xref: /openbmc/linux/arch/ia64/kernel/irq_ia64.c (revision 62e7ca52)
1 /*
2  * linux/arch/ia64/kernel/irq_ia64.c
3  *
4  * Copyright (C) 1998-2001 Hewlett-Packard Co
5  *	Stephane Eranian <eranian@hpl.hp.com>
6  *	David Mosberger-Tang <davidm@hpl.hp.com>
7  *
8  *  6/10/99: Updated to bring in sync with x86 version to facilitate
9  *	     support for SMP and different interrupt controllers.
10  *
11  * 09/15/00 Goutham Rao <goutham.rao@intel.com> Implemented pci_irq_to_vector
12  *                      PCI to vector allocation routine.
13  * 04/14/2004 Ashok Raj <ashok.raj@intel.com>
14  *						Added CPU Hotplug handling for IPF.
15  */
16 
17 #include <linux/module.h>
18 
19 #include <linux/jiffies.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/interrupt.h>
23 #include <linux/ioport.h>
24 #include <linux/kernel_stat.h>
25 #include <linux/ptrace.h>
26 #include <linux/signal.h>
27 #include <linux/smp.h>
28 #include <linux/threads.h>
29 #include <linux/bitops.h>
30 #include <linux/irq.h>
31 #include <linux/ratelimit.h>
32 #include <linux/acpi.h>
33 #include <linux/sched.h>
34 
35 #include <asm/delay.h>
36 #include <asm/intrinsics.h>
37 #include <asm/io.h>
38 #include <asm/hw_irq.h>
39 #include <asm/machvec.h>
40 #include <asm/pgtable.h>
41 #include <asm/tlbflush.h>
42 
43 #ifdef CONFIG_PERFMON
44 # include <asm/perfmon.h>
45 #endif
46 
47 #define IRQ_DEBUG	0
48 
49 #define IRQ_VECTOR_UNASSIGNED	(0)
50 
51 #define IRQ_UNUSED		(0)
52 #define IRQ_USED		(1)
53 #define IRQ_RSVD		(2)
54 
55 /* These can be overridden in platform_irq_init */
56 int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
57 int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;
58 
59 /* default base addr of IPI table */
60 void __iomem *ipi_base_addr = ((void __iomem *)
61 			       (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));
62 
63 static cpumask_t vector_allocation_domain(int cpu);
64 
65 /*
66  * Legacy IRQ to IA-64 vector translation table.
67  */
68 __u8 isa_irq_to_vector_map[16] = {
69 	/* 8259 IRQ translation, first 16 entries */
70 	0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
71 	0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
72 };
73 EXPORT_SYMBOL(isa_irq_to_vector_map);
74 
75 DEFINE_SPINLOCK(vector_lock);
76 
77 struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
78 	[0 ... NR_IRQS - 1] = {
79 		.vector = IRQ_VECTOR_UNASSIGNED,
80 		.domain = CPU_MASK_NONE
81 	}
82 };
83 
84 DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
85 	[0 ... IA64_NUM_VECTORS - 1] = -1
86 };
87 
88 static cpumask_t vector_table[IA64_NUM_VECTORS] = {
89 	[0 ... IA64_NUM_VECTORS - 1] = CPU_MASK_NONE
90 };
91 
92 static int irq_status[NR_IRQS] = {
93 	[0 ... NR_IRQS -1] = IRQ_UNUSED
94 };
95 
96 static inline int find_unassigned_irq(void)
97 {
98 	int irq;
99 
100 	for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
101 		if (irq_status[irq] == IRQ_UNUSED)
102 			return irq;
103 	return -ENOSPC;
104 }
105 
106 static inline int find_unassigned_vector(cpumask_t domain)
107 {
108 	cpumask_t mask;
109 	int pos, vector;
110 
111 	cpumask_and(&mask, &domain, cpu_online_mask);
112 	if (cpus_empty(mask))
113 		return -EINVAL;
114 
115 	for (pos = 0; pos < IA64_NUM_DEVICE_VECTORS; pos++) {
116 		vector = IA64_FIRST_DEVICE_VECTOR + pos;
117 		cpus_and(mask, domain, vector_table[vector]);
118 		if (!cpus_empty(mask))
119 			continue;
120 		return vector;
121 	}
122 	return -ENOSPC;
123 }
124 
125 static int __bind_irq_vector(int irq, int vector, cpumask_t domain)
126 {
127 	cpumask_t mask;
128 	int cpu;
129 	struct irq_cfg *cfg = &irq_cfg[irq];
130 
131 	BUG_ON((unsigned)irq >= NR_IRQS);
132 	BUG_ON((unsigned)vector >= IA64_NUM_VECTORS);
133 
134 	cpumask_and(&mask, &domain, cpu_online_mask);
135 	if (cpus_empty(mask))
136 		return -EINVAL;
137 	if ((cfg->vector == vector) && cpus_equal(cfg->domain, domain))
138 		return 0;
139 	if (cfg->vector != IRQ_VECTOR_UNASSIGNED)
140 		return -EBUSY;
141 	for_each_cpu_mask(cpu, mask)
142 		per_cpu(vector_irq, cpu)[vector] = irq;
143 	cfg->vector = vector;
144 	cfg->domain = domain;
145 	irq_status[irq] = IRQ_USED;
146 	cpus_or(vector_table[vector], vector_table[vector], domain);
147 	return 0;
148 }
149 
150 int bind_irq_vector(int irq, int vector, cpumask_t domain)
151 {
152 	unsigned long flags;
153 	int ret;
154 
155 	spin_lock_irqsave(&vector_lock, flags);
156 	ret = __bind_irq_vector(irq, vector, domain);
157 	spin_unlock_irqrestore(&vector_lock, flags);
158 	return ret;
159 }
160 
161 static void __clear_irq_vector(int irq)
162 {
163 	int vector, cpu;
164 	cpumask_t mask;
165 	cpumask_t domain;
166 	struct irq_cfg *cfg = &irq_cfg[irq];
167 
168 	BUG_ON((unsigned)irq >= NR_IRQS);
169 	BUG_ON(cfg->vector == IRQ_VECTOR_UNASSIGNED);
170 	vector = cfg->vector;
171 	domain = cfg->domain;
172 	cpumask_and(&mask, &cfg->domain, cpu_online_mask);
173 	for_each_cpu_mask(cpu, mask)
174 		per_cpu(vector_irq, cpu)[vector] = -1;
175 	cfg->vector = IRQ_VECTOR_UNASSIGNED;
176 	cfg->domain = CPU_MASK_NONE;
177 	irq_status[irq] = IRQ_UNUSED;
178 	cpus_andnot(vector_table[vector], vector_table[vector], domain);
179 }
180 
181 static void clear_irq_vector(int irq)
182 {
183 	unsigned long flags;
184 
185 	spin_lock_irqsave(&vector_lock, flags);
186 	__clear_irq_vector(irq);
187 	spin_unlock_irqrestore(&vector_lock, flags);
188 }
189 
190 int
191 ia64_native_assign_irq_vector (int irq)
192 {
193 	unsigned long flags;
194 	int vector, cpu;
195 	cpumask_t domain = CPU_MASK_NONE;
196 
197 	vector = -ENOSPC;
198 
199 	spin_lock_irqsave(&vector_lock, flags);
200 	for_each_online_cpu(cpu) {
201 		domain = vector_allocation_domain(cpu);
202 		vector = find_unassigned_vector(domain);
203 		if (vector >= 0)
204 			break;
205 	}
206 	if (vector < 0)
207 		goto out;
208 	if (irq == AUTO_ASSIGN)
209 		irq = vector;
210 	BUG_ON(__bind_irq_vector(irq, vector, domain));
211  out:
212 	spin_unlock_irqrestore(&vector_lock, flags);
213 	return vector;
214 }
215 
216 void
217 ia64_native_free_irq_vector (int vector)
218 {
219 	if (vector < IA64_FIRST_DEVICE_VECTOR ||
220 	    vector > IA64_LAST_DEVICE_VECTOR)
221 		return;
222 	clear_irq_vector(vector);
223 }
224 
225 int
226 reserve_irq_vector (int vector)
227 {
228 	if (vector < IA64_FIRST_DEVICE_VECTOR ||
229 	    vector > IA64_LAST_DEVICE_VECTOR)
230 		return -EINVAL;
231 	return !!bind_irq_vector(vector, vector, CPU_MASK_ALL);
232 }
233 
234 /*
235  * Initialize vector_irq on a new cpu. This function must be called
236  * with vector_lock held.
237  */
238 void __setup_vector_irq(int cpu)
239 {
240 	int irq, vector;
241 
242 	/* Clear vector_irq */
243 	for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
244 		per_cpu(vector_irq, cpu)[vector] = -1;
245 	/* Mark the inuse vectors */
246 	for (irq = 0; irq < NR_IRQS; ++irq) {
247 		if (!cpu_isset(cpu, irq_cfg[irq].domain))
248 			continue;
249 		vector = irq_to_vector(irq);
250 		per_cpu(vector_irq, cpu)[vector] = irq;
251 	}
252 }
253 
254 #if defined(CONFIG_SMP) && (defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG))
255 
256 static enum vector_domain_type {
257 	VECTOR_DOMAIN_NONE,
258 	VECTOR_DOMAIN_PERCPU
259 } vector_domain_type = VECTOR_DOMAIN_NONE;
260 
261 static cpumask_t vector_allocation_domain(int cpu)
262 {
263 	if (vector_domain_type == VECTOR_DOMAIN_PERCPU)
264 		return cpumask_of_cpu(cpu);
265 	return CPU_MASK_ALL;
266 }
267 
268 static int __irq_prepare_move(int irq, int cpu)
269 {
270 	struct irq_cfg *cfg = &irq_cfg[irq];
271 	int vector;
272 	cpumask_t domain;
273 
274 	if (cfg->move_in_progress || cfg->move_cleanup_count)
275 		return -EBUSY;
276 	if (cfg->vector == IRQ_VECTOR_UNASSIGNED || !cpu_online(cpu))
277 		return -EINVAL;
278 	if (cpu_isset(cpu, cfg->domain))
279 		return 0;
280 	domain = vector_allocation_domain(cpu);
281 	vector = find_unassigned_vector(domain);
282 	if (vector < 0)
283 		return -ENOSPC;
284 	cfg->move_in_progress = 1;
285 	cfg->old_domain = cfg->domain;
286 	cfg->vector = IRQ_VECTOR_UNASSIGNED;
287 	cfg->domain = CPU_MASK_NONE;
288 	BUG_ON(__bind_irq_vector(irq, vector, domain));
289 	return 0;
290 }
291 
292 int irq_prepare_move(int irq, int cpu)
293 {
294 	unsigned long flags;
295 	int ret;
296 
297 	spin_lock_irqsave(&vector_lock, flags);
298 	ret = __irq_prepare_move(irq, cpu);
299 	spin_unlock_irqrestore(&vector_lock, flags);
300 	return ret;
301 }
302 
303 void irq_complete_move(unsigned irq)
304 {
305 	struct irq_cfg *cfg = &irq_cfg[irq];
306 	cpumask_t cleanup_mask;
307 	int i;
308 
309 	if (likely(!cfg->move_in_progress))
310 		return;
311 
312 	if (unlikely(cpu_isset(smp_processor_id(), cfg->old_domain)))
313 		return;
314 
315 	cpumask_and(&cleanup_mask, &cfg->old_domain, cpu_online_mask);
316 	cfg->move_cleanup_count = cpus_weight(cleanup_mask);
317 	for_each_cpu_mask(i, cleanup_mask)
318 		platform_send_ipi(i, IA64_IRQ_MOVE_VECTOR, IA64_IPI_DM_INT, 0);
319 	cfg->move_in_progress = 0;
320 }
321 
322 static irqreturn_t smp_irq_move_cleanup_interrupt(int irq, void *dev_id)
323 {
324 	int me = smp_processor_id();
325 	ia64_vector vector;
326 	unsigned long flags;
327 
328 	for (vector = IA64_FIRST_DEVICE_VECTOR;
329 	     vector < IA64_LAST_DEVICE_VECTOR; vector++) {
330 		int irq;
331 		struct irq_desc *desc;
332 		struct irq_cfg *cfg;
333 		irq = __get_cpu_var(vector_irq)[vector];
334 		if (irq < 0)
335 			continue;
336 
337 		desc = irq_to_desc(irq);
338 		cfg = irq_cfg + irq;
339 		raw_spin_lock(&desc->lock);
340 		if (!cfg->move_cleanup_count)
341 			goto unlock;
342 
343 		if (!cpu_isset(me, cfg->old_domain))
344 			goto unlock;
345 
346 		spin_lock_irqsave(&vector_lock, flags);
347 		__get_cpu_var(vector_irq)[vector] = -1;
348 		cpu_clear(me, vector_table[vector]);
349 		spin_unlock_irqrestore(&vector_lock, flags);
350 		cfg->move_cleanup_count--;
351 	unlock:
352 		raw_spin_unlock(&desc->lock);
353 	}
354 	return IRQ_HANDLED;
355 }
356 
357 static struct irqaction irq_move_irqaction = {
358 	.handler =	smp_irq_move_cleanup_interrupt,
359 	.name =		"irq_move"
360 };
361 
362 static int __init parse_vector_domain(char *arg)
363 {
364 	if (!arg)
365 		return -EINVAL;
366 	if (!strcmp(arg, "percpu")) {
367 		vector_domain_type = VECTOR_DOMAIN_PERCPU;
368 		no_int_routing = 1;
369 	}
370 	return 0;
371 }
372 early_param("vector", parse_vector_domain);
373 #else
374 static cpumask_t vector_allocation_domain(int cpu)
375 {
376 	return CPU_MASK_ALL;
377 }
378 #endif
379 
380 
381 void destroy_and_reserve_irq(unsigned int irq)
382 {
383 	unsigned long flags;
384 
385 	irq_init_desc(irq);
386 	spin_lock_irqsave(&vector_lock, flags);
387 	__clear_irq_vector(irq);
388 	irq_status[irq] = IRQ_RSVD;
389 	spin_unlock_irqrestore(&vector_lock, flags);
390 }
391 
392 /*
393  * Dynamic irq allocate and deallocation for MSI
394  */
395 int create_irq(void)
396 {
397 	unsigned long flags;
398 	int irq, vector, cpu;
399 	cpumask_t domain = CPU_MASK_NONE;
400 
401 	irq = vector = -ENOSPC;
402 	spin_lock_irqsave(&vector_lock, flags);
403 	for_each_online_cpu(cpu) {
404 		domain = vector_allocation_domain(cpu);
405 		vector = find_unassigned_vector(domain);
406 		if (vector >= 0)
407 			break;
408 	}
409 	if (vector < 0)
410 		goto out;
411 	irq = find_unassigned_irq();
412 	if (irq < 0)
413 		goto out;
414 	BUG_ON(__bind_irq_vector(irq, vector, domain));
415  out:
416 	spin_unlock_irqrestore(&vector_lock, flags);
417 	if (irq >= 0)
418 		irq_init_desc(irq);
419 	return irq;
420 }
421 
422 void destroy_irq(unsigned int irq)
423 {
424 	irq_init_desc(irq);
425 	clear_irq_vector(irq);
426 }
427 
428 #ifdef CONFIG_SMP
429 #	define IS_RESCHEDULE(vec)	(vec == IA64_IPI_RESCHEDULE)
430 #	define IS_LOCAL_TLB_FLUSH(vec)	(vec == IA64_IPI_LOCAL_TLB_FLUSH)
431 #else
432 #	define IS_RESCHEDULE(vec)	(0)
433 #	define IS_LOCAL_TLB_FLUSH(vec)	(0)
434 #endif
435 /*
436  * That's where the IVT branches when we get an external
437  * interrupt. This branches to the correct hardware IRQ handler via
438  * function ptr.
439  */
440 void
441 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
442 {
443 	struct pt_regs *old_regs = set_irq_regs(regs);
444 	unsigned long saved_tpr;
445 
446 #if IRQ_DEBUG
447 	{
448 		unsigned long bsp, sp;
449 
450 		/*
451 		 * Note: if the interrupt happened while executing in
452 		 * the context switch routine (ia64_switch_to), we may
453 		 * get a spurious stack overflow here.  This is
454 		 * because the register and the memory stack are not
455 		 * switched atomically.
456 		 */
457 		bsp = ia64_getreg(_IA64_REG_AR_BSP);
458 		sp = ia64_getreg(_IA64_REG_SP);
459 
460 		if ((sp - bsp) < 1024) {
461 			static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
462 
463 			if (__ratelimit(&ratelimit)) {
464 				printk("ia64_handle_irq: DANGER: less than "
465 				       "1KB of free stack space!!\n"
466 				       "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
467 			}
468 		}
469 	}
470 #endif /* IRQ_DEBUG */
471 
472 	/*
473 	 * Always set TPR to limit maximum interrupt nesting depth to
474 	 * 16 (without this, it would be ~240, which could easily lead
475 	 * to kernel stack overflows).
476 	 */
477 	irq_enter();
478 	saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
479 	ia64_srlz_d();
480 	while (vector != IA64_SPURIOUS_INT_VECTOR) {
481 		int irq = local_vector_to_irq(vector);
482 
483 		if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
484 			smp_local_flush_tlb();
485 			kstat_incr_irq_this_cpu(irq);
486 		} else if (unlikely(IS_RESCHEDULE(vector))) {
487 			scheduler_ipi();
488 			kstat_incr_irq_this_cpu(irq);
489 		} else {
490 			ia64_setreg(_IA64_REG_CR_TPR, vector);
491 			ia64_srlz_d();
492 
493 			if (unlikely(irq < 0)) {
494 				printk(KERN_ERR "%s: Unexpected interrupt "
495 				       "vector %d on CPU %d is not mapped "
496 				       "to any IRQ!\n", __func__, vector,
497 				       smp_processor_id());
498 			} else
499 				generic_handle_irq(irq);
500 
501 			/*
502 			 * Disable interrupts and send EOI:
503 			 */
504 			local_irq_disable();
505 			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
506 		}
507 		ia64_eoi();
508 		vector = ia64_get_ivr();
509 	}
510 	/*
511 	 * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
512 	 * handler needs to be able to wait for further keyboard interrupts, which can't
513 	 * come through until ia64_eoi() has been done.
514 	 */
515 	irq_exit();
516 	set_irq_regs(old_regs);
517 }
518 
519 #ifdef CONFIG_HOTPLUG_CPU
520 /*
521  * This function emulates a interrupt processing when a cpu is about to be
522  * brought down.
523  */
524 void ia64_process_pending_intr(void)
525 {
526 	ia64_vector vector;
527 	unsigned long saved_tpr;
528 	extern unsigned int vectors_in_migration[NR_IRQS];
529 
530 	vector = ia64_get_ivr();
531 
532 	irq_enter();
533 	saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
534 	ia64_srlz_d();
535 
536 	 /*
537 	  * Perform normal interrupt style processing
538 	  */
539 	while (vector != IA64_SPURIOUS_INT_VECTOR) {
540 		int irq = local_vector_to_irq(vector);
541 
542 		if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
543 			smp_local_flush_tlb();
544 			kstat_incr_irq_this_cpu(irq);
545 		} else if (unlikely(IS_RESCHEDULE(vector))) {
546 			kstat_incr_irq_this_cpu(irq);
547 		} else {
548 			struct pt_regs *old_regs = set_irq_regs(NULL);
549 
550 			ia64_setreg(_IA64_REG_CR_TPR, vector);
551 			ia64_srlz_d();
552 
553 			/*
554 			 * Now try calling normal ia64_handle_irq as it would have got called
555 			 * from a real intr handler. Try passing null for pt_regs, hopefully
556 			 * it will work. I hope it works!.
557 			 * Probably could shared code.
558 			 */
559 			if (unlikely(irq < 0)) {
560 				printk(KERN_ERR "%s: Unexpected interrupt "
561 				       "vector %d on CPU %d not being mapped "
562 				       "to any IRQ!!\n", __func__, vector,
563 				       smp_processor_id());
564 			} else {
565 				vectors_in_migration[irq]=0;
566 				generic_handle_irq(irq);
567 			}
568 			set_irq_regs(old_regs);
569 
570 			/*
571 			 * Disable interrupts and send EOI
572 			 */
573 			local_irq_disable();
574 			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
575 		}
576 		ia64_eoi();
577 		vector = ia64_get_ivr();
578 	}
579 	irq_exit();
580 }
581 #endif
582 
583 
584 #ifdef CONFIG_SMP
585 
586 static irqreturn_t dummy_handler (int irq, void *dev_id)
587 {
588 	BUG();
589 }
590 
591 static struct irqaction ipi_irqaction = {
592 	.handler =	handle_IPI,
593 	.name =		"IPI"
594 };
595 
596 /*
597  * KVM uses this interrupt to force a cpu out of guest mode
598  */
599 static struct irqaction resched_irqaction = {
600 	.handler =	dummy_handler,
601 	.name =		"resched"
602 };
603 
604 static struct irqaction tlb_irqaction = {
605 	.handler =	dummy_handler,
606 	.name =		"tlb_flush"
607 };
608 
609 #endif
610 
611 void
612 ia64_native_register_percpu_irq (ia64_vector vec, struct irqaction *action)
613 {
614 	unsigned int irq;
615 
616 	irq = vec;
617 	BUG_ON(bind_irq_vector(irq, vec, CPU_MASK_ALL));
618 	irq_set_status_flags(irq, IRQ_PER_CPU);
619 	irq_set_chip(irq, &irq_type_ia64_lsapic);
620 	if (action)
621 		setup_irq(irq, action);
622 	irq_set_handler(irq, handle_percpu_irq);
623 }
624 
625 void __init
626 ia64_native_register_ipi(void)
627 {
628 #ifdef CONFIG_SMP
629 	register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
630 	register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
631 	register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &tlb_irqaction);
632 #endif
633 }
634 
635 void __init
636 init_IRQ (void)
637 {
638 #ifdef CONFIG_ACPI
639 	acpi_boot_init();
640 #endif
641 	ia64_register_ipi();
642 	register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
643 #ifdef CONFIG_SMP
644 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG)
645 	if (vector_domain_type != VECTOR_DOMAIN_NONE)
646 		register_percpu_irq(IA64_IRQ_MOVE_VECTOR, &irq_move_irqaction);
647 #endif
648 #endif
649 #ifdef CONFIG_PERFMON
650 	pfm_init_percpu();
651 #endif
652 	platform_irq_init();
653 }
654 
655 void
656 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
657 {
658 	void __iomem *ipi_addr;
659 	unsigned long ipi_data;
660 	unsigned long phys_cpu_id;
661 
662 	phys_cpu_id = cpu_physical_id(cpu);
663 
664 	/*
665 	 * cpu number is in 8bit ID and 8bit EID
666 	 */
667 
668 	ipi_data = (delivery_mode << 8) | (vector & 0xff);
669 	ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
670 
671 	writeq(ipi_data, ipi_addr);
672 }
673