Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6.git] / arch / ia64 / kernel / irq_ia64.c
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/slab.h>
26 #include <linux/ptrace.h>
27 #include <linux/random.h>       /* for rand_initialize_irq() */
28 #include <linux/signal.h>
29 #include <linux/smp.h>
30 #include <linux/threads.h>
31 #include <linux/bitops.h>
32 #include <linux/irq.h>
33
34 #include <asm/delay.h>
35 #include <asm/intrinsics.h>
36 #include <asm/io.h>
37 #include <asm/hw_irq.h>
38 #include <asm/machvec.h>
39 #include <asm/pgtable.h>
40 #include <asm/system.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 int check_irq_used(int irq)
97 {
98         if (irq_status[irq] == IRQ_USED)
99                 return 1;
100
101         return -1;
102 }
103
104 static inline int find_unassigned_irq(void)
105 {
106         int irq;
107
108         for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
109                 if (irq_status[irq] == IRQ_UNUSED)
110                         return irq;
111         return -ENOSPC;
112 }
113
114 static inline int find_unassigned_vector(cpumask_t domain)
115 {
116         cpumask_t mask;
117         int pos, vector;
118
119         cpus_and(mask, domain, cpu_online_map);
120         if (cpus_empty(mask))
121                 return -EINVAL;
122
123         for (pos = 0; pos < IA64_NUM_DEVICE_VECTORS; pos++) {
124                 vector = IA64_FIRST_DEVICE_VECTOR + pos;
125                 cpus_and(mask, domain, vector_table[vector]);
126                 if (!cpus_empty(mask))
127                         continue;
128                 return vector;
129         }
130         return -ENOSPC;
131 }
132
133 static int __bind_irq_vector(int irq, int vector, cpumask_t domain)
134 {
135         cpumask_t mask;
136         int cpu;
137         struct irq_cfg *cfg = &irq_cfg[irq];
138
139         BUG_ON((unsigned)irq >= NR_IRQS);
140         BUG_ON((unsigned)vector >= IA64_NUM_VECTORS);
141
142         cpus_and(mask, domain, cpu_online_map);
143         if (cpus_empty(mask))
144                 return -EINVAL;
145         if ((cfg->vector == vector) && cpus_equal(cfg->domain, domain))
146                 return 0;
147         if (cfg->vector != IRQ_VECTOR_UNASSIGNED)
148                 return -EBUSY;
149         for_each_cpu_mask(cpu, mask)
150                 per_cpu(vector_irq, cpu)[vector] = irq;
151         cfg->vector = vector;
152         cfg->domain = domain;
153         irq_status[irq] = IRQ_USED;
154         cpus_or(vector_table[vector], vector_table[vector], domain);
155         return 0;
156 }
157
158 int bind_irq_vector(int irq, int vector, cpumask_t domain)
159 {
160         unsigned long flags;
161         int ret;
162
163         spin_lock_irqsave(&vector_lock, flags);
164         ret = __bind_irq_vector(irq, vector, domain);
165         spin_unlock_irqrestore(&vector_lock, flags);
166         return ret;
167 }
168
169 static void __clear_irq_vector(int irq)
170 {
171         int vector, cpu;
172         cpumask_t mask;
173         cpumask_t domain;
174         struct irq_cfg *cfg = &irq_cfg[irq];
175
176         BUG_ON((unsigned)irq >= NR_IRQS);
177         BUG_ON(cfg->vector == IRQ_VECTOR_UNASSIGNED);
178         vector = cfg->vector;
179         domain = cfg->domain;
180         cpus_and(mask, cfg->domain, cpu_online_map);
181         for_each_cpu_mask(cpu, mask)
182                 per_cpu(vector_irq, cpu)[vector] = -1;
183         cfg->vector = IRQ_VECTOR_UNASSIGNED;
184         cfg->domain = CPU_MASK_NONE;
185         irq_status[irq] = IRQ_UNUSED;
186         cpus_andnot(vector_table[vector], vector_table[vector], domain);
187 }
188
189 static void clear_irq_vector(int irq)
190 {
191         unsigned long flags;
192
193         spin_lock_irqsave(&vector_lock, flags);
194         __clear_irq_vector(irq);
195         spin_unlock_irqrestore(&vector_lock, flags);
196 }
197
198 int
199 ia64_native_assign_irq_vector (int irq)
200 {
201         unsigned long flags;
202         int vector, cpu;
203         cpumask_t domain = CPU_MASK_NONE;
204
205         vector = -ENOSPC;
206
207         spin_lock_irqsave(&vector_lock, flags);
208         for_each_online_cpu(cpu) {
209                 domain = vector_allocation_domain(cpu);
210                 vector = find_unassigned_vector(domain);
211                 if (vector >= 0)
212                         break;
213         }
214         if (vector < 0)
215                 goto out;
216         if (irq == AUTO_ASSIGN)
217                 irq = vector;
218         BUG_ON(__bind_irq_vector(irq, vector, domain));
219  out:
220         spin_unlock_irqrestore(&vector_lock, flags);
221         return vector;
222 }
223
224 void
225 ia64_native_free_irq_vector (int vector)
226 {
227         if (vector < IA64_FIRST_DEVICE_VECTOR ||
228             vector > IA64_LAST_DEVICE_VECTOR)
229                 return;
230         clear_irq_vector(vector);
231 }
232
233 int
234 reserve_irq_vector (int vector)
235 {
236         if (vector < IA64_FIRST_DEVICE_VECTOR ||
237             vector > IA64_LAST_DEVICE_VECTOR)
238                 return -EINVAL;
239         return !!bind_irq_vector(vector, vector, CPU_MASK_ALL);
240 }
241
242 /*
243  * Initialize vector_irq on a new cpu. This function must be called
244  * with vector_lock held.
245  */
246 void __setup_vector_irq(int cpu)
247 {
248         int irq, vector;
249
250         /* Clear vector_irq */
251         for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
252                 per_cpu(vector_irq, cpu)[vector] = -1;
253         /* Mark the inuse vectors */
254         for (irq = 0; irq < NR_IRQS; ++irq) {
255                 if (!cpu_isset(cpu, irq_cfg[irq].domain))
256                         continue;
257                 vector = irq_to_vector(irq);
258                 per_cpu(vector_irq, cpu)[vector] = irq;
259         }
260 }
261
262 #if defined(CONFIG_SMP) && (defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG))
263 #define IA64_IRQ_MOVE_VECTOR    IA64_DEF_FIRST_DEVICE_VECTOR
264
265 static enum vector_domain_type {
266         VECTOR_DOMAIN_NONE,
267         VECTOR_DOMAIN_PERCPU
268 } vector_domain_type = VECTOR_DOMAIN_NONE;
269
270 static cpumask_t vector_allocation_domain(int cpu)
271 {
272         if (vector_domain_type == VECTOR_DOMAIN_PERCPU)
273                 return cpumask_of_cpu(cpu);
274         return CPU_MASK_ALL;
275 }
276
277 static int __irq_prepare_move(int irq, int cpu)
278 {
279         struct irq_cfg *cfg = &irq_cfg[irq];
280         int vector;
281         cpumask_t domain;
282
283         if (cfg->move_in_progress || cfg->move_cleanup_count)
284                 return -EBUSY;
285         if (cfg->vector == IRQ_VECTOR_UNASSIGNED || !cpu_online(cpu))
286                 return -EINVAL;
287         if (cpu_isset(cpu, cfg->domain))
288                 return 0;
289         domain = vector_allocation_domain(cpu);
290         vector = find_unassigned_vector(domain);
291         if (vector < 0)
292                 return -ENOSPC;
293         cfg->move_in_progress = 1;
294         cfg->old_domain = cfg->domain;
295         cfg->vector = IRQ_VECTOR_UNASSIGNED;
296         cfg->domain = CPU_MASK_NONE;
297         BUG_ON(__bind_irq_vector(irq, vector, domain));
298         return 0;
299 }
300
301 int irq_prepare_move(int irq, int cpu)
302 {
303         unsigned long flags;
304         int ret;
305
306         spin_lock_irqsave(&vector_lock, flags);
307         ret = __irq_prepare_move(irq, cpu);
308         spin_unlock_irqrestore(&vector_lock, flags);
309         return ret;
310 }
311
312 void irq_complete_move(unsigned irq)
313 {
314         struct irq_cfg *cfg = &irq_cfg[irq];
315         cpumask_t cleanup_mask;
316         int i;
317
318         if (likely(!cfg->move_in_progress))
319                 return;
320
321         if (unlikely(cpu_isset(smp_processor_id(), cfg->old_domain)))
322                 return;
323
324         cpus_and(cleanup_mask, cfg->old_domain, cpu_online_map);
325         cfg->move_cleanup_count = cpus_weight(cleanup_mask);
326         for_each_cpu_mask(i, cleanup_mask)
327                 platform_send_ipi(i, IA64_IRQ_MOVE_VECTOR, IA64_IPI_DM_INT, 0);
328         cfg->move_in_progress = 0;
329 }
330
331 static irqreturn_t smp_irq_move_cleanup_interrupt(int irq, void *dev_id)
332 {
333         int me = smp_processor_id();
334         ia64_vector vector;
335         unsigned long flags;
336
337         for (vector = IA64_FIRST_DEVICE_VECTOR;
338              vector < IA64_LAST_DEVICE_VECTOR; vector++) {
339                 int irq;
340                 struct irq_desc *desc;
341                 struct irq_cfg *cfg;
342                 irq = __get_cpu_var(vector_irq)[vector];
343                 if (irq < 0)
344                         continue;
345
346                 desc = irq_desc + irq;
347                 cfg = irq_cfg + irq;
348                 spin_lock(&desc->lock);
349                 if (!cfg->move_cleanup_count)
350                         goto unlock;
351
352                 if (!cpu_isset(me, cfg->old_domain))
353                         goto unlock;
354
355                 spin_lock_irqsave(&vector_lock, flags);
356                 __get_cpu_var(vector_irq)[vector] = -1;
357                 cpu_clear(me, vector_table[vector]);
358                 spin_unlock_irqrestore(&vector_lock, flags);
359                 cfg->move_cleanup_count--;
360         unlock:
361                 spin_unlock(&desc->lock);
362         }
363         return IRQ_HANDLED;
364 }
365
366 static struct irqaction irq_move_irqaction = {
367         .handler =      smp_irq_move_cleanup_interrupt,
368         .flags =        IRQF_DISABLED,
369         .name =         "irq_move"
370 };
371
372 static int __init parse_vector_domain(char *arg)
373 {
374         if (!arg)
375                 return -EINVAL;
376         if (!strcmp(arg, "percpu")) {
377                 vector_domain_type = VECTOR_DOMAIN_PERCPU;
378                 no_int_routing = 1;
379         }
380         return 0;
381 }
382 early_param("vector", parse_vector_domain);
383 #else
384 static cpumask_t vector_allocation_domain(int cpu)
385 {
386         return CPU_MASK_ALL;
387 }
388 #endif
389
390
391 void destroy_and_reserve_irq(unsigned int irq)
392 {
393         unsigned long flags;
394
395         dynamic_irq_cleanup(irq);
396
397         spin_lock_irqsave(&vector_lock, flags);
398         __clear_irq_vector(irq);
399         irq_status[irq] = IRQ_RSVD;
400         spin_unlock_irqrestore(&vector_lock, flags);
401 }
402
403 /*
404  * Dynamic irq allocate and deallocation for MSI
405  */
406 int create_irq(void)
407 {
408         unsigned long flags;
409         int irq, vector, cpu;
410         cpumask_t domain = CPU_MASK_NONE;
411
412         irq = vector = -ENOSPC;
413         spin_lock_irqsave(&vector_lock, flags);
414         for_each_online_cpu(cpu) {
415                 domain = vector_allocation_domain(cpu);
416                 vector = find_unassigned_vector(domain);
417                 if (vector >= 0)
418                         break;
419         }
420         if (vector < 0)
421                 goto out;
422         irq = find_unassigned_irq();
423         if (irq < 0)
424                 goto out;
425         BUG_ON(__bind_irq_vector(irq, vector, domain));
426  out:
427         spin_unlock_irqrestore(&vector_lock, flags);
428         if (irq >= 0)
429                 dynamic_irq_init(irq);
430         return irq;
431 }
432
433 void destroy_irq(unsigned int irq)
434 {
435         dynamic_irq_cleanup(irq);
436         clear_irq_vector(irq);
437 }
438
439 #ifdef CONFIG_SMP
440 #       define IS_RESCHEDULE(vec)       (vec == IA64_IPI_RESCHEDULE)
441 #       define IS_LOCAL_TLB_FLUSH(vec)  (vec == IA64_IPI_LOCAL_TLB_FLUSH)
442 #else
443 #       define IS_RESCHEDULE(vec)       (0)
444 #       define IS_LOCAL_TLB_FLUSH(vec)  (0)
445 #endif
446 /*
447  * That's where the IVT branches when we get an external
448  * interrupt. This branches to the correct hardware IRQ handler via
449  * function ptr.
450  */
451 void
452 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
453 {
454         struct pt_regs *old_regs = set_irq_regs(regs);
455         unsigned long saved_tpr;
456
457 #if IRQ_DEBUG
458         {
459                 unsigned long bsp, sp;
460
461                 /*
462                  * Note: if the interrupt happened while executing in
463                  * the context switch routine (ia64_switch_to), we may
464                  * get a spurious stack overflow here.  This is
465                  * because the register and the memory stack are not
466                  * switched atomically.
467                  */
468                 bsp = ia64_getreg(_IA64_REG_AR_BSP);
469                 sp = ia64_getreg(_IA64_REG_SP);
470
471                 if ((sp - bsp) < 1024) {
472                         static unsigned char count;
473                         static long last_time;
474
475                         if (time_after(jiffies, last_time + 5 * HZ))
476                                 count = 0;
477                         if (++count < 5) {
478                                 last_time = jiffies;
479                                 printk("ia64_handle_irq: DANGER: less than "
480                                        "1KB of free stack space!!\n"
481                                        "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
482                         }
483                 }
484         }
485 #endif /* IRQ_DEBUG */
486
487         /*
488          * Always set TPR to limit maximum interrupt nesting depth to
489          * 16 (without this, it would be ~240, which could easily lead
490          * to kernel stack overflows).
491          */
492         irq_enter();
493         saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
494         ia64_srlz_d();
495         while (vector != IA64_SPURIOUS_INT_VECTOR) {
496                 struct irq_desc *desc;
497                 int irq = local_vector_to_irq(vector);
498
499                 desc = irq_desc + irq;
500                 if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
501                         smp_local_flush_tlb();
502                         kstat_incr_irqs_this_cpu(irq, desc);
503                 } else if (unlikely(IS_RESCHEDULE(vector)))
504                         kstat_incr_irqs_this_cpu(irq, desc);
505                 else {
506                         ia64_setreg(_IA64_REG_CR_TPR, vector);
507                         ia64_srlz_d();
508
509                         if (unlikely(irq < 0)) {
510                                 printk(KERN_ERR "%s: Unexpected interrupt "
511                                        "vector %d on CPU %d is not mapped "
512                                        "to any IRQ!\n", __func__, vector,
513                                        smp_processor_id());
514                         } else
515                                 generic_handle_irq(irq);
516
517                         /*
518                          * Disable interrupts and send EOI:
519                          */
520                         local_irq_disable();
521                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
522                 }
523                 ia64_eoi();
524                 vector = ia64_get_ivr();
525         }
526         /*
527          * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
528          * handler needs to be able to wait for further keyboard interrupts, which can't
529          * come through until ia64_eoi() has been done.
530          */
531         irq_exit();
532         set_irq_regs(old_regs);
533 }
534
535 #ifdef CONFIG_HOTPLUG_CPU
536 /*
537  * This function emulates a interrupt processing when a cpu is about to be
538  * brought down.
539  */
540 void ia64_process_pending_intr(void)
541 {
542         ia64_vector vector;
543         unsigned long saved_tpr;
544         extern unsigned int vectors_in_migration[NR_IRQS];
545
546         vector = ia64_get_ivr();
547
548         irq_enter();
549         saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
550         ia64_srlz_d();
551
552          /*
553           * Perform normal interrupt style processing
554           */
555         while (vector != IA64_SPURIOUS_INT_VECTOR) {
556                 struct irq_desc *desc;
557                 int irq = local_vector_to_irq(vector);
558                 desc = irq_desc + irq;
559
560                 if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
561                         smp_local_flush_tlb();
562                         kstat_incr_irqs_this_cpu(irq, desc);
563                 } else if (unlikely(IS_RESCHEDULE(vector)))
564                         kstat_incr_irqs_this_cpu(irq, desc);
565                 else {
566                         struct pt_regs *old_regs = set_irq_regs(NULL);
567
568                         ia64_setreg(_IA64_REG_CR_TPR, vector);
569                         ia64_srlz_d();
570
571                         /*
572                          * Now try calling normal ia64_handle_irq as it would have got called
573                          * from a real intr handler. Try passing null for pt_regs, hopefully
574                          * it will work. I hope it works!.
575                          * Probably could shared code.
576                          */
577                         if (unlikely(irq < 0)) {
578                                 printk(KERN_ERR "%s: Unexpected interrupt "
579                                        "vector %d on CPU %d not being mapped "
580                                        "to any IRQ!!\n", __func__, vector,
581                                        smp_processor_id());
582                         } else {
583                                 vectors_in_migration[irq]=0;
584                                 generic_handle_irq(irq);
585                         }
586                         set_irq_regs(old_regs);
587
588                         /*
589                          * Disable interrupts and send EOI
590                          */
591                         local_irq_disable();
592                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
593                 }
594                 ia64_eoi();
595                 vector = ia64_get_ivr();
596         }
597         irq_exit();
598 }
599 #endif
600
601
602 #ifdef CONFIG_SMP
603
604 static irqreturn_t dummy_handler (int irq, void *dev_id)
605 {
606         BUG();
607 }
608
609 static struct irqaction ipi_irqaction = {
610         .handler =      handle_IPI,
611         .flags =        IRQF_DISABLED,
612         .name =         "IPI"
613 };
614
615 static struct irqaction resched_irqaction = {
616         .handler =      dummy_handler,
617         .flags =        IRQF_DISABLED,
618         .name =         "resched"
619 };
620
621 static struct irqaction tlb_irqaction = {
622         .handler =      dummy_handler,
623         .flags =        IRQF_DISABLED,
624         .name =         "tlb_flush"
625 };
626
627 #endif
628
629 void
630 ia64_native_register_percpu_irq (ia64_vector vec, struct irqaction *action)
631 {
632         irq_desc_t *desc;
633         unsigned int irq;
634
635         irq = vec;
636         BUG_ON(bind_irq_vector(irq, vec, CPU_MASK_ALL));
637         desc = irq_desc + irq;
638         desc->status |= IRQ_PER_CPU;
639         desc->chip = &irq_type_ia64_lsapic;
640         if (action)
641                 setup_irq(irq, action);
642 }
643
644 void __init
645 ia64_native_register_ipi(void)
646 {
647 #ifdef CONFIG_SMP
648         register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
649         register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
650         register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &tlb_irqaction);
651 #endif
652 }
653
654 void __init
655 init_IRQ (void)
656 {
657         ia64_register_ipi();
658         register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
659 #ifdef CONFIG_SMP
660 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG)
661         if (vector_domain_type != VECTOR_DOMAIN_NONE) {
662                 BUG_ON(IA64_FIRST_DEVICE_VECTOR != IA64_IRQ_MOVE_VECTOR);
663                 IA64_FIRST_DEVICE_VECTOR++;
664                 register_percpu_irq(IA64_IRQ_MOVE_VECTOR, &irq_move_irqaction);
665         }
666 #endif
667 #endif
668 #ifdef CONFIG_PERFMON
669         pfm_init_percpu();
670 #endif
671         platform_irq_init();
672 }
673
674 void
675 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
676 {
677         void __iomem *ipi_addr;
678         unsigned long ipi_data;
679         unsigned long phys_cpu_id;
680
681         phys_cpu_id = cpu_physical_id(cpu);
682
683         /*
684          * cpu number is in 8bit ID and 8bit EID
685          */
686
687         ipi_data = (delivery_mode << 8) | (vector & 0xff);
688         ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
689
690         writeq(ipi_data, ipi_addr);
691 }