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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Dimitri Sivanich76832c22006-01-06 11:33:41 -06002 * Timer device implementation for SGI SN platforms.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
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 *
Dimitri Sivanich76832c22006-01-06 11:33:41 -06008 * Copyright (c) 2001-2006 Silicon Graphics, Inc. All rights reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 *
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#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"
Dimitri Sivanich76832c22006-01-06 11:33:41 -060047#define MMTIMER_VERSION "2.1"
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
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
Arjan van de Ven62322d22006-07-03 00:24:21 -070066static const struct file_operations mmtimer_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 .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
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600229static mmtimer_t ** timers;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 *
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
David Howells7d12e782006-10-05 14:55:46 +0100435mmtimer_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436{
437 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 unsigned long expires = 0;
439 int result = IRQ_NONE;
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600440 unsigned indx = cpu_to_node(smp_processor_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441
442 /*
443 * Do this once for each comparison register
444 */
445 for (i = 0; i < NUM_COMPARATORS; i++) {
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600446 mmtimer_t *base = timers[indx] + i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 /* Make sure this doesn't get reused before tasklet_sched */
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600448 spin_lock(&base->lock);
449 if (base->cpu == smp_processor_id()) {
450 if (base->timer)
451 expires = base->timer->it.mmtimer.expires;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 /* 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);
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600456 tasklet_schedule(&base->tasklet);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 result = IRQ_HANDLED;
458 }
459 }
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600460 spin_unlock(&base->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 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
Christoph Lameter8d38ead2005-04-16 15:23:53 -0700482 if (posix_timer_event(t, 0) != 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
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;
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600520 mmtimer_t *t = timers[nodeid] + i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 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
Tony Luck55642d32005-09-15 17:00:10 -0700605 nodeid = cpu_to_node(smp_processor_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606retry:
607 /* Don't use an allocated timer, or a deleted one that's pending */
608 for(i = 0; i< NUM_COMPARATORS; i++) {
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600609 base = timers[nodeid] + i;
610 if (!base->timer && !base->tasklet.state) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 break;
612 }
613 }
614
615 if (i == NUM_COMPARATORS) {
616 preempt_enable();
617 return -EBUSY;
618 }
619
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600620 spin_lock_irqsave(&base->lock, irqflags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600622 if (base->timer || base->tasklet.state != 0) {
623 spin_unlock_irqrestore(&base->lock, irqflags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 goto retry;
625 }
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600626 base->timer = timr;
627 base->cpu = smp_processor_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
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;
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600642 if (reschedule_periodic_timer(base))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 err = -EINVAL;
644 }
645
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600646 spin_unlock_irqrestore(&base->lock, irqflags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
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;
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600672 cnodeid_t node, maxn = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673
674 if (!ia64_platform_is("sn2"))
Bjorn Helgaasf032f902006-03-03 15:34:34 -0700675 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
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);
Neil Horman5d469ec2006-12-06 20:37:08 -0800683 goto out1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 }
685
686 mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
687 2) / sn_rtc_cycles_per_second;
688
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700689 if (request_irq(SGI_MMTIMER_VECTOR, mmtimer_interrupt, IRQF_PERCPU, MMTIMER_NAME, NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 printk(KERN_WARNING "%s: unable to allocate interrupt.",
691 MMTIMER_NAME);
Neil Horman5d469ec2006-12-06 20:37:08 -0800692 goto out1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 }
694
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 if (misc_register(&mmtimer_miscdev)) {
696 printk(KERN_ERR "%s: failed to register device\n",
697 MMTIMER_NAME);
Neil Horman5d469ec2006-12-06 20:37:08 -0800698 goto out2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 }
700
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600701 /* 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 */
vignesh babu1cfb9c92007-05-08 11:53:27 -0700708 timers = kzalloc(sizeof(mmtimer_t *)*maxn, GFP_KERNEL);
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600709 if (timers == NULL) {
710 printk(KERN_ERR "%s: failed to allocate memory for device\n",
711 MMTIMER_NAME);
Neil Horman5d469ec2006-12-06 20:37:08 -0800712 goto out3;
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600713 }
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);
Neil Horman5d469ec2006-12-06 20:37:08 -0800721 goto out4;
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600722 }
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 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;
Neil Horman5d469ec2006-12-06 20:37:08 -0800742
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753}
754
755module_init(mmtimer_init);
756