summaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/cpwd.c
blob: 51ae4e84f4f9efe9bedcdd30a9a090f43b60e35b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
/* cpwd.c - driver implementation for hardware watchdog
 * timers found on Sun Microsystems CP1400 and CP1500 boards.
 *
 * This device supports both the generic Linux watchdog
 * interface and Solaris-compatible ioctls as best it is
 * able.
 *
 * NOTE: 	CP1400 systems appear to have a defective intr_mask
 * 			register on the PLD, preventing the disabling of
 * 			timer interrupts.  We use a timer to periodically
 * 			reset 'stopped' watchdogs on affected platforms.
 *
 * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/major.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/uaccess.h>

#include <asm/irq.h>
#include <asm/watchdog.h>

#define DRIVER_NAME	"cpwd"
#define PFX		DRIVER_NAME ": "

#define WD_OBPNAME	"watchdog"
#define WD_BADMODEL	"SUNW,501-5336"
#define WD_BTIMEOUT	(jiffies + (HZ * 1000))
#define WD_BLIMIT	0xFFFF

#define WD0_MINOR	212
#define WD1_MINOR	213
#define WD2_MINOR	214

/* Internal driver definitions.  */
#define WD0_ID			0
#define WD1_ID			1
#define WD2_ID			2
#define WD_NUMDEVS		3

#define WD_INTR_OFF		0
#define WD_INTR_ON		1

#define WD_STAT_INIT	0x01	/* Watchdog timer is initialized	*/
#define WD_STAT_BSTOP	0x02	/* Watchdog timer is brokenstopped	*/
#define WD_STAT_SVCD	0x04	/* Watchdog interrupt occurred		*/

/* Register value definitions
 */
#define WD0_INTR_MASK	0x01	/* Watchdog device interrupt masks	*/
#define WD1_INTR_MASK	0x02
#define WD2_INTR_MASK	0x04

#define WD_S_RUNNING	0x01	/* Watchdog device status running	*/
#define WD_S_EXPIRED	0x02	/* Watchdog device status expired	*/

struct cpwd {
	void __iomem	*regs;
	spinlock_t	lock;

	unsigned int	irq;

	unsigned long	timeout;
	bool		enabled;
	bool		reboot;
	bool		broken;
	bool		initialized;

	struct {
		struct miscdevice	misc;
		void __iomem		*regs;
		u8			intr_mask;
		u8			runstatus;
		u16			timeout;
	} devs[WD_NUMDEVS];
};

static struct cpwd *cpwd_device;

/* Sun uses Altera PLD EPF8820ATC144-4
 * providing three hardware watchdogs:
 *
 * 1) RIC - sends an interrupt when triggered
 * 2) XIR - asserts XIR_B_RESET when triggered, resets CPU
 * 3) POR - asserts POR_B_RESET when triggered, resets CPU, backplane, board
 *
 *** Timer register block definition (struct wd_timer_regblk)
 *
 * dcntr and limit registers (halfword access):
 * -------------------
 * | 15 | ...| 1 | 0 |
 * -------------------
 * |-  counter val  -|
 * -------------------
 * dcntr - 	Current 16-bit downcounter value.
 * 			When downcounter reaches '0' watchdog expires.
 * 			Reading this register resets downcounter with
 * 			'limit' value.
 * limit - 	16-bit countdown value in 1/10th second increments.
 * 			Writing this register begins countdown with input value.
 * 			Reading from this register does not affect counter.
 * NOTES:	After watchdog reset, dcntr and limit contain '1'
 *
 * status register (byte access):
 * ---------------------------
 * | 7 | ... | 2 |  1  |  0  |
 * --------------+------------
 * |-   UNUSED  -| EXP | RUN |
 * ---------------------------
 * status-	Bit 0 - Watchdog is running
 * 			Bit 1 - Watchdog has expired
 *
 *** PLD register block definition (struct wd_pld_regblk)
 *
 * intr_mask register (byte access):
 * ---------------------------------
 * | 7 | ... | 3 |  2  |  1  |  0  |
 * +-------------+------------------
 * |-   UNUSED  -| WD3 | WD2 | WD1 |
 * ---------------------------------
 * WD3 -  1 == Interrupt disabled for watchdog 3
 * WD2 -  1 == Interrupt disabled for watchdog 2
 * WD1 -  1 == Interrupt disabled for watchdog 1
 *
 * pld_status register (byte access):
 * UNKNOWN, MAGICAL MYSTERY REGISTER
 *
 */
#define WD_TIMER_REGSZ	16
#define WD0_OFF		0
#define WD1_OFF		(WD_TIMER_REGSZ * 1)
#define WD2_OFF		(WD_TIMER_REGSZ * 2)
#define PLD_OFF		(WD_TIMER_REGSZ * 3)

#define WD_DCNTR	0x00
#define WD_LIMIT	0x04
#define WD_STATUS	0x08

#define PLD_IMASK	(PLD_OFF + 0x00)
#define PLD_STATUS	(PLD_OFF + 0x04)

static struct timer_list cpwd_timer;

static int wd0_timeout;
static int wd1_timeout;
static int wd2_timeout;

module_param(wd0_timeout, int, 0);
MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs");
module_param(wd1_timeout, int, 0);
MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs");
module_param(wd2_timeout, int, 0);
MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs");

MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
MODULE_DESCRIPTION("Hardware watchdog driver for Sun Microsystems CP1400/1500");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("watchdog");

static void cpwd_writew(u16 val, void __iomem *addr)
{
	writew(cpu_to_le16(val), addr);
}
static u16 cpwd_readw(void __iomem *addr)
{
	u16 val = readw(addr);

	return le16_to_cpu(val);
}

static void cpwd_writeb(u8 val, void __iomem *addr)
{
	writeb(val, addr);
}

static u8 cpwd_readb(void __iomem *addr)
{
	return readb(addr);
}

/* Enable or disable watchdog interrupts
 * Because of the CP1400 defect this should only be
 * called during initialzation or by wd_[start|stop]timer()
 *
 * index 	- sub-device index, or -1 for 'all'
 * enable	- non-zero to enable interrupts, zero to disable
 */
static void cpwd_toggleintr(struct cpwd *p, int index, int enable)
{
	unsigned char curregs = cpwd_readb(p->regs + PLD_IMASK);
	unsigned char setregs =
		(index == -1) ?
		(WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) :
		(p->devs[index].intr_mask);

	if (enable == WD_INTR_ON)
		curregs &= ~setregs;
	else
		curregs |= setregs;

	cpwd_writeb(curregs, p->regs + PLD_IMASK);
}

/* Restarts timer with maximum limit value and
 * does not unset 'brokenstop' value.
 */
static void cpwd_resetbrokentimer(struct cpwd *p, int index)
{
	cpwd_toggleintr(p, index, WD_INTR_ON);
	cpwd_writew(WD_BLIMIT, p->devs[index].regs + WD_LIMIT);
}

/* Timer method called to reset stopped watchdogs--
 * because of the PLD bug on CP1400, we cannot mask
 * interrupts within the PLD so me must continually
 * reset the timers ad infinitum.
 */
static void cpwd_brokentimer(unsigned long data)
{
	struct cpwd *p = (struct cpwd *) data;
	int id, tripped = 0;

	/* kill a running timer instance, in case we
	 * were called directly instead of by kernel timer
	 */
	if (timer_pending(&cpwd_timer))
		del_timer(&cpwd_timer);

	for (id = 0; id < WD_NUMDEVS; id++) {
		if (p->devs[id].runstatus & WD_STAT_BSTOP) {
			++tripped;
			cpwd_resetbrokentimer(p, id);
		}
	}

	if (tripped) {
		/* there is at least one timer brokenstopped-- reschedule */
		cpwd_timer.expires = WD_BTIMEOUT;
		add_timer(&cpwd_timer);
	}
}

/* Reset countdown timer with 'limit' value and continue countdown.
 * This will not start a stopped timer.
 */
static void cpwd_pingtimer(struct cpwd *p, int index)
{
	if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING)
		cpwd_readw(p->devs[index].regs + WD_DCNTR);
}

/* Stop a running watchdog timer-- the timer actually keeps
 * running, but the interrupt is masked so that no action is
 * taken upon expiration.
 */
static void cpwd_stoptimer(struct cpwd *p, int index)
{
	if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING) {
		cpwd_toggleintr(p, index, WD_INTR_OFF);

		if (p->broken) {
			p->devs[index].runstatus |= WD_STAT_BSTOP;
			cpwd_brokentimer((unsigned long) p);
		}
	}
}

/* Start a watchdog timer with the specified limit value
 * If the watchdog is running, it will be restarted with
 * the provided limit value.
 *
 * This function will enable interrupts on the specified
 * watchdog.
 */
static void cpwd_starttimer(struct cpwd *p, int index)
{
	if (p->broken)
		p->devs[index].runstatus &= ~WD_STAT_BSTOP;

	p->devs[index].runstatus &= ~WD_STAT_SVCD;

	cpwd_writew(p->devs[index].timeout, p->devs[index].regs + WD_LIMIT);
	cpwd_toggleintr(p, index, WD_INTR_ON);
}

static int cpwd_getstatus(struct cpwd *p, int index)
{
	unsigned char stat = cpwd_readb(p->devs[index].regs + WD_STATUS);
	unsigned char intr = cpwd_readb(p->devs[index].regs + PLD_IMASK);
	unsigned char ret  = WD_STOPPED;

	/* determine STOPPED */
	if (!stat)
		return ret;

	/* determine EXPIRED vs FREERUN vs RUNNING */
	else if (WD_S_EXPIRED & stat) {
		ret = WD_EXPIRED;
	} else if (WD_S_RUNNING & stat) {
		if (intr & p->devs[index].intr_mask) {
			ret = WD_FREERUN;
		} else {
			/* Fudge WD_EXPIRED status for defective CP1400--
			 * IF timer is running
			 * 	AND brokenstop is set
			 * 	AND an interrupt has been serviced
			 * we are WD_EXPIRED.
			 *
			 * IF timer is running
			 * 	AND brokenstop is set
			 * 	AND no interrupt has been serviced
			 * we are WD_FREERUN.
			 */
			if (p->broken &&
			    (p->devs[index].runstatus & WD_STAT_BSTOP)) {
				if (p->devs[index].runstatus & WD_STAT_SVCD) {
					ret = WD_EXPIRED;
				} else {
					/* we could as well pretend
					 * we are expired */
					ret = WD_FREERUN;
				}
			} else {
				ret = WD_RUNNING;
			}
		}
	}

	/* determine SERVICED */
	if (p->devs[index].runstatus & WD_STAT_SVCD)
		ret |= WD_SERVICED;

	return ret;
}

static irqreturn_t cpwd_interrupt(int irq, void *dev_id)
{
	struct cpwd *p = dev_id;

	/* Only WD0 will interrupt-- others are NMI and we won't
	 * see them here....
	 */
	spin_lock_irq(&p->lock);

	cpwd_stoptimer(p, WD0_ID);
	p->devs[WD0_ID].runstatus |=  WD_STAT_SVCD;

	spin_unlock_irq(&p->lock);

	return IRQ_HANDLED;
}

static int cpwd_open(struct inode *inode, struct file *f)
{
	struct cpwd *p = cpwd_device;

	lock_kernel();
	switch (iminor(inode)) {
	case WD0_MINOR:
	case WD1_MINOR:
	case WD2_MINOR:
		break;

	default:
		unlock_kernel();
		return -ENODEV;
	}

	/* Register IRQ on first open of device */
	if (!p->initialized) {
		if (request_irq(p->irq, &cpwd_interrupt,
				IRQF_SHARED, DRIVER_NAME, p)) {
			printk(KERN_ERR PFX "Cannot register IRQ %d\n",
				p->irq);
			unlock_kernel();
			return -EBUSY;
		}
		p->initialized = true;
	}

	unlock_kernel();

	return nonseekable_open(inode, f);
}

static int cpwd_release(struct inode *inode, struct file *file)
{
	return 0;
}

static long cpwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	static const struct watchdog_info info = {
		.options		= WDIOF_SETTIMEOUT,
		.firmware_version	= 1,
		.identity		= DRIVER_NAME,
	};
	void __user *argp = (void __user *)arg;
	struct inode *inode = file->f_path.dentry->d_inode;
	int index = iminor(inode) - WD0_MINOR;
	struct cpwd *p = cpwd_device;
	int setopt = 0;

	switch (cmd) {
	/* Generic Linux IOCTLs */
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &info, sizeof(struct watchdog_info)))
			return -EFAULT;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		if (put_user(0, (int __user *)argp))
			return -EFAULT;
		break;

	case WDIOC_KEEPALIVE:
		cpwd_pingtimer(p, index);
		break;

	case WDIOC_SETOPTIONS:
		if (copy_from_user(&setopt, argp, sizeof(unsigned int)))
			return -EFAULT;

		if (setopt & WDIOS_DISABLECARD) {
			if (p->enabled)
				return -EINVAL;
			cpwd_stoptimer(p, index);
		} else if (setopt & WDIOS_ENABLECARD) {
			cpwd_starttimer(p, index);
		} else {
			return -EINVAL;
		}
		break;

	/* Solaris-compatible IOCTLs */
	case WIOCGSTAT:
		setopt = cpwd_getstatus(p, index);
		if (copy_to_user(argp, &setopt, sizeof(unsigned int)))
			return -EFAULT;
		break;

	case WIOCSTART:
		cpwd_starttimer(p, index);
		break;

	case WIOCSTOP:
		if (p->enabled)
			return -EINVAL;

		cpwd_stoptimer(p, index);
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static long cpwd_compat_ioctl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
	int rval = -ENOIOCTLCMD;

	switch (cmd) {
	/* solaris ioctls are specific to this driver */
	case WIOCSTART:
	case WIOCSTOP:
	case WIOCGSTAT:
		lock_kernel();
		rval = cpwd_ioctl(file, cmd, arg);
		unlock_kernel();
		break;

	/* everything else is handled by the generic compat layer */
	default:
		break;
	}

	return rval;
}

static ssize_t cpwd_write(struct file *file, const char __user *buf,
			  size_t count, loff_t *ppos)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct cpwd *p = cpwd_device;
	int index = iminor(inode);

	if (count) {
		cpwd_pingtimer(p, index);
		return 1;
	}

	return 0;
}

static ssize_t cpwd_read(struct file *file, char __user *buffer,
			 size_t count, loff_t *ppos)
{
	return -EINVAL;
}

static const struct file_operations cpwd_fops = {
	.owner =		THIS_MODULE,
	.unlocked_ioctl =	cpwd_ioctl,
	.compat_ioctl =		cpwd_compat_ioctl,
	.open =			cpwd_open,
	.write =		cpwd_write,
	.read =			cpwd_read,
	.release =		cpwd_release,
	.llseek =		no_llseek,
};

static int __devinit cpwd_probe(struct platform_device *op,
				const struct of_device_id *match)
{
	struct device_node *options;
	const char *str_prop;
	const void *prop_val;
	int i, err = -EINVAL;
	struct cpwd *p;

	if (cpwd_device)
		return -EINVAL;

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	err = -ENOMEM;
	if (!p) {
		printk(KERN_ERR PFX "Unable to allocate struct cpwd.\n");
		goto out;
	}

	p->irq = op->archdata.irqs[0];

	spin_lock_init(&p->lock);

	p->regs = of_ioremap(&op->resource[0], 0,
			     4 * WD_TIMER_REGSZ, DRIVER_NAME);
	if (!p->regs) {
		printk(KERN_ERR PFX "Unable to map registers.\n");
		goto out_free;
	}

	options = of_find_node_by_path("/options");
	err = -ENODEV;
	if (!options) {
		printk(KERN_ERR PFX "Unable to find /options node.\n");
		goto out_iounmap;
	}

	prop_val = of_get_property(options, "watchdog-enable?", NULL);
	p->enabled = (prop_val ? true : false);

	prop_val = of_get_property(options, "watchdog-reboot?", NULL);
	p->reboot = (prop_val ? true : false);

	str_prop = of_get_property(options, "watchdog-timeout", NULL);
	if (str_prop)
		p->timeout = simple_strtoul(str_prop, NULL, 10);

	/* CP1400s seem to have broken PLD implementations-- the
	 * interrupt_mask register cannot be written, so no timer
	 * interrupts can be masked within the PLD.
	 */
	str_prop = of_get_property(op->dev.of_node, "model", NULL);
	p->broken = (str_prop && !strcmp(str_prop, WD_BADMODEL));

	if (!p->enabled)
		cpwd_toggleintr(p, -1, WD_INTR_OFF);

	for (i = 0; i < WD_NUMDEVS; i++) {
		static const char *cpwd_names[] = { "RIC", "XIR", "POR" };
		static int *parms[] = { &wd0_timeout,
					&wd1_timeout,
					&wd2_timeout };
		struct miscdevice *mp = &p->devs[i].misc;

		mp->minor = WD0_MINOR + i;
		mp->name = cpwd_names[i];
		mp->fops = &cpwd_fops;

		p->devs[i].regs = p->regs + (i * WD_TIMER_REGSZ);
		p->devs[i].intr_mask = (WD0_INTR_MASK << i);
		p->devs[i].runstatus &= ~WD_STAT_BSTOP;
		p->devs[i].runstatus |= WD_STAT_INIT;
		p->devs[i].timeout = p->timeout;
		if (*parms[i])
			p->devs[i].timeout = *parms[i];

		err = misc_register(&p->devs[i].misc);
		if (err) {
			printk(KERN_ERR "Could not register misc device for "
			       "dev %d\n", i);
			goto out_unregister;
		}
	}

	if (p->broken) {
		init_timer(&cpwd_timer);
		cpwd_timer.function 	= cpwd_brokentimer;
		cpwd_timer.data		= (unsigned long) p;
		cpwd_timer.expires	= WD_BTIMEOUT;

		printk(KERN_INFO PFX "PLD defect workaround enabled for "
		       "model " WD_BADMODEL ".\n");
	}

	dev_set_drvdata(&op->dev, p);
	cpwd_device = p;
	err = 0;

out:
	return err;

out_unregister:
	for (i--; i >= 0; i--)
		misc_deregister(&p->devs[i].misc);

out_iounmap:
	of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);

out_free:
	kfree(p);
	goto out;
}

static int __devexit cpwd_remove(struct platform_device *op)
{
	struct cpwd *p = dev_get_drvdata(&op->dev);
	int i;

	for (i = 0; i < 4; i++) {
		misc_deregister(&p->devs[i].misc);

		if (!p->enabled) {
			cpwd_stoptimer(p, i);
			if (p->devs[i].runstatus & WD_STAT_BSTOP)
				cpwd_resetbrokentimer(p, i);
		}
	}

	if (p->broken)
		del_timer_sync(&cpwd_timer);

	if (p->initialized)
		free_irq(p->irq, p);

	of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
	kfree(p);

	cpwd_device = NULL;

	return 0;
}

static const struct of_device_id cpwd_match[] = {
	{
		.name = "watchdog",
	},
	{},
};
MODULE_DEVICE_TABLE(of, cpwd_match);

static struct of_platform_driver cpwd_driver = {
	.driver = {
		.name = DRIVER_NAME,
		.owner = THIS_MODULE,
		.of_match_table = cpwd_match,
	},
	.probe		= cpwd_probe,
	.remove		= __devexit_p(cpwd_remove),
};

static int __init cpwd_init(void)
{
	return of_register_platform_driver(&cpwd_driver);
}

static void __exit cpwd_exit(void)
{
	of_unregister_platform_driver(&cpwd_driver);
}

module_init(cpwd_init);
module_exit(cpwd_exit);