xref: /titanic_41/usr/src/uts/sun4v/io/n2rng/n2rng.c (revision 0bb073995ac5a95bd35f2dd790df1ea3d8c2d507)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 
27 /*
28  * Niagara 2 Random Number Generator (RNG) driver
29  */
30 
31 #include <sys/types.h>
32 #include <sys/sysmacros.h>
33 #include <sys/modctl.h>
34 #include <sys/conf.h>
35 #include <sys/devops.h>
36 #include <sys/cmn_err.h>
37 #include <sys/ksynch.h>
38 #include <sys/kmem.h>
39 #include <sys/stat.h>
40 #include <sys/open.h>
41 #include <sys/file.h>
42 #include <sys/ddi.h>
43 #include <sys/sunddi.h>
44 #include <sys/param.h>
45 #include <sys/cpuvar.h>
46 #include <sys/disp.h>
47 #include <sys/hsvc.h>
48 #include <sys/machsystm.h>
49 #include <sys/hypervisor_api.h>
50 #include <sys/n2rng.h>
51 
52 static int	n2rng_attach(dev_info_t *, ddi_attach_cmd_t);
53 static int	n2rng_detach(dev_info_t *, ddi_detach_cmd_t);
54 static int	n2rng_suspend(n2rng_t *);
55 static int	n2rng_resume(n2rng_t *);
56 static uint64_t sticks_per_usec(void);
57 u_longlong_t	gettick(void);
58 static int	n2rng_init_ctl(n2rng_t *);
59 static void	n2rng_uninit_ctl(n2rng_t *);
60 static int	n2rng_config(n2rng_t *);
61 static void	n2rng_config_task(void * targ);
62 
63 /*
64  * Device operations.
65  */
66 
67 static struct dev_ops devops = {
68 	DEVO_REV,		/* devo_rev */
69 	0,			/* devo_refcnt */
70 	nodev,			/* devo_getinfo */
71 	nulldev,		/* devo_identify */
72 	nulldev,		/* devo_probe */
73 	n2rng_attach,		/* devo_attach */
74 	n2rng_detach,		/* devo_detach */
75 	nodev,			/* devo_reset */
76 	NULL,			/* devo_cb_ops */
77 	NULL,			/* devo_bus_ops */
78 	ddi_power,		/* devo_power */
79 	ddi_quiesce_not_supported,	/* devo_quiesce */
80 };
81 
82 /*
83  * Module linkage.
84  */
85 static struct modldrv modldrv = {
86 	&mod_driverops,			/* drv_modops */
87 	"N2 RNG Driver",		/* drv_linkinfo */
88 	&devops,			/* drv_dev_ops */
89 };
90 
91 static struct modlinkage modlinkage = {
92 	MODREV_1,			/* ml_rev */
93 	&modldrv,			/* ml_linkage */
94 	NULL
95 };
96 
97 /*
98  * Driver globals Soft state.
99  */
100 static void	*n2rng_softstate = NULL;
101 
102 /*
103  * Hypervisor NCS services information.
104  */
105 static boolean_t ncs_hsvc_available = B_FALSE;
106 
107 #define	NVERSIONS	2
108 
109 /*
110  * HV API versions supported by this driver.
111  */
112 static hsvc_info_t ncs_hsvc[NVERSIONS] = {
113 	{ HSVC_REV_1, NULL, HSVC_GROUP_RNG, 2, 0, DRIVER },	/* v2.0 */
114 	{ HSVC_REV_1, NULL, HSVC_GROUP_RNG, 1, 0, DRIVER },	/* v1.0 */
115 };
116 int	ncs_version_index;	/* index into ncs_hsvc[] */
117 
118 /*
119  * DDI entry points.
120  */
121 int
122 _init(void)
123 {
124 	int	rv;
125 
126 	rv = ddi_soft_state_init(&n2rng_softstate, sizeof (n2rng_t), 1);
127 	if (rv != 0) {
128 		/* this should *never* happen! */
129 		return (rv);
130 	}
131 
132 	if ((rv = mod_install(&modlinkage)) != 0) {
133 		/* cleanup here */
134 		ddi_soft_state_fini(&n2rng_softstate);
135 		return (rv);
136 	}
137 
138 	return (0);
139 }
140 
141 int
142 _fini(void)
143 {
144 	int	rv;
145 
146 	rv = mod_remove(&modlinkage);
147 	if (rv == 0) {
148 		/* cleanup here */
149 		ddi_soft_state_fini(&n2rng_softstate);
150 	}
151 
152 	return (rv);
153 }
154 
155 int
156 _info(struct modinfo *modinfop)
157 {
158 	return (mod_info(&modlinkage, modinfop));
159 }
160 
161 static int
162 n2rng_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
163 {
164 	n2rng_t		*n2rng = NULL;
165 	int		instance;
166 	int		rv;
167 	int		version;
168 	uint64_t	ncs_minor_ver;
169 
170 	instance = ddi_get_instance(dip);
171 	DBG1(NULL, DENTRY, "n2rng_attach called, instance %d", instance);
172 	/*
173 	 * Only instance 0 of n2rng driver is allowed.
174 	 */
175 	if (instance != 0) {
176 		n2rng_diperror(dip, "only one instance (0) allowed");
177 		return (DDI_FAILURE);
178 	}
179 
180 	switch (cmd) {
181 	case DDI_RESUME:
182 		n2rng = (n2rng_t *)ddi_get_soft_state(n2rng_softstate,
183 		    instance);
184 		if (n2rng == NULL) {
185 			n2rng_diperror(dip, "no soft state in attach");
186 			return (DDI_FAILURE);
187 		}
188 		return (n2rng_resume(n2rng));
189 
190 	case DDI_ATTACH:
191 		break;
192 	default:
193 		return (DDI_FAILURE);
194 	}
195 
196 	rv = ddi_soft_state_zalloc(n2rng_softstate, instance);
197 	if (rv != DDI_SUCCESS) {
198 		n2rng_diperror(dip, "unable to allocate soft state");
199 		return (DDI_FAILURE);
200 	}
201 	n2rng = (n2rng_t *)ddi_get_soft_state(n2rng_softstate, instance);
202 	ASSERT(n2rng != NULL);
203 	n2rng->n_dip = dip;
204 
205 	mutex_init(&n2rng->n_lock, NULL, MUTEX_DRIVER, NULL);
206 	n2rng->n_flags = 0;
207 	n2rng->n_timeout_id = 0;
208 	n2rng->n_sticks_per_usec = sticks_per_usec();
209 
210 	/* Determine binding type */
211 	n2rng->n_binding_name = ddi_binding_name(dip);
212 	if (strncmp(n2rng->n_binding_name, N2RNG_BINDNAME_N2,
213 	    strlen(N2RNG_BINDNAME_N2)) == 0) {
214 		/*
215 		 * Niagara 2
216 		 */
217 		n2rng->n_binding = N2RNG_CPU_N2;
218 	} else if (strncmp(n2rng->n_binding_name, N2RNG_BINDNAME_VF,
219 	    strlen(N2RNG_BINDNAME_VF)) == 0) {
220 		/*
221 		 * Victoria Falls
222 		 */
223 		n2rng->n_binding = N2RNG_CPU_VF;
224 	} else {
225 		n2rng_diperror(dip,
226 		    "unable to determine n2rng (cpu) binding (%s)",
227 		    n2rng->n_binding_name);
228 		goto errorexit;
229 	}
230 	DBG1(n2rng, DCHATTY, "n2rng_attach: n2rng->n_binding_name = %s",
231 	    n2rng->n_binding_name);
232 
233 	/* Negotiate HV api version number */
234 	for (version = 0; version < NVERSIONS; version++) {
235 		rv = hsvc_register(&ncs_hsvc[version], &ncs_minor_ver);
236 		if (rv == 0)
237 			break;
238 
239 		DBG4(n2rng, DCHATTY, "n2rng_attach: grp: 0x%lx, maj: %ld, "
240 		    "min: %ld, errno: %d", ncs_hsvc[version].hsvc_group,
241 		    ncs_hsvc[version].hsvc_major,
242 		    ncs_hsvc[version].hsvc_minor, rv);
243 	}
244 	if (version == NVERSIONS) {
245 		for (version = 0; version < NVERSIONS; version++) {
246 			cmn_err(CE_WARN,
247 			    "%s: cannot negotiate hypervisor services "
248 			    "group: 0x%lx major: %ld minor: %ld errno: %d",
249 			    ncs_hsvc[version].hsvc_modname,
250 			    ncs_hsvc[version].hsvc_group,
251 			    ncs_hsvc[version].hsvc_major,
252 			    ncs_hsvc[version].hsvc_minor, rv);
253 		}
254 		goto errorexit;
255 	}
256 	ncs_version_index = version;
257 	ncs_hsvc_available = B_TRUE;
258 	DBG2(n2rng, DATTACH, "n2rng_attach: ncs api version (%ld.%ld)",
259 	    ncs_hsvc[ncs_version_index].hsvc_major, ncs_minor_ver);
260 	n2rng->n_hvapi_major_version = ncs_hsvc[ncs_version_index].hsvc_major;
261 	n2rng->n_hvapi_minor_version = (uint_t)ncs_minor_ver;
262 
263 	/*
264 	 * Verify that we are running version 2.0 or later api on multiple
265 	 * rng systems.
266 	 */
267 	if ((n2rng->n_binding != N2RNG_CPU_N2) &&
268 	    (n2rng->n_hvapi_major_version < 2)) {
269 		cmn_err(CE_NOTE, "n2rng: Incompatible hyperviser api "
270 		    "version %d.%d detected", n2rng->n_hvapi_major_version,
271 		    n2rng->n_hvapi_minor_version);
272 	}
273 
274 	/* Initialize ctl structure if runnning in the control domain */
275 	if (n2rng_init_ctl(n2rng) != DDI_SUCCESS) {
276 		cmn_err(CE_WARN, "n2rng: unable to initialize rng "
277 		    "control structures");
278 		goto errorexit;
279 	}
280 
281 	/* Allocate single thread task queue for rng diags and registration */
282 	n2rng->n_taskq = ddi_taskq_create(dip, "n2rng_taskq", 1,
283 	    TASKQ_DEFAULTPRI, 0);
284 
285 	if (n2rng->n_taskq == NULL) {
286 		n2rng_diperror(dip, "ddi_taskq_create() failed");
287 		goto errorexit;
288 	}
289 
290 	/* Dispatch task to configure the RNG and register with KCF */
291 	if (ddi_taskq_dispatch(n2rng->n_taskq, n2rng_config_task,
292 	    (void *)n2rng, DDI_SLEEP) != DDI_SUCCESS) {
293 		n2rng_diperror(dip, "ddi_taskq_dispatch() failed");
294 		goto errorexit;
295 	}
296 
297 	return (DDI_SUCCESS);
298 
299 errorexit:
300 	/* Wait for pending config tasks to complete and delete the taskq */
301 	if (n2rng->n_taskq != NULL) {
302 		ddi_taskq_destroy(n2rng->n_taskq);
303 		n2rng->n_taskq = NULL;
304 	}
305 
306 	n2rng_uninit_ctl(n2rng);
307 
308 	(void) n2rng_uninit(n2rng);
309 
310 	if (ncs_hsvc_available == B_TRUE) {
311 		(void) hsvc_unregister(&ncs_hsvc[ncs_version_index]);
312 		ncs_hsvc_available = B_FALSE;
313 	}
314 
315 	mutex_destroy(&n2rng->n_lock);
316 	ddi_soft_state_free(n2rng_softstate, instance);
317 
318 	return (DDI_FAILURE);
319 }
320 
321 static int
322 n2rng_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
323 {
324 	int		instance;
325 	int		rv;
326 	n2rng_t		*n2rng;
327 	timeout_id_t	tid;
328 
329 	instance = ddi_get_instance(dip);
330 	n2rng = (n2rng_t *)ddi_get_soft_state(n2rng_softstate, instance);
331 	if (n2rng == NULL) {
332 		n2rng_diperror(dip, "no soft state in detach");
333 		return (DDI_FAILURE);
334 	}
335 
336 	switch (cmd) {
337 	case DDI_SUSPEND:
338 		return (n2rng_suspend(n2rng));
339 	case DDI_DETACH:
340 		break;
341 	default:
342 		return (DDI_FAILURE);
343 	}
344 
345 	/* Destroy task queue first to insure configuration has completed */
346 	if (n2rng->n_taskq != NULL) {
347 		ddi_taskq_destroy(n2rng->n_taskq);
348 		n2rng->n_taskq = NULL;
349 	}
350 
351 	/* Untimeout pending config retry operations */
352 	mutex_enter(&n2rng->n_lock);
353 	tid = n2rng->n_timeout_id;
354 	n2rng->n_timeout_id = 0;
355 	mutex_exit(&n2rng->n_lock);
356 	if (tid) {
357 		DBG1(n2rng, DCHATTY, "n2rng_detach: untimeout pending retry "
358 		    "id = %x", tid);
359 		(void) untimeout(tid);
360 	}
361 
362 	n2rng_uninit_ctl(n2rng);
363 
364 	/* unregister with KCF---also tears down FIPS state */
365 	rv = n2rng_uninit(n2rng) ? DDI_FAILURE : DDI_SUCCESS;
366 
367 	if (ncs_hsvc_available == B_TRUE) {
368 		(void) hsvc_unregister(&ncs_hsvc[ncs_version_index]);
369 		ncs_hsvc_available = B_FALSE;
370 	}
371 
372 	mutex_destroy(&n2rng->n_lock);
373 	ddi_soft_state_free(n2rng_softstate, instance);
374 
375 	return (rv);
376 }
377 
378 /*ARGSUSED*/
379 static int
380 n2rng_suspend(n2rng_t *n2rng)
381 {
382 	/* unregister with KCF---also tears down FIPS state */
383 	if (n2rng_uninit(n2rng) != DDI_SUCCESS) {
384 		cmn_err(CE_WARN, "n2rng: unable to unregister from KCF");
385 		return (DDI_FAILURE);
386 	}
387 
388 	return (DDI_SUCCESS);
389 }
390 
391 /*ARGSUSED*/
392 static int
393 n2rng_resume(n2rng_t *n2rng)
394 {
395 	/* Assume clock is same speed and all data structures are intact */
396 
397 	/* Re-configure the RNG hardware and register with KCF */
398 	return (n2rng_config(n2rng));
399 }
400 
401 /*
402  * Map hypervisor error code to solaris. Only
403  * H_ENORADDR, H_EBADALIGN, H_EWOULDBLOCK, and EIO
404  * are meaningful to this device. Any other error
405  * codes are mapped EINVAL.
406  */
407 int
408 n2rng_herr2kerr(uint64_t hv_errcode)
409 {
410 	int	s_errcode;
411 
412 	switch (hv_errcode) {
413 	case H_EWOULDBLOCK:
414 		s_errcode = EWOULDBLOCK;
415 		break;
416 	case H_EIO:
417 		s_errcode = EIO;
418 		break;
419 	case H_EBUSY:
420 		s_errcode = EBUSY;
421 		break;
422 	case H_EOK:
423 		s_errcode = 0;
424 		break;
425 	case H_ENOACCESS:
426 		s_errcode = EPERM;
427 		break;
428 	case H_ENORADDR:
429 	case H_EBADALIGN:
430 	default:
431 		s_errcode = EINVAL;
432 		break;
433 	}
434 	return (s_errcode);
435 }
436 
437 /*
438  * Waits approximately delay_sticks counts of the stick register.
439  * Times shorter than one sys clock tick (10ms on most systems) are
440  * done by busy waiting.
441  */
442 void
443 cyclesleep(n2rng_t *n2rng, uint64_t delay_sticks)
444 {
445 	uint64_t	end_stick = gettick() + delay_sticks;
446 	int64_t		sticks_to_wait;
447 	clock_t		sys_ticks_to_wait;
448 	clock_t		usecs_to_wait;
449 
450 	/*CONSTCOND*/
451 	while (1) {
452 		sticks_to_wait = end_stick - gettick();
453 		if (sticks_to_wait <= 0) {
454 			return;
455 		}
456 
457 		usecs_to_wait = sticks_to_wait / n2rng->n_sticks_per_usec;
458 		sys_ticks_to_wait = drv_usectohz(usecs_to_wait);
459 
460 		if (sys_ticks_to_wait > 0) {
461 			/* sleep */
462 			delay(sys_ticks_to_wait);
463 		} else if (usecs_to_wait > 0) {
464 			/* busy wait */
465 			drv_usecwait(usecs_to_wait);
466 		}
467 	}
468 }
469 
470 static void
471 log_internal_errors(uint64_t hverr, char *fname)
472 {
473 	switch (hverr) {
474 	case H_EBADALIGN:
475 		cmn_err(CE_WARN,
476 		    "n2rng: internal alignment "
477 		    "problem");
478 		break;
479 	case H_ENORADDR:
480 		cmn_err(CE_WARN, "n2rng: internal "
481 		    "invalid address");
482 		break;
483 	case H_ENOACCESS:
484 		cmn_err(CE_WARN, "n2rng: access failure");
485 		break;
486 	case H_EWOULDBLOCK:
487 		cmn_err(CE_WARN, "n2rng: hardware busy");
488 		break;
489 	default:
490 		cmn_err(CE_NOTE,
491 		    "n2rng: %s "
492 		    "unexpectedly "
493 		    "returned hverr %ld", fname, hverr);
494 		break;
495 	}
496 }
497 
498 /*
499  * Collects a buffer full of bits, using the specified setup. numbytes
500  * must be a multiple of 8. If a sub-operation fails with EIO (handle
501  * mismatch), returns EIO.  If collect_setupp is NULL, the current
502  * setup is used.  If exit_setupp is NULL, the control configuratin
503  * and state are not set at exit.  WARNING: the buffer must be 8-byte
504  * aligned and in contiguous physical addresses.  Contiguousness is
505  * not checked!
506  */
507 int
508 n2rng_collect_diag_bits(n2rng_t *n2rng, int rngid,
509     n2rng_setup_t *collect_setupp, void *buffer, int numbytes,
510     n2rng_setup_t *exit_setupp, uint64_t exitstate)
511 {
512 	int		rv;
513 	int		override_rv = 0;
514 	uint64_t	hverr;
515 	int		i;
516 	uint64_t	tdelta;
517 	n2rng_setup_t	setupbuffer[2];
518 	n2rng_setup_t	*setupcontigp;
519 	uint64_t	setupphys;
520 	int		numchunks;
521 	boolean_t	rnglooping;
522 	int		busycount = 0;
523 	int		blockcount = 0;
524 
525 	if (numbytes % sizeof (uint64_t)) {
526 		return (EINVAL);
527 	}
528 
529 	if ((uint64_t)buffer % sizeof (uint64_t) != 0) {
530 		return (EINVAL);
531 	}
532 
533 	numchunks = ((numbytes / sizeof (uint64_t)) + RNG_DIAG_CHUNK_SIZE - 1)
534 	    / RNG_DIAG_CHUNK_SIZE;
535 	/*
536 	 * Use setupbuffer[0] if it is contiguous, otherwise
537 	 * setupbuffer[1].
538 	 */
539 	setupcontigp = &setupbuffer[
540 	    CONTIGUOUS(&setupbuffer[0], n2rng_setup_t) ? 0 : 1];
541 	setupphys = va_to_pa(setupcontigp);
542 
543 	/*
544 	 * If a non-null collect_setupp pointer has been provided,
545 	 * push the specified setup into the hardware.
546 	 */
547 	if (collect_setupp != NULL) {
548 		/* copy the specified state to the aligned buffer */
549 		*setupcontigp = *collect_setupp;
550 		rnglooping = B_TRUE;
551 		while (rnglooping) {
552 			hverr = n2rng_ctl_write(n2rng, rngid, setupphys,
553 			    CTL_STATE_HEALTHCHECK,
554 			    n2rng->n_ctl_data->n_watchdog_cycles, &tdelta);
555 			rv = n2rng_herr2kerr(hverr);
556 			switch (hverr) {
557 			case H_EOK:
558 				rnglooping = B_FALSE;
559 				break;
560 			case H_EIO: /* control yanked from us */
561 			case H_ENOACCESS: /* We are not control domain */
562 				return (rv);
563 			case H_EWOULDBLOCK:
564 				/* Data currently not available, try again */
565 				if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
566 					DBG1(n2rng, DHEALTH,
567 					    "n2rng_collect_diag_bits(1) : "
568 					    "exceeded block count of %d",
569 					    RNG_MAX_BLOCK_ATTEMPTS);
570 					return (rv);
571 				} else {
572 					cyclesleep(n2rng, tdelta);
573 				}
574 				break;
575 			case H_EBUSY:
576 				/*
577 				 * A control write is already in progress.
578 				 * Note: This shouldn't happen since
579 				 * n2rng_ctl_write() waits for the
580 				 * write to complete.
581 				 */
582 				if (++busycount > RNG_MAX_BUSY_ATTEMPTS) {
583 					DBG1(n2rng, DHEALTH,
584 					    "n2rng_collect_diag_bits(1): "
585 					    "exceeded busy count of %d",
586 					    RNG_MAX_BUSY_ATTEMPTS);
587 					return (rv);
588 				} else {
589 					delay(RNG_RETRY_BUSY_DELAY);
590 				}
591 				break;
592 			default:
593 				log_internal_errors(hverr, "hv_rng_ctl_write");
594 				override_rv = rv;
595 				goto restore_state;
596 			}
597 		} /* while (rnglooping) */
598 	} /* if (collect_setupp != NULL) */
599 
600 	/* If the caller asks for some bytes, collect the data */
601 	if (numbytes > 0) {
602 		for (i = 0; i < numchunks; i++) {
603 			size_t thisnumbytes = (i == numchunks - 1) ?
604 			    numbytes - i * (RNG_DIAG_CHUNK_SIZE *
605 			    sizeof (uint64_t)) :
606 			    RNG_DIAG_CHUNK_SIZE * sizeof (uint64_t);
607 
608 			/* try until we successfully read a word of data */
609 			rnglooping = B_TRUE;
610 			busycount = 0;
611 			blockcount = 0;
612 			while (rnglooping) {
613 				hverr = n2rng_data_read_diag(n2rng, rngid,
614 				    va_to_pa((uint64_t *)buffer +
615 				    RNG_DIAG_CHUNK_SIZE * i),
616 				    thisnumbytes, &tdelta);
617 				rv = n2rng_herr2kerr(hverr);
618 				switch (hverr) {
619 				case H_EOK:
620 					rnglooping = B_FALSE;
621 					break;
622 				case H_EIO:
623 				case H_ENOACCESS:
624 					return (rv);
625 				case H_EWOULDBLOCK:
626 					/* Data not available, try again */
627 					if (++blockcount >
628 					    RNG_MAX_BLOCK_ATTEMPTS) {
629 						DBG1(n2rng, DHEALTH,
630 						    "n2rng_collect_diag_bits"
631 						    "(2): exceeded block count"
632 						    " of %d",
633 						    RNG_MAX_BLOCK_ATTEMPTS);
634 						return (rv);
635 					} else {
636 						cyclesleep(n2rng, tdelta);
637 					}
638 					break;
639 				default:
640 					log_internal_errors(hverr,
641 					    "hv_rng_data_read_diag");
642 					override_rv = rv;
643 					goto restore_state;
644 				}
645 			} /* while (!rnglooping) */
646 		} /* for */
647 	}
648 
649 restore_state:
650 
651 	/* restore the preferred configuration and set exit state */
652 	if (exit_setupp != NULL) {
653 
654 		*setupcontigp = *exit_setupp;
655 		rnglooping = B_TRUE;
656 		busycount = 0;
657 		blockcount = 0;
658 		while (rnglooping) {
659 			hverr = n2rng_ctl_write(n2rng, rngid, setupphys,
660 			    exitstate, n2rng->n_ctl_data->n_watchdog_cycles,
661 			    &tdelta);
662 			rv = n2rng_herr2kerr(hverr);
663 			switch (hverr) {
664 			case H_EOK:
665 			case H_EIO: /* control yanked from us */
666 			case H_EINVAL: /* some external error, probably */
667 			case H_ENOACCESS: /* We are not control domain */
668 				rnglooping = B_FALSE;
669 				break;
670 			case H_EWOULDBLOCK:
671 				/* Data currently not available, try again */
672 				if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
673 					DBG1(n2rng, DHEALTH,
674 					    "n2rng_collect_diag_bits(3): "
675 					    "exceeded block count of %d",
676 					    RNG_MAX_BLOCK_ATTEMPTS);
677 					return (rv);
678 				} else {
679 					cyclesleep(n2rng, tdelta);
680 				}
681 				break;
682 			case H_EBUSY:
683 				/*
684 				 * A control write is already in progress.
685 				 * Note: This shouldn't happen since
686 				 * n2rng_ctl_write() waits for the
687 				 * write to complete.
688 				 */
689 				if (++busycount > RNG_MAX_BUSY_ATTEMPTS) {
690 					DBG1(n2rng, DHEALTH,
691 					    "n2rng_collect_diag_bits(3): "
692 					    "exceeded busy count of %d",
693 					    RNG_MAX_BUSY_ATTEMPTS);
694 					return (rv);
695 				} else {
696 					delay(RNG_RETRY_BUSY_DELAY);
697 				}
698 				break;
699 			default:
700 				rnglooping = B_FALSE;
701 				log_internal_errors(hverr, "hv_rng_ctl_write");
702 				break;
703 			}
704 		} /* while */
705 	} /* if */
706 
707 	/*
708 	 * override_rv takes care of the case where we abort becuase
709 	 * of some error, but still want to restore the peferred state
710 	 * and return the first error, even if other error occur.
711 	 */
712 	return (override_rv ? override_rv : rv);
713 }
714 
715 int
716 n2rng_getentropy(n2rng_t *n2rng, void *buffer, size_t size)
717 {
718 	int		i, rv = 0;  /* so it works if size is zero */
719 	uint64_t	hverr;
720 	uint64_t	*buffer_w = (uint64_t *)buffer;
721 	int		num_w = size / sizeof (uint64_t);
722 	uint64_t	randval;
723 	uint64_t	randvalphys = va_to_pa(&randval);
724 	uint64_t	tdelta;
725 	int		failcount = 0;
726 	int		blockcount = 0;
727 	boolean_t	rnglooping;
728 
729 	for (i = 0; i < num_w; i++) {
730 		rnglooping = B_TRUE;
731 		while (rnglooping) {
732 			hverr = hv_rng_data_read(randvalphys, &tdelta);
733 			rv = n2rng_herr2kerr(hverr);
734 			switch (hverr) {
735 			case H_EOK:
736 				buffer_w[i] = randval;
737 				failcount = 0;
738 				rnglooping = B_FALSE;
739 				break;
740 			case H_EIO:
741 				/*
742 				 * Either a health check is in progress, or
743 				 * the watchdog timer has expired while running
744 				 * hv api version 2.0 or higher with health
745 				 * checks enabled.
746 				 */
747 				if (n2rng->n_hvapi_major_version < 2) {
748 					/*
749 					 * A health check is in progress.
750 					 * Wait RNG_RETRY_HLCHK_USECS and fail
751 					 * after RNG_MAX_DATA_READ_ATTEMPTS
752 					 * failures.
753 					 */
754 					if (++failcount >
755 					    RNG_MAX_DATA_READ_ATTEMPTS) {
756 						DBG2(n2rng, DHEALTH,
757 						    "n2rng_getentropy: exceeded"
758 						    "EIO count of %d on cpu %d",
759 						    RNG_MAX_DATA_READ_ATTEMPTS,
760 						    CPU->cpu_id);
761 						goto exitpoint;
762 					} else {
763 						delay(drv_usectohz
764 						    (RNG_RETRY_HLCHK_USECS));
765 					}
766 				} else {
767 					/*
768 					 * Just return the error. If a flurry of
769 					 * random data requests happen to occur
770 					 * during a health check, there are
771 					 * multiple levels of defense:
772 					 * - 2.0 HV provides random data pool
773 					 * - FIPS algorithm tolerates failures
774 					 * - Software failover
775 					 * - Automatic configuration retries
776 					 * - Hardware failover on some systems
777 					 */
778 					goto exitpoint;
779 				}
780 				break;
781 			case H_EWOULDBLOCK:
782 				/* Data currently not available, try again */
783 				if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
784 					DBG1(n2rng, DHEALTH,
785 					    "n2rng_getentropy: "
786 					    "exceeded block count of %d",
787 					    RNG_MAX_BLOCK_ATTEMPTS);
788 					goto exitpoint;
789 				} else {
790 					cyclesleep(n2rng, tdelta);
791 				}
792 				break;
793 			default:
794 				log_internal_errors(hverr, "hv_rng_data_read");
795 				goto exitpoint;
796 			}
797 		} /* while */
798 	} /* for */
799 
800 exitpoint:
801 	return (rv);
802 }
803 
804 uint64_t
805 n2rng_ctl_read(n2rng_t *n2rng, int rngid, uint64_t ctlregs_pa, uint64_t *state,
806     uint64_t *tdelta, uint64_t *wdelta)
807 {
808 	uint64_t	rv;
809 	uint64_t	wstatus;
810 
811 	/* Call correct hv function based on api version */
812 	if (n2rng->n_hvapi_major_version == 2) {
813 		rv = hv_rng_ctl_read_v2(ctlregs_pa, (uint64_t)rngid, state,
814 		    tdelta, wdelta, &wstatus);
815 		if (rv == 0) {
816 			rv = wstatus;
817 		}
818 	} else {
819 		rv = hv_rng_ctl_read(ctlregs_pa, state, tdelta);
820 		*wdelta = 0;
821 	}
822 
823 	return (rv);
824 }
825 
826 uint64_t
827 n2rng_ctl_wait(n2rng_t *n2rng, int rngid)
828 {
829 	uint64_t	state;
830 	uint64_t	tdelta;
831 	uint64_t	wdelta;
832 	uint64_t	wstatus;
833 	boolean_t	rnglooping = B_TRUE;
834 	uint64_t	rv;
835 	n2rng_setup_t	setupbuffer[2];
836 	n2rng_setup_t	*setupcontigp;
837 	uint64_t	setupphys;
838 	int		busycount = 0;
839 	int		blockcount = 0;
840 
841 	/*
842 	 * Use setupbuffer[0] if it is contiguous, otherwise
843 	 * setupbuffer[1].
844 	 */
845 	setupcontigp = &setupbuffer[
846 	    CONTIGUOUS(&setupbuffer[0], n2rng_setup_t) ? 0 : 1];
847 	setupphys = va_to_pa(setupcontigp);
848 
849 	while (rnglooping) {
850 		rv = hv_rng_ctl_read_v2(setupphys, (uint64_t)rngid, &state,
851 		    &tdelta, &wdelta, &wstatus);
852 		switch (rv) {
853 		case H_EOK:
854 			rv = wstatus;
855 			rnglooping = B_FALSE;
856 			break;
857 		case H_EWOULDBLOCK:
858 			/* Data currently not available, try again */
859 			if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
860 				DBG1(n2rng, DHEALTH, "n2rng_ctl_wait: "
861 				    "exceeded block count of %d",
862 				    RNG_MAX_BLOCK_ATTEMPTS);
863 				return (rv);
864 			} else {
865 				cyclesleep(n2rng, tdelta);
866 			}
867 			break;
868 		case H_EBUSY:
869 			/* Control write still pending, try again */
870 			if (++busycount > RNG_MAX_BUSY_ATTEMPTS) {
871 				DBG1(n2rng, DHEALTH, "n2rng_ctl_wait: "
872 				    "exceeded busy count of %d",
873 				    RNG_MAX_BUSY_ATTEMPTS);
874 				return (rv);
875 			} else {
876 				delay(RNG_RETRY_BUSY_DELAY);
877 			}
878 			break;
879 		default:
880 			log_internal_errors(rv, "n2rng_ctl_wait");
881 			rnglooping = B_FALSE;
882 		}
883 	} /* while (rnglooping) */
884 
885 	return (rv);
886 }
887 
888 uint64_t
889 n2rng_ctl_write(n2rng_t *n2rng, int rngid, uint64_t ctlregs_pa,
890     uint64_t newstate, uint64_t wtimeout, uint64_t *tdelta)
891 {
892 	uint64_t	rv;
893 
894 	/* Call correct hv function based on api version */
895 	if (n2rng->n_hvapi_major_version == 2) {
896 		rv = hv_rng_ctl_write_v2(ctlregs_pa, newstate, wtimeout,
897 		    (uint64_t)rngid);
898 		if (rv == H_EOK) {
899 			/* Wait for control registers to be written */
900 			rv = n2rng_ctl_wait(n2rng, rngid);
901 		}
902 		*tdelta = RNG_DEFAULT_ACCUMULATE_CYCLES;
903 	} else {
904 		rv = hv_rng_ctl_write(ctlregs_pa, newstate, wtimeout, tdelta);
905 	}
906 
907 	return (rv);
908 }
909 
910 uint64_t
911 n2rng_data_read_diag(n2rng_t *n2rng, int rngid, uint64_t data_pa,
912     size_t  datalen, uint64_t *tdelta)
913 {
914 	uint64_t	rv;
915 
916 	/* Call correct hv function based on api version */
917 	if (n2rng->n_hvapi_major_version == 2) {
918 		rv = hv_rng_data_read_diag_v2(data_pa, datalen,
919 		    (uint64_t)rngid, tdelta);
920 		if (*tdelta == 0) {
921 			*tdelta = RNG_DEFAULT_ACCUMULATE_CYCLES;
922 		}
923 	} else {
924 		rv = hv_rng_data_read_diag(data_pa, datalen, tdelta);
925 	}
926 
927 	return (rv);
928 }
929 
930 uint64_t
931 n2rng_check_ctl_access(n2rng_t *n2rng)
932 {
933 	uint64_t	rv;
934 	uint64_t	unused_64;
935 
936 	/* Call correct hv function based on api version */
937 	if (n2rng->n_hvapi_major_version == 2) {
938 		/*
939 		 * Attempt to read control registers with invalid ID and data
940 		 * just to see if we get an access error
941 		 */
942 		rv = hv_rng_ctl_read_v2(NULL, N2RNG_INVALID_ID,
943 		    &unused_64, &unused_64, &unused_64, &unused_64);
944 	} else {
945 		rv = hv_rng_get_diag_control();
946 	}
947 
948 	return (rv);
949 }
950 
951 /*
952  * n2rng_config_retry()
953  *
954  * Schedule a timed call to n2rng_config() if one is not already pending
955  */
956 void
957 n2rng_config_retry(n2rng_t *n2rng, clock_t seconds)
958 {
959 	mutex_enter(&n2rng->n_lock);
960 	/* Check if a config retry is already pending */
961 	if (n2rng->n_timeout_id) {
962 		DBG1(n2rng, DCFG, "n2rng_config_retry: retry pending "
963 		    "id = %x", n2rng->n_timeout_id);
964 	} else {
965 		n2rng->n_timeout_id = timeout(n2rng_config_task,
966 		    (void *)n2rng, drv_usectohz(seconds * SECOND));
967 		DBG2(n2rng, DCFG, "n2rng_config_retry: retry scheduled in "
968 		    "%d seconds, id = %x", seconds, n2rng->n_timeout_id);
969 	}
970 	mutex_exit(&n2rng->n_lock);
971 }
972 
973 static uint64_t
974 sticks_per_usec(void)
975 {
976 	uint64_t starttick = gettick();
977 	hrtime_t starttime = gethrtime();
978 	uint64_t endtick;
979 	hrtime_t endtime;
980 
981 	delay(2);
982 
983 	endtick = gettick();
984 	endtime = gethrtime();
985 
986 	return ((1000 * (endtick - starttick)) / (endtime - starttime));
987 }
988 
989 static int
990 n2rng_init_ctl(n2rng_t *n2rng)
991 {
992 	int		rv;
993 	int		hverr;
994 	rng_entry_t	*rng;
995 	int		rngid;
996 	int		blockcount = 0;
997 
998 	n2rng->n_ctl_data = NULL;
999 
1000 	/* Attempt to gain diagnostic control */
1001 	do {
1002 		hverr = n2rng_check_ctl_access(n2rng);
1003 		rv = n2rng_herr2kerr(hverr);
1004 		if ((hverr == H_EWOULDBLOCK) &&
1005 		    (++blockcount > RNG_MAX_BUSY_ATTEMPTS)) {
1006 			DBG1(n2rng, DHEALTH, "n2rng_int_ctl: exceeded busy "
1007 			    "count of %d", RNG_MAX_BUSY_ATTEMPTS);
1008 			return (rv);
1009 		} else {
1010 			delay(RNG_RETRY_BUSY_DELAY);
1011 		}
1012 	} while (hverr == H_EWOULDBLOCK);
1013 
1014 	/*
1015 	 * If attempt fails with EPERM, the driver is not running in the
1016 	 * control domain
1017 	 */
1018 	if (rv == EPERM) {
1019 		DBG0(n2rng, DATTACH,
1020 		    "n2rng_init_ctl: Running in guest domain");
1021 		return (DDI_SUCCESS);
1022 	}
1023 
1024 	/* Allocate control stucture only used in control domain */
1025 	n2rng->n_ctl_data = kmem_alloc(sizeof (rng_ctl_data_t), KM_SLEEP);
1026 	n2rng->n_ctl_data->n_num_rngs_online = 0;
1027 
1028 	/*
1029 	 * If running with an API version less than 2.0 default to one rng.
1030 	 * Otherwise get number of rngs from device properties.
1031 	 */
1032 	if (n2rng->n_hvapi_major_version < 2) {
1033 		n2rng->n_ctl_data->n_num_rngs = 1;
1034 	} else {
1035 		n2rng->n_ctl_data->n_num_rngs =
1036 		    ddi_getprop(DDI_DEV_T_ANY, n2rng->n_dip,
1037 		    DDI_PROP_CANSLEEP | DDI_PROP_DONTPASS,
1038 		    N2RNG_PROP_NUM_UNITS, 0);
1039 		if (n2rng->n_ctl_data->n_num_rngs == 0) {
1040 			cmn_err(CE_WARN, "n2rng: %s property not found",
1041 			    N2RNG_PROP_NUM_UNITS);
1042 			return (DDI_FAILURE);
1043 		}
1044 	}
1045 
1046 	/* Allocate space for all rng entries */
1047 	n2rng->n_ctl_data->n_rngs =
1048 	    kmem_zalloc(n2rng->n_ctl_data->n_num_rngs *
1049 	    sizeof (rng_entry_t), KM_SLEEP);
1050 
1051 	/* Get accumulate cycles from .conf file. */
1052 	n2rng->n_ctl_data->n_accumulate_cycles =
1053 	    ddi_getprop(DDI_DEV_T_ANY, n2rng->n_dip,
1054 	    DDI_PROP_CANSLEEP | DDI_PROP_DONTPASS, "acc_cycles",
1055 	    RNG_DEFAULT_ACCUMULATE_CYCLES);
1056 
1057 	/* Get health check frequency from .conf file */
1058 	n2rng->n_ctl_data->n_hc_secs = ddi_getprop(DDI_DEV_T_ANY, n2rng->n_dip,
1059 	    DDI_PROP_CANSLEEP | DDI_PROP_DONTPASS, "hc_seconds",
1060 	    RNG_DEFAULT_HC_SECS);
1061 
1062 	/* API versions prior to 2.0 do not support health checks */
1063 	if ((n2rng->n_hvapi_major_version < 2) &&
1064 	    (n2rng->n_ctl_data->n_hc_secs > 0)) {
1065 		cmn_err(CE_WARN, "n2rng: Hyperviser api "
1066 		    "version %d.%d does not support health checks",
1067 		    n2rng->n_hvapi_major_version,
1068 		    n2rng->n_hvapi_minor_version);
1069 		n2rng->n_ctl_data->n_hc_secs = 0;
1070 	}
1071 
1072 	/* Calculate watchdog timeout value */
1073 	if (n2rng->n_ctl_data->n_hc_secs <= 0) {
1074 		n2rng->n_ctl_data->n_watchdog_cycles = 0;
1075 	} else {
1076 		n2rng->n_ctl_data->n_watchdog_cycles =
1077 		    ((uint64_t)(RNG_EXTRA_WATCHDOG_SECS) +
1078 		    n2rng->n_ctl_data->n_hc_secs) *
1079 		    n2rng->n_sticks_per_usec * 1000000;
1080 	}
1081 
1082 	/*
1083 	 * Set some plausible state into the preferred configuration.
1084 	 * The intent is that the health check will immediately overwrite it.
1085 	 */
1086 	for (rngid = 0; rngid < n2rng->n_ctl_data->n_num_rngs; rngid++) {
1087 
1088 		rng = &n2rng->n_ctl_data->n_rngs[rngid];
1089 
1090 		rng->n_preferred_config.ctlwds[0].word = 0;
1091 		rng->n_preferred_config.ctlwds[0].fields.rnc_anlg_sel =
1092 		    N2RNG_NOANALOGOUT;
1093 		rng->n_preferred_config.ctlwds[0].fields.rnc_cnt =
1094 		    RNG_DEFAULT_ACCUMULATE_CYCLES;
1095 		rng->n_preferred_config.ctlwds[0].fields.rnc_mode =
1096 		    RNG_MODE_NORMAL;
1097 		rng->n_preferred_config.ctlwds[1].word =
1098 		    rng->n_preferred_config.ctlwds[0].word;
1099 		rng->n_preferred_config.ctlwds[2].word =
1100 		    rng->n_preferred_config.ctlwds[0].word;
1101 		rng->n_preferred_config.ctlwds[3].word =
1102 		    rng->n_preferred_config.ctlwds[0].word;
1103 		rng->n_preferred_config.ctlwds[0].fields.rnc_vcoctl = 1;
1104 		rng->n_preferred_config.ctlwds[0].fields.rnc_selbits = 1;
1105 		rng->n_preferred_config.ctlwds[1].fields.rnc_vcoctl = 2;
1106 		rng->n_preferred_config.ctlwds[1].fields.rnc_selbits = 2;
1107 		rng->n_preferred_config.ctlwds[2].fields.rnc_vcoctl = 3;
1108 		rng->n_preferred_config.ctlwds[2].fields.rnc_selbits = 4;
1109 		rng->n_preferred_config.ctlwds[3].fields.rnc_vcoctl = 0;
1110 		rng->n_preferred_config.ctlwds[3].fields.rnc_selbits = 7;
1111 	}
1112 
1113 	n2rng_setcontrol(n2rng);
1114 	DBG2(n2rng, DATTACH,
1115 	    "n2rng_init_ctl: Running in control domain with %d rng device%s",
1116 	    n2rng->n_ctl_data->n_num_rngs,
1117 	    (n2rng->n_ctl_data->n_num_rngs == 1) ? "" : "s");
1118 	DBG2(n2rng, DCFG,
1119 	    "n2rng_init_ctl: n_sticks_per_usec = %ld, n_hc_secs = %d",
1120 	    n2rng->n_sticks_per_usec,
1121 	    n2rng->n_ctl_data->n_hc_secs);
1122 	DBG2(n2rng, DCFG,
1123 	    "n2rng_init_ctl: n_watchdog_cycles = %ld, "
1124 	    "n_accumulate_cycles = %ld", n2rng->n_ctl_data->n_watchdog_cycles,
1125 	    n2rng->n_ctl_data->n_accumulate_cycles);
1126 
1127 	return (DDI_SUCCESS);
1128 }
1129 
1130 static void
1131 n2rng_uninit_ctl(n2rng_t *n2rng)
1132 {
1133 	if (n2rng->n_ctl_data) {
1134 		if (n2rng->n_ctl_data->n_num_rngs) {
1135 			kmem_free(n2rng->n_ctl_data->n_rngs,
1136 			    n2rng->n_ctl_data->n_num_rngs *
1137 			    sizeof (rng_entry_t));
1138 			n2rng->n_ctl_data->n_rngs = NULL;
1139 			n2rng->n_ctl_data->n_num_rngs = 0;
1140 		}
1141 		kmem_free(n2rng->n_ctl_data, sizeof (rng_ctl_data_t));
1142 		n2rng->n_ctl_data = NULL;
1143 	}
1144 }
1145 
1146 
1147 /*
1148  * n2rng_config_test()
1149  *
1150  * Attempt read random data to see if the rng is configured.
1151  */
1152 int
1153 n2rng_config_test(n2rng_t *n2rng)
1154 {
1155 	int		rv = 0;
1156 	uint64_t	hverr;
1157 	uint64_t	randval = 0;
1158 	uint64_t	randvalphys = va_to_pa(&randval);
1159 	uint64_t	tdelta;
1160 	int		failcount = 0;
1161 	int		blockcount = 0;
1162 	boolean_t	rnglooping = B_TRUE;
1163 
1164 	while (rnglooping) {
1165 		hverr = hv_rng_data_read(randvalphys, &tdelta);
1166 		rv = n2rng_herr2kerr(hverr);
1167 		switch (hverr) {
1168 		case H_EOK:
1169 			failcount = 0;
1170 			rnglooping = B_FALSE;
1171 			break;
1172 		case H_EIO:
1173 			/*
1174 			 * A health check is in progress.
1175 			 * Wait RNG_RETRY_HLCHK_USECS and fail
1176 			 * after RNG_MAX_DATA_READ_ATTEMPTS
1177 			 * failures.
1178 			 */
1179 			if (++failcount > RNG_MAX_DATA_READ_ATTEMPTS) {
1180 				goto exitpoint;
1181 			} else {
1182 				delay(drv_usectohz(RNG_RETRY_HLCHK_USECS));
1183 			}
1184 			break;
1185 		case H_EWOULDBLOCK:
1186 			/* Data currently not available, try again */
1187 			if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
1188 				DBG1(n2rng, DHEALTH, "n2rng_config_test: "
1189 				    "exceeded block count of %d",
1190 				    RNG_MAX_BLOCK_ATTEMPTS);
1191 				goto exitpoint;
1192 			} else {
1193 				cyclesleep(n2rng, tdelta);
1194 			}
1195 			break;
1196 		case H_ENOACCESS:
1197 			/* An rng error has occured during health check */
1198 			goto exitpoint;
1199 		default:
1200 			log_internal_errors(hverr, "hv_rng_data_read");
1201 			goto exitpoint;
1202 		}
1203 	} /* while */
1204 
1205 exitpoint:
1206 	return (rv);
1207 }
1208 
1209 /*
1210  * n2rng_config()
1211  *
1212  * Run health check on the RNG hardware
1213  * Configure the RNG hardware
1214  * Register with crypto framework
1215  */
1216 static int
1217 n2rng_config(n2rng_t *n2rng)
1218 {
1219 	int		rv;
1220 	rng_entry_t	*rng;
1221 	int		rngid;
1222 
1223 	/*
1224 	 * Run health checks and configure rngs if running in control domain,
1225 	 * otherwise just check if at least one rng is available.
1226 	 */
1227 	if (n2rng_iscontrol(n2rng)) {
1228 
1229 		for (rngid = 0; rngid < n2rng->n_ctl_data->n_num_rngs;
1230 		    rngid++) {
1231 
1232 			rng = &n2rng->n_ctl_data->n_rngs[rngid];
1233 
1234 			/* Only test rngs that have not already failed */
1235 			if (rng->n_rng_state == CTL_STATE_ERROR) {
1236 				continue;
1237 			}
1238 
1239 			if ((n2rng->n_binding == N2RNG_CPU_VF) &&
1240 			    (n2rng->n_hvapi_major_version < 2)) {
1241 				/*
1242 				 * Since api versions prior to 2.0 do not
1243 				 * support multiple rngs, bind to the current
1244 				 * processor for the entire health check
1245 				 * process.
1246 				 */
1247 				thread_affinity_set(curthread, CPU_CURRENT);
1248 				DBG1(n2rng, DCFG, "n2rng_config: "
1249 				    "Configuring single rng from cpu %d",
1250 				    CPU->cpu_id);
1251 				rv = n2rng_do_health_check(n2rng, rngid);
1252 				thread_affinity_clear(curthread);
1253 			} else {
1254 				rv = n2rng_do_health_check(n2rng, rngid);
1255 			}
1256 
1257 			switch (rv) {
1258 			case 0:
1259 				/*
1260 				 * Successful, increment online count if
1261 				 * necessary
1262 				 */
1263 				DBG1(n2rng, DCFG, "n2rng_config: rng(%d) "
1264 				    "passed health checks", rngid);
1265 				if (rng->n_rng_state != CTL_STATE_CONFIGURED) {
1266 					rng->n_rng_state =
1267 					    CTL_STATE_CONFIGURED;
1268 					n2rng->n_ctl_data->n_num_rngs_online++;
1269 				}
1270 				break;
1271 			default:
1272 				/*
1273 				 * Health checks failed, decrement online
1274 				 * count if necessary
1275 				 */
1276 				cmn_err(CE_WARN, "n2rng: rng(%d) "
1277 				    "failed health checks", rngid);
1278 				if (rng->n_rng_state == CTL_STATE_CONFIGURED) {
1279 					n2rng->n_ctl_data->n_num_rngs_online--;
1280 				}
1281 				rng->n_rng_state = CTL_STATE_ERROR;
1282 				break;
1283 			}
1284 		}
1285 		DBG2(n2rng, DCFG, "n2rng_config: %d rng%s online",
1286 		    n2rng->n_ctl_data->n_num_rngs_online,
1287 		    (n2rng->n_ctl_data->n_num_rngs_online == 1) ? "" : "s");
1288 
1289 		/* Check if all rngs have failed */
1290 		if (n2rng->n_ctl_data->n_num_rngs_online == 0) {
1291 			cmn_err(CE_WARN, "n2rng: %d RNG device%s failed",
1292 			    n2rng->n_ctl_data->n_num_rngs,
1293 			    (n2rng->n_ctl_data->n_num_rngs == 1) ? "" : "s");
1294 			goto errorexit;
1295 		} else {
1296 			n2rng_setconfigured(n2rng);
1297 		}
1298 	} else {
1299 		/* Running in guest domain, just check if rng is configured */
1300 		rv = n2rng_config_test(n2rng);
1301 		switch (rv) {
1302 		case 0:
1303 			n2rng_setconfigured(n2rng);
1304 			break;
1305 		case EIO:
1306 			/* Don't set configured to force a retry */
1307 			break;
1308 		default:
1309 			goto errorexit;
1310 		}
1311 	}
1312 
1313 	/*
1314 	 * Initialize FIPS state and register with KCF if we have at least one
1315 	 * RNG configured.  Otherwise schedule a retry if all rngs have not
1316 	 * failed.
1317 	 */
1318 	if (n2rng_isconfigured(n2rng)) {
1319 
1320 		if (n2rng_init(n2rng) != DDI_SUCCESS) {
1321 			cmn_err(CE_WARN, "n2rng: unable to register with KCF");
1322 			goto errorexit;
1323 		}
1324 
1325 		/*
1326 		 * Schedule a retry if running in the control domain and a
1327 		 * health check time has been specified.
1328 		 */
1329 		if (n2rng_iscontrol(n2rng) &&
1330 		    (n2rng->n_ctl_data->n_hc_secs > 0)) {
1331 			n2rng_config_retry(n2rng,
1332 			    n2rng->n_ctl_data->n_hc_secs);
1333 		}
1334 	} else if (!n2rng_isfailed(n2rng)) {
1335 		/* Schedule a retry if one is not already pending */
1336 		n2rng_config_retry(n2rng, RNG_CFG_RETRY_SECS);
1337 	}
1338 	return (DDI_SUCCESS);
1339 
1340 errorexit:
1341 	/* Unregister from kCF if we are registered */
1342 	(void) n2rng_unregister_provider(n2rng);
1343 	n2rng_setfailed(n2rng);
1344 	cmn_err(CE_WARN, "n2rng: hardware failure detected");
1345 	return (DDI_FAILURE);
1346 }
1347 
1348 /*
1349  * n2rng_config_task()
1350  *
1351  * Call n2rng_config() from the task queue or after a timeout, ignore result.
1352  */
1353 static void
1354 n2rng_config_task(void *targ)
1355 {
1356 	n2rng_t *n2rng = (n2rng_t *)targ;
1357 
1358 	mutex_enter(&n2rng->n_lock);
1359 	n2rng->n_timeout_id = 0;
1360 	mutex_exit(&n2rng->n_lock);
1361 	(void) n2rng_config(n2rng);
1362 }
1363