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1/*
2 * I/O SAPIC support.
3 *
4 * Copyright (C) 1999 Intel Corp.
5 * Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com>
6 * Copyright (C) 2000-2002 J.I. Lee <jung-ik.lee@intel.com>
7 * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co.
8 *	David Mosberger-Tang <davidm@hpl.hp.com>
9 * Copyright (C) 1999 VA Linux Systems
10 * Copyright (C) 1999,2000 Walt Drummond <drummond@valinux.com>
11 *
12 * 00/04/19	D. Mosberger	Rewritten to mirror more closely the x86 I/O
13 *				APIC code.  In particular, we now have separate
14 *				handlers for edge and level triggered
15 *				interrupts.
16 * 00/10/27	Asit Mallick, Goutham Rao <goutham.rao@intel.com> IRQ vector
17 *				allocation PCI to vector mapping, shared PCI
18 *				interrupts.
19 * 00/10/27	D. Mosberger	Document things a bit more to make them more
20 *				understandable.  Clean up much of the old
21 *				IOSAPIC cruft.
22 * 01/07/27	J.I. Lee	PCI irq routing, Platform/Legacy interrupts
23 *				and fixes for ACPI S5(SoftOff) support.
24 * 02/01/23	J.I. Lee	iosapic pgm fixes for PCI irq routing from _PRT
25 * 02/01/07     E. Focht        <efocht@ess.nec.de> Redirectable interrupt
26 *				vectors in iosapic_set_affinity(),
27 *				initializations for /proc/irq/#/smp_affinity
28 * 02/04/02	P. Diefenbaugh	Cleaned up ACPI PCI IRQ routing.
29 * 02/04/18	J.I. Lee	bug fix in iosapic_init_pci_irq
30 * 02/04/30	J.I. Lee	bug fix in find_iosapic to fix ACPI PCI IRQ to
31 *				IOSAPIC mapping error
32 * 02/07/29	T. Kochi	Allocate interrupt vectors dynamically
33 * 02/08/04	T. Kochi	Cleaned up terminology (irq, global system
34 *				interrupt, vector, etc.)
35 * 02/09/20	D. Mosberger	Simplified by taking advantage of ACPI's
36 *				pci_irq code.
37 * 03/02/19	B. Helgaas	Make pcat_compat system-wide, not per-IOSAPIC.
38 *				Remove iosapic_address & gsi_base from
39 *				external interfaces.  Rationalize
40 *				__init/__devinit attributes.
41 * 04/12/04 Ashok Raj	<ashok.raj@intel.com> Intel Corporation 2004
42 *				Updated to work with irq migration necessary
43 *				for CPU Hotplug
44 */
45/*
46 * Here is what the interrupt logic between a PCI device and the kernel looks
47 * like:
48 *
49 * (1) A PCI device raises one of the four interrupt pins (INTA, INTB, INTC,
50 *     INTD).  The device is uniquely identified by its bus-, and slot-number
51 *     (the function number does not matter here because all functions share
52 *     the same interrupt lines).
53 *
54 * (2) The motherboard routes the interrupt line to a pin on a IOSAPIC
55 *     controller.  Multiple interrupt lines may have to share the same
56 *     IOSAPIC pin (if they're level triggered and use the same polarity).
57 *     Each interrupt line has a unique Global System Interrupt (GSI) number
58 *     which can be calculated as the sum of the controller's base GSI number
59 *     and the IOSAPIC pin number to which the line connects.
60 *
61 * (3) The IOSAPIC uses an internal routing table entries (RTEs) to map the
62 * IOSAPIC pin into the IA-64 interrupt vector.  This interrupt vector is then
63 * sent to the CPU.
64 *
65 * (4) The kernel recognizes an interrupt as an IRQ.  The IRQ interface is
66 *     used as architecture-independent interrupt handling mechanism in Linux.
67 *     As an IRQ is a number, we have to have
68 *     IA-64 interrupt vector number <-> IRQ number mapping.  On smaller
69 *     systems, we use one-to-one mapping between IA-64 vector and IRQ.  A
70 *     platform can implement platform_irq_to_vector(irq) and
71 *     platform_local_vector_to_irq(vector) APIs to differentiate the mapping.
72 *     Please see also arch/ia64/include/asm/hw_irq.h for those APIs.
73 *
74 * To sum up, there are three levels of mappings involved:
75 *
76 *	PCI pin -> global system interrupt (GSI) -> IA-64 vector <-> IRQ
77 *
78 * Note: The term "IRQ" is loosely used everywhere in Linux kernel to
79 * describeinterrupts.  Now we use "IRQ" only for Linux IRQ's.  ISA IRQ
80 * (isa_irq) is the only exception in this source code.
81 */
82
83#include <linux/acpi.h>
84#include <linux/init.h>
85#include <linux/irq.h>
86#include <linux/kernel.h>
87#include <linux/list.h>
88#include <linux/pci.h>
89#include <linux/slab.h>
90#include <linux/smp.h>
91#include <linux/string.h>
92#include <linux/bootmem.h>
93
94#include <asm/delay.h>
95#include <asm/hw_irq.h>
96#include <asm/io.h>
97#include <asm/iosapic.h>
98#include <asm/machvec.h>
99#include <asm/processor.h>
100#include <asm/ptrace.h>
101#include <asm/system.h>
102
103#undef DEBUG_INTERRUPT_ROUTING
104
105#ifdef DEBUG_INTERRUPT_ROUTING
106#define DBG(fmt...)	printk(fmt)
107#else
108#define DBG(fmt...)
109#endif
110
111#define NR_PREALLOCATE_RTE_ENTRIES \
112	(PAGE_SIZE / sizeof(struct iosapic_rte_info))
113#define RTE_PREALLOCATED	(1)
114
115static DEFINE_SPINLOCK(iosapic_lock);
116
117/*
118 * These tables map IA-64 vectors to the IOSAPIC pin that generates this
119 * vector.
120 */
121
122#define NO_REF_RTE	0
123
124static struct iosapic {
125	char __iomem	*addr;		/* base address of IOSAPIC */
126	unsigned int	gsi_base;	/* GSI base */
127	unsigned short	num_rte;	/* # of RTEs on this IOSAPIC */
128	int		rtes_inuse;	/* # of RTEs in use on this IOSAPIC */
129#ifdef CONFIG_NUMA
130	unsigned short	node;		/* numa node association via pxm */
131#endif
132	spinlock_t	lock;		/* lock for indirect reg access */
133} iosapic_lists[NR_IOSAPICS];
134
135struct iosapic_rte_info {
136	struct list_head rte_list;	/* RTEs sharing the same vector */
137	char		rte_index;	/* IOSAPIC RTE index */
138	int		refcnt;		/* reference counter */
139	unsigned int	flags;		/* flags */
140	struct iosapic	*iosapic;
141} ____cacheline_aligned;
142
143static struct iosapic_intr_info {
144	struct list_head rtes;		/* RTEs using this vector (empty =>
145					 * not an IOSAPIC interrupt) */
146	int		count;		/* # of registered RTEs */
147	u32		low32;		/* current value of low word of
148					 * Redirection table entry */
149	unsigned int	dest;		/* destination CPU physical ID */
150	unsigned char	dmode	: 3;	/* delivery mode (see iosapic.h) */
151	unsigned char 	polarity: 1;	/* interrupt polarity
152					 * (see iosapic.h) */
153	unsigned char	trigger	: 1;	/* trigger mode (see iosapic.h) */
154} iosapic_intr_info[NR_IRQS];
155
156static unsigned char pcat_compat __devinitdata;	/* 8259 compatibility flag */
157
158static int iosapic_kmalloc_ok;
159static LIST_HEAD(free_rte_list);
160
161static inline void
162iosapic_write(struct iosapic *iosapic, unsigned int reg, u32 val)
163{
164	unsigned long flags;
165
166	spin_lock_irqsave(&iosapic->lock, flags);
167	__iosapic_write(iosapic->addr, reg, val);
168	spin_unlock_irqrestore(&iosapic->lock, flags);
169}
170
171/*
172 * Find an IOSAPIC associated with a GSI
173 */
174static inline int
175find_iosapic (unsigned int gsi)
176{
177	int i;
178
179	for (i = 0; i < NR_IOSAPICS; i++) {
180		if ((unsigned) (gsi - iosapic_lists[i].gsi_base) <
181		    iosapic_lists[i].num_rte)
182			return i;
183	}
184
185	return -1;
186}
187
188static inline int __gsi_to_irq(unsigned int gsi)
189{
190	int irq;
191	struct iosapic_intr_info *info;
192	struct iosapic_rte_info *rte;
193
194	for (irq = 0; irq < NR_IRQS; irq++) {
195		info = &iosapic_intr_info[irq];
196		list_for_each_entry(rte, &info->rtes, rte_list)
197			if (rte->iosapic->gsi_base + rte->rte_index == gsi)
198				return irq;
199	}
200	return -1;
201}
202
203int
204gsi_to_irq (unsigned int gsi)
205{
206	unsigned long flags;
207	int irq;
208
209	spin_lock_irqsave(&iosapic_lock, flags);
210	irq = __gsi_to_irq(gsi);
211	spin_unlock_irqrestore(&iosapic_lock, flags);
212	return irq;
213}
214
215static struct iosapic_rte_info *find_rte(unsigned int irq, unsigned int gsi)
216{
217	struct iosapic_rte_info *rte;
218
219	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list)
220		if (rte->iosapic->gsi_base + rte->rte_index == gsi)
221			return rte;
222	return NULL;
223}
224
225static void
226set_rte (unsigned int gsi, unsigned int irq, unsigned int dest, int mask)
227{
228	unsigned long pol, trigger, dmode;
229	u32 low32, high32;
230	int rte_index;
231	char redir;
232	struct iosapic_rte_info *rte;
233	ia64_vector vector = irq_to_vector(irq);
234
235	DBG(KERN_DEBUG"IOSAPIC: routing vector %d to 0x%x\n", vector, dest);
236
237	rte = find_rte(irq, gsi);
238	if (!rte)
239		return;		/* not an IOSAPIC interrupt */
240
241	rte_index = rte->rte_index;
242	pol     = iosapic_intr_info[irq].polarity;
243	trigger = iosapic_intr_info[irq].trigger;
244	dmode   = iosapic_intr_info[irq].dmode;
245
246	redir = (dmode == IOSAPIC_LOWEST_PRIORITY) ? 1 : 0;
247
248#ifdef CONFIG_SMP
249	set_irq_affinity_info(irq, (int)(dest & 0xffff), redir);
250#endif
251
252	low32 = ((pol << IOSAPIC_POLARITY_SHIFT) |
253		 (trigger << IOSAPIC_TRIGGER_SHIFT) |
254		 (dmode << IOSAPIC_DELIVERY_SHIFT) |
255		 ((mask ? 1 : 0) << IOSAPIC_MASK_SHIFT) |
256		 vector);
257
258	/* dest contains both id and eid */
259	high32 = (dest << IOSAPIC_DEST_SHIFT);
260
261	iosapic_write(rte->iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
262	iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
263	iosapic_intr_info[irq].low32 = low32;
264	iosapic_intr_info[irq].dest = dest;
265}
266
267static void
268nop (unsigned int irq)
269{
270	/* do nothing... */
271}
272
273
274#ifdef CONFIG_KEXEC
275void
276kexec_disable_iosapic(void)
277{
278	struct iosapic_intr_info *info;
279	struct iosapic_rte_info *rte;
280	ia64_vector vec;
281	int irq;
282
283	for (irq = 0; irq < NR_IRQS; irq++) {
284		info = &iosapic_intr_info[irq];
285		vec = irq_to_vector(irq);
286		list_for_each_entry(rte, &info->rtes,
287				rte_list) {
288			iosapic_write(rte->iosapic,
289					IOSAPIC_RTE_LOW(rte->rte_index),
290					IOSAPIC_MASK|vec);
291			iosapic_eoi(rte->iosapic->addr, vec);
292		}
293	}
294}
295#endif
296
297static void
298mask_irq (unsigned int irq)
299{
300	u32 low32;
301	int rte_index;
302	struct iosapic_rte_info *rte;
303
304	if (!iosapic_intr_info[irq].count)
305		return;			/* not an IOSAPIC interrupt! */
306
307	/* set only the mask bit */
308	low32 = iosapic_intr_info[irq].low32 |= IOSAPIC_MASK;
309	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
310		rte_index = rte->rte_index;
311		iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
312	}
313}
314
315static void
316unmask_irq (unsigned int irq)
317{
318	u32 low32;
319	int rte_index;
320	struct iosapic_rte_info *rte;
321
322	if (!iosapic_intr_info[irq].count)
323		return;			/* not an IOSAPIC interrupt! */
324
325	low32 = iosapic_intr_info[irq].low32 &= ~IOSAPIC_MASK;
326	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
327		rte_index = rte->rte_index;
328		iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
329	}
330}
331
332
333static int
334iosapic_set_affinity(unsigned int irq, const struct cpumask *mask)
335{
336#ifdef CONFIG_SMP
337	u32 high32, low32;
338	int cpu, dest, rte_index;
339	int redir = (irq & IA64_IRQ_REDIRECTED) ? 1 : 0;
340	struct iosapic_rte_info *rte;
341	struct iosapic *iosapic;
342
343	irq &= (~IA64_IRQ_REDIRECTED);
344
345	cpu = cpumask_first_and(cpu_online_mask, mask);
346	if (cpu >= nr_cpu_ids)
347		return -1;
348
349	if (irq_prepare_move(irq, cpu))
350		return -1;
351
352	dest = cpu_physical_id(cpu);
353
354	if (!iosapic_intr_info[irq].count)
355		return -1;			/* not an IOSAPIC interrupt */
356
357	set_irq_affinity_info(irq, dest, redir);
358
359	/* dest contains both id and eid */
360	high32 = dest << IOSAPIC_DEST_SHIFT;
361
362	low32 = iosapic_intr_info[irq].low32 & ~(7 << IOSAPIC_DELIVERY_SHIFT);
363	if (redir)
364		/* change delivery mode to lowest priority */
365		low32 |= (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
366	else
367		/* change delivery mode to fixed */
368		low32 |= (IOSAPIC_FIXED << IOSAPIC_DELIVERY_SHIFT);
369	low32 &= IOSAPIC_VECTOR_MASK;
370	low32 |= irq_to_vector(irq);
371
372	iosapic_intr_info[irq].low32 = low32;
373	iosapic_intr_info[irq].dest = dest;
374	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list) {
375		iosapic = rte->iosapic;
376		rte_index = rte->rte_index;
377		iosapic_write(iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
378		iosapic_write(iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
379	}
380
381#endif
382	return 0;
383}
384
385/*
386 * Handlers for level-triggered interrupts.
387 */
388
389static unsigned int
390iosapic_startup_level_irq (unsigned int irq)
391{
392	unmask_irq(irq);
393	return 0;
394}
395
396static void
397iosapic_end_level_irq (unsigned int irq)
398{
399	ia64_vector vec = irq_to_vector(irq);
400	struct iosapic_rte_info *rte;
401	int do_unmask_irq = 0;
402
403	irq_complete_move(irq);
404	if (unlikely(irq_desc[irq].status & IRQ_MOVE_PENDING)) {
405		do_unmask_irq = 1;
406		mask_irq(irq);
407	}
408
409	list_for_each_entry(rte, &iosapic_intr_info[irq].rtes, rte_list)
410		iosapic_eoi(rte->iosapic->addr, vec);
411
412	if (unlikely(do_unmask_irq)) {
413		move_masked_irq(irq);
414		unmask_irq(irq);
415	}
416}
417
418#define iosapic_shutdown_level_irq	mask_irq
419#define iosapic_enable_level_irq	unmask_irq
420#define iosapic_disable_level_irq	mask_irq
421#define iosapic_ack_level_irq		nop
422
423static struct irq_chip irq_type_iosapic_level = {
424	.name =		"IO-SAPIC-level",
425	.startup =	iosapic_startup_level_irq,
426	.shutdown =	iosapic_shutdown_level_irq,
427	.enable =	iosapic_enable_level_irq,
428	.disable =	iosapic_disable_level_irq,
429	.ack =		iosapic_ack_level_irq,
430	.end =		iosapic_end_level_irq,
431	.mask =		mask_irq,
432	.unmask =	unmask_irq,
433	.set_affinity =	iosapic_set_affinity
434};
435
436/*
437 * Handlers for edge-triggered interrupts.
438 */
439
440static unsigned int
441iosapic_startup_edge_irq (unsigned int irq)
442{
443	unmask_irq(irq);
444	/*
445	 * IOSAPIC simply drops interrupts pended while the
446	 * corresponding pin was masked, so we can't know if an
447	 * interrupt is pending already.  Let's hope not...
448	 */
449	return 0;
450}
451
452static void
453iosapic_ack_edge_irq (unsigned int irq)
454{
455	struct irq_desc *idesc = irq_desc + irq;
456
457	irq_complete_move(irq);
458	move_native_irq(irq);
459	/*
460	 * Once we have recorded IRQ_PENDING already, we can mask the
461	 * interrupt for real. This prevents IRQ storms from unhandled
462	 * devices.
463	 */
464	if ((idesc->status & (IRQ_PENDING|IRQ_DISABLED)) ==
465	    (IRQ_PENDING|IRQ_DISABLED))
466		mask_irq(irq);
467}
468
469#define iosapic_enable_edge_irq		unmask_irq
470#define iosapic_disable_edge_irq	nop
471#define iosapic_end_edge_irq		nop
472
473static struct irq_chip irq_type_iosapic_edge = {
474	.name =		"IO-SAPIC-edge",
475	.startup =	iosapic_startup_edge_irq,
476	.shutdown =	iosapic_disable_edge_irq,
477	.enable =	iosapic_enable_edge_irq,
478	.disable =	iosapic_disable_edge_irq,
479	.ack =		iosapic_ack_edge_irq,
480	.end =		iosapic_end_edge_irq,
481	.mask =		mask_irq,
482	.unmask =	unmask_irq,
483	.set_affinity =	iosapic_set_affinity
484};
485
486static unsigned int
487iosapic_version (char __iomem *addr)
488{
489	/*
490	 * IOSAPIC Version Register return 32 bit structure like:
491	 * {
492	 *	unsigned int version   : 8;
493	 *	unsigned int reserved1 : 8;
494	 *	unsigned int max_redir : 8;
495	 *	unsigned int reserved2 : 8;
496	 * }
497	 */
498	return __iosapic_read(addr, IOSAPIC_VERSION);
499}
500
501static int iosapic_find_sharable_irq(unsigned long trigger, unsigned long pol)
502{
503	int i, irq = -ENOSPC, min_count = -1;
504	struct iosapic_intr_info *info;
505
506	/*
507	 * shared vectors for edge-triggered interrupts are not
508	 * supported yet
509	 */
510	if (trigger == IOSAPIC_EDGE)
511		return -EINVAL;
512
513	for (i = 0; i < NR_IRQS; i++) {
514		info = &iosapic_intr_info[i];
515		if (info->trigger == trigger && info->polarity == pol &&
516		    (info->dmode == IOSAPIC_FIXED ||
517		     info->dmode == IOSAPIC_LOWEST_PRIORITY) &&
518		    can_request_irq(i, IRQF_SHARED)) {
519			if (min_count == -1 || info->count < min_count) {
520				irq = i;
521				min_count = info->count;
522			}
523		}
524	}
525	return irq;
526}
527
528/*
529 * if the given vector is already owned by other,
530 *  assign a new vector for the other and make the vector available
531 */
532static void __init
533iosapic_reassign_vector (int irq)
534{
535	int new_irq;
536
537	if (iosapic_intr_info[irq].count) {
538		new_irq = create_irq();
539		if (new_irq < 0)
540			panic("%s: out of interrupt vectors!\n", __func__);
541		printk(KERN_INFO "Reassigning vector %d to %d\n",
542		       irq_to_vector(irq), irq_to_vector(new_irq));
543		memcpy(&iosapic_intr_info[new_irq], &iosapic_intr_info[irq],
544		       sizeof(struct iosapic_intr_info));
545		INIT_LIST_HEAD(&iosapic_intr_info[new_irq].rtes);
546		list_move(iosapic_intr_info[irq].rtes.next,
547			  &iosapic_intr_info[new_irq].rtes);
548		memset(&iosapic_intr_info[irq], 0,
549		       sizeof(struct iosapic_intr_info));
550		iosapic_intr_info[irq].low32 = IOSAPIC_MASK;
551		INIT_LIST_HEAD(&iosapic_intr_info[irq].rtes);
552	}
553}
554
555static struct iosapic_rte_info * __init_refok iosapic_alloc_rte (void)
556{
557	int i;
558	struct iosapic_rte_info *rte;
559	int preallocated = 0;
560
561	if (!iosapic_kmalloc_ok && list_empty(&free_rte_list)) {
562		rte = alloc_bootmem(sizeof(struct iosapic_rte_info) *
563				    NR_PREALLOCATE_RTE_ENTRIES);
564		for (i = 0; i < NR_PREALLOCATE_RTE_ENTRIES; i++, rte++)
565			list_add(&rte->rte_list, &free_rte_list);
566	}
567
568	if (!list_empty(&free_rte_list)) {
569		rte = list_entry(free_rte_list.next, struct iosapic_rte_info,
570				 rte_list);
571		list_del(&rte->rte_list);
572		preallocated++;
573	} else {
574		rte = kmalloc(sizeof(struct iosapic_rte_info), GFP_ATOMIC);
575		if (!rte)
576			return NULL;
577	}
578
579	memset(rte, 0, sizeof(struct iosapic_rte_info));
580	if (preallocated)
581		rte->flags |= RTE_PREALLOCATED;
582
583	return rte;
584}
585
586static inline int irq_is_shared (int irq)
587{
588	return (iosapic_intr_info[irq].count > 1);
589}
590
591struct irq_chip*
592ia64_native_iosapic_get_irq_chip(unsigned long trigger)
593{
594	if (trigger == IOSAPIC_EDGE)
595		return &irq_type_iosapic_edge;
596	else
597		return &irq_type_iosapic_level;
598}
599
600static int
601register_intr (unsigned int gsi, int irq, unsigned char delivery,
602	       unsigned long polarity, unsigned long trigger)
603{
604	struct irq_desc *idesc;
605	struct irq_chip *irq_type;
606	int index;
607	struct iosapic_rte_info *rte;
608
609	index = find_iosapic(gsi);
610	if (index < 0) {
611		printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
612		       __func__, gsi);
613		return -ENODEV;
614	}
615
616	rte = find_rte(irq, gsi);
617	if (!rte) {
618		rte = iosapic_alloc_rte();
619		if (!rte) {
620			printk(KERN_WARNING "%s: cannot allocate memory\n",
621			       __func__);
622			return -ENOMEM;
623		}
624
625		rte->iosapic	= &iosapic_lists[index];
626		rte->rte_index	= gsi - rte->iosapic->gsi_base;
627		rte->refcnt++;
628		list_add_tail(&rte->rte_list, &iosapic_intr_info[irq].rtes);
629		iosapic_intr_info[irq].count++;
630		iosapic_lists[index].rtes_inuse++;
631	}
632	else if (rte->refcnt == NO_REF_RTE) {
633		struct iosapic_intr_info *info = &iosapic_intr_info[irq];
634		if (info->count > 0 &&
635		    (info->trigger != trigger || info->polarity != polarity)){
636			printk (KERN_WARNING
637				"%s: cannot override the interrupt\n",
638				__func__);
639			return -EINVAL;
640		}
641		rte->refcnt++;
642		iosapic_intr_info[irq].count++;
643		iosapic_lists[index].rtes_inuse++;
644	}
645
646	iosapic_intr_info[irq].polarity = polarity;
647	iosapic_intr_info[irq].dmode    = delivery;
648	iosapic_intr_info[irq].trigger  = trigger;
649
650	irq_type = iosapic_get_irq_chip(trigger);
651
652	idesc = irq_desc + irq;
653	if (irq_type != NULL && idesc->chip != irq_type) {
654		if (idesc->chip != &no_irq_chip)
655			printk(KERN_WARNING
656			       "%s: changing vector %d from %s to %s\n",
657			       __func__, irq_to_vector(irq),
658			       idesc->chip->name, irq_type->name);
659		idesc->chip = irq_type;
660	}
661	return 0;
662}
663
664static unsigned int
665get_target_cpu (unsigned int gsi, int irq)
666{
667#ifdef CONFIG_SMP
668	static int cpu = -1;
669	extern int cpe_vector;
670	cpumask_t domain = irq_to_domain(irq);
671
672	/*
673	 * In case of vector shared by multiple RTEs, all RTEs that
674	 * share the vector need to use the same destination CPU.
675	 */
676	if (iosapic_intr_info[irq].count)
677		return iosapic_intr_info[irq].dest;
678
679	/*
680	 * If the platform supports redirection via XTP, let it
681	 * distribute interrupts.
682	 */
683	if (smp_int_redirect & SMP_IRQ_REDIRECTION)
684		return cpu_physical_id(smp_processor_id());
685
686	/*
687	 * Some interrupts (ACPI SCI, for instance) are registered
688	 * before the BSP is marked as online.
689	 */
690	if (!cpu_online(smp_processor_id()))
691		return cpu_physical_id(smp_processor_id());
692
693#ifdef CONFIG_ACPI
694	if (cpe_vector > 0 && irq_to_vector(irq) == IA64_CPEP_VECTOR)
695		return get_cpei_target_cpu();
696#endif
697
698#ifdef CONFIG_NUMA
699	{
700		int num_cpus, cpu_index, iosapic_index, numa_cpu, i = 0;
701		const struct cpumask *cpu_mask;
702
703		iosapic_index = find_iosapic(gsi);
704		if (iosapic_index < 0 ||
705		    iosapic_lists[iosapic_index].node == MAX_NUMNODES)
706			goto skip_numa_setup;
707
708		cpu_mask = cpumask_of_node(iosapic_lists[iosapic_index].node);
709		num_cpus = 0;
710		for_each_cpu_and(numa_cpu, cpu_mask, &domain) {
711			if (cpu_online(numa_cpu))
712				num_cpus++;
713		}
714
715		if (!num_cpus)
716			goto skip_numa_setup;
717
718		/* Use irq assignment to distribute across cpus in node */
719		cpu_index = irq % num_cpus;
720
721		for_each_cpu_and(numa_cpu, cpu_mask, &domain)
722			if (cpu_online(numa_cpu) && i++ >= cpu_index)
723				break;
724
725		if (numa_cpu < nr_cpu_ids)
726			return cpu_physical_id(numa_cpu);
727	}
728skip_numa_setup:
729#endif
730	/*
731	 * Otherwise, round-robin interrupt vectors across all the
732	 * processors.  (It'd be nice if we could be smarter in the
733	 * case of NUMA.)
734	 */
735	do {
736		if (++cpu >= nr_cpu_ids)
737			cpu = 0;
738	} while (!cpu_online(cpu) || !cpu_isset(cpu, domain));
739
740	return cpu_physical_id(cpu);
741#else  /* CONFIG_SMP */
742	return cpu_physical_id(smp_processor_id());
743#endif
744}
745
746static inline unsigned char choose_dmode(void)
747{
748#ifdef CONFIG_SMP
749	if (smp_int_redirect & SMP_IRQ_REDIRECTION)
750		return IOSAPIC_LOWEST_PRIORITY;
751#endif
752	return IOSAPIC_FIXED;
753}
754
755/*
756 * ACPI can describe IOSAPIC interrupts via static tables and namespace
757 * methods.  This provides an interface to register those interrupts and
758 * program the IOSAPIC RTE.
759 */
760int
761iosapic_register_intr (unsigned int gsi,
762		       unsigned long polarity, unsigned long trigger)
763{
764	int irq, mask = 1, err;
765	unsigned int dest;
766	unsigned long flags;
767	struct iosapic_rte_info *rte;
768	u32 low32;
769	unsigned char dmode;
770
771	/*
772	 * If this GSI has already been registered (i.e., it's a
773	 * shared interrupt, or we lost a race to register it),
774	 * don't touch the RTE.
775	 */
776	spin_lock_irqsave(&iosapic_lock, flags);
777	irq = __gsi_to_irq(gsi);
778	if (irq > 0) {
779		rte = find_rte(irq, gsi);
780		if(iosapic_intr_info[irq].count == 0) {
781			assign_irq_vector(irq);
782			dynamic_irq_init(irq);
783		} else if (rte->refcnt != NO_REF_RTE) {
784			rte->refcnt++;
785			goto unlock_iosapic_lock;
786		}
787	} else
788		irq = create_irq();
789
790	/* If vector is running out, we try to find a sharable vector */
791	if (irq < 0) {
792		irq = iosapic_find_sharable_irq(trigger, polarity);
793		if (irq < 0)
794			goto unlock_iosapic_lock;
795	}
796
797	raw_spin_lock(&irq_desc[irq].lock);
798	dest = get_target_cpu(gsi, irq);
799	dmode = choose_dmode();
800	err = register_intr(gsi, irq, dmode, polarity, trigger);
801	if (err < 0) {
802		raw_spin_unlock(&irq_desc[irq].lock);
803		irq = err;
804		goto unlock_iosapic_lock;
805	}
806
807	/*
808	 * If the vector is shared and already unmasked for other
809	 * interrupt sources, don't mask it.
810	 */
811	low32 = iosapic_intr_info[irq].low32;
812	if (irq_is_shared(irq) && !(low32 & IOSAPIC_MASK))
813		mask = 0;
814	set_rte(gsi, irq, dest, mask);
815
816	printk(KERN_INFO "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d\n",
817	       gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
818	       (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
819	       cpu_logical_id(dest), dest, irq_to_vector(irq));
820
821	raw_spin_unlock(&irq_desc[irq].lock);
822 unlock_iosapic_lock:
823	spin_unlock_irqrestore(&iosapic_lock, flags);
824	return irq;
825}
826
827void
828iosapic_unregister_intr (unsigned int gsi)
829{
830	unsigned long flags;
831	int irq, index;
832	struct irq_desc *idesc;
833	u32 low32;
834	unsigned long trigger, polarity;
835	unsigned int dest;
836	struct iosapic_rte_info *rte;
837
838	/*
839	 * If the irq associated with the gsi is not found,
840	 * iosapic_unregister_intr() is unbalanced. We need to check
841	 * this again after getting locks.
842	 */
843	irq = gsi_to_irq(gsi);
844	if (irq < 0) {
845		printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
846		       gsi);
847		WARN_ON(1);
848		return;
849	}
850
851	spin_lock_irqsave(&iosapic_lock, flags);
852	if ((rte = find_rte(irq, gsi)) == NULL) {
853		printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
854		       gsi);
855		WARN_ON(1);
856		goto out;
857	}
858
859	if (--rte->refcnt > 0)
860		goto out;
861
862	idesc = irq_desc + irq;
863	rte->refcnt = NO_REF_RTE;
864
865	/* Mask the interrupt */
866	low32 = iosapic_intr_info[irq].low32 | IOSAPIC_MASK;
867	iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte->rte_index), low32);
868
869	iosapic_intr_info[irq].count--;
870	index = find_iosapic(gsi);
871	iosapic_lists[index].rtes_inuse--;
872	WARN_ON(iosapic_lists[index].rtes_inuse < 0);
873
874	trigger  = iosapic_intr_info[irq].trigger;
875	polarity = iosapic_intr_info[irq].polarity;
876	dest     = iosapic_intr_info[irq].dest;
877	printk(KERN_INFO
878	       "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d unregistered\n",
879	       gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
880	       (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
881	       cpu_logical_id(dest), dest, irq_to_vector(irq));
882
883	if (iosapic_intr_info[irq].count == 0) {
884#ifdef CONFIG_SMP
885		/* Clear affinity */
886		cpumask_setall(idesc->affinity);
887#endif
888		/* Clear the interrupt information */
889		iosapic_intr_info[irq].dest = 0;
890		iosapic_intr_info[irq].dmode = 0;
891		iosapic_intr_info[irq].polarity = 0;
892		iosapic_intr_info[irq].trigger = 0;
893		iosapic_intr_info[irq].low32 |= IOSAPIC_MASK;
894
895		/* Destroy and reserve IRQ */
896		destroy_and_reserve_irq(irq);
897	}
898 out:
899	spin_unlock_irqrestore(&iosapic_lock, flags);
900}
901
902/*
903 * ACPI calls this when it finds an entry for a platform interrupt.
904 */
905int __init
906iosapic_register_platform_intr (u32 int_type, unsigned int gsi,
907				int iosapic_vector, u16 eid, u16 id,
908				unsigned long polarity, unsigned long trigger)
909{
910	static const char * const name[] = {"unknown", "PMI", "INIT", "CPEI"};
911	unsigned char delivery;
912	int irq, vector, mask = 0;
913	unsigned int dest = ((id << 8) | eid) & 0xffff;
914
915	switch (int_type) {
916	      case ACPI_INTERRUPT_PMI:
917		irq = vector = iosapic_vector;
918		bind_irq_vector(irq, vector, CPU_MASK_ALL);
919		/*
920		 * since PMI vector is alloc'd by FW(ACPI) not by kernel,
921		 * we need to make sure the vector is available
922		 */
923		iosapic_reassign_vector(irq);
924		delivery = IOSAPIC_PMI;
925		break;
926	      case ACPI_INTERRUPT_INIT:
927		irq = create_irq();
928		if (irq < 0)
929			panic("%s: out of interrupt vectors!\n", __func__);
930		vector = irq_to_vector(irq);
931		delivery = IOSAPIC_INIT;
932		break;
933	      case ACPI_INTERRUPT_CPEI:
934		irq = vector = IA64_CPE_VECTOR;
935		BUG_ON(bind_irq_vector(irq, vector, CPU_MASK_ALL));
936		delivery = IOSAPIC_FIXED;
937		mask = 1;
938		break;
939	      default:
940		printk(KERN_ERR "%s: invalid int type 0x%x\n", __func__,
941		       int_type);
942		return -1;
943	}
944
945	register_intr(gsi, irq, delivery, polarity, trigger);
946
947	printk(KERN_INFO
948	       "PLATFORM int %s (0x%x): GSI %u (%s, %s) -> CPU %d (0x%04x)"
949	       " vector %d\n",
950	       int_type < ARRAY_SIZE(name) ? name[int_type] : "unknown",
951	       int_type, gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
952	       (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
953	       cpu_logical_id(dest), dest, vector);
954
955	set_rte(gsi, irq, dest, mask);
956	return vector;
957}
958
959/*
960 * ACPI calls this when it finds an entry for a legacy ISA IRQ override.
961 */
962void __devinit
963iosapic_override_isa_irq (unsigned int isa_irq, unsigned int gsi,
964			  unsigned long polarity,
965			  unsigned long trigger)
966{
967	int vector, irq;
968	unsigned int dest = cpu_physical_id(smp_processor_id());
969	unsigned char dmode;
970
971	irq = vector = isa_irq_to_vector(isa_irq);
972	BUG_ON(bind_irq_vector(irq, vector, CPU_MASK_ALL));
973	dmode = choose_dmode();
974	register_intr(gsi, irq, dmode, polarity, trigger);
975
976	DBG("ISA: IRQ %u -> GSI %u (%s,%s) -> CPU %d (0x%04x) vector %d\n",
977	    isa_irq, gsi, trigger == IOSAPIC_EDGE ? "edge" : "level",
978	    polarity == IOSAPIC_POL_HIGH ? "high" : "low",
979	    cpu_logical_id(dest), dest, vector);
980
981	set_rte(gsi, irq, dest, 1);
982}
983
984void __init
985ia64_native_iosapic_pcat_compat_init(void)
986{
987	if (pcat_compat) {
988		/*
989		 * Disable the compatibility mode interrupts (8259 style),
990		 * needs IN/OUT support enabled.
991		 */
992		printk(KERN_INFO
993		       "%s: Disabling PC-AT compatible 8259 interrupts\n",
994		       __func__);
995		outb(0xff, 0xA1);
996		outb(0xff, 0x21);
997	}
998}
999
1000void __init
1001iosapic_system_init (int system_pcat_compat)
1002{
1003	int irq;
1004
1005	for (irq = 0; irq < NR_IRQS; ++irq) {
1006		iosapic_intr_info[irq].low32 = IOSAPIC_MASK;
1007		/* mark as unused */
1008		INIT_LIST_HEAD(&iosapic_intr_info[irq].rtes);
1009
1010		iosapic_intr_info[irq].count = 0;
1011	}
1012
1013	pcat_compat = system_pcat_compat;
1014	if (pcat_compat)
1015		iosapic_pcat_compat_init();
1016}
1017
1018static inline int
1019iosapic_alloc (void)
1020{
1021	int index;
1022
1023	for (index = 0; index < NR_IOSAPICS; index++)
1024		if (!iosapic_lists[index].addr)
1025			return index;
1026
1027	printk(KERN_WARNING "%s: failed to allocate iosapic\n", __func__);
1028	return -1;
1029}
1030
1031static inline void
1032iosapic_free (int index)
1033{
1034	memset(&iosapic_lists[index], 0, sizeof(iosapic_lists[0]));
1035}
1036
1037static inline int
1038iosapic_check_gsi_range (unsigned int gsi_base, unsigned int ver)
1039{
1040	int index;
1041	unsigned int gsi_end, base, end;
1042
1043	/* check gsi range */
1044	gsi_end = gsi_base + ((ver >> 16) & 0xff);
1045	for (index = 0; index < NR_IOSAPICS; index++) {
1046		if (!iosapic_lists[index].addr)
1047			continue;
1048
1049		base = iosapic_lists[index].gsi_base;
1050		end  = base + iosapic_lists[index].num_rte - 1;
1051
1052		if (gsi_end < base || end < gsi_base)
1053			continue; /* OK */
1054
1055		return -EBUSY;
1056	}
1057	return 0;
1058}
1059
1060int __devinit
1061iosapic_init (unsigned long phys_addr, unsigned int gsi_base)
1062{
1063	int num_rte, err, index;
1064	unsigned int isa_irq, ver;
1065	char __iomem *addr;
1066	unsigned long flags;
1067
1068	spin_lock_irqsave(&iosapic_lock, flags);
1069	index = find_iosapic(gsi_base);
1070	if (index >= 0) {
1071		spin_unlock_irqrestore(&iosapic_lock, flags);
1072		return -EBUSY;
1073	}
1074
1075	addr = ioremap(phys_addr, 0);
1076	if (addr == NULL) {
1077		spin_unlock_irqrestore(&iosapic_lock, flags);
1078		return -ENOMEM;
1079	}
1080	ver = iosapic_version(addr);
1081	if ((err = iosapic_check_gsi_range(gsi_base, ver))) {
1082		iounmap(addr);
1083		spin_unlock_irqrestore(&iosapic_lock, flags);
1084		return err;
1085	}
1086
1087	/*
1088	 * The MAX_REDIR register holds the highest input pin number
1089	 * (starting from 0).  We add 1 so that we can use it for
1090	 * number of pins (= RTEs)
1091	 */
1092	num_rte = ((ver >> 16) & 0xff) + 1;
1093
1094	index = iosapic_alloc();
1095	iosapic_lists[index].addr = addr;
1096	iosapic_lists[index].gsi_base = gsi_base;
1097	iosapic_lists[index].num_rte = num_rte;
1098#ifdef CONFIG_NUMA
1099	iosapic_lists[index].node = MAX_NUMNODES;
1100#endif
1101	spin_lock_init(&iosapic_lists[index].lock);
1102	spin_unlock_irqrestore(&iosapic_lock, flags);
1103
1104	if ((gsi_base == 0) && pcat_compat) {
1105		/*
1106		 * Map the legacy ISA devices into the IOSAPIC data.  Some of
1107		 * these may get reprogrammed later on with data from the ACPI
1108		 * Interrupt Source Override table.
1109		 */
1110		for (isa_irq = 0; isa_irq < 16; ++isa_irq)
1111			iosapic_override_isa_irq(isa_irq, isa_irq,
1112						 IOSAPIC_POL_HIGH,
1113						 IOSAPIC_EDGE);
1114	}
1115	return 0;
1116}
1117
1118#ifdef CONFIG_HOTPLUG
1119int
1120iosapic_remove (unsigned int gsi_base)
1121{
1122	int index, err = 0;
1123	unsigned long flags;
1124
1125	spin_lock_irqsave(&iosapic_lock, flags);
1126	index = find_iosapic(gsi_base);
1127	if (index < 0) {
1128		printk(KERN_WARNING "%s: No IOSAPIC for GSI base %u\n",
1129		       __func__, gsi_base);
1130		goto out;
1131	}
1132
1133	if (iosapic_lists[index].rtes_inuse) {
1134		err = -EBUSY;
1135		printk(KERN_WARNING "%s: IOSAPIC for GSI base %u is busy\n",
1136		       __func__, gsi_base);
1137		goto out;
1138	}
1139
1140	iounmap(iosapic_lists[index].addr);
1141	iosapic_free(index);
1142 out:
1143	spin_unlock_irqrestore(&iosapic_lock, flags);
1144	return err;
1145}
1146#endif /* CONFIG_HOTPLUG */
1147
1148#ifdef CONFIG_NUMA
1149void __devinit
1150map_iosapic_to_node(unsigned int gsi_base, int node)
1151{
1152	int index;
1153
1154	index = find_iosapic(gsi_base);
1155	if (index < 0) {
1156		printk(KERN_WARNING "%s: No IOSAPIC for GSI %u\n",
1157		       __func__, gsi_base);
1158		return;
1159	}
1160	iosapic_lists[index].node = node;
1161	return;
1162}
1163#endif
1164
1165static int __init iosapic_enable_kmalloc (void)
1166{
1167	iosapic_kmalloc_ok = 1;
1168	return 0;
1169}
1170core_initcall (iosapic_enable_kmalloc);
1171