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/random.h> /* for rand_initialize_irq() */
27 #include <linux/signal.h>
28 #include <linux/smp.h>
29 #include <linux/threads.h>
30 #include <linux/bitops.h>
31 #include <linux/irq.h>
32 #include <linux/ratelimit.h>
33 #include <linux/acpi.h>
34 #include <linux/sched.h>
35
36 #include <asm/delay.h>
37 #include <asm/intrinsics.h>
38 #include <asm/io.h>
39 #include <asm/hw_irq.h>
40 #include <asm/machvec.h>
41 #include <asm/pgtable.h>
42 #include <asm/system.h>
43 #include <asm/tlbflush.h>
44
45 #ifdef CONFIG_PERFMON
46 # include <asm/perfmon.h>
47 #endif
48
49 #define IRQ_DEBUG 0
50
51 #define IRQ_VECTOR_UNASSIGNED (0)
52
53 #define IRQ_UNUSED (0)
54 #define IRQ_USED (1)
55 #define IRQ_RSVD (2)
56
57 /* These can be overridden in platform_irq_init */
58 int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
59 int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;
60
61 /* default base addr of IPI table */
62 void __iomem *ipi_base_addr = ((void __iomem *)
63 (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));
64
65 static cpumask_t vector_allocation_domain(int cpu);
66
67 /*
68 * Legacy IRQ to IA-64 vector translation table.
69 */
70 __u8 isa_irq_to_vector_map[16] = {
71 /* 8259 IRQ translation, first 16 entries */
72 0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
73 0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
74 };
75 EXPORT_SYMBOL(isa_irq_to_vector_map);
76
77 DEFINE_SPINLOCK(vector_lock);
78
79 struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
80 [0 ... NR_IRQS - 1] = {
81 .vector = IRQ_VECTOR_UNASSIGNED,
82 .domain = CPU_MASK_NONE
83 }
84 };
85
86 DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
87 [0 ... IA64_NUM_VECTORS - 1] = -1
88 };
89
90 static cpumask_t vector_table[IA64_NUM_VECTORS] = {
91 [0 ... IA64_NUM_VECTORS - 1] = CPU_MASK_NONE
92 };
93
94 static int irq_status[NR_IRQS] = {
95 [0 ... NR_IRQS -1] = IRQ_UNUSED
96 };
97
check_irq_used(int irq)98 int check_irq_used(int irq)
99 {
100 if (irq_status[irq] == IRQ_USED)
101 return 1;
102
103 return -1;
104 }
105
find_unassigned_irq(void)106 static inline int find_unassigned_irq(void)
107 {
108 int irq;
109
110 for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
111 if (irq_status[irq] == IRQ_UNUSED)
112 return irq;
113 return -ENOSPC;
114 }
115
find_unassigned_vector(cpumask_t domain)116 static inline int find_unassigned_vector(cpumask_t domain)
117 {
118 cpumask_t mask;
119 int pos, vector;
120
121 cpus_and(mask, domain, cpu_online_map);
122 if (cpus_empty(mask))
123 return -EINVAL;
124
125 for (pos = 0; pos < IA64_NUM_DEVICE_VECTORS; pos++) {
126 vector = IA64_FIRST_DEVICE_VECTOR + pos;
127 cpus_and(mask, domain, vector_table[vector]);
128 if (!cpus_empty(mask))
129 continue;
130 return vector;
131 }
132 return -ENOSPC;
133 }
134
__bind_irq_vector(int irq,int vector,cpumask_t domain)135 static int __bind_irq_vector(int irq, int vector, cpumask_t domain)
136 {
137 cpumask_t mask;
138 int cpu;
139 struct irq_cfg *cfg = &irq_cfg[irq];
140
141 BUG_ON((unsigned)irq >= NR_IRQS);
142 BUG_ON((unsigned)vector >= IA64_NUM_VECTORS);
143
144 cpus_and(mask, domain, cpu_online_map);
145 if (cpus_empty(mask))
146 return -EINVAL;
147 if ((cfg->vector == vector) && cpus_equal(cfg->domain, domain))
148 return 0;
149 if (cfg->vector != IRQ_VECTOR_UNASSIGNED)
150 return -EBUSY;
151 for_each_cpu_mask(cpu, mask)
152 per_cpu(vector_irq, cpu)[vector] = irq;
153 cfg->vector = vector;
154 cfg->domain = domain;
155 irq_status[irq] = IRQ_USED;
156 cpus_or(vector_table[vector], vector_table[vector], domain);
157 return 0;
158 }
159
bind_irq_vector(int irq,int vector,cpumask_t domain)160 int bind_irq_vector(int irq, int vector, cpumask_t domain)
161 {
162 unsigned long flags;
163 int ret;
164
165 spin_lock_irqsave(&vector_lock, flags);
166 ret = __bind_irq_vector(irq, vector, domain);
167 spin_unlock_irqrestore(&vector_lock, flags);
168 return ret;
169 }
170
__clear_irq_vector(int irq)171 static void __clear_irq_vector(int irq)
172 {
173 int vector, cpu;
174 cpumask_t mask;
175 cpumask_t domain;
176 struct irq_cfg *cfg = &irq_cfg[irq];
177
178 BUG_ON((unsigned)irq >= NR_IRQS);
179 BUG_ON(cfg->vector == IRQ_VECTOR_UNASSIGNED);
180 vector = cfg->vector;
181 domain = cfg->domain;
182 cpus_and(mask, cfg->domain, cpu_online_map);
183 for_each_cpu_mask(cpu, mask)
184 per_cpu(vector_irq, cpu)[vector] = -1;
185 cfg->vector = IRQ_VECTOR_UNASSIGNED;
186 cfg->domain = CPU_MASK_NONE;
187 irq_status[irq] = IRQ_UNUSED;
188 cpus_andnot(vector_table[vector], vector_table[vector], domain);
189 }
190
clear_irq_vector(int irq)191 static void clear_irq_vector(int irq)
192 {
193 unsigned long flags;
194
195 spin_lock_irqsave(&vector_lock, flags);
196 __clear_irq_vector(irq);
197 spin_unlock_irqrestore(&vector_lock, flags);
198 }
199
200 int
ia64_native_assign_irq_vector(int irq)201 ia64_native_assign_irq_vector (int irq)
202 {
203 unsigned long flags;
204 int vector, cpu;
205 cpumask_t domain = CPU_MASK_NONE;
206
207 vector = -ENOSPC;
208
209 spin_lock_irqsave(&vector_lock, flags);
210 for_each_online_cpu(cpu) {
211 domain = vector_allocation_domain(cpu);
212 vector = find_unassigned_vector(domain);
213 if (vector >= 0)
214 break;
215 }
216 if (vector < 0)
217 goto out;
218 if (irq == AUTO_ASSIGN)
219 irq = vector;
220 BUG_ON(__bind_irq_vector(irq, vector, domain));
221 out:
222 spin_unlock_irqrestore(&vector_lock, flags);
223 return vector;
224 }
225
226 void
ia64_native_free_irq_vector(int vector)227 ia64_native_free_irq_vector (int vector)
228 {
229 if (vector < IA64_FIRST_DEVICE_VECTOR ||
230 vector > IA64_LAST_DEVICE_VECTOR)
231 return;
232 clear_irq_vector(vector);
233 }
234
235 int
reserve_irq_vector(int vector)236 reserve_irq_vector (int vector)
237 {
238 if (vector < IA64_FIRST_DEVICE_VECTOR ||
239 vector > IA64_LAST_DEVICE_VECTOR)
240 return -EINVAL;
241 return !!bind_irq_vector(vector, vector, CPU_MASK_ALL);
242 }
243
244 /*
245 * Initialize vector_irq on a new cpu. This function must be called
246 * with vector_lock held.
247 */
__setup_vector_irq(int cpu)248 void __setup_vector_irq(int cpu)
249 {
250 int irq, vector;
251
252 /* Clear vector_irq */
253 for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
254 per_cpu(vector_irq, cpu)[vector] = -1;
255 /* Mark the inuse vectors */
256 for (irq = 0; irq < NR_IRQS; ++irq) {
257 if (!cpu_isset(cpu, irq_cfg[irq].domain))
258 continue;
259 vector = irq_to_vector(irq);
260 per_cpu(vector_irq, cpu)[vector] = irq;
261 }
262 }
263
264 #if defined(CONFIG_SMP) && (defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG))
265
266 static enum vector_domain_type {
267 VECTOR_DOMAIN_NONE,
268 VECTOR_DOMAIN_PERCPU
269 } vector_domain_type = VECTOR_DOMAIN_NONE;
270
vector_allocation_domain(int cpu)271 static cpumask_t vector_allocation_domain(int cpu)
272 {
273 if (vector_domain_type == VECTOR_DOMAIN_PERCPU)
274 return cpumask_of_cpu(cpu);
275 return CPU_MASK_ALL;
276 }
277
__irq_prepare_move(int irq,int cpu)278 static int __irq_prepare_move(int irq, int cpu)
279 {
280 struct irq_cfg *cfg = &irq_cfg[irq];
281 int vector;
282 cpumask_t domain;
283
284 if (cfg->move_in_progress || cfg->move_cleanup_count)
285 return -EBUSY;
286 if (cfg->vector == IRQ_VECTOR_UNASSIGNED || !cpu_online(cpu))
287 return -EINVAL;
288 if (cpu_isset(cpu, cfg->domain))
289 return 0;
290 domain = vector_allocation_domain(cpu);
291 vector = find_unassigned_vector(domain);
292 if (vector < 0)
293 return -ENOSPC;
294 cfg->move_in_progress = 1;
295 cfg->old_domain = cfg->domain;
296 cfg->vector = IRQ_VECTOR_UNASSIGNED;
297 cfg->domain = CPU_MASK_NONE;
298 BUG_ON(__bind_irq_vector(irq, vector, domain));
299 return 0;
300 }
301
irq_prepare_move(int irq,int cpu)302 int irq_prepare_move(int irq, int cpu)
303 {
304 unsigned long flags;
305 int ret;
306
307 spin_lock_irqsave(&vector_lock, flags);
308 ret = __irq_prepare_move(irq, cpu);
309 spin_unlock_irqrestore(&vector_lock, flags);
310 return ret;
311 }
312
irq_complete_move(unsigned irq)313 void irq_complete_move(unsigned irq)
314 {
315 struct irq_cfg *cfg = &irq_cfg[irq];
316 cpumask_t cleanup_mask;
317 int i;
318
319 if (likely(!cfg->move_in_progress))
320 return;
321
322 if (unlikely(cpu_isset(smp_processor_id(), cfg->old_domain)))
323 return;
324
325 cpus_and(cleanup_mask, cfg->old_domain, cpu_online_map);
326 cfg->move_cleanup_count = cpus_weight(cleanup_mask);
327 for_each_cpu_mask(i, cleanup_mask)
328 platform_send_ipi(i, IA64_IRQ_MOVE_VECTOR, IA64_IPI_DM_INT, 0);
329 cfg->move_in_progress = 0;
330 }
331
smp_irq_move_cleanup_interrupt(int irq,void * dev_id)332 static irqreturn_t smp_irq_move_cleanup_interrupt(int irq, void *dev_id)
333 {
334 int me = smp_processor_id();
335 ia64_vector vector;
336 unsigned long flags;
337
338 for (vector = IA64_FIRST_DEVICE_VECTOR;
339 vector < IA64_LAST_DEVICE_VECTOR; vector++) {
340 int irq;
341 struct irq_desc *desc;
342 struct irq_cfg *cfg;
343 irq = __get_cpu_var(vector_irq)[vector];
344 if (irq < 0)
345 continue;
346
347 desc = irq_to_desc(irq);
348 cfg = irq_cfg + irq;
349 raw_spin_lock(&desc->lock);
350 if (!cfg->move_cleanup_count)
351 goto unlock;
352
353 if (!cpu_isset(me, cfg->old_domain))
354 goto unlock;
355
356 spin_lock_irqsave(&vector_lock, flags);
357 __get_cpu_var(vector_irq)[vector] = -1;
358 cpu_clear(me, vector_table[vector]);
359 spin_unlock_irqrestore(&vector_lock, flags);
360 cfg->move_cleanup_count--;
361 unlock:
362 raw_spin_unlock(&desc->lock);
363 }
364 return IRQ_HANDLED;
365 }
366
367 static struct irqaction irq_move_irqaction = {
368 .handler = smp_irq_move_cleanup_interrupt,
369 .flags = IRQF_DISABLED,
370 .name = "irq_move"
371 };
372
parse_vector_domain(char * arg)373 static int __init parse_vector_domain(char *arg)
374 {
375 if (!arg)
376 return -EINVAL;
377 if (!strcmp(arg, "percpu")) {
378 vector_domain_type = VECTOR_DOMAIN_PERCPU;
379 no_int_routing = 1;
380 }
381 return 0;
382 }
383 early_param("vector", parse_vector_domain);
384 #else
vector_allocation_domain(int cpu)385 static cpumask_t vector_allocation_domain(int cpu)
386 {
387 return CPU_MASK_ALL;
388 }
389 #endif
390
391
destroy_and_reserve_irq(unsigned int irq)392 void destroy_and_reserve_irq(unsigned int irq)
393 {
394 unsigned long flags;
395
396 dynamic_irq_cleanup(irq);
397
398 spin_lock_irqsave(&vector_lock, flags);
399 __clear_irq_vector(irq);
400 irq_status[irq] = IRQ_RSVD;
401 spin_unlock_irqrestore(&vector_lock, flags);
402 }
403
404 /*
405 * Dynamic irq allocate and deallocation for MSI
406 */
create_irq(void)407 int create_irq(void)
408 {
409 unsigned long flags;
410 int irq, vector, cpu;
411 cpumask_t domain = CPU_MASK_NONE;
412
413 irq = vector = -ENOSPC;
414 spin_lock_irqsave(&vector_lock, flags);
415 for_each_online_cpu(cpu) {
416 domain = vector_allocation_domain(cpu);
417 vector = find_unassigned_vector(domain);
418 if (vector >= 0)
419 break;
420 }
421 if (vector < 0)
422 goto out;
423 irq = find_unassigned_irq();
424 if (irq < 0)
425 goto out;
426 BUG_ON(__bind_irq_vector(irq, vector, domain));
427 out:
428 spin_unlock_irqrestore(&vector_lock, flags);
429 if (irq >= 0)
430 dynamic_irq_init(irq);
431 return irq;
432 }
433
destroy_irq(unsigned int irq)434 void destroy_irq(unsigned int irq)
435 {
436 dynamic_irq_cleanup(irq);
437 clear_irq_vector(irq);
438 }
439
440 #ifdef CONFIG_SMP
441 # define IS_RESCHEDULE(vec) (vec == IA64_IPI_RESCHEDULE)
442 # define IS_LOCAL_TLB_FLUSH(vec) (vec == IA64_IPI_LOCAL_TLB_FLUSH)
443 #else
444 # define IS_RESCHEDULE(vec) (0)
445 # define IS_LOCAL_TLB_FLUSH(vec) (0)
446 #endif
447 /*
448 * That's where the IVT branches when we get an external
449 * interrupt. This branches to the correct hardware IRQ handler via
450 * function ptr.
451 */
452 void
ia64_handle_irq(ia64_vector vector,struct pt_regs * regs)453 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
454 {
455 struct pt_regs *old_regs = set_irq_regs(regs);
456 unsigned long saved_tpr;
457
458 #if IRQ_DEBUG
459 {
460 unsigned long bsp, sp;
461
462 /*
463 * Note: if the interrupt happened while executing in
464 * the context switch routine (ia64_switch_to), we may
465 * get a spurious stack overflow here. This is
466 * because the register and the memory stack are not
467 * switched atomically.
468 */
469 bsp = ia64_getreg(_IA64_REG_AR_BSP);
470 sp = ia64_getreg(_IA64_REG_SP);
471
472 if ((sp - bsp) < 1024) {
473 static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
474
475 if (__ratelimit(&ratelimit)) {
476 printk("ia64_handle_irq: DANGER: less than "
477 "1KB of free stack space!!\n"
478 "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
479 }
480 }
481 }
482 #endif /* IRQ_DEBUG */
483
484 /*
485 * Always set TPR to limit maximum interrupt nesting depth to
486 * 16 (without this, it would be ~240, which could easily lead
487 * to kernel stack overflows).
488 */
489 irq_enter();
490 saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
491 ia64_srlz_d();
492 while (vector != IA64_SPURIOUS_INT_VECTOR) {
493 int irq = local_vector_to_irq(vector);
494 struct irq_desc *desc = irq_to_desc(irq);
495
496 if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
497 smp_local_flush_tlb();
498 kstat_incr_irqs_this_cpu(irq, desc);
499 } else if (unlikely(IS_RESCHEDULE(vector))) {
500 scheduler_ipi();
501 kstat_incr_irqs_this_cpu(irq, desc);
502 } else {
503 ia64_setreg(_IA64_REG_CR_TPR, vector);
504 ia64_srlz_d();
505
506 if (unlikely(irq < 0)) {
507 printk(KERN_ERR "%s: Unexpected interrupt "
508 "vector %d on CPU %d is not mapped "
509 "to any IRQ!\n", __func__, vector,
510 smp_processor_id());
511 } else
512 generic_handle_irq(irq);
513
514 /*
515 * Disable interrupts and send EOI:
516 */
517 local_irq_disable();
518 ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
519 }
520 ia64_eoi();
521 vector = ia64_get_ivr();
522 }
523 /*
524 * This must be done *after* the ia64_eoi(). For example, the keyboard softirq
525 * handler needs to be able to wait for further keyboard interrupts, which can't
526 * come through until ia64_eoi() has been done.
527 */
528 irq_exit();
529 set_irq_regs(old_regs);
530 }
531
532 #ifdef CONFIG_HOTPLUG_CPU
533 /*
534 * This function emulates a interrupt processing when a cpu is about to be
535 * brought down.
536 */
ia64_process_pending_intr(void)537 void ia64_process_pending_intr(void)
538 {
539 ia64_vector vector;
540 unsigned long saved_tpr;
541 extern unsigned int vectors_in_migration[NR_IRQS];
542
543 vector = ia64_get_ivr();
544
545 irq_enter();
546 saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
547 ia64_srlz_d();
548
549 /*
550 * Perform normal interrupt style processing
551 */
552 while (vector != IA64_SPURIOUS_INT_VECTOR) {
553 int irq = local_vector_to_irq(vector);
554 struct irq_desc *desc = irq_to_desc(irq);
555
556 if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
557 smp_local_flush_tlb();
558 kstat_incr_irqs_this_cpu(irq, desc);
559 } else if (unlikely(IS_RESCHEDULE(vector))) {
560 kstat_incr_irqs_this_cpu(irq, desc);
561 } else {
562 struct pt_regs *old_regs = set_irq_regs(NULL);
563
564 ia64_setreg(_IA64_REG_CR_TPR, vector);
565 ia64_srlz_d();
566
567 /*
568 * Now try calling normal ia64_handle_irq as it would have got called
569 * from a real intr handler. Try passing null for pt_regs, hopefully
570 * it will work. I hope it works!.
571 * Probably could shared code.
572 */
573 if (unlikely(irq < 0)) {
574 printk(KERN_ERR "%s: Unexpected interrupt "
575 "vector %d on CPU %d not being mapped "
576 "to any IRQ!!\n", __func__, vector,
577 smp_processor_id());
578 } else {
579 vectors_in_migration[irq]=0;
580 generic_handle_irq(irq);
581 }
582 set_irq_regs(old_regs);
583
584 /*
585 * Disable interrupts and send EOI
586 */
587 local_irq_disable();
588 ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
589 }
590 ia64_eoi();
591 vector = ia64_get_ivr();
592 }
593 irq_exit();
594 }
595 #endif
596
597
598 #ifdef CONFIG_SMP
599
dummy_handler(int irq,void * dev_id)600 static irqreturn_t dummy_handler (int irq, void *dev_id)
601 {
602 BUG();
603 }
604
605 static struct irqaction ipi_irqaction = {
606 .handler = handle_IPI,
607 .flags = IRQF_DISABLED,
608 .name = "IPI"
609 };
610
611 /*
612 * KVM uses this interrupt to force a cpu out of guest mode
613 */
614 static struct irqaction resched_irqaction = {
615 .handler = dummy_handler,
616 .flags = IRQF_DISABLED,
617 .name = "resched"
618 };
619
620 static struct irqaction tlb_irqaction = {
621 .handler = dummy_handler,
622 .flags = IRQF_DISABLED,
623 .name = "tlb_flush"
624 };
625
626 #endif
627
628 void
ia64_native_register_percpu_irq(ia64_vector vec,struct irqaction * action)629 ia64_native_register_percpu_irq (ia64_vector vec, struct irqaction *action)
630 {
631 unsigned int irq;
632
633 irq = vec;
634 BUG_ON(bind_irq_vector(irq, vec, CPU_MASK_ALL));
635 irq_set_status_flags(irq, IRQ_PER_CPU);
636 irq_set_chip(irq, &irq_type_ia64_lsapic);
637 if (action)
638 setup_irq(irq, action);
639 irq_set_handler(irq, handle_percpu_irq);
640 }
641
642 void __init
ia64_native_register_ipi(void)643 ia64_native_register_ipi(void)
644 {
645 #ifdef CONFIG_SMP
646 register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
647 register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
648 register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &tlb_irqaction);
649 #endif
650 }
651
652 void __init
init_IRQ(void)653 init_IRQ (void)
654 {
655 #ifdef CONFIG_ACPI
656 acpi_boot_init();
657 #endif
658 ia64_register_ipi();
659 register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
660 #ifdef CONFIG_SMP
661 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG)
662 if (vector_domain_type != VECTOR_DOMAIN_NONE)
663 register_percpu_irq(IA64_IRQ_MOVE_VECTOR, &irq_move_irqaction);
664 #endif
665 #endif
666 #ifdef CONFIG_PERFMON
667 pfm_init_percpu();
668 #endif
669 platform_irq_init();
670 }
671
672 void
ia64_send_ipi(int cpu,int vector,int delivery_mode,int redirect)673 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
674 {
675 void __iomem *ipi_addr;
676 unsigned long ipi_data;
677 unsigned long phys_cpu_id;
678
679 phys_cpu_id = cpu_physical_id(cpu);
680
681 /*
682 * cpu number is in 8bit ID and 8bit EID
683 */
684
685 ipi_data = (delivery_mode << 8) | (vector & 0xff);
686 ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
687
688 writeq(ipi_data, ipi_addr);
689 }
690