1 /* $Id: irq.c,v 1.114 2002/01/11 08:45:38 davem Exp $
2 * irq.c: UltraSparc IRQ handling/init/registry.
4 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
6 * Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz)
9 #include <linux/module.h>
10 #include <linux/sched.h>
11 #include <linux/ptrace.h>
12 #include <linux/errno.h>
13 #include <linux/kernel_stat.h>
14 #include <linux/signal.h>
16 #include <linux/interrupt.h>
17 #include <linux/slab.h>
18 #include <linux/random.h>
19 #include <linux/init.h>
20 #include <linux/delay.h>
21 #include <linux/proc_fs.h>
22 #include <linux/seq_file.h>
23 #include <linux/bootmem.h>
24 #include <linux/irq.h>
25 #include <linux/msi.h>
27 #include <asm/ptrace.h>
28 #include <asm/processor.h>
29 #include <asm/atomic.h>
30 #include <asm/system.h>
34 #include <asm/iommu.h>
36 #include <asm/oplib.h>
38 #include <asm/timer.h>
40 #include <asm/starfire.h>
41 #include <asm/uaccess.h>
42 #include <asm/cache.h>
43 #include <asm/cpudata.h>
44 #include <asm/auxio.h>
47 /* UPA nodes send interrupt packet to UltraSparc with first data reg
48 * value low 5 (7 on Starfire) bits holding the IRQ identifier being
49 * delivered. We must translate this into a non-vector IRQ so we can
50 * set the softint on this cpu.
52 * To make processing these packets efficient and race free we use
53 * an array of irq buckets below. The interrupt vector handler in
54 * entry.S feeds incoming packets into per-cpu pil-indexed lists.
55 * The IVEC handler does not need to act atomically, the PIL dispatch
56 * code uses CAS to get an atomic snapshot of the list and clear it
59 * If you make changes to ino_bucket, please update hand coded assembler
60 * of the vectored interrupt trap handler(s) in entry.S and sun4v_ivec.S
63 /* Next handler in per-CPU IRQ worklist. We know that
64 * bucket pointers have the high 32-bits clear, so to
65 * save space we only store the bits we need.
67 /*0x00*/unsigned int irq_chain
;
69 /* Virtual interrupt number assigned to this INO. */
70 /*0x04*/unsigned int virt_irq
;
73 #define NUM_IVECS (IMAP_INR + 1)
74 struct ino_bucket ivector_table
[NUM_IVECS
] __attribute__ ((aligned (SMP_CACHE_BYTES
)));
76 #define __irq_ino(irq) \
77 (((struct ino_bucket *)(unsigned long)(irq)) - &ivector_table[0])
78 #define __bucket(irq) ((struct ino_bucket *)(unsigned long)(irq))
79 #define __irq(bucket) ((unsigned int)(unsigned long)(bucket))
81 /* This has to be in the main kernel image, it cannot be
82 * turned into per-cpu data. The reason is that the main
83 * kernel image is locked into the TLB and this structure
84 * is accessed from the vectored interrupt trap handler. If
85 * access to this structure takes a TLB miss it could cause
86 * the 5-level sparc v9 trap stack to overflow.
88 #define irq_work(__cpu) &(trap_block[(__cpu)].irq_worklist)
90 static unsigned int virt_to_real_irq_table
[NR_IRQS
];
92 static unsigned char virt_irq_alloc(unsigned int real_irq
)
96 BUILD_BUG_ON(NR_IRQS
>= 256);
98 for (ent
= 1; ent
< NR_IRQS
; ent
++) {
99 if (!virt_to_real_irq_table
[ent
])
102 if (ent
>= NR_IRQS
) {
103 printk(KERN_ERR
"IRQ: Out of virtual IRQs.\n");
107 virt_to_real_irq_table
[ent
] = real_irq
;
112 #ifdef CONFIG_PCI_MSI
113 static void virt_irq_free(unsigned int virt_irq
)
115 unsigned int real_irq
;
117 if (virt_irq
>= NR_IRQS
)
120 real_irq
= virt_to_real_irq_table
[virt_irq
];
121 virt_to_real_irq_table
[virt_irq
] = 0;
123 __bucket(real_irq
)->virt_irq
= 0;
127 static unsigned int virt_to_real_irq(unsigned char virt_irq
)
129 return virt_to_real_irq_table
[virt_irq
];
133 * /proc/interrupts printing:
136 int show_interrupts(struct seq_file
*p
, void *v
)
138 int i
= *(loff_t
*) v
, j
;
139 struct irqaction
* action
;
144 for_each_online_cpu(j
)
145 seq_printf(p
, "CPU%d ",j
);
150 spin_lock_irqsave(&irq_desc
[i
].lock
, flags
);
151 action
= irq_desc
[i
].action
;
154 seq_printf(p
, "%3d: ",i
);
156 seq_printf(p
, "%10u ", kstat_irqs(i
));
158 for_each_online_cpu(j
)
159 seq_printf(p
, "%10u ", kstat_cpu(j
).irqs
[i
]);
161 seq_printf(p
, " %9s", irq_desc
[i
].chip
->typename
);
162 seq_printf(p
, " %s", action
->name
);
164 for (action
=action
->next
; action
; action
= action
->next
)
165 seq_printf(p
, ", %s", action
->name
);
169 spin_unlock_irqrestore(&irq_desc
[i
].lock
, flags
);
174 extern unsigned long real_hard_smp_processor_id(void);
176 static unsigned int sun4u_compute_tid(unsigned long imap
, unsigned long cpuid
)
180 if (this_is_starfire
) {
181 tid
= starfire_translate(imap
, cpuid
);
182 tid
<<= IMAP_TID_SHIFT
;
185 if (tlb_type
== cheetah
|| tlb_type
== cheetah_plus
) {
188 __asm__ ("rdpr %%ver, %0" : "=r" (ver
));
189 if ((ver
>> 32UL) == __JALAPENO_ID
||
190 (ver
>> 32UL) == __SERRANO_ID
) {
191 tid
= cpuid
<< IMAP_TID_SHIFT
;
192 tid
&= IMAP_TID_JBUS
;
194 unsigned int a
= cpuid
& 0x1f;
195 unsigned int n
= (cpuid
>> 5) & 0x1f;
197 tid
= ((a
<< IMAP_AID_SHIFT
) |
198 (n
<< IMAP_NID_SHIFT
));
199 tid
&= (IMAP_AID_SAFARI
|
203 tid
= cpuid
<< IMAP_TID_SHIFT
;
211 struct irq_handler_data
{
215 void (*pre_handler
)(unsigned int, void *, void *);
216 void *pre_handler_arg1
;
217 void *pre_handler_arg2
;
220 static inline struct ino_bucket
*virt_irq_to_bucket(unsigned int virt_irq
)
222 unsigned int real_irq
= virt_to_real_irq(virt_irq
);
223 struct ino_bucket
*bucket
= NULL
;
225 if (likely(real_irq
))
226 bucket
= __bucket(real_irq
);
232 static int irq_choose_cpu(unsigned int virt_irq
)
234 cpumask_t mask
= irq_desc
[virt_irq
].affinity
;
237 if (cpus_equal(mask
, CPU_MASK_ALL
)) {
238 static int irq_rover
;
239 static DEFINE_SPINLOCK(irq_rover_lock
);
242 /* Round-robin distribution... */
244 spin_lock_irqsave(&irq_rover_lock
, flags
);
246 while (!cpu_online(irq_rover
)) {
247 if (++irq_rover
>= NR_CPUS
)
252 if (++irq_rover
>= NR_CPUS
)
254 } while (!cpu_online(irq_rover
));
256 spin_unlock_irqrestore(&irq_rover_lock
, flags
);
260 cpus_and(tmp
, cpu_online_map
, mask
);
265 cpuid
= first_cpu(tmp
);
271 static int irq_choose_cpu(unsigned int virt_irq
)
273 return real_hard_smp_processor_id();
277 static void sun4u_irq_enable(unsigned int virt_irq
)
279 struct irq_handler_data
*data
= get_irq_chip_data(virt_irq
);
282 unsigned long cpuid
, imap
;
285 cpuid
= irq_choose_cpu(virt_irq
);
288 tid
= sun4u_compute_tid(imap
, cpuid
);
290 upa_writel(tid
| IMAP_VALID
, imap
);
294 static void sun4u_irq_disable(unsigned int virt_irq
)
296 struct irq_handler_data
*data
= get_irq_chip_data(virt_irq
);
299 unsigned long imap
= data
->imap
;
300 u32 tmp
= upa_readl(imap
);
303 upa_writel(tmp
, imap
);
307 static void sun4u_irq_end(unsigned int virt_irq
)
309 struct irq_handler_data
*data
= get_irq_chip_data(virt_irq
);
312 upa_writel(ICLR_IDLE
, data
->iclr
);
315 static void sun4v_irq_enable(unsigned int virt_irq
)
317 struct ino_bucket
*bucket
= virt_irq_to_bucket(virt_irq
);
318 unsigned int ino
= bucket
- &ivector_table
[0];
320 if (likely(bucket
)) {
324 cpuid
= irq_choose_cpu(virt_irq
);
326 err
= sun4v_intr_settarget(ino
, cpuid
);
328 printk("sun4v_intr_settarget(%x,%lu): err(%d)\n",
330 err
= sun4v_intr_setenabled(ino
, HV_INTR_ENABLED
);
332 printk("sun4v_intr_setenabled(%x): err(%d)\n",
337 static void sun4v_irq_disable(unsigned int virt_irq
)
339 struct ino_bucket
*bucket
= virt_irq_to_bucket(virt_irq
);
340 unsigned int ino
= bucket
- &ivector_table
[0];
342 if (likely(bucket
)) {
345 err
= sun4v_intr_setenabled(ino
, HV_INTR_DISABLED
);
347 printk("sun4v_intr_setenabled(%x): "
348 "err(%d)\n", ino
, err
);
352 #ifdef CONFIG_PCI_MSI
353 static void sun4v_msi_enable(unsigned int virt_irq
)
355 sun4v_irq_enable(virt_irq
);
356 unmask_msi_irq(virt_irq
);
359 static void sun4v_msi_disable(unsigned int virt_irq
)
361 mask_msi_irq(virt_irq
);
362 sun4v_irq_disable(virt_irq
);
366 static void sun4v_irq_end(unsigned int virt_irq
)
368 struct ino_bucket
*bucket
= virt_irq_to_bucket(virt_irq
);
369 unsigned int ino
= bucket
- &ivector_table
[0];
371 if (likely(bucket
)) {
374 err
= sun4v_intr_setstate(ino
, HV_INTR_STATE_IDLE
);
376 printk("sun4v_intr_setstate(%x): "
377 "err(%d)\n", ino
, err
);
381 static void run_pre_handler(unsigned int virt_irq
)
383 struct ino_bucket
*bucket
= virt_irq_to_bucket(virt_irq
);
384 struct irq_handler_data
*data
= get_irq_chip_data(virt_irq
);
386 if (likely(data
->pre_handler
)) {
387 data
->pre_handler(__irq_ino(__irq(bucket
)),
388 data
->pre_handler_arg1
,
389 data
->pre_handler_arg2
);
393 static struct irq_chip sun4u_irq
= {
395 .enable
= sun4u_irq_enable
,
396 .disable
= sun4u_irq_disable
,
397 .end
= sun4u_irq_end
,
400 static struct irq_chip sun4u_irq_ack
= {
401 .typename
= "sun4u+ack",
402 .enable
= sun4u_irq_enable
,
403 .disable
= sun4u_irq_disable
,
404 .ack
= run_pre_handler
,
405 .end
= sun4u_irq_end
,
408 static struct irq_chip sun4v_irq
= {
410 .enable
= sun4v_irq_enable
,
411 .disable
= sun4v_irq_disable
,
412 .end
= sun4v_irq_end
,
415 static struct irq_chip sun4v_irq_ack
= {
416 .typename
= "sun4v+ack",
417 .enable
= sun4v_irq_enable
,
418 .disable
= sun4v_irq_disable
,
419 .ack
= run_pre_handler
,
420 .end
= sun4v_irq_end
,
423 #ifdef CONFIG_PCI_MSI
424 static struct irq_chip sun4v_msi
= {
425 .typename
= "sun4v+msi",
426 .mask
= mask_msi_irq
,
427 .unmask
= unmask_msi_irq
,
428 .enable
= sun4v_msi_enable
,
429 .disable
= sun4v_msi_disable
,
430 .ack
= run_pre_handler
,
431 .end
= sun4v_irq_end
,
435 void irq_install_pre_handler(int virt_irq
,
436 void (*func
)(unsigned int, void *, void *),
437 void *arg1
, void *arg2
)
439 struct irq_handler_data
*data
= get_irq_chip_data(virt_irq
);
440 struct irq_chip
*chip
;
442 data
->pre_handler
= func
;
443 data
->pre_handler_arg1
= arg1
;
444 data
->pre_handler_arg2
= arg2
;
446 chip
= get_irq_chip(virt_irq
);
447 if (chip
== &sun4u_irq_ack
||
448 chip
== &sun4v_irq_ack
449 #ifdef CONFIG_PCI_MSI
450 || chip
== &sun4v_msi
455 chip
= (chip
== &sun4u_irq
?
456 &sun4u_irq_ack
: &sun4v_irq_ack
);
457 set_irq_chip(virt_irq
, chip
);
460 unsigned int build_irq(int inofixup
, unsigned long iclr
, unsigned long imap
)
462 struct ino_bucket
*bucket
;
463 struct irq_handler_data
*data
;
466 BUG_ON(tlb_type
== hypervisor
);
468 ino
= (upa_readl(imap
) & (IMAP_IGN
| IMAP_INO
)) + inofixup
;
469 bucket
= &ivector_table
[ino
];
470 if (!bucket
->virt_irq
) {
471 bucket
->virt_irq
= virt_irq_alloc(__irq(bucket
));
472 set_irq_chip(bucket
->virt_irq
, &sun4u_irq
);
475 data
= get_irq_chip_data(bucket
->virt_irq
);
479 data
= kzalloc(sizeof(struct irq_handler_data
), GFP_ATOMIC
);
480 if (unlikely(!data
)) {
481 prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
484 set_irq_chip_data(bucket
->virt_irq
, data
);
490 return bucket
->virt_irq
;
493 unsigned int sun4v_build_irq(u32 devhandle
, unsigned int devino
)
495 struct ino_bucket
*bucket
;
496 struct irq_handler_data
*data
;
497 unsigned long sysino
;
499 BUG_ON(tlb_type
!= hypervisor
);
501 sysino
= sun4v_devino_to_sysino(devhandle
, devino
);
502 bucket
= &ivector_table
[sysino
];
503 if (!bucket
->virt_irq
) {
504 bucket
->virt_irq
= virt_irq_alloc(__irq(bucket
));
505 set_irq_chip(bucket
->virt_irq
, &sun4v_irq
);
508 data
= get_irq_chip_data(bucket
->virt_irq
);
512 data
= kzalloc(sizeof(struct irq_handler_data
), GFP_ATOMIC
);
513 if (unlikely(!data
)) {
514 prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
517 set_irq_chip_data(bucket
->virt_irq
, data
);
519 /* Catch accidental accesses to these things. IMAP/ICLR handling
520 * is done by hypervisor calls on sun4v platforms, not by direct
527 return bucket
->virt_irq
;
530 #ifdef CONFIG_PCI_MSI
531 unsigned int sun4v_build_msi(u32 devhandle
, unsigned int *virt_irq_p
,
532 unsigned int msi_start
, unsigned int msi_end
)
534 struct ino_bucket
*bucket
;
535 struct irq_handler_data
*data
;
536 unsigned long sysino
;
539 BUG_ON(tlb_type
!= hypervisor
);
541 /* Find a free devino in the given range. */
542 for (devino
= msi_start
; devino
< msi_end
; devino
++) {
543 sysino
= sun4v_devino_to_sysino(devhandle
, devino
);
544 bucket
= &ivector_table
[sysino
];
545 if (!bucket
->virt_irq
)
548 if (devino
>= msi_end
)
551 sysino
= sun4v_devino_to_sysino(devhandle
, devino
);
552 bucket
= &ivector_table
[sysino
];
553 bucket
->virt_irq
= virt_irq_alloc(__irq(bucket
));
554 *virt_irq_p
= bucket
->virt_irq
;
555 set_irq_chip(bucket
->virt_irq
, &sun4v_msi
);
557 data
= get_irq_chip_data(bucket
->virt_irq
);
561 data
= kzalloc(sizeof(struct irq_handler_data
), GFP_ATOMIC
);
562 if (unlikely(!data
)) {
563 prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
566 set_irq_chip_data(bucket
->virt_irq
, data
);
574 void sun4v_destroy_msi(unsigned int virt_irq
)
576 virt_irq_free(virt_irq
);
580 void ack_bad_irq(unsigned int virt_irq
)
582 struct ino_bucket
*bucket
= virt_irq_to_bucket(virt_irq
);
583 unsigned int ino
= 0xdeadbeef;
586 ino
= bucket
- &ivector_table
[0];
588 printk(KERN_CRIT
"Unexpected IRQ from ino[%x] virt_irq[%u]\n",
593 extern irqreturn_t
timer_interrupt(int, void *);
595 void timer_irq(int irq
, struct pt_regs
*regs
)
597 unsigned long clr_mask
= 1 << irq
;
598 unsigned long tick_mask
= tick_ops
->softint_mask
;
599 struct pt_regs
*old_regs
;
601 if (get_softint() & tick_mask
) {
603 clr_mask
= tick_mask
;
605 clear_softint(clr_mask
);
607 old_regs
= set_irq_regs(regs
);
610 kstat_this_cpu
.irqs
[0]++;
611 timer_interrupt(irq
, NULL
);
614 set_irq_regs(old_regs
);
618 void handler_irq(int irq
, struct pt_regs
*regs
)
620 struct ino_bucket
*bucket
;
621 struct pt_regs
*old_regs
;
623 clear_softint(1 << irq
);
625 old_regs
= set_irq_regs(regs
);
629 bucket
= __bucket(xchg32(irq_work(smp_processor_id()), 0));
631 struct ino_bucket
*next
= __bucket(bucket
->irq_chain
);
633 bucket
->irq_chain
= 0;
634 __do_IRQ(bucket
->virt_irq
);
640 set_irq_regs(old_regs
);
650 static struct sun5_timer
*prom_timers
;
651 static u64 prom_limit0
, prom_limit1
;
653 static void map_prom_timers(void)
655 struct device_node
*dp
;
658 /* PROM timer node hangs out in the top level of device siblings... */
659 dp
= of_find_node_by_path("/");
662 if (!strcmp(dp
->name
, "counter-timer"))
667 /* Assume if node is not present, PROM uses different tick mechanism
668 * which we should not care about.
671 prom_timers
= (struct sun5_timer
*) 0;
675 /* If PROM is really using this, it must be mapped by him. */
676 addr
= of_get_property(dp
, "address", NULL
);
678 prom_printf("PROM does not have timer mapped, trying to continue.\n");
679 prom_timers
= (struct sun5_timer
*) 0;
682 prom_timers
= (struct sun5_timer
*) ((unsigned long)addr
[0]);
685 static void kill_prom_timer(void)
690 /* Save them away for later. */
691 prom_limit0
= prom_timers
->limit0
;
692 prom_limit1
= prom_timers
->limit1
;
694 /* Just as in sun4c/sun4m PROM uses timer which ticks at IRQ 14.
695 * We turn both off here just to be paranoid.
697 prom_timers
->limit0
= 0;
698 prom_timers
->limit1
= 0;
700 /* Wheee, eat the interrupt packet too... */
701 __asm__
__volatile__(
703 " ldxa [%%g0] %0, %%g1\n"
704 " ldxa [%%g2] %1, %%g1\n"
705 " stxa %%g0, [%%g0] %0\n"
708 : "i" (ASI_INTR_RECEIVE
), "i" (ASI_INTR_R
)
712 void init_irqwork_curcpu(void)
714 int cpu
= hard_smp_processor_id();
716 trap_block
[cpu
].irq_worklist
= 0;
719 static void __cpuinit
register_one_mondo(unsigned long paddr
, unsigned long type
)
721 unsigned long num_entries
= 128;
722 unsigned long status
;
724 status
= sun4v_cpu_qconf(type
, paddr
, num_entries
);
725 if (status
!= HV_EOK
) {
726 prom_printf("SUN4V: sun4v_cpu_qconf(%lu:%lx:%lu) failed, "
727 "err %lu\n", type
, paddr
, num_entries
, status
);
732 static void __cpuinit
sun4v_register_mondo_queues(int this_cpu
)
734 struct trap_per_cpu
*tb
= &trap_block
[this_cpu
];
736 register_one_mondo(tb
->cpu_mondo_pa
, HV_CPU_QUEUE_CPU_MONDO
);
737 register_one_mondo(tb
->dev_mondo_pa
, HV_CPU_QUEUE_DEVICE_MONDO
);
738 register_one_mondo(tb
->resum_mondo_pa
, HV_CPU_QUEUE_RES_ERROR
);
739 register_one_mondo(tb
->nonresum_mondo_pa
, HV_CPU_QUEUE_NONRES_ERROR
);
742 static void __cpuinit
alloc_one_mondo(unsigned long *pa_ptr
, int use_bootmem
)
747 page
= alloc_bootmem_low_pages(PAGE_SIZE
);
749 page
= (void *) get_zeroed_page(GFP_ATOMIC
);
752 prom_printf("SUN4V: Error, cannot allocate mondo queue.\n");
756 *pa_ptr
= __pa(page
);
759 static void __cpuinit
alloc_one_kbuf(unsigned long *pa_ptr
, int use_bootmem
)
764 page
= alloc_bootmem_low_pages(PAGE_SIZE
);
766 page
= (void *) get_zeroed_page(GFP_ATOMIC
);
769 prom_printf("SUN4V: Error, cannot allocate kbuf page.\n");
773 *pa_ptr
= __pa(page
);
776 static void __cpuinit
init_cpu_send_mondo_info(struct trap_per_cpu
*tb
, int use_bootmem
)
781 BUILD_BUG_ON((NR_CPUS
* sizeof(u16
)) > (PAGE_SIZE
- 64));
784 page
= alloc_bootmem_low_pages(PAGE_SIZE
);
786 page
= (void *) get_zeroed_page(GFP_ATOMIC
);
789 prom_printf("SUN4V: Error, cannot allocate cpu mondo page.\n");
793 tb
->cpu_mondo_block_pa
= __pa(page
);
794 tb
->cpu_list_pa
= __pa(page
+ 64);
798 /* Allocate and register the mondo and error queues for this cpu. */
799 void __cpuinit
sun4v_init_mondo_queues(int use_bootmem
, int cpu
, int alloc
, int load
)
801 struct trap_per_cpu
*tb
= &trap_block
[cpu
];
804 alloc_one_mondo(&tb
->cpu_mondo_pa
, use_bootmem
);
805 alloc_one_mondo(&tb
->dev_mondo_pa
, use_bootmem
);
806 alloc_one_mondo(&tb
->resum_mondo_pa
, use_bootmem
);
807 alloc_one_kbuf(&tb
->resum_kernel_buf_pa
, use_bootmem
);
808 alloc_one_mondo(&tb
->nonresum_mondo_pa
, use_bootmem
);
809 alloc_one_kbuf(&tb
->nonresum_kernel_buf_pa
, use_bootmem
);
811 init_cpu_send_mondo_info(tb
, use_bootmem
);
815 if (cpu
!= hard_smp_processor_id()) {
816 prom_printf("SUN4V: init mondo on cpu %d not %d\n",
817 cpu
, hard_smp_processor_id());
820 sun4v_register_mondo_queues(cpu
);
824 static struct irqaction timer_irq_action
= {
828 /* Only invoked on boot processor. */
829 void __init
init_IRQ(void)
833 memset(&ivector_table
[0], 0, sizeof(ivector_table
));
835 if (tlb_type
== hypervisor
)
836 sun4v_init_mondo_queues(1, hard_smp_processor_id(), 1, 1);
838 /* We need to clear any IRQ's pending in the soft interrupt
839 * registers, a spurious one could be left around from the
840 * PROM timer which we just disabled.
842 clear_softint(get_softint());
844 /* Now that ivector table is initialized, it is safe
845 * to receive IRQ vector traps. We will normally take
846 * one or two right now, in case some device PROM used
847 * to boot us wants to speak to us. We just ignore them.
849 __asm__
__volatile__("rdpr %%pstate, %%g1\n\t"
850 "or %%g1, %0, %%g1\n\t"
851 "wrpr %%g1, 0x0, %%pstate"
856 irq_desc
[0].action
= &timer_irq_action
;