2 * Timer device implementation for SGI SN platforms.
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
8 * Copyright (c) 2001-2006 Silicon Graphics, Inc. All rights reserved.
10 * This driver exports an API that should be supportable by any HPET or IA-PC
11 * multimedia timer. The code below is currently specific to the SGI Altix
14 * 11/01/01 - jbarnes - initial revision
15 * 9/10/04 - Christoph Lameter - remove interrupt support for kernel inclusion
16 * 10/1/04 - Christoph Lameter - provide posix clock CLOCK_SGI_CYCLE
17 * 10/13/04 - Christoph Lameter, Dimitri Sivanich - provide timer interrupt
18 * support via the posix timer interface
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/ioctl.h>
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/errno.h>
29 #include <linux/mmtimer.h>
30 #include <linux/miscdevice.h>
31 #include <linux/posix-timers.h>
32 #include <linux/interrupt.h>
34 #include <asm/uaccess.h>
35 #include <asm/sn/addrs.h>
36 #include <asm/sn/intr.h>
37 #include <asm/sn/shub_mmr.h>
38 #include <asm/sn/nodepda.h>
39 #include <asm/sn/shubio.h>
41 MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
42 MODULE_DESCRIPTION("SGI Altix RTC Timer");
43 MODULE_LICENSE("GPL");
45 /* name of the device, usually in /dev */
46 #define MMTIMER_NAME "mmtimer"
47 #define MMTIMER_DESC "SGI Altix RTC Timer"
48 #define MMTIMER_VERSION "2.1"
50 #define RTC_BITS 55 /* 55 bits for this implementation */
52 extern unsigned long sn_rtc_cycles_per_second
;
54 #define RTC_COUNTER_ADDR ((long *)LOCAL_MMR_ADDR(SH_RTC))
56 #define rtc_time() (*RTC_COUNTER_ADDR)
58 static int mmtimer_ioctl(struct inode
*inode
, struct file
*file
,
59 unsigned int cmd
, unsigned long arg
);
60 static int mmtimer_mmap(struct file
*file
, struct vm_area_struct
*vma
);
63 * Period in femtoseconds (10^-15 s)
65 static unsigned long mmtimer_femtoperiod
= 0;
67 static const struct file_operations mmtimer_fops
= {
70 .ioctl
= mmtimer_ioctl
,
74 * We only have comparison registers RTC1-4 currently available per
75 * node. RTC0 is used by SAL.
77 /* Check for an RTC interrupt pending */
78 static int mmtimer_int_pending(int comparator
)
80 if (HUB_L((unsigned long *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED
)) &
81 SH_EVENT_OCCURRED_RTC1_INT_MASK
<< comparator
)
87 /* Clear the RTC interrupt pending bit */
88 static void mmtimer_clr_int_pending(int comparator
)
90 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS
),
91 SH_EVENT_OCCURRED_RTC1_INT_MASK
<< comparator
);
94 /* Setup timer on comparator RTC1 */
95 static void mmtimer_setup_int_0(int cpu
, u64 expires
)
99 /* Disable interrupt */
100 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE
), 0UL);
102 /* Initialize comparator value */
103 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_INT_CMPB
), -1L);
105 /* Clear pending bit */
106 mmtimer_clr_int_pending(0);
108 val
= ((u64
)SGI_MMTIMER_VECTOR
<< SH_RTC1_INT_CONFIG_IDX_SHFT
) |
109 ((u64
)cpu_physical_id(cpu
) <<
110 SH_RTC1_INT_CONFIG_PID_SHFT
);
112 /* Set configuration */
113 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC1_INT_CONFIG
), val
);
115 /* Enable RTC interrupts */
116 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE
), 1UL);
118 /* Initialize comparator value */
119 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_INT_CMPB
), expires
);
124 /* Setup timer on comparator RTC2 */
125 static void mmtimer_setup_int_1(int cpu
, u64 expires
)
129 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE
), 0UL);
131 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_INT_CMPC
), -1L);
133 mmtimer_clr_int_pending(1);
135 val
= ((u64
)SGI_MMTIMER_VECTOR
<< SH_RTC2_INT_CONFIG_IDX_SHFT
) |
136 ((u64
)cpu_physical_id(cpu
) <<
137 SH_RTC2_INT_CONFIG_PID_SHFT
);
139 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC2_INT_CONFIG
), val
);
141 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE
), 1UL);
143 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_INT_CMPC
), expires
);
146 /* Setup timer on comparator RTC3 */
147 static void mmtimer_setup_int_2(int cpu
, u64 expires
)
151 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE
), 0UL);
153 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_INT_CMPD
), -1L);
155 mmtimer_clr_int_pending(2);
157 val
= ((u64
)SGI_MMTIMER_VECTOR
<< SH_RTC3_INT_CONFIG_IDX_SHFT
) |
158 ((u64
)cpu_physical_id(cpu
) <<
159 SH_RTC3_INT_CONFIG_PID_SHFT
);
161 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC3_INT_CONFIG
), val
);
163 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE
), 1UL);
165 HUB_S((u64
*)LOCAL_MMR_ADDR(SH_INT_CMPD
), expires
);
169 * This function must be called with interrupts disabled and preemption off
170 * in order to insure that the setup succeeds in a deterministic time frame.
171 * It will check if the interrupt setup succeeded.
173 static int mmtimer_setup(int cpu
, int comparator
, unsigned long expires
)
176 switch (comparator
) {
178 mmtimer_setup_int_0(cpu
, expires
);
181 mmtimer_setup_int_1(cpu
, expires
);
184 mmtimer_setup_int_2(cpu
, expires
);
187 /* We might've missed our expiration time */
188 if (rtc_time() <= expires
)
192 * If an interrupt is already pending then its okay
193 * if not then we failed
195 return mmtimer_int_pending(comparator
);
198 static int mmtimer_disable_int(long nasid
, int comparator
)
200 switch (comparator
) {
202 nasid
== -1 ? HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE
),
203 0UL) : REMOTE_HUB_S(nasid
, SH_RTC1_INT_ENABLE
, 0UL);
206 nasid
== -1 ? HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE
),
207 0UL) : REMOTE_HUB_S(nasid
, SH_RTC2_INT_ENABLE
, 0UL);
210 nasid
== -1 ? HUB_S((u64
*)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE
),
211 0UL) : REMOTE_HUB_S(nasid
, SH_RTC3_INT_ENABLE
, 0UL);
219 #define COMPARATOR 1 /* The comparator to use */
221 #define TIMER_OFF 0xbadcabLL /* Timer is not setup */
222 #define TIMER_SET 0 /* Comparator is set for this timer */
224 /* There is one of these for each timer */
227 struct k_itimer
*timer
;
231 struct mmtimer_node
{
232 spinlock_t lock ____cacheline_aligned
;
233 struct rb_root timer_head
;
234 struct rb_node
*next
;
235 struct tasklet_struct tasklet
;
237 static struct mmtimer_node
*timers
;
241 * Add a new mmtimer struct to the node's mmtimer list.
242 * This function assumes the struct mmtimer_node is locked.
244 static void mmtimer_add_list(struct mmtimer
*n
)
246 int nodeid
= n
->timer
->it
.mmtimer
.node
;
247 unsigned long expires
= n
->timer
->it
.mmtimer
.expires
;
248 struct rb_node
**link
= &timers
[nodeid
].timer_head
.rb_node
;
249 struct rb_node
*parent
= NULL
;
253 * Find the right place in the rbtree:
257 x
= rb_entry(parent
, struct mmtimer
, list
);
259 if (expires
< x
->timer
->it
.mmtimer
.expires
)
260 link
= &(*link
)->rb_left
;
262 link
= &(*link
)->rb_right
;
266 * Insert the timer to the rbtree and check whether it
267 * replaces the first pending timer
269 rb_link_node(&n
->list
, parent
, link
);
270 rb_insert_color(&n
->list
, &timers
[nodeid
].timer_head
);
272 if (!timers
[nodeid
].next
|| expires
< rb_entry(timers
[nodeid
].next
,
273 struct mmtimer
, list
)->timer
->it
.mmtimer
.expires
)
274 timers
[nodeid
].next
= &n
->list
;
278 * Set the comparator for the next timer.
279 * This function assumes the struct mmtimer_node is locked.
281 static void mmtimer_set_next_timer(int nodeid
)
283 struct mmtimer_node
*n
= &timers
[nodeid
];
292 x
= rb_entry(n
->next
, struct mmtimer
, list
);
294 if (!t
->it
.mmtimer
.incr
) {
295 /* Not an interval timer */
296 if (!mmtimer_setup(x
->cpu
, COMPARATOR
,
297 t
->it
.mmtimer
.expires
)) {
298 /* Late setup, fire now */
299 tasklet_schedule(&n
->tasklet
);
306 while (!mmtimer_setup(x
->cpu
, COMPARATOR
, t
->it
.mmtimer
.expires
)) {
308 struct rb_node
*next
;
309 t
->it
.mmtimer
.expires
+= t
->it
.mmtimer
.incr
<< o
;
310 t
->it_overrun
+= 1 << o
;
313 printk(KERN_ALERT
"mmtimer: cannot reschedule timer\n");
314 t
->it
.mmtimer
.clock
= TIMER_OFF
;
315 n
->next
= rb_next(&x
->list
);
316 rb_erase(&x
->list
, &n
->timer_head
);
321 e
= t
->it
.mmtimer
.expires
;
322 next
= rb_next(&x
->list
);
327 e1
= rb_entry(next
, struct mmtimer
, list
)->
328 timer
->it
.mmtimer
.expires
;
331 rb_erase(&x
->list
, &n
->timer_head
);
339 * mmtimer_ioctl - ioctl interface for /dev/mmtimer
340 * @inode: inode of the device
341 * @file: file structure for the device
342 * @cmd: command to execute
343 * @arg: optional argument to command
345 * Executes the command specified by @cmd. Returns 0 for success, < 0 for
350 * %MMTIMER_GETOFFSET - Should return the offset (relative to the start
351 * of the page where the registers are mapped) for the counter in question.
353 * %MMTIMER_GETRES - Returns the resolution of the clock in femto (10^-15)
356 * %MMTIMER_GETFREQ - Copies the frequency of the clock in Hz to the address
359 * %MMTIMER_GETBITS - Returns the number of bits in the clock's counter
361 * %MMTIMER_MMAPAVAIL - Returns 1 if the registers can be mmap'd into userspace
363 * %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it
364 * in the address specified by @arg.
366 static int mmtimer_ioctl(struct inode
*inode
, struct file
*file
,
367 unsigned int cmd
, unsigned long arg
)
372 case MMTIMER_GETOFFSET
: /* offset of the counter */
374 * SN RTC registers are on their own 64k page
376 if(PAGE_SIZE
<= (1 << 16))
377 ret
= (((long)RTC_COUNTER_ADDR
) & (PAGE_SIZE
-1)) / 8;
382 case MMTIMER_GETRES
: /* resolution of the clock in 10^-15 s */
383 if(copy_to_user((unsigned long __user
*)arg
,
384 &mmtimer_femtoperiod
, sizeof(unsigned long)))
388 case MMTIMER_GETFREQ
: /* frequency in Hz */
389 if(copy_to_user((unsigned long __user
*)arg
,
390 &sn_rtc_cycles_per_second
,
391 sizeof(unsigned long)))
396 case MMTIMER_GETBITS
: /* number of bits in the clock */
400 case MMTIMER_MMAPAVAIL
: /* can we mmap the clock into userspace? */
401 ret
= (PAGE_SIZE
<= (1 << 16)) ? 1 : 0;
404 case MMTIMER_GETCOUNTER
:
405 if(copy_to_user((unsigned long __user
*)arg
,
406 RTC_COUNTER_ADDR
, sizeof(unsigned long)))
418 * mmtimer_mmap - maps the clock's registers into userspace
419 * @file: file structure for the device
420 * @vma: VMA to map the registers into
422 * Calls remap_pfn_range() to map the clock's registers into
423 * the calling process' address space.
425 static int mmtimer_mmap(struct file
*file
, struct vm_area_struct
*vma
)
427 unsigned long mmtimer_addr
;
429 if (vma
->vm_end
- vma
->vm_start
!= PAGE_SIZE
)
432 if (vma
->vm_flags
& VM_WRITE
)
435 if (PAGE_SIZE
> (1 << 16))
438 vma
->vm_page_prot
= pgprot_noncached(vma
->vm_page_prot
);
440 mmtimer_addr
= __pa(RTC_COUNTER_ADDR
);
441 mmtimer_addr
&= ~(PAGE_SIZE
- 1);
442 mmtimer_addr
&= 0xfffffffffffffffUL
;
444 if (remap_pfn_range(vma
, vma
->vm_start
, mmtimer_addr
>> PAGE_SHIFT
,
445 PAGE_SIZE
, vma
->vm_page_prot
)) {
446 printk(KERN_ERR
"remap_pfn_range failed in mmtimer.c\n");
453 static struct miscdevice mmtimer_miscdev
= {
459 static struct timespec sgi_clock_offset
;
460 static int sgi_clock_period
;
463 * Posix Timer Interface
466 static struct timespec sgi_clock_offset
;
467 static int sgi_clock_period
;
469 static int sgi_clock_get(clockid_t clockid
, struct timespec
*tp
)
473 nsec
= rtc_time() * sgi_clock_period
474 + sgi_clock_offset
.tv_nsec
;
475 tp
->tv_sec
= div_long_long_rem(nsec
, NSEC_PER_SEC
, &tp
->tv_nsec
)
476 + sgi_clock_offset
.tv_sec
;
480 static int sgi_clock_set(clockid_t clockid
, struct timespec
*tp
)
486 nsec
= rtc_time() * sgi_clock_period
;
488 sgi_clock_offset
.tv_sec
= tp
->tv_sec
- div_long_long_rem(nsec
, NSEC_PER_SEC
, &rem
);
490 if (rem
<= tp
->tv_nsec
)
491 sgi_clock_offset
.tv_nsec
= tp
->tv_sec
- rem
;
493 sgi_clock_offset
.tv_nsec
= tp
->tv_sec
+ NSEC_PER_SEC
- rem
;
494 sgi_clock_offset
.tv_sec
--;
500 * mmtimer_interrupt - timer interrupt handler
502 * @dev_id: device the irq came from
504 * Called when one of the comarators matches the counter, This
505 * routine will send signals to processes that have requested
508 * This interrupt is run in an interrupt context
509 * by the SHUB. It is therefore safe to locally access SHub
513 mmtimer_interrupt(int irq
, void *dev_id
)
515 unsigned long expires
= 0;
516 int result
= IRQ_NONE
;
517 unsigned indx
= cpu_to_node(smp_processor_id());
518 struct mmtimer
*base
;
520 spin_lock(&timers
[indx
].lock
);
521 base
= rb_entry(timers
[indx
].next
, struct mmtimer
, list
);
523 spin_unlock(&timers
[indx
].lock
);
527 if (base
->cpu
== smp_processor_id()) {
529 expires
= base
->timer
->it
.mmtimer
.expires
;
530 /* expires test won't work with shared irqs */
531 if ((mmtimer_int_pending(COMPARATOR
) > 0) ||
532 (expires
&& (expires
<= rtc_time()))) {
533 mmtimer_clr_int_pending(COMPARATOR
);
534 tasklet_schedule(&timers
[indx
].tasklet
);
535 result
= IRQ_HANDLED
;
538 spin_unlock(&timers
[indx
].lock
);
542 static void mmtimer_tasklet(unsigned long data
)
545 struct mmtimer_node
*mn
= &timers
[nodeid
];
546 struct mmtimer
*x
= rb_entry(mn
->next
, struct mmtimer
, list
);
550 /* Send signal and deal with periodic signals */
551 spin_lock_irqsave(&mn
->lock
, flags
);
555 x
= rb_entry(mn
->next
, struct mmtimer
, list
);
558 if (t
->it
.mmtimer
.clock
== TIMER_OFF
)
563 mn
->next
= rb_next(&x
->list
);
564 rb_erase(&x
->list
, &mn
->timer_head
);
566 if (posix_timer_event(t
, 0) != 0)
569 if(t
->it
.mmtimer
.incr
) {
570 t
->it
.mmtimer
.expires
+= t
->it
.mmtimer
.incr
;
573 /* Ensure we don't false trigger in mmtimer_interrupt */
574 t
->it
.mmtimer
.clock
= TIMER_OFF
;
575 t
->it
.mmtimer
.expires
= 0;
578 /* Set comparator for next timer, if there is one */
579 mmtimer_set_next_timer(nodeid
);
581 t
->it_overrun_last
= t
->it_overrun
;
583 spin_unlock_irqrestore(&mn
->lock
, flags
);
586 static int sgi_timer_create(struct k_itimer
*timer
)
588 /* Insure that a newly created timer is off */
589 timer
->it
.mmtimer
.clock
= TIMER_OFF
;
593 /* This does not really delete a timer. It just insures
594 * that the timer is not active
596 * Assumption: it_lock is already held with irq's disabled
598 static int sgi_timer_del(struct k_itimer
*timr
)
600 cnodeid_t nodeid
= timr
->it
.mmtimer
.node
;
601 unsigned long irqflags
;
603 spin_lock_irqsave(&timers
[nodeid
].lock
, irqflags
);
604 if (timr
->it
.mmtimer
.clock
!= TIMER_OFF
) {
605 unsigned long expires
= timr
->it
.mmtimer
.expires
;
606 struct rb_node
*n
= timers
[nodeid
].timer_head
.rb_node
;
607 struct mmtimer
*uninitialized_var(t
);
610 timr
->it
.mmtimer
.clock
= TIMER_OFF
;
611 timr
->it
.mmtimer
.expires
= 0;
614 t
= rb_entry(n
, struct mmtimer
, list
);
615 if (t
->timer
== timr
)
618 if (expires
< t
->timer
->it
.mmtimer
.expires
)
625 spin_unlock_irqrestore(&timers
[nodeid
].lock
, irqflags
);
629 if (timers
[nodeid
].next
== n
) {
630 timers
[nodeid
].next
= rb_next(n
);
634 rb_erase(n
, &timers
[nodeid
].timer_head
);
638 mmtimer_disable_int(cnodeid_to_nasid(nodeid
),
640 mmtimer_set_next_timer(nodeid
);
643 spin_unlock_irqrestore(&timers
[nodeid
].lock
, irqflags
);
647 #define timespec_to_ns(x) ((x).tv_nsec + (x).tv_sec * NSEC_PER_SEC)
648 #define ns_to_timespec(ts, nsec) (ts).tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &(ts).tv_nsec)
650 /* Assumption: it_lock is already held with irq's disabled */
651 static void sgi_timer_get(struct k_itimer
*timr
, struct itimerspec
*cur_setting
)
654 if (timr
->it
.mmtimer
.clock
== TIMER_OFF
) {
655 cur_setting
->it_interval
.tv_nsec
= 0;
656 cur_setting
->it_interval
.tv_sec
= 0;
657 cur_setting
->it_value
.tv_nsec
= 0;
658 cur_setting
->it_value
.tv_sec
=0;
662 ns_to_timespec(cur_setting
->it_interval
, timr
->it
.mmtimer
.incr
* sgi_clock_period
);
663 ns_to_timespec(cur_setting
->it_value
, (timr
->it
.mmtimer
.expires
- rtc_time())* sgi_clock_period
);
668 static int sgi_timer_set(struct k_itimer
*timr
, int flags
,
669 struct itimerspec
* new_setting
,
670 struct itimerspec
* old_setting
)
672 unsigned long when
, period
, irqflags
;
675 struct mmtimer
*base
;
679 sgi_timer_get(timr
, old_setting
);
682 when
= timespec_to_ns(new_setting
->it_value
);
683 period
= timespec_to_ns(new_setting
->it_interval
);
689 base
= kmalloc(sizeof(struct mmtimer
), GFP_KERNEL
);
693 if (flags
& TIMER_ABSTIME
) {
698 now
= timespec_to_ns(n
);
702 /* Fire the timer immediately */
707 * Convert to sgi clock period. Need to keep rtc_time() as near as possible
708 * to getnstimeofday() in order to be as faithful as possible to the time
711 when
= (when
+ sgi_clock_period
- 1) / sgi_clock_period
+ rtc_time();
712 period
= (period
+ sgi_clock_period
- 1) / sgi_clock_period
;
715 * We are allocating a local SHub comparator. If we would be moved to another
716 * cpu then another SHub may be local to us. Prohibit that by switching off
721 nodeid
= cpu_to_node(smp_processor_id());
723 /* Lock the node timer structure */
724 spin_lock_irqsave(&timers
[nodeid
].lock
, irqflags
);
727 base
->cpu
= smp_processor_id();
729 timr
->it
.mmtimer
.clock
= TIMER_SET
;
730 timr
->it
.mmtimer
.node
= nodeid
;
731 timr
->it
.mmtimer
.incr
= period
;
732 timr
->it
.mmtimer
.expires
= when
;
734 n
= timers
[nodeid
].next
;
736 /* Add the new struct mmtimer to node's timer list */
737 mmtimer_add_list(base
);
739 if (timers
[nodeid
].next
== n
) {
740 /* No need to reprogram comparator for now */
741 spin_unlock_irqrestore(&timers
[nodeid
].lock
, irqflags
);
746 /* We need to reprogram the comparator */
748 mmtimer_disable_int(cnodeid_to_nasid(nodeid
), COMPARATOR
);
750 mmtimer_set_next_timer(nodeid
);
752 /* Unlock the node timer structure */
753 spin_unlock_irqrestore(&timers
[nodeid
].lock
, irqflags
);
760 static struct k_clock sgi_clock
= {
762 .clock_set
= sgi_clock_set
,
763 .clock_get
= sgi_clock_get
,
764 .timer_create
= sgi_timer_create
,
765 .nsleep
= do_posix_clock_nonanosleep
,
766 .timer_set
= sgi_timer_set
,
767 .timer_del
= sgi_timer_del
,
768 .timer_get
= sgi_timer_get
772 * mmtimer_init - device initialization routine
774 * Does initial setup for the mmtimer device.
776 static int __init
mmtimer_init(void)
778 cnodeid_t node
, maxn
= -1;
780 if (!ia64_platform_is("sn2"))
784 * Sanity check the cycles/sec variable
786 if (sn_rtc_cycles_per_second
< 100000) {
787 printk(KERN_ERR
"%s: unable to determine clock frequency\n",
792 mmtimer_femtoperiod
= ((unsigned long)1E15
+ sn_rtc_cycles_per_second
/
793 2) / sn_rtc_cycles_per_second
;
795 if (request_irq(SGI_MMTIMER_VECTOR
, mmtimer_interrupt
, IRQF_PERCPU
, MMTIMER_NAME
, NULL
)) {
796 printk(KERN_WARNING
"%s: unable to allocate interrupt.",
801 if (misc_register(&mmtimer_miscdev
)) {
802 printk(KERN_ERR
"%s: failed to register device\n",
807 /* Get max numbered node, calculate slots needed */
808 for_each_online_node(node
) {
813 /* Allocate list of node ptrs to mmtimer_t's */
814 timers
= kzalloc(sizeof(struct mmtimer_node
)*maxn
, GFP_KERNEL
);
815 if (timers
== NULL
) {
816 printk(KERN_ERR
"%s: failed to allocate memory for device\n",
821 /* Initialize struct mmtimer's for each online node */
822 for_each_online_node(node
) {
823 spin_lock_init(&timers
[node
].lock
);
824 tasklet_init(&timers
[node
].tasklet
, mmtimer_tasklet
,
825 (unsigned long) node
);
828 sgi_clock_period
= sgi_clock
.res
= NSEC_PER_SEC
/ sn_rtc_cycles_per_second
;
829 register_posix_clock(CLOCK_SGI_CYCLE
, &sgi_clock
);
831 printk(KERN_INFO
"%s: v%s, %ld MHz\n", MMTIMER_DESC
, MMTIMER_VERSION
,
832 sn_rtc_cycles_per_second
/(unsigned long)1E6
);
838 misc_deregister(&mmtimer_miscdev
);
840 free_irq(SGI_MMTIMER_VECTOR
, NULL
);
845 module_init(mmtimer_init
);