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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>
Alexey Dobriyan4e950f62007-07-30 02:36:13 +040028#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/mmtimer.h>
30#include <linux/miscdevice.h>
31#include <linux/posix-timers.h>
32#include <linux/interrupt.h>
Roman Zippelf8bd2252008-05-01 04:34:31 -070033#include <linux/time.h>
34#include <linux/math64.h>
Alan Cox4cddb882008-05-22 21:42:44 +010035#include <linux/smp_lock.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090036#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38#include <asm/uaccess.h>
39#include <asm/sn/addrs.h>
40#include <asm/sn/intr.h>
41#include <asm/sn/shub_mmr.h>
42#include <asm/sn/nodepda.h>
43#include <asm/sn/shubio.h>
44
45MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
46MODULE_DESCRIPTION("SGI Altix RTC Timer");
47MODULE_LICENSE("GPL");
48
49/* name of the device, usually in /dev */
50#define MMTIMER_NAME "mmtimer"
51#define MMTIMER_DESC "SGI Altix RTC Timer"
Dimitri Sivanich76832c22006-01-06 11:33:41 -060052#define MMTIMER_VERSION "2.1"
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54#define RTC_BITS 55 /* 55 bits for this implementation */
55
56extern unsigned long sn_rtc_cycles_per_second;
57
58#define RTC_COUNTER_ADDR ((long *)LOCAL_MMR_ADDR(SH_RTC))
59
60#define rtc_time() (*RTC_COUNTER_ADDR)
61
Alan Cox4cddb882008-05-22 21:42:44 +010062static long mmtimer_ioctl(struct file *file, unsigned int cmd,
63 unsigned long arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
65
66/*
67 * Period in femtoseconds (10^-15 s)
68 */
69static unsigned long mmtimer_femtoperiod = 0;
70
Arjan van de Ven62322d22006-07-03 00:24:21 -070071static const struct file_operations mmtimer_fops = {
Alan Cox4cddb882008-05-22 21:42:44 +010072 .owner = THIS_MODULE,
73 .mmap = mmtimer_mmap,
74 .unlocked_ioctl = mmtimer_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -070075};
76
77/*
78 * We only have comparison registers RTC1-4 currently available per
79 * node. RTC0 is used by SAL.
80 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070081/* Check for an RTC interrupt pending */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -070082static int mmtimer_int_pending(int comparator)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
84 if (HUB_L((unsigned long *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED)) &
85 SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator)
86 return 1;
87 else
88 return 0;
89}
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -070090
Linus Torvalds1da177e2005-04-16 15:20:36 -070091/* Clear the RTC interrupt pending bit */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -070092static void mmtimer_clr_int_pending(int comparator)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093{
94 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS),
95 SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator);
96}
97
98/* Setup timer on comparator RTC1 */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -070099static void mmtimer_setup_int_0(int cpu, u64 expires)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100{
101 u64 val;
102
103 /* Disable interrupt */
104 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 0UL);
105
106 /* Initialize comparator value */
107 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), -1L);
108
109 /* Clear pending bit */
110 mmtimer_clr_int_pending(0);
111
112 val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC1_INT_CONFIG_IDX_SHFT) |
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700113 ((u64)cpu_physical_id(cpu) <<
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 SH_RTC1_INT_CONFIG_PID_SHFT);
115
116 /* Set configuration */
117 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_CONFIG), val);
118
119 /* Enable RTC interrupts */
120 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 1UL);
121
122 /* Initialize comparator value */
123 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), expires);
124
125
126}
127
128/* Setup timer on comparator RTC2 */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700129static void mmtimer_setup_int_1(int cpu, u64 expires)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130{
131 u64 val;
132
133 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 0UL);
134
135 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), -1L);
136
137 mmtimer_clr_int_pending(1);
138
139 val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC2_INT_CONFIG_IDX_SHFT) |
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700140 ((u64)cpu_physical_id(cpu) <<
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 SH_RTC2_INT_CONFIG_PID_SHFT);
142
143 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_CONFIG), val);
144
145 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 1UL);
146
147 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), expires);
148}
149
150/* Setup timer on comparator RTC3 */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700151static void mmtimer_setup_int_2(int cpu, u64 expires)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152{
153 u64 val;
154
155 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 0UL);
156
157 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), -1L);
158
159 mmtimer_clr_int_pending(2);
160
161 val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC3_INT_CONFIG_IDX_SHFT) |
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700162 ((u64)cpu_physical_id(cpu) <<
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 SH_RTC3_INT_CONFIG_PID_SHFT);
164
165 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_CONFIG), val);
166
167 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 1UL);
168
169 HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), expires);
170}
171
172/*
173 * This function must be called with interrupts disabled and preemption off
174 * in order to insure that the setup succeeds in a deterministic time frame.
175 * It will check if the interrupt setup succeeded.
176 */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700177static int mmtimer_setup(int cpu, int comparator, unsigned long expires)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178{
179
180 switch (comparator) {
181 case 0:
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700182 mmtimer_setup_int_0(cpu, expires);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 break;
184 case 1:
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700185 mmtimer_setup_int_1(cpu, expires);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 break;
187 case 2:
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700188 mmtimer_setup_int_2(cpu, expires);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 break;
190 }
191 /* We might've missed our expiration time */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700192 if (rtc_time() <= expires)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 return 1;
194
195 /*
196 * If an interrupt is already pending then its okay
197 * if not then we failed
198 */
199 return mmtimer_int_pending(comparator);
200}
201
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700202static int mmtimer_disable_int(long nasid, int comparator)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203{
204 switch (comparator) {
205 case 0:
206 nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE),
207 0UL) : REMOTE_HUB_S(nasid, SH_RTC1_INT_ENABLE, 0UL);
208 break;
209 case 1:
210 nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE),
211 0UL) : REMOTE_HUB_S(nasid, SH_RTC2_INT_ENABLE, 0UL);
212 break;
213 case 2:
214 nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE),
215 0UL) : REMOTE_HUB_S(nasid, SH_RTC3_INT_ENABLE, 0UL);
216 break;
217 default:
218 return -EFAULT;
219 }
220 return 0;
221}
222
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700223#define COMPARATOR 1 /* The comparator to use */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700225#define TIMER_OFF 0xbadcabLL /* Timer is not setup */
226#define TIMER_SET 0 /* Comparator is set for this timer */
227
228/* There is one of these for each timer */
229struct mmtimer {
230 struct rb_node list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 struct k_itimer *timer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 int cpu;
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700233};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700235struct mmtimer_node {
236 spinlock_t lock ____cacheline_aligned;
237 struct rb_root timer_head;
238 struct rb_node *next;
239 struct tasklet_struct tasklet;
240};
241static struct mmtimer_node *timers;
242
243
244/*
245 * Add a new mmtimer struct to the node's mmtimer list.
246 * This function assumes the struct mmtimer_node is locked.
247 */
248static void mmtimer_add_list(struct mmtimer *n)
249{
250 int nodeid = n->timer->it.mmtimer.node;
251 unsigned long expires = n->timer->it.mmtimer.expires;
252 struct rb_node **link = &timers[nodeid].timer_head.rb_node;
253 struct rb_node *parent = NULL;
254 struct mmtimer *x;
255
256 /*
257 * Find the right place in the rbtree:
258 */
259 while (*link) {
260 parent = *link;
261 x = rb_entry(parent, struct mmtimer, list);
262
263 if (expires < x->timer->it.mmtimer.expires)
264 link = &(*link)->rb_left;
265 else
266 link = &(*link)->rb_right;
267 }
268
269 /*
270 * Insert the timer to the rbtree and check whether it
271 * replaces the first pending timer
272 */
273 rb_link_node(&n->list, parent, link);
274 rb_insert_color(&n->list, &timers[nodeid].timer_head);
275
276 if (!timers[nodeid].next || expires < rb_entry(timers[nodeid].next,
277 struct mmtimer, list)->timer->it.mmtimer.expires)
278 timers[nodeid].next = &n->list;
279}
280
281/*
282 * Set the comparator for the next timer.
283 * This function assumes the struct mmtimer_node is locked.
284 */
285static void mmtimer_set_next_timer(int nodeid)
286{
287 struct mmtimer_node *n = &timers[nodeid];
288 struct mmtimer *x;
289 struct k_itimer *t;
290 int o;
291
292restart:
293 if (n->next == NULL)
294 return;
295
296 x = rb_entry(n->next, struct mmtimer, list);
297 t = x->timer;
298 if (!t->it.mmtimer.incr) {
299 /* Not an interval timer */
300 if (!mmtimer_setup(x->cpu, COMPARATOR,
301 t->it.mmtimer.expires)) {
302 /* Late setup, fire now */
303 tasklet_schedule(&n->tasklet);
304 }
305 return;
306 }
307
308 /* Interval timer */
309 o = 0;
310 while (!mmtimer_setup(x->cpu, COMPARATOR, t->it.mmtimer.expires)) {
311 unsigned long e, e1;
312 struct rb_node *next;
313 t->it.mmtimer.expires += t->it.mmtimer.incr << o;
314 t->it_overrun += 1 << o;
315 o++;
316 if (o > 20) {
317 printk(KERN_ALERT "mmtimer: cannot reschedule timer\n");
318 t->it.mmtimer.clock = TIMER_OFF;
319 n->next = rb_next(&x->list);
320 rb_erase(&x->list, &n->timer_head);
321 kfree(x);
322 goto restart;
323 }
324
325 e = t->it.mmtimer.expires;
326 next = rb_next(&x->list);
327
328 if (next == NULL)
329 continue;
330
331 e1 = rb_entry(next, struct mmtimer, list)->
332 timer->it.mmtimer.expires;
333 if (e > e1) {
334 n->next = next;
335 rb_erase(&x->list, &n->timer_head);
336 mmtimer_add_list(x);
337 goto restart;
338 }
339 }
340}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
342/**
343 * mmtimer_ioctl - ioctl interface for /dev/mmtimer
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 * @file: file structure for the device
345 * @cmd: command to execute
346 * @arg: optional argument to command
347 *
348 * Executes the command specified by @cmd. Returns 0 for success, < 0 for
349 * failure.
350 *
351 * Valid commands:
352 *
353 * %MMTIMER_GETOFFSET - Should return the offset (relative to the start
354 * of the page where the registers are mapped) for the counter in question.
355 *
356 * %MMTIMER_GETRES - Returns the resolution of the clock in femto (10^-15)
357 * seconds
358 *
359 * %MMTIMER_GETFREQ - Copies the frequency of the clock in Hz to the address
360 * specified by @arg
361 *
362 * %MMTIMER_GETBITS - Returns the number of bits in the clock's counter
363 *
364 * %MMTIMER_MMAPAVAIL - Returns 1 if the registers can be mmap'd into userspace
365 *
366 * %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it
367 * in the address specified by @arg.
368 */
Alan Cox4cddb882008-05-22 21:42:44 +0100369static long mmtimer_ioctl(struct file *file, unsigned int cmd,
370 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371{
372 int ret = 0;
373
Alan Cox4cddb882008-05-22 21:42:44 +0100374 lock_kernel();
375
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 switch (cmd) {
377 case MMTIMER_GETOFFSET: /* offset of the counter */
378 /*
379 * SN RTC registers are on their own 64k page
380 */
381 if(PAGE_SIZE <= (1 << 16))
382 ret = (((long)RTC_COUNTER_ADDR) & (PAGE_SIZE-1)) / 8;
383 else
384 ret = -ENOSYS;
385 break;
386
387 case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */
388 if(copy_to_user((unsigned long __user *)arg,
389 &mmtimer_femtoperiod, sizeof(unsigned long)))
Alan Cox4cddb882008-05-22 21:42:44 +0100390 ret = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 break;
392
393 case MMTIMER_GETFREQ: /* frequency in Hz */
394 if(copy_to_user((unsigned long __user *)arg,
395 &sn_rtc_cycles_per_second,
396 sizeof(unsigned long)))
Alan Cox4cddb882008-05-22 21:42:44 +0100397 ret = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 break;
399
400 case MMTIMER_GETBITS: /* number of bits in the clock */
401 ret = RTC_BITS;
402 break;
403
404 case MMTIMER_MMAPAVAIL: /* can we mmap the clock into userspace? */
405 ret = (PAGE_SIZE <= (1 << 16)) ? 1 : 0;
406 break;
407
408 case MMTIMER_GETCOUNTER:
409 if(copy_to_user((unsigned long __user *)arg,
410 RTC_COUNTER_ADDR, sizeof(unsigned long)))
Alan Cox4cddb882008-05-22 21:42:44 +0100411 ret = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 break;
413 default:
Alan Cox4cddb882008-05-22 21:42:44 +0100414 ret = -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 break;
416 }
Alan Cox4cddb882008-05-22 21:42:44 +0100417 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 return ret;
419}
420
421/**
422 * mmtimer_mmap - maps the clock's registers into userspace
423 * @file: file structure for the device
424 * @vma: VMA to map the registers into
425 *
426 * Calls remap_pfn_range() to map the clock's registers into
427 * the calling process' address space.
428 */
429static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
430{
431 unsigned long mmtimer_addr;
432
433 if (vma->vm_end - vma->vm_start != PAGE_SIZE)
434 return -EINVAL;
435
436 if (vma->vm_flags & VM_WRITE)
437 return -EPERM;
438
439 if (PAGE_SIZE > (1 << 16))
440 return -ENOSYS;
441
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
443
444 mmtimer_addr = __pa(RTC_COUNTER_ADDR);
445 mmtimer_addr &= ~(PAGE_SIZE - 1);
446 mmtimer_addr &= 0xfffffffffffffffUL;
447
448 if (remap_pfn_range(vma, vma->vm_start, mmtimer_addr >> PAGE_SHIFT,
449 PAGE_SIZE, vma->vm_page_prot)) {
450 printk(KERN_ERR "remap_pfn_range failed in mmtimer.c\n");
451 return -EAGAIN;
452 }
453
454 return 0;
455}
456
457static struct miscdevice mmtimer_miscdev = {
458 SGI_MMTIMER,
459 MMTIMER_NAME,
460 &mmtimer_fops
461};
462
463static struct timespec sgi_clock_offset;
464static int sgi_clock_period;
465
466/*
467 * Posix Timer Interface
468 */
469
470static struct timespec sgi_clock_offset;
471static int sgi_clock_period;
472
473static int sgi_clock_get(clockid_t clockid, struct timespec *tp)
474{
475 u64 nsec;
476
477 nsec = rtc_time() * sgi_clock_period
478 + sgi_clock_offset.tv_nsec;
Roman Zippelf8bd2252008-05-01 04:34:31 -0700479 *tp = ns_to_timespec(nsec);
480 tp->tv_sec += sgi_clock_offset.tv_sec;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 return 0;
482};
483
484static int sgi_clock_set(clockid_t clockid, struct timespec *tp)
485{
486
487 u64 nsec;
Roman Zippelf8bd2252008-05-01 04:34:31 -0700488 u32 rem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
490 nsec = rtc_time() * sgi_clock_period;
491
Roman Zippelf8bd2252008-05-01 04:34:31 -0700492 sgi_clock_offset.tv_sec = tp->tv_sec - div_u64_rem(nsec, NSEC_PER_SEC, &rem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
494 if (rem <= tp->tv_nsec)
495 sgi_clock_offset.tv_nsec = tp->tv_sec - rem;
496 else {
497 sgi_clock_offset.tv_nsec = tp->tv_sec + NSEC_PER_SEC - rem;
498 sgi_clock_offset.tv_sec--;
499 }
500 return 0;
501}
502
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503/**
504 * mmtimer_interrupt - timer interrupt handler
505 * @irq: irq received
506 * @dev_id: device the irq came from
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 *
508 * Called when one of the comarators matches the counter, This
509 * routine will send signals to processes that have requested
510 * them.
511 *
512 * This interrupt is run in an interrupt context
513 * by the SHUB. It is therefore safe to locally access SHub
514 * registers.
515 */
516static irqreturn_t
David Howells7d12e782006-10-05 14:55:46 +0100517mmtimer_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 unsigned long expires = 0;
520 int result = IRQ_NONE;
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600521 unsigned indx = cpu_to_node(smp_processor_id());
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700522 struct mmtimer *base;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700524 spin_lock(&timers[indx].lock);
525 base = rb_entry(timers[indx].next, struct mmtimer, list);
526 if (base == NULL) {
527 spin_unlock(&timers[indx].lock);
528 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 }
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700530
531 if (base->cpu == smp_processor_id()) {
532 if (base->timer)
533 expires = base->timer->it.mmtimer.expires;
534 /* expires test won't work with shared irqs */
535 if ((mmtimer_int_pending(COMPARATOR) > 0) ||
536 (expires && (expires <= rtc_time()))) {
537 mmtimer_clr_int_pending(COMPARATOR);
538 tasklet_schedule(&timers[indx].tasklet);
539 result = IRQ_HANDLED;
540 }
541 }
542 spin_unlock(&timers[indx].lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 return result;
544}
545
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700546static void mmtimer_tasklet(unsigned long data)
547{
548 int nodeid = data;
549 struct mmtimer_node *mn = &timers[nodeid];
Julia Lawall0fbcae22010-03-10 15:23:52 -0800550 struct mmtimer *x;
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700551 struct k_itimer *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 unsigned long flags;
553
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 /* Send signal and deal with periodic signals */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700555 spin_lock_irqsave(&mn->lock, flags);
556 if (!mn->next)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 goto out;
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700558
559 x = rb_entry(mn->next, struct mmtimer, list);
560 t = x->timer;
561
562 if (t->it.mmtimer.clock == TIMER_OFF)
563 goto out;
564
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 t->it_overrun = 0;
566
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700567 mn->next = rb_next(&x->list);
568 rb_erase(&x->list, &mn->timer_head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700570 if (posix_timer_event(t, 0) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 t->it_overrun++;
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700572
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 if(t->it.mmtimer.incr) {
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700574 t->it.mmtimer.expires += t->it.mmtimer.incr;
575 mmtimer_add_list(x);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 } else {
577 /* Ensure we don't false trigger in mmtimer_interrupt */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700578 t->it.mmtimer.clock = TIMER_OFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 t->it.mmtimer.expires = 0;
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700580 kfree(x);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 }
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700582 /* Set comparator for next timer, if there is one */
583 mmtimer_set_next_timer(nodeid);
584
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 t->it_overrun_last = t->it_overrun;
586out:
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700587 spin_unlock_irqrestore(&mn->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588}
589
590static int sgi_timer_create(struct k_itimer *timer)
591{
592 /* Insure that a newly created timer is off */
593 timer->it.mmtimer.clock = TIMER_OFF;
594 return 0;
595}
596
597/* This does not really delete a timer. It just insures
598 * that the timer is not active
599 *
600 * Assumption: it_lock is already held with irq's disabled
601 */
602static int sgi_timer_del(struct k_itimer *timr)
603{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 cnodeid_t nodeid = timr->it.mmtimer.node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 unsigned long irqflags;
606
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700607 spin_lock_irqsave(&timers[nodeid].lock, irqflags);
608 if (timr->it.mmtimer.clock != TIMER_OFF) {
609 unsigned long expires = timr->it.mmtimer.expires;
610 struct rb_node *n = timers[nodeid].timer_head.rb_node;
611 struct mmtimer *uninitialized_var(t);
612 int r = 0;
613
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 timr->it.mmtimer.clock = TIMER_OFF;
615 timr->it.mmtimer.expires = 0;
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700616
617 while (n) {
618 t = rb_entry(n, struct mmtimer, list);
619 if (t->timer == timr)
620 break;
621
622 if (expires < t->timer->it.mmtimer.expires)
623 n = n->rb_left;
624 else
625 n = n->rb_right;
626 }
627
628 if (!n) {
629 spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
630 return 0;
631 }
632
633 if (timers[nodeid].next == n) {
634 timers[nodeid].next = rb_next(n);
635 r = 1;
636 }
637
638 rb_erase(n, &timers[nodeid].timer_head);
639 kfree(t);
640
641 if (r) {
642 mmtimer_disable_int(cnodeid_to_nasid(nodeid),
643 COMPARATOR);
644 mmtimer_set_next_timer(nodeid);
645 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 }
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700647 spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 return 0;
649}
650
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651/* Assumption: it_lock is already held with irq's disabled */
652static void sgi_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
653{
654
655 if (timr->it.mmtimer.clock == TIMER_OFF) {
656 cur_setting->it_interval.tv_nsec = 0;
657 cur_setting->it_interval.tv_sec = 0;
658 cur_setting->it_value.tv_nsec = 0;
659 cur_setting->it_value.tv_sec =0;
660 return;
661 }
662
Roman Zippelf8bd2252008-05-01 04:34:31 -0700663 cur_setting->it_interval = ns_to_timespec(timr->it.mmtimer.incr * sgi_clock_period);
664 cur_setting->it_value = ns_to_timespec((timr->it.mmtimer.expires - rtc_time()) * sgi_clock_period);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665}
666
667
668static int sgi_timer_set(struct k_itimer *timr, int flags,
669 struct itimerspec * new_setting,
670 struct itimerspec * old_setting)
671{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 unsigned long when, period, irqflags;
673 int err = 0;
674 cnodeid_t nodeid;
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700675 struct mmtimer *base;
676 struct rb_node *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
678 if (old_setting)
679 sgi_timer_get(timr, old_setting);
680
681 sgi_timer_del(timr);
Roman Zippelf8bd2252008-05-01 04:34:31 -0700682 when = timespec_to_ns(&new_setting->it_value);
683 period = timespec_to_ns(&new_setting->it_interval);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
685 if (when == 0)
686 /* Clear timer */
687 return 0;
688
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700689 base = kmalloc(sizeof(struct mmtimer), GFP_KERNEL);
690 if (base == NULL)
691 return -ENOMEM;
692
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 if (flags & TIMER_ABSTIME) {
694 struct timespec n;
695 unsigned long now;
696
697 getnstimeofday(&n);
Roman Zippelf8bd2252008-05-01 04:34:31 -0700698 now = timespec_to_ns(&n);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 if (when > now)
700 when -= now;
701 else
702 /* Fire the timer immediately */
703 when = 0;
704 }
705
706 /*
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
709 * specified.
710 */
711 when = (when + sgi_clock_period - 1) / sgi_clock_period + rtc_time();
712 period = (period + sgi_clock_period - 1) / sgi_clock_period;
713
714 /*
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
717 * preemption.
718 */
719 preempt_disable();
720
Tony Luck55642d32005-09-15 17:00:10 -0700721 nodeid = cpu_to_node(smp_processor_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700723 /* Lock the node timer structure */
724 spin_lock_irqsave(&timers[nodeid].lock, irqflags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600726 base->timer = timr;
727 base->cpu = smp_processor_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700729 timr->it.mmtimer.clock = TIMER_SET;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 timr->it.mmtimer.node = nodeid;
731 timr->it.mmtimer.incr = period;
732 timr->it.mmtimer.expires = when;
733
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700734 n = timers[nodeid].next;
735
736 /* Add the new struct mmtimer to node's timer list */
737 mmtimer_add_list(base);
738
739 if (timers[nodeid].next == n) {
740 /* No need to reprogram comparator for now */
741 spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
742 preempt_enable();
743 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 }
745
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700746 /* We need to reprogram the comparator */
747 if (n)
748 mmtimer_disable_int(cnodeid_to_nasid(nodeid), COMPARATOR);
749
750 mmtimer_set_next_timer(nodeid);
751
752 /* Unlock the node timer structure */
753 spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754
755 preempt_enable();
756
757 return err;
758}
759
760static struct k_clock sgi_clock = {
761 .res = 0,
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
769};
770
771/**
772 * mmtimer_init - device initialization routine
773 *
774 * Does initial setup for the mmtimer device.
775 */
776static int __init mmtimer_init(void)
777{
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600778 cnodeid_t node, maxn = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
780 if (!ia64_platform_is("sn2"))
Bjorn Helgaasf032f902006-03-03 15:34:34 -0700781 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782
783 /*
784 * Sanity check the cycles/sec variable
785 */
786 if (sn_rtc_cycles_per_second < 100000) {
787 printk(KERN_ERR "%s: unable to determine clock frequency\n",
788 MMTIMER_NAME);
Neil Horman5d469ec2006-12-06 20:37:08 -0800789 goto out1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 }
791
792 mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
793 2) / sn_rtc_cycles_per_second;
794
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700795 if (request_irq(SGI_MMTIMER_VECTOR, mmtimer_interrupt, IRQF_PERCPU, MMTIMER_NAME, NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 printk(KERN_WARNING "%s: unable to allocate interrupt.",
797 MMTIMER_NAME);
Neil Horman5d469ec2006-12-06 20:37:08 -0800798 goto out1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 }
800
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 if (misc_register(&mmtimer_miscdev)) {
802 printk(KERN_ERR "%s: failed to register device\n",
803 MMTIMER_NAME);
Neil Horman5d469ec2006-12-06 20:37:08 -0800804 goto out2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 }
806
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600807 /* Get max numbered node, calculate slots needed */
808 for_each_online_node(node) {
809 maxn = node;
810 }
811 maxn++;
812
813 /* Allocate list of node ptrs to mmtimer_t's */
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700814 timers = kzalloc(sizeof(struct mmtimer_node)*maxn, GFP_KERNEL);
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600815 if (timers == NULL) {
816 printk(KERN_ERR "%s: failed to allocate memory for device\n",
817 MMTIMER_NAME);
Neil Horman5d469ec2006-12-06 20:37:08 -0800818 goto out3;
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600819 }
820
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700821 /* Initialize struct mmtimer's for each online node */
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600822 for_each_online_node(node) {
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700823 spin_lock_init(&timers[node].lock);
824 tasklet_init(&timers[node].tasklet, mmtimer_tasklet,
825 (unsigned long) node);
Dimitri Sivanich76832c22006-01-06 11:33:41 -0600826 }
827
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 sgi_clock_period = sgi_clock.res = NSEC_PER_SEC / sn_rtc_cycles_per_second;
829 register_posix_clock(CLOCK_SGI_CYCLE, &sgi_clock);
830
831 printk(KERN_INFO "%s: v%s, %ld MHz\n", MMTIMER_DESC, MMTIMER_VERSION,
832 sn_rtc_cycles_per_second/(unsigned long)1E6);
833
834 return 0;
Neil Horman5d469ec2006-12-06 20:37:08 -0800835
Neil Horman5d469ec2006-12-06 20:37:08 -0800836out3:
Dimitri Sivanichcbacdd92008-04-30 00:53:35 -0700837 kfree(timers);
Neil Horman5d469ec2006-12-06 20:37:08 -0800838 misc_deregister(&mmtimer_miscdev);
839out2:
840 free_irq(SGI_MMTIMER_VECTOR, NULL);
841out1:
842 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843}
844
845module_init(mmtimer_init);