summaryrefslogtreecommitdiffstats
path: root/arch/ia64/kernel/irq_ia64.c
blob: 2b8cf6e85af4efa9e51a4f3b2b669daaa0bcd1de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
/*
 * linux/arch/ia64/kernel/irq_ia64.c
 *
 * Copyright (C) 1998-2001 Hewlett-Packard Co
 *	Stephane Eranian <eranian@hpl.hp.com>
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 *
 *  6/10/99: Updated to bring in sync with x86 version to facilitate
 *	     support for SMP and different interrupt controllers.
 *
 * 09/15/00 Goutham Rao <goutham.rao@intel.com> Implemented pci_irq_to_vector
 *                      PCI to vector allocation routine.
 * 04/14/2004 Ashok Raj <ashok.raj@intel.com>
 *						Added CPU Hotplug handling for IPF.
 */

#include <linux/module.h>

#include <linux/jiffies.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel_stat.h>
#include <linux/slab.h>
#include <linux/ptrace.h>
#include <linux/random.h>	/* for rand_initialize_irq() */
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/threads.h>
#include <linux/bitops.h>
#include <linux/irq.h>

#include <asm/delay.h>
#include <asm/intrinsics.h>
#include <asm/io.h>
#include <asm/hw_irq.h>
#include <asm/machvec.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/tlbflush.h>

#ifdef CONFIG_PERFMON
# include <asm/perfmon.h>
#endif

#define IRQ_DEBUG	0

#define IRQ_VECTOR_UNASSIGNED	(0)

#define IRQ_UNUSED		(0)
#define IRQ_USED		(1)
#define IRQ_RSVD		(2)

/* These can be overridden in platform_irq_init */
int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;

/* default base addr of IPI table */
void __iomem *ipi_base_addr = ((void __iomem *)
			       (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));

static cpumask_t vector_allocation_domain(int cpu);

/*
 * Legacy IRQ to IA-64 vector translation table.
 */
__u8 isa_irq_to_vector_map[16] = {
	/* 8259 IRQ translation, first 16 entries */
	0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
	0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
};
EXPORT_SYMBOL(isa_irq_to_vector_map);

DEFINE_SPINLOCK(vector_lock);

struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
	[0 ... NR_IRQS - 1] = {
		.vector = IRQ_VECTOR_UNASSIGNED,
		.domain = CPU_MASK_NONE
	}
};

DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
	[0 ... IA64_NUM_VECTORS - 1] = -1
};

static cpumask_t vector_table[IA64_NUM_VECTORS] = {
	[0 ... IA64_NUM_VECTORS - 1] = CPU_MASK_NONE
};

static int irq_status[NR_IRQS] = {
	[0 ... NR_IRQS -1] = IRQ_UNUSED
};

int check_irq_used(int irq)
{
	if (irq_status[irq] == IRQ_USED)
		return 1;

	return -1;
}

static inline int find_unassigned_irq(void)
{
	int irq;

	for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
		if (irq_status[irq] == IRQ_UNUSED)
			return irq;
	return -ENOSPC;
}

static inline int find_unassigned_vector(cpumask_t domain)
{
	cpumask_t mask;
	int pos, vector;

	cpus_and(mask, domain, cpu_online_map);
	if (cpus_empty(mask))
		return -EINVAL;

	for (pos = 0; pos < IA64_NUM_DEVICE_VECTORS; pos++) {
		vector = IA64_FIRST_DEVICE_VECTOR + pos;
		cpus_and(mask, domain, vector_table[vector]);
		if (!cpus_empty(mask))
			continue;
		return vector;
	}
	return -ENOSPC;
}

static int __bind_irq_vector(int irq, int vector, cpumask_t domain)
{
	cpumask_t mask;
	int cpu;
	struct irq_cfg *cfg = &irq_cfg[irq];

	BUG_ON((unsigned)irq >= NR_IRQS);
	BUG_ON((unsigned)vector >= IA64_NUM_VECTORS);

	cpus_and(mask, domain, cpu_online_map);
	if (cpus_empty(mask))
		return -EINVAL;
	if ((cfg->vector == vector) && cpus_equal(cfg->domain, domain))
		return 0;
	if (cfg->vector != IRQ_VECTOR_UNASSIGNED)
		return -EBUSY;
	for_each_cpu_mask(cpu, mask)
		per_cpu(vector_irq, cpu)[vector] = irq;
	cfg->vector = vector;
	cfg->domain = domain;
	irq_status[irq] = IRQ_USED;
	cpus_or(vector_table[vector], vector_table[vector], domain);
	return 0;
}

int bind_irq_vector(int irq, int vector, cpumask_t domain)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&vector_lock, flags);
	ret = __bind_irq_vector(irq, vector, domain);
	spin_unlock_irqrestore(&vector_lock, flags);
	return ret;
}

static void __clear_irq_vector(int irq)
{
	int vector, cpu;
	cpumask_t mask;
	cpumask_t domain;
	struct irq_cfg *cfg = &irq_cfg[irq];

	BUG_ON((unsigned)irq >= NR_IRQS);
	BUG_ON(cfg->vector == IRQ_VECTOR_UNASSIGNED);
	vector = cfg->vector;
	domain = cfg->domain;
	cpus_and(mask, cfg->domain, cpu_online_map);
	for_each_cpu_mask(cpu, mask)
		per_cpu(vector_irq, cpu)[vector] = -1;
	cfg->vector = IRQ_VECTOR_UNASSIGNED;
	cfg->domain = CPU_MASK_NONE;
	irq_status[irq] = IRQ_UNUSED;
	cpus_andnot(vector_table[vector], vector_table[vector], domain);
}

static void clear_irq_vector(int irq)
{
	unsigned long flags;

	spin_lock_irqsave(&vector_lock, flags);
	__clear_irq_vector(irq);
	spin_unlock_irqrestore(&vector_lock, flags);
}

int
assign_irq_vector (int irq)
{
	unsigned long flags;
	int vector, cpu;
	cpumask_t domain = CPU_MASK_NONE;

	vector = -ENOSPC;

	spin_lock_irqsave(&vector_lock, flags);
	for_each_online_cpu(cpu) {
		domain = vector_allocation_domain(cpu);
		vector = find_unassigned_vector(domain);
		if (vector >= 0)
			break;
	}
	if (vector < 0)
		goto out;
	if (irq == AUTO_ASSIGN)
		irq = vector;
	BUG_ON(__bind_irq_vector(irq, vector, domain));
 out:
	spin_unlock_irqrestore(&vector_lock, flags);
	return vector;
}

void
free_irq_vector (int vector)
{
	if (vector < IA64_FIRST_DEVICE_VECTOR ||
	    vector > IA64_LAST_DEVICE_VECTOR)
		return;
	clear_irq_vector(vector);
}

int
reserve_irq_vector (int vector)
{
	if (vector < IA64_FIRST_DEVICE_VECTOR ||
	    vector > IA64_LAST_DEVICE_VECTOR)
		return -EINVAL;
	return !!bind_irq_vector(vector, vector, CPU_MASK_ALL);
}

/*
 * Initialize vector_irq on a new cpu. This function must be called
 * with vector_lock held.
 */
void __setup_vector_irq(int cpu)
{
	int irq, vector;

	/* Clear vector_irq */
	for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
		per_cpu(vector_irq, cpu)[vector] = -1;
	/* Mark the inuse vectors */
	for (irq = 0; irq < NR_IRQS; ++irq) {
		if (!cpu_isset(cpu, irq_cfg[irq].domain))
			continue;
		vector = irq_to_vector(irq);
		per_cpu(vector_irq, cpu)[vector] = irq;
	}
}

#if defined(CONFIG_SMP) && (defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG))
#define IA64_IRQ_MOVE_VECTOR	IA64_DEF_FIRST_DEVICE_VECTOR

static enum vector_domain_type {
	VECTOR_DOMAIN_NONE,
	VECTOR_DOMAIN_PERCPU
} vector_domain_type = VECTOR_DOMAIN_NONE;

static cpumask_t vector_allocation_domain(int cpu)
{
	if (vector_domain_type == VECTOR_DOMAIN_PERCPU)
		return cpumask_of_cpu(cpu);
	return CPU_MASK_ALL;
}

static int __irq_prepare_move(int irq, int cpu)
{
	struct irq_cfg *cfg = &irq_cfg[irq];
	int vector;
	cpumask_t domain;

	if (cfg->move_in_progress || cfg->move_cleanup_count)
		return -EBUSY;
	if (cfg->vector == IRQ_VECTOR_UNASSIGNED || !cpu_online(cpu))
		return -EINVAL;
	if (cpu_isset(cpu, cfg->domain))
		return 0;
	domain = vector_allocation_domain(cpu);
	vector = find_unassigned_vector(domain);
	if (vector < 0)
		return -ENOSPC;
	cfg->move_in_progress = 1;
	cfg->old_domain = cfg->domain;
	cfg->vector = IRQ_VECTOR_UNASSIGNED;
	cfg->domain = CPU_MASK_NONE;
	BUG_ON(__bind_irq_vector(irq, vector, domain));
	return 0;
}

int irq_prepare_move(int irq, int cpu)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&vector_lock, flags);
	ret = __irq_prepare_move(irq, cpu);
	spin_unlock_irqrestore(&vector_lock, flags);
	return ret;
}

void irq_complete_move(unsigned irq)
{
	struct irq_cfg *cfg = &irq_cfg[irq];
	cpumask_t cleanup_mask;
	int i;

	if (likely(!cfg->move_in_progress))
		return;

	if (unlikely(cpu_isset(smp_processor_id(), cfg->old_domain)))
		return;

	cpus_and(cleanup_mask, cfg->old_domain, cpu_online_map);
	cfg->move_cleanup_count = cpus_weight(cleanup_mask);
	for_each_cpu_mask(i, cleanup_mask)
		platform_send_ipi(i, IA64_IRQ_MOVE_VECTOR, IA64_IPI_DM_INT, 0);
	cfg->move_in_progress = 0;
}

static irqreturn_t smp_irq_move_cleanup_interrupt(int irq, void *dev_id)
{
	int me = smp_processor_id();
	ia64_vector vector;
	unsigned long flags;

	for (vector = IA64_FIRST_DEVICE_VECTOR;
	     vector < IA64_LAST_DEVICE_VECTOR; vector++) {
		int irq;
		struct irq_desc *desc;
		struct irq_cfg *cfg;
		irq = __get_cpu_var(vector_irq)[vector];
		if (irq < 0)
			continue;

		desc = irq_desc + irq;
		cfg = irq_cfg + irq;
		spin_lock(&desc->lock);
		if (!cfg->move_cleanup_count)
			goto unlock;

		if (!cpu_isset(me, cfg->old_domain))
			goto unlock;

		spin_lock_irqsave(&vector_lock, flags);
		__get_cpu_var(vector_irq)[vector] = -1;
		cpu_clear(me, vector_table[vector]);
		spin_unlock_irqrestore(&vector_lock, flags);
		cfg->move_cleanup_count--;
	unlock:
		spin_unlock(&desc->lock);
	}
	return IRQ_HANDLED;
}

static struct irqaction irq_move_irqaction = {
	.handler =	smp_irq_move_cleanup_interrupt,
	.flags =	IRQF_DISABLED,
	.name =		"irq_move"
};

static int __init parse_vector_domain(char *arg)
{
	if (!arg)
		return -EINVAL;
	if (!strcmp(arg, "percpu")) {
		vector_domain_type = VECTOR_DOMAIN_PERCPU;
		no_int_routing = 1;
	}
	return 0;
}
early_param("vector", parse_vector_domain);
#else
static cpumask_t vector_allocation_domain(int cpu)
{
	return CPU_MASK_ALL;
}
#endif


void destroy_and_reserve_irq(unsigned int irq)
{
	unsigned long flags;

	dynamic_irq_cleanup(irq);

	spin_lock_irqsave(&vector_lock, flags);
	__clear_irq_vector(irq);
	irq_status[irq] = IRQ_RSVD;
	spin_unlock_irqrestore(&vector_lock, flags);
}

/*
 * Dynamic irq allocate and deallocation for MSI
 */
int create_irq(void)
{
	unsigned long flags;
	int irq, vector, cpu;
	cpumask_t domain = CPU_MASK_NONE;

	irq = vector = -ENOSPC;
	spin_lock_irqsave(&vector_lock, flags);
	for_each_online_cpu(cpu) {
		domain = vector_allocation_domain(cpu);
		vector = find_unassigned_vector(domain);
		if (vector >= 0)
			break;
	}
	if (vector < 0)
		goto out;
	irq = find_unassigned_irq();
	if (irq < 0)
		goto out;
	BUG_ON(__bind_irq_vector(irq, vector, domain));
 out:
	spin_unlock_irqrestore(&vector_lock, flags);
	if (irq >= 0)
		dynamic_irq_init(irq);
	return irq;
}

void destroy_irq(unsigned int irq)
{
	dynamic_irq_cleanup(irq);
	clear_irq_vector(irq);
}

#ifdef CONFIG_SMP
#	define IS_RESCHEDULE(vec)	(vec == IA64_IPI_RESCHEDULE)
#	define IS_LOCAL_TLB_FLUSH(vec)	(vec == IA64_IPI_LOCAL_TLB_FLUSH)
#else
#	define IS_RESCHEDULE(vec)	(0)
#	define IS_LOCAL_TLB_FLUSH(vec)	(0)
#endif
/*
 * That's where the IVT branches when we get an external
 * interrupt. This branches to the correct hardware IRQ handler via
 * function ptr.
 */
void
ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);
	unsigned long saved_tpr;

#if IRQ_DEBUG
	{
		unsigned long bsp, sp;

		/*
		 * Note: if the interrupt happened while executing in
		 * the context switch routine (ia64_switch_to), we may
		 * get a spurious stack overflow here.  This is
		 * because the register and the memory stack are not
		 * switched atomically.
		 */
		bsp = ia64_getreg(_IA64_REG_AR_BSP);
		sp = ia64_getreg(_IA64_REG_SP);

		if ((sp - bsp) < 1024) {
			static unsigned char count;
			static long last_time;

			if (jiffies - last_time > 5*HZ)
				count = 0;
			if (++count < 5) {
				last_time = jiffies;
				printk("ia64_handle_irq: DANGER: less than "
				       "1KB of free stack space!!\n"
				       "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
			}
		}
	}
#endif /* IRQ_DEBUG */

	/*
	 * Always set TPR to limit maximum interrupt nesting depth to
	 * 16 (without this, it would be ~240, which could easily lead
	 * to kernel stack overflows).
	 */
	irq_enter();
	saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
	ia64_srlz_d();
	while (vector != IA64_SPURIOUS_INT_VECTOR) {
		if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
			smp_local_flush_tlb();
			kstat_this_cpu.irqs[vector]++;
		} else if (unlikely(IS_RESCHEDULE(vector)))
			kstat_this_cpu.irqs[vector]++;
		else {
			int irq = local_vector_to_irq(vector);

			ia64_setreg(_IA64_REG_CR_TPR, vector);
			ia64_srlz_d();

			if (unlikely(irq < 0)) {
				printk(KERN_ERR "%s: Unexpected interrupt "
				       "vector %d on CPU %d is not mapped "
				       "to any IRQ!\n", __FUNCTION__, vector,
				       smp_processor_id());
			} else
				generic_handle_irq(irq);

			/*
			 * Disable interrupts and send EOI:
			 */
			local_irq_disable();
			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
		}
		ia64_eoi();
		vector = ia64_get_ivr();
	}
	/*
	 * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
	 * handler needs to be able to wait for further keyboard interrupts, which can't
	 * come through until ia64_eoi() has been done.
	 */
	irq_exit();
	set_irq_regs(old_regs);
}

#ifdef CONFIG_HOTPLUG_CPU
/*
 * This function emulates a interrupt processing when a cpu is about to be
 * brought down.
 */
void ia64_process_pending_intr(void)
{
	ia64_vector vector;
	unsigned long saved_tpr;
	extern unsigned int vectors_in_migration[NR_IRQS];

	vector = ia64_get_ivr();

	 irq_enter();
	 saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
	 ia64_srlz_d();

	 /*
	  * Perform normal interrupt style processing
	  */
	while (vector != IA64_SPURIOUS_INT_VECTOR) {
		if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
			smp_local_flush_tlb();
			kstat_this_cpu.irqs[vector]++;
		} else if (unlikely(IS_RESCHEDULE(vector)))
			kstat_this_cpu.irqs[vector]++;
		else {
			struct pt_regs *old_regs = set_irq_regs(NULL);
			int irq = local_vector_to_irq(vector);

			ia64_setreg(_IA64_REG_CR_TPR, vector);
			ia64_srlz_d();

			/*
			 * Now try calling normal ia64_handle_irq as it would have got called
			 * from a real intr handler. Try passing null for pt_regs, hopefully
			 * it will work. I hope it works!.
			 * Probably could shared code.
			 */
			if (unlikely(irq < 0)) {
				printk(KERN_ERR "%s: Unexpected interrupt "
				       "vector %d on CPU %d not being mapped "
				       "to any IRQ!!\n", __FUNCTION__, vector,
				       smp_processor_id());
			} else {
				vectors_in_migration[irq]=0;
				generic_handle_irq(irq);
			}
			set_irq_regs(old_regs);

			/*
			 * Disable interrupts and send EOI
			 */
			local_irq_disable();
			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
		}
		ia64_eoi();
		vector = ia64_get_ivr();
	}
	irq_exit();
}
#endif


#ifdef CONFIG_SMP

static irqreturn_t dummy_handler (int irq, void *dev_id)
{
	BUG();
}
extern irqreturn_t handle_IPI (int irq, void *dev_id);

static struct irqaction ipi_irqaction = {
	.handler =	handle_IPI,
	.flags =	IRQF_DISABLED,
	.name =		"IPI"
};

static struct irqaction resched_irqaction = {
	.handler =	dummy_handler,
	.flags =	IRQF_DISABLED,
	.name =		"resched"
};

static struct irqaction tlb_irqaction = {
	.handler =	dummy_handler,
	.flags =	IRQF_DISABLED,
	.name =		"tlb_flush"
};

#endif

void
register_percpu_irq (ia64_vector vec, struct irqaction *action)
{
	irq_desc_t *desc;
	unsigned int irq;

	irq = vec;
	BUG_ON(bind_irq_vector(irq, vec, CPU_MASK_ALL));
	desc = irq_desc + irq;
	desc->status |= IRQ_PER_CPU;
	desc->chip = &irq_type_ia64_lsapic;
	if (action)
		setup_irq(irq, action);
}

void __init
init_IRQ (void)
{
	register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
#ifdef CONFIG_SMP
	register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
	register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
	register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &tlb_irqaction);
#if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG)
	if (vector_domain_type != VECTOR_DOMAIN_NONE) {
		BUG_ON(IA64_FIRST_DEVICE_VECTOR != IA64_IRQ_MOVE_VECTOR);
		IA64_FIRST_DEVICE_VECTOR++;
		register_percpu_irq(IA64_IRQ_MOVE_VECTOR, &irq_move_irqaction);
	}
#endif
#endif
#ifdef CONFIG_PERFMON
	pfm_init_percpu();
#endif
	platform_irq_init();
}

void
ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
{
	void __iomem *ipi_addr;
	unsigned long ipi_data;
	unsigned long phys_cpu_id;

#ifdef CONFIG_SMP
	phys_cpu_id = cpu_physical_id(cpu);
#else
	phys_cpu_id = (ia64_getreg(_IA64_REG_CR_LID) >> 16) & 0xffff;
#endif

	/*
	 * cpu number is in 8bit ID and 8bit EID
	 */

	ipi_data = (delivery_mode << 8) | (vector & 0xff);
	ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));

	writeq(ipi_data, ipi_addr);
}