1/*
2 * Timer device implementation for SGI SN platforms.
3 *
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
6 * for more details.
7 *
8 * Copyright (c) 2001-2006 Silicon Graphics, Inc.  All rights reserved.
9 *
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
12 * SHub RTC, however.
13 *
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
19 */
20
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>
27#include <linux/mm.h>
28#include <linux/mmtimer.h>
29#include <linux/miscdevice.h>
30#include <linux/posix-timers.h>
31#include <linux/interrupt.h>
32
33#include <asm/uaccess.h>
34#include <asm/sn/addrs.h>
35#include <asm/sn/intr.h>
36#include <asm/sn/shub_mmr.h>
37#include <asm/sn/nodepda.h>
38#include <asm/sn/shubio.h>
39
40MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
41MODULE_DESCRIPTION("SGI Altix RTC Timer");
42MODULE_LICENSE("GPL");
43
44/* name of the device, usually in /dev */
45#define MMTIMER_NAME "mmtimer"
46#define MMTIMER_DESC "SGI Altix RTC Timer"
47#define MMTIMER_VERSION "2.1"
48
49#define RTC_BITS 55 /* 55 bits for this implementation */
50
51extern unsigned long sn_rtc_cycles_per_second;
52
53#define RTC_COUNTER_ADDR        ((long *)LOCAL_MMR_ADDR(SH_RTC))
54
55#define rtc_time()              (*RTC_COUNTER_ADDR)
56
57static int mmtimer_ioctl(struct inode *inode, struct file *file,
58			 unsigned int cmd, unsigned long arg);
59static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
60
61/*
62 * Period in femtoseconds (10^-15 s)
63 */
64static unsigned long mmtimer_femtoperiod = 0;
65
66static const struct file_operations mmtimer_fops = {
67	.owner =	THIS_MODULE,
68	.mmap =		mmtimer_mmap,
69	.ioctl =	mmtimer_ioctl,
70};
71
72/*
73 * We only have comparison registers RTC1-4 currently available per
74 * node.  RTC0 is used by SAL.
75 */
76#define NUM_COMPARATORS 3
77/* Check for an RTC interrupt pending */
78static int inline mmtimer_int_pending(int comparator)
79{
80	if (HUB_L((unsigned long *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED)) &
81			SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator)
82		return 1;
83	else
84		return 0;
85}
86/* Clear the RTC interrupt pending bit */
87static void inline mmtimer_clr_int_pending(int comparator)
88{
89	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS),
90		SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator);
91}
92
93/* Setup timer on comparator RTC1 */
94static void inline mmtimer_setup_int_0(u64 expires)
95{
96	u64 val;
97
98	/* Disable interrupt */
99	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 0UL);
100
101	/* Initialize comparator value */
102	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), -1L);
103
104	/* Clear pending bit */
105	mmtimer_clr_int_pending(0);
106
107	val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC1_INT_CONFIG_IDX_SHFT) |
108		((u64)cpu_physical_id(smp_processor_id()) <<
109			SH_RTC1_INT_CONFIG_PID_SHFT);
110
111	/* Set configuration */
112	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_CONFIG), val);
113
114	/* Enable RTC interrupts */
115	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 1UL);
116
117	/* Initialize comparator value */
118	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), expires);
119
120
121}
122
123/* Setup timer on comparator RTC2 */
124static void inline mmtimer_setup_int_1(u64 expires)
125{
126	u64 val;
127
128	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 0UL);
129
130	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), -1L);
131
132	mmtimer_clr_int_pending(1);
133
134	val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC2_INT_CONFIG_IDX_SHFT) |
135		((u64)cpu_physical_id(smp_processor_id()) <<
136			SH_RTC2_INT_CONFIG_PID_SHFT);
137
138	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_CONFIG), val);
139
140	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 1UL);
141
142	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), expires);
143}
144
145/* Setup timer on comparator RTC3 */
146static void inline mmtimer_setup_int_2(u64 expires)
147{
148	u64 val;
149
150	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 0UL);
151
152	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), -1L);
153
154	mmtimer_clr_int_pending(2);
155
156	val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC3_INT_CONFIG_IDX_SHFT) |
157		((u64)cpu_physical_id(smp_processor_id()) <<
158			SH_RTC3_INT_CONFIG_PID_SHFT);
159
160	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_CONFIG), val);
161
162	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 1UL);
163
164	HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), expires);
165}
166
167/*
168 * This function must be called with interrupts disabled and preemption off
169 * in order to insure that the setup succeeds in a deterministic time frame.
170 * It will check if the interrupt setup succeeded.
171 */
172static int inline mmtimer_setup(int comparator, unsigned long expires)
173{
174
175	switch (comparator) {
176	case 0:
177		mmtimer_setup_int_0(expires);
178		break;
179	case 1:
180		mmtimer_setup_int_1(expires);
181		break;
182	case 2:
183		mmtimer_setup_int_2(expires);
184		break;
185	}
186	/* We might've missed our expiration time */
187	if (rtc_time() < expires)
188		return 1;
189
190	/*
191	 * If an interrupt is already pending then its okay
192	 * if not then we failed
193	 */
194	return mmtimer_int_pending(comparator);
195}
196
197static int inline mmtimer_disable_int(long nasid, int comparator)
198{
199	switch (comparator) {
200	case 0:
201		nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE),
202			0UL) : REMOTE_HUB_S(nasid, SH_RTC1_INT_ENABLE, 0UL);
203		break;
204	case 1:
205		nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE),
206			0UL) : REMOTE_HUB_S(nasid, SH_RTC2_INT_ENABLE, 0UL);
207		break;
208	case 2:
209		nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE),
210			0UL) : REMOTE_HUB_S(nasid, SH_RTC3_INT_ENABLE, 0UL);
211		break;
212	default:
213		return -EFAULT;
214	}
215	return 0;
216}
217
218#define TIMER_OFF 0xbadcabLL
219
220/* There is one of these for each comparator */
221typedef struct mmtimer {
222	spinlock_t lock ____cacheline_aligned;
223	struct k_itimer *timer;
224	int i;
225	int cpu;
226	struct tasklet_struct tasklet;
227} mmtimer_t;
228
229static mmtimer_t ** timers;
230
231/**
232 * mmtimer_ioctl - ioctl interface for /dev/mmtimer
233 * @inode: inode of the device
234 * @file: file structure for the device
235 * @cmd: command to execute
236 * @arg: optional argument to command
237 *
238 * Executes the command specified by @cmd.  Returns 0 for success, < 0 for
239 * failure.
240 *
241 * Valid commands:
242 *
243 * %MMTIMER_GETOFFSET - Should return the offset (relative to the start
244 * of the page where the registers are mapped) for the counter in question.
245 *
246 * %MMTIMER_GETRES - Returns the resolution of the clock in femto (10^-15)
247 * seconds
248 *
249 * %MMTIMER_GETFREQ - Copies the frequency of the clock in Hz to the address
250 * specified by @arg
251 *
252 * %MMTIMER_GETBITS - Returns the number of bits in the clock's counter
253 *
254 * %MMTIMER_MMAPAVAIL - Returns 1 if the registers can be mmap'd into userspace
255 *
256 * %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it
257 * in the address specified by @arg.
258 */
259static int mmtimer_ioctl(struct inode *inode, struct file *file,
260			 unsigned int cmd, unsigned long arg)
261{
262	int ret = 0;
263
264	switch (cmd) {
265	case MMTIMER_GETOFFSET:	/* offset of the counter */
266		/*
267		 * SN RTC registers are on their own 64k page
268		 */
269		if(PAGE_SIZE <= (1 << 16))
270			ret = (((long)RTC_COUNTER_ADDR) & (PAGE_SIZE-1)) / 8;
271		else
272			ret = -ENOSYS;
273		break;
274
275	case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */
276		if(copy_to_user((unsigned long __user *)arg,
277				&mmtimer_femtoperiod, sizeof(unsigned long)))
278			return -EFAULT;
279		break;
280
281	case MMTIMER_GETFREQ: /* frequency in Hz */
282		if(copy_to_user((unsigned long __user *)arg,
283				&sn_rtc_cycles_per_second,
284				sizeof(unsigned long)))
285			return -EFAULT;
286		ret = 0;
287		break;
288
289	case MMTIMER_GETBITS: /* number of bits in the clock */
290		ret = RTC_BITS;
291		break;
292
293	case MMTIMER_MMAPAVAIL: /* can we mmap the clock into userspace? */
294		ret = (PAGE_SIZE <= (1 << 16)) ? 1 : 0;
295		break;
296
297	case MMTIMER_GETCOUNTER:
298		if(copy_to_user((unsigned long __user *)arg,
299				RTC_COUNTER_ADDR, sizeof(unsigned long)))
300			return -EFAULT;
301		break;
302	default:
303		ret = -ENOSYS;
304		break;
305	}
306
307	return ret;
308}
309
310/**
311 * mmtimer_mmap - maps the clock's registers into userspace
312 * @file: file structure for the device
313 * @vma: VMA to map the registers into
314 *
315 * Calls remap_pfn_range() to map the clock's registers into
316 * the calling process' address space.
317 */
318static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
319{
320	unsigned long mmtimer_addr;
321
322	if (vma->vm_end - vma->vm_start != PAGE_SIZE)
323		return -EINVAL;
324
325	if (vma->vm_flags & VM_WRITE)
326		return -EPERM;
327
328	if (PAGE_SIZE > (1 << 16))
329		return -ENOSYS;
330
331	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
332
333	mmtimer_addr = __pa(RTC_COUNTER_ADDR);
334	mmtimer_addr &= ~(PAGE_SIZE - 1);
335	mmtimer_addr &= 0xfffffffffffffffUL;
336
337	if (remap_pfn_range(vma, vma->vm_start, mmtimer_addr >> PAGE_SHIFT,
338					PAGE_SIZE, vma->vm_page_prot)) {
339		printk(KERN_ERR "remap_pfn_range failed in mmtimer.c\n");
340		return -EAGAIN;
341	}
342
343	return 0;
344}
345
346static struct miscdevice mmtimer_miscdev = {
347	SGI_MMTIMER,
348	MMTIMER_NAME,
349	&mmtimer_fops
350};
351
352static struct timespec sgi_clock_offset;
353static int sgi_clock_period;
354
355/*
356 * Posix Timer Interface
357 */
358
359static struct timespec sgi_clock_offset;
360static int sgi_clock_period;
361
362static int sgi_clock_get(clockid_t clockid, struct timespec *tp)
363{
364	u64 nsec;
365
366	nsec = rtc_time() * sgi_clock_period
367			+ sgi_clock_offset.tv_nsec;
368	tp->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &tp->tv_nsec)
369			+ sgi_clock_offset.tv_sec;
370	return 0;
371};
372
373static int sgi_clock_set(clockid_t clockid, struct timespec *tp)
374{
375
376	u64 nsec;
377	u64 rem;
378
379	nsec = rtc_time() * sgi_clock_period;
380
381	sgi_clock_offset.tv_sec = tp->tv_sec - div_long_long_rem(nsec, NSEC_PER_SEC, &rem);
382
383	if (rem <= tp->tv_nsec)
384		sgi_clock_offset.tv_nsec = tp->tv_sec - rem;
385	else {
386		sgi_clock_offset.tv_nsec = tp->tv_sec + NSEC_PER_SEC - rem;
387		sgi_clock_offset.tv_sec--;
388	}
389	return 0;
390}
391
392/*
393 * Schedule the next periodic interrupt. This function will attempt
394 * to schedule a periodic interrupt later if necessary. If the scheduling
395 * of an interrupt fails then the time to skip is lengthened
396 * exponentially in order to ensure that the next interrupt
397 * can be properly scheduled..
398 */
399static int inline reschedule_periodic_timer(mmtimer_t *x)
400{
401	int n;
402	struct k_itimer *t = x->timer;
403
404	t->it.mmtimer.clock = x->i;
405	t->it_overrun--;
406
407	n = 0;
408	do {
409
410		t->it.mmtimer.expires += t->it.mmtimer.incr << n;
411		t->it_overrun += 1 << n;
412		n++;
413		if (n > 20)
414			return 1;
415
416	} while (!mmtimer_setup(x->i, t->it.mmtimer.expires));
417
418	return 0;
419}
420
421/**
422 * mmtimer_interrupt - timer interrupt handler
423 * @irq: irq received
424 * @dev_id: device the irq came from
425 *
426 * Called when one of the comarators matches the counter, This
427 * routine will send signals to processes that have requested
428 * them.
429 *
430 * This interrupt is run in an interrupt context
431 * by the SHUB. It is therefore safe to locally access SHub
432 * registers.
433 */
434static irqreturn_t
435mmtimer_interrupt(int irq, void *dev_id)
436{
437	int i;
438	unsigned long expires = 0;
439	int result = IRQ_NONE;
440	unsigned indx = cpu_to_node(smp_processor_id());
441
442	/*
443	 * Do this once for each comparison register
444	 */
445	for (i = 0; i < NUM_COMPARATORS; i++) {
446		mmtimer_t *base = timers[indx] + i;
447		/* Make sure this doesn't get reused before tasklet_sched */
448		spin_lock(&base->lock);
449		if (base->cpu == smp_processor_id()) {
450			if (base->timer)
451				expires = base->timer->it.mmtimer.expires;
452			/* expires test won't work with shared irqs */
453			if ((mmtimer_int_pending(i) > 0) ||
454				(expires && (expires < rtc_time()))) {
455				mmtimer_clr_int_pending(i);
456				tasklet_schedule(&base->tasklet);
457				result = IRQ_HANDLED;
458			}
459		}
460		spin_unlock(&base->lock);
461		expires = 0;
462	}
463	return result;
464}
465
466void mmtimer_tasklet(unsigned long data) {
467	mmtimer_t *x = (mmtimer_t *)data;
468	struct k_itimer *t = x->timer;
469	unsigned long flags;
470
471	if (t == NULL)
472		return;
473
474	/* Send signal and deal with periodic signals */
475	spin_lock_irqsave(&t->it_lock, flags);
476	spin_lock(&x->lock);
477	/* If timer was deleted between interrupt and here, leave */
478	if (t != x->timer)
479		goto out;
480	t->it_overrun = 0;
481
482	if (posix_timer_event(t, 0) != 0) {
483
484		// printk(KERN_WARNING "mmtimer: cannot deliver signal.\n");
485
486		t->it_overrun++;
487	}
488	if(t->it.mmtimer.incr) {
489		/* Periodic timer */
490		if (reschedule_periodic_timer(x)) {
491			printk(KERN_WARNING "mmtimer: unable to reschedule\n");
492			x->timer = NULL;
493		}
494	} else {
495		/* Ensure we don't false trigger in mmtimer_interrupt */
496		t->it.mmtimer.expires = 0;
497	}
498	t->it_overrun_last = t->it_overrun;
499out:
500	spin_unlock(&x->lock);
501	spin_unlock_irqrestore(&t->it_lock, flags);
502}
503
504static int sgi_timer_create(struct k_itimer *timer)
505{
506	/* Insure that a newly created timer is off */
507	timer->it.mmtimer.clock = TIMER_OFF;
508	return 0;
509}
510
511/* This does not really delete a timer. It just insures
512 * that the timer is not active
513 *
514 * Assumption: it_lock is already held with irq's disabled
515 */
516static int sgi_timer_del(struct k_itimer *timr)
517{
518	int i = timr->it.mmtimer.clock;
519	cnodeid_t nodeid = timr->it.mmtimer.node;
520	mmtimer_t *t = timers[nodeid] + i;
521	unsigned long irqflags;
522
523	if (i != TIMER_OFF) {
524		spin_lock_irqsave(&t->lock, irqflags);
525		mmtimer_disable_int(cnodeid_to_nasid(nodeid),i);
526		t->timer = NULL;
527		timr->it.mmtimer.clock = TIMER_OFF;
528		timr->it.mmtimer.expires = 0;
529		spin_unlock_irqrestore(&t->lock, irqflags);
530	}
531	return 0;
532}
533
534#define timespec_to_ns(x) ((x).tv_nsec + (x).tv_sec * NSEC_PER_SEC)
535#define ns_to_timespec(ts, nsec) (ts).tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &(ts).tv_nsec)
536
537/* Assumption: it_lock is already held with irq's disabled */
538static void sgi_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
539{
540
541	if (timr->it.mmtimer.clock == TIMER_OFF) {
542		cur_setting->it_interval.tv_nsec = 0;
543		cur_setting->it_interval.tv_sec = 0;
544		cur_setting->it_value.tv_nsec = 0;
545		cur_setting->it_value.tv_sec =0;
546		return;
547	}
548
549	ns_to_timespec(cur_setting->it_interval, timr->it.mmtimer.incr * sgi_clock_period);
550	ns_to_timespec(cur_setting->it_value, (timr->it.mmtimer.expires - rtc_time())* sgi_clock_period);
551	return;
552}
553
554
555static int sgi_timer_set(struct k_itimer *timr, int flags,
556	struct itimerspec * new_setting,
557	struct itimerspec * old_setting)
558{
559
560	int i;
561	unsigned long when, period, irqflags;
562	int err = 0;
563	cnodeid_t nodeid;
564	mmtimer_t *base;
565
566	if (old_setting)
567		sgi_timer_get(timr, old_setting);
568
569	sgi_timer_del(timr);
570	when = timespec_to_ns(new_setting->it_value);
571	period = timespec_to_ns(new_setting->it_interval);
572
573	if (when == 0)
574		/* Clear timer */
575		return 0;
576
577	if (flags & TIMER_ABSTIME) {
578		struct timespec n;
579		unsigned long now;
580
581		getnstimeofday(&n);
582		now = timespec_to_ns(n);
583		if (when > now)
584			when -= now;
585		else
586			/* Fire the timer immediately */
587			when = 0;
588	}
589
590	/*
591	 * Convert to sgi clock period. Need to keep rtc_time() as near as possible
592	 * to getnstimeofday() in order to be as faithful as possible to the time
593	 * specified.
594	 */
595	when = (when + sgi_clock_period - 1) / sgi_clock_period + rtc_time();
596	period = (period + sgi_clock_period - 1)  / sgi_clock_period;
597
598	/*
599	 * We are allocating a local SHub comparator. If we would be moved to another
600	 * cpu then another SHub may be local to us. Prohibit that by switching off
601	 * preemption.
602	 */
603	preempt_disable();
604
605	nodeid =  cpu_to_node(smp_processor_id());
606retry:
607	/* Don't use an allocated timer, or a deleted one that's pending */
608	for(i = 0; i< NUM_COMPARATORS; i++) {
609		base = timers[nodeid] + i;
610		if (!base->timer && !base->tasklet.state) {
611			break;
612		}
613	}
614
615	if (i == NUM_COMPARATORS) {
616		preempt_enable();
617		return -EBUSY;
618	}
619
620	spin_lock_irqsave(&base->lock, irqflags);
621
622	if (base->timer || base->tasklet.state != 0) {
623		spin_unlock_irqrestore(&base->lock, irqflags);
624		goto retry;
625	}
626	base->timer = timr;
627	base->cpu = smp_processor_id();
628
629	timr->it.mmtimer.clock = i;
630	timr->it.mmtimer.node = nodeid;
631	timr->it.mmtimer.incr = period;
632	timr->it.mmtimer.expires = when;
633
634	if (period == 0) {
635		if (!mmtimer_setup(i, when)) {
636			mmtimer_disable_int(-1, i);
637			posix_timer_event(timr, 0);
638			timr->it.mmtimer.expires = 0;
639		}
640	} else {
641		timr->it.mmtimer.expires -= period;
642		if (reschedule_periodic_timer(base))
643			err = -EINVAL;
644	}
645
646	spin_unlock_irqrestore(&base->lock, irqflags);
647
648	preempt_enable();
649
650	return err;
651}
652
653static struct k_clock sgi_clock = {
654	.res = 0,
655	.clock_set = sgi_clock_set,
656	.clock_get = sgi_clock_get,
657	.timer_create = sgi_timer_create,
658	.nsleep = do_posix_clock_nonanosleep,
659	.timer_set = sgi_timer_set,
660	.timer_del = sgi_timer_del,
661	.timer_get = sgi_timer_get
662};
663
664/**
665 * mmtimer_init - device initialization routine
666 *
667 * Does initial setup for the mmtimer device.
668 */
669static int __init mmtimer_init(void)
670{
671	unsigned i;
672	cnodeid_t node, maxn = -1;
673
674	if (!ia64_platform_is("sn2"))
675		return 0;
676
677	/*
678	 * Sanity check the cycles/sec variable
679	 */
680	if (sn_rtc_cycles_per_second < 100000) {
681		printk(KERN_ERR "%s: unable to determine clock frequency\n",
682		       MMTIMER_NAME);
683		goto out1;
684	}
685
686	mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
687			       2) / sn_rtc_cycles_per_second;
688
689	if (request_irq(SGI_MMTIMER_VECTOR, mmtimer_interrupt, IRQF_PERCPU, MMTIMER_NAME, NULL)) {
690		printk(KERN_WARNING "%s: unable to allocate interrupt.",
691			MMTIMER_NAME);
692		goto out1;
693	}
694
695	if (misc_register(&mmtimer_miscdev)) {
696		printk(KERN_ERR "%s: failed to register device\n",
697		       MMTIMER_NAME);
698		goto out2;
699	}
700
701	/* Get max numbered node, calculate slots needed */
702	for_each_online_node(node) {
703		maxn = node;
704	}
705	maxn++;
706
707	/* Allocate list of node ptrs to mmtimer_t's */
708	timers = kzalloc(sizeof(mmtimer_t *)*maxn, GFP_KERNEL);
709	if (timers == NULL) {
710		printk(KERN_ERR "%s: failed to allocate memory for device\n",
711				MMTIMER_NAME);
712		goto out3;
713	}
714
715	/* Allocate mmtimer_t's for each online node */
716	for_each_online_node(node) {
717		timers[node] = kmalloc_node(sizeof(mmtimer_t)*NUM_COMPARATORS, GFP_KERNEL, node);
718		if (timers[node] == NULL) {
719			printk(KERN_ERR "%s: failed to allocate memory for device\n",
720				MMTIMER_NAME);
721			goto out4;
722		}
723		for (i=0; i< NUM_COMPARATORS; i++) {
724			mmtimer_t * base = timers[node] + i;
725
726			spin_lock_init(&base->lock);
727			base->timer = NULL;
728			base->cpu = 0;
729			base->i = i;
730			tasklet_init(&base->tasklet, mmtimer_tasklet,
731				(unsigned long) (base));
732		}
733	}
734
735	sgi_clock_period = sgi_clock.res = NSEC_PER_SEC / sn_rtc_cycles_per_second;
736	register_posix_clock(CLOCK_SGI_CYCLE, &sgi_clock);
737
738	printk(KERN_INFO "%s: v%s, %ld MHz\n", MMTIMER_DESC, MMTIMER_VERSION,
739	       sn_rtc_cycles_per_second/(unsigned long)1E6);
740
741	return 0;
742
743out4:
744	for_each_online_node(node) {
745		kfree(timers[node]);
746	}
747out3:
748	misc_deregister(&mmtimer_miscdev);
749out2:
750	free_irq(SGI_MMTIMER_VECTOR, NULL);
751out1:
752	return -1;
753}
754
755module_init(mmtimer_init);
756