101	/* It won't be called for IRQ with multiple IOAPIC pins associated */
3102	ioapic_mask_entry(apic: mp_irqdomain_ioapic_idx(domain),
3103	pin: (int)irq_data->hwirq);
3104	}
3105
3106	int mp_irqdomain_ioapic_idx(struct irq_domain *domain)
3107	{
3108	return (int)(long)domain->host_data;
3109	}
3110
3111	const struct irq_domain_ops mp_ioapic_irqdomain_ops = {
3112	.alloc = mp_irqdomain_alloc,
3113	.free = mp_irqdomain_free,
3114	.activate = mp_irqdomain_activate,
3115	.deactivate = mp_irqdomain_deactivate,
3116	};
3117