xref: /illumos-gate/usr/src/uts/sun4v/io/n2rng/n2rng.c (revision 4f364e7c95ee7fd9d5bbeddc1940e92405bb0e72)
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 (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 
26 /*
27  * Niagara 2 Random Number Generator (RNG) driver
28  */
29 
30 #include <sys/types.h>
31 #include <sys/sysmacros.h>
32 #include <sys/modctl.h>
33 #include <sys/conf.h>
34 #include <sys/devops.h>
35 #include <sys/cmn_err.h>
36 #include <sys/ksynch.h>
37 #include <sys/kmem.h>
38 #include <sys/stat.h>
39 #include <sys/open.h>
40 #include <sys/file.h>
41 #include <sys/ddi.h>
42 #include <sys/sunddi.h>
43 #include <sys/param.h>
44 #include <sys/cpuvar.h>
45 #include <sys/disp.h>
46 #include <sys/hsvc.h>
47 #include <sys/machsystm.h>
48 #include <sys/hypervisor_api.h>
49 #include <sys/n2rng.h>
50 
51 static int	n2rng_attach(dev_info_t *, ddi_attach_cmd_t);
52 static int	n2rng_detach(dev_info_t *, ddi_detach_cmd_t);
53 static int	n2rng_suspend(n2rng_t *);
54 static int	n2rng_resume(n2rng_t *);
55 static uint64_t sticks_per_usec(void);
56 u_longlong_t	gettick(void);
57 static int	n2rng_init_ctl(n2rng_t *);
58 static void	n2rng_uninit_ctl(n2rng_t *);
59 static int	n2rng_config(n2rng_t *);
60 static void	n2rng_config_task(void * targ);
61 
62 /*
63  * Device operations.
64  */
65 
66 static struct dev_ops devops = {
67 	DEVO_REV,		/* devo_rev */
68 	0,			/* devo_refcnt */
69 	nodev,			/* devo_getinfo */
70 	nulldev,		/* devo_identify */
71 	nulldev,		/* devo_probe */
72 	n2rng_attach,		/* devo_attach */
73 	n2rng_detach,		/* devo_detach */
74 	nodev,			/* devo_reset */
75 	NULL,			/* devo_cb_ops */
76 	NULL,			/* devo_bus_ops */
77 	ddi_power,		/* devo_power */
78 	ddi_quiesce_not_supported,	/* devo_quiesce */
79 };
80 
81 /*
82  * Module linkage.
83  */
84 static struct modldrv modldrv = {
85 	&mod_driverops,			/* drv_modops */
86 	"N2 RNG Driver",		/* drv_linkinfo */
87 	&devops,			/* drv_dev_ops */
88 };
89 
90 static struct modlinkage modlinkage = {
91 	MODREV_1,			/* ml_rev */
92 	&modldrv,			/* ml_linkage */
93 	NULL
94 };
95 
96 /*
97  * Driver globals Soft state.
98  */
99 static void	*n2rng_softstate = NULL;
100 
101 /*
102  * Hypervisor NCS services information.
103  */
104 static boolean_t ncs_hsvc_available = B_FALSE;
105 
106 #define	NVERSIONS	2
107 
108 /*
109  * HV API versions supported by this driver.
110  */
111 static hsvc_info_t ncs_hsvc[NVERSIONS] = {
112 	{ HSVC_REV_1, NULL, HSVC_GROUP_RNG, 2, 0, DRIVER },	/* v2.0 */
113 	{ HSVC_REV_1, NULL, HSVC_GROUP_RNG, 1, 0, DRIVER },	/* v1.0 */
114 };
115 int	ncs_version_index;	/* index into ncs_hsvc[] */
116 
117 /*
118  * DDI entry points.
119  */
120 int
121 _init(void)
122 {
123 	int	rv;
124 
125 	rv = ddi_soft_state_init(&n2rng_softstate, sizeof (n2rng_t), 1);
126 	if (rv != 0) {
127 		/* this should *never* happen! */
128 		return (rv);
129 	}
130 
131 	if ((rv = mod_install(&modlinkage)) != 0) {
132 		/* cleanup here */
133 		ddi_soft_state_fini(&n2rng_softstate);
134 		return (rv);
135 	}
136 
137 	return (0);
138 }
139 
140 int
141 _fini(void)
142 {
143 	int	rv;
144 
145 	rv = mod_remove(&modlinkage);
146 	if (rv == 0) {
147 		/* cleanup here */
148 		ddi_soft_state_fini(&n2rng_softstate);
149 	}
150 
151 	return (rv);
152 }
153 
154 int
155 _info(struct modinfo *modinfop)
156 {
157 	return (mod_info(&modlinkage, modinfop));
158 }
159 
160 static int
161 n2rng_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
162 {
163 	n2rng_t		*n2rng = NULL;
164 	int		instance;
165 	int		rv;
166 	int		version;
167 	uint64_t	ncs_minor_ver;
168 
169 	instance = ddi_get_instance(dip);
170 	DBG1(NULL, DENTRY, "n2rng_attach called, instance %d", instance);
171 	/*
172 	 * Only instance 0 of n2rng driver is allowed.
173 	 */
174 	if (instance != 0) {
175 		n2rng_diperror(dip, "only one instance (0) allowed");
176 		return (DDI_FAILURE);
177 	}
178 
179 	switch (cmd) {
180 	case DDI_RESUME:
181 		n2rng = (n2rng_t *)ddi_get_soft_state(n2rng_softstate,
182 		    instance);
183 		if (n2rng == NULL) {
184 			n2rng_diperror(dip, "no soft state in attach");
185 			return (DDI_FAILURE);
186 		}
187 		return (n2rng_resume(n2rng));
188 
189 	case DDI_ATTACH:
190 		break;
191 	default:
192 		return (DDI_FAILURE);
193 	}
194 
195 	rv = ddi_soft_state_zalloc(n2rng_softstate, instance);
196 	if (rv != DDI_SUCCESS) {
197 		n2rng_diperror(dip, "unable to allocate soft state");
198 		return (DDI_FAILURE);
199 	}
200 	n2rng = (n2rng_t *)ddi_get_soft_state(n2rng_softstate, instance);
201 	ASSERT(n2rng != NULL);
202 	n2rng->n_dip = dip;
203 
204 	mutex_init(&n2rng->n_lock, NULL, MUTEX_DRIVER, NULL);
205 	n2rng->n_flags = 0;
206 	n2rng->n_timeout_id = 0;
207 	n2rng->n_sticks_per_usec = sticks_per_usec();
208 
209 	/* Determine binding type */
210 	n2rng->n_binding_name = ddi_binding_name(dip);
211 	if (strncmp(n2rng->n_binding_name, N2RNG_BINDNAME_N2,
212 	    strlen(N2RNG_BINDNAME_N2)) == 0) {
213 		/*
214 		 * Niagara 2
215 		 */
216 		n2rng->n_binding = N2RNG_CPU_N2;
217 	} else if (strncmp(n2rng->n_binding_name, N2RNG_BINDNAME_VF,
218 	    strlen(N2RNG_BINDNAME_VF)) == 0) {
219 		/*
220 		 * Victoria Falls
221 		 */
222 		n2rng->n_binding = N2RNG_CPU_VF;
223 	} else if (strncmp(n2rng->n_binding_name, N2RNG_BINDNAME_KT,
224 	    strlen(N2RNG_BINDNAME_KT)) == 0) {
225 		/*
226 		 * Rainbow Falls
227 		 */
228 		n2rng->n_binding = N2RNG_CPU_KT;
229 	} else {
230 		n2rng_diperror(dip,
231 		    "unable to determine n2rng (cpu) binding (%s)",
232 		    n2rng->n_binding_name);
233 		goto errorexit;
234 	}
235 	DBG1(n2rng, DCHATTY, "n2rng_attach: n2rng->n_binding_name = %s",
236 	    n2rng->n_binding_name);
237 
238 	/* Negotiate HV api version number */
239 	for (version = 0; version < NVERSIONS; version++) {
240 		rv = hsvc_register(&ncs_hsvc[version], &ncs_minor_ver);
241 		if (rv == 0)
242 			break;
243 
244 		DBG4(n2rng, DCHATTY, "n2rng_attach: grp: 0x%lx, maj: %ld, "
245 		    "min: %ld, errno: %d", ncs_hsvc[version].hsvc_group,
246 		    ncs_hsvc[version].hsvc_major,
247 		    ncs_hsvc[version].hsvc_minor, rv);
248 	}
249 	if (version == NVERSIONS) {
250 		for (version = 0; version < NVERSIONS; version++) {
251 			cmn_err(CE_WARN,
252 			    "%s: cannot negotiate hypervisor services "
253 			    "group: 0x%lx major: %ld minor: %ld errno: %d",
254 			    ncs_hsvc[version].hsvc_modname,
255 			    ncs_hsvc[version].hsvc_group,
256 			    ncs_hsvc[version].hsvc_major,
257 			    ncs_hsvc[version].hsvc_minor, rv);
258 		}
259 		goto errorexit;
260 	}
261 	ncs_version_index = version;
262 	ncs_hsvc_available = B_TRUE;
263 	DBG2(n2rng, DATTACH, "n2rng_attach: ncs api version (%ld.%ld)",
264 	    ncs_hsvc[ncs_version_index].hsvc_major, ncs_minor_ver);
265 	n2rng->n_hvapi_major_version = ncs_hsvc[ncs_version_index].hsvc_major;
266 	n2rng->n_hvapi_minor_version = (uint_t)ncs_minor_ver;
267 
268 	/*
269 	 * Verify that we are running version 2.0 or later api on multiple
270 	 * rng systems.
271 	 */
272 	if ((n2rng->n_binding != N2RNG_CPU_N2) &&
273 	    (n2rng->n_hvapi_major_version < 2)) {
274 		cmn_err(CE_NOTE, "n2rng: Incompatible hyperviser api "
275 		    "version %d.%d detected", n2rng->n_hvapi_major_version,
276 		    n2rng->n_hvapi_minor_version);
277 	}
278 
279 	/* Initialize ctl structure if runnning in the control domain */
280 	if (n2rng_init_ctl(n2rng) != DDI_SUCCESS) {
281 		cmn_err(CE_WARN, "n2rng: unable to initialize rng "
282 		    "control structures");
283 		goto errorexit;
284 	}
285 
286 	/* Allocate single thread task queue for rng diags and registration */
287 	n2rng->n_taskq = ddi_taskq_create(dip, "n2rng_taskq", 1,
288 	    TASKQ_DEFAULTPRI, 0);
289 
290 	if (n2rng->n_taskq == NULL) {
291 		n2rng_diperror(dip, "ddi_taskq_create() failed");
292 		goto errorexit;
293 	}
294 
295 	/* Dispatch task to configure the RNG and register with KCF */
296 	if (ddi_taskq_dispatch(n2rng->n_taskq, n2rng_config_task,
297 	    (void *)n2rng, DDI_SLEEP) != DDI_SUCCESS) {
298 		n2rng_diperror(dip, "ddi_taskq_dispatch() failed");
299 		goto errorexit;
300 	}
301 
302 	return (DDI_SUCCESS);
303 
304 errorexit:
305 	/* Wait for pending config tasks to complete and delete the taskq */
306 	if (n2rng->n_taskq != NULL) {
307 		ddi_taskq_destroy(n2rng->n_taskq);
308 		n2rng->n_taskq = NULL;
309 	}
310 
311 	n2rng_uninit_ctl(n2rng);
312 
313 	(void) n2rng_uninit(n2rng);
314 
315 	if (ncs_hsvc_available == B_TRUE) {
316 		(void) hsvc_unregister(&ncs_hsvc[ncs_version_index]);
317 		ncs_hsvc_available = B_FALSE;
318 	}
319 
320 	mutex_destroy(&n2rng->n_lock);
321 	ddi_soft_state_free(n2rng_softstate, instance);
322 
323 	return (DDI_FAILURE);
324 }
325 
326 static int
327 n2rng_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
328 {
329 	int		instance;
330 	int		rv;
331 	n2rng_t		*n2rng;
332 	timeout_id_t	tid;
333 
334 	instance = ddi_get_instance(dip);
335 	n2rng = (n2rng_t *)ddi_get_soft_state(n2rng_softstate, instance);
336 	if (n2rng == NULL) {
337 		n2rng_diperror(dip, "no soft state in detach");
338 		return (DDI_FAILURE);
339 	}
340 
341 	switch (cmd) {
342 	case DDI_SUSPEND:
343 		return (n2rng_suspend(n2rng));
344 	case DDI_DETACH:
345 		break;
346 	default:
347 		return (DDI_FAILURE);
348 	}
349 
350 	/* Destroy task queue first to insure configuration has completed */
351 	if (n2rng->n_taskq != NULL) {
352 		ddi_taskq_destroy(n2rng->n_taskq);
353 		n2rng->n_taskq = NULL;
354 	}
355 
356 	/* Untimeout pending config retry operations */
357 	mutex_enter(&n2rng->n_lock);
358 	tid = n2rng->n_timeout_id;
359 	n2rng->n_timeout_id = 0;
360 	mutex_exit(&n2rng->n_lock);
361 	if (tid) {
362 		DBG1(n2rng, DCHATTY, "n2rng_detach: untimeout pending retry "
363 		    "id = %x", tid);
364 		(void) untimeout(tid);
365 	}
366 
367 	n2rng_uninit_ctl(n2rng);
368 
369 	/* unregister with KCF---also tears down FIPS state */
370 	rv = n2rng_uninit(n2rng) ? DDI_FAILURE : DDI_SUCCESS;
371 
372 	if (ncs_hsvc_available == B_TRUE) {
373 		(void) hsvc_unregister(&ncs_hsvc[ncs_version_index]);
374 		ncs_hsvc_available = B_FALSE;
375 	}
376 
377 	mutex_destroy(&n2rng->n_lock);
378 	ddi_soft_state_free(n2rng_softstate, instance);
379 
380 	return (rv);
381 }
382 
383 /*ARGSUSED*/
384 static int
385 n2rng_suspend(n2rng_t *n2rng)
386 {
387 	/* unregister with KCF---also tears down FIPS state */
388 	if (n2rng_uninit(n2rng) != DDI_SUCCESS) {
389 		cmn_err(CE_WARN, "n2rng: unable to unregister from KCF");
390 		return (DDI_FAILURE);
391 	}
392 
393 	return (DDI_SUCCESS);
394 }
395 
396 /*ARGSUSED*/
397 static int
398 n2rng_resume(n2rng_t *n2rng)
399 {
400 	/* Assume clock is same speed and all data structures are intact */
401 
402 	/* Re-configure the RNG hardware and register with KCF */
403 	return (n2rng_config(n2rng));
404 }
405 
406 /*
407  * Map hypervisor error code to solaris. Only
408  * H_ENORADDR, H_EBADALIGN, H_EWOULDBLOCK, and EIO
409  * are meaningful to this device. Any other error
410  * codes are mapped EINVAL.
411  */
412 int
413 n2rng_herr2kerr(uint64_t hv_errcode)
414 {
415 	int	s_errcode;
416 
417 	switch (hv_errcode) {
418 	case H_EWOULDBLOCK:
419 		s_errcode = EWOULDBLOCK;
420 		break;
421 	case H_EIO:
422 		s_errcode = EIO;
423 		break;
424 	case H_EBUSY:
425 		s_errcode = EBUSY;
426 		break;
427 	case H_EOK:
428 		s_errcode = 0;
429 		break;
430 	case H_ENOACCESS:
431 		s_errcode = EPERM;
432 		break;
433 	case H_ENORADDR:
434 	case H_EBADALIGN:
435 	default:
436 		s_errcode = EINVAL;
437 		break;
438 	}
439 	return (s_errcode);
440 }
441 
442 /*
443  * Waits approximately delay_sticks counts of the stick register.
444  * Times shorter than one sys clock tick (10ms on most systems) are
445  * done by busy waiting.
446  */
447 void
448 cyclesleep(n2rng_t *n2rng, uint64_t delay_sticks)
449 {
450 	uint64_t	end_stick = gettick() + delay_sticks;
451 	int64_t		sticks_to_wait;
452 	clock_t		sys_ticks_to_wait;
453 	clock_t		usecs_to_wait;
454 
455 	/*CONSTCOND*/
456 	while (1) {
457 		sticks_to_wait = end_stick - gettick();
458 		if (sticks_to_wait <= 0) {
459 			return;
460 		}
461 
462 		usecs_to_wait = sticks_to_wait / n2rng->n_sticks_per_usec;
463 		sys_ticks_to_wait = drv_usectohz(usecs_to_wait);
464 
465 		if (sys_ticks_to_wait > 0) {
466 			/* sleep */
467 			delay(sys_ticks_to_wait);
468 		} else if (usecs_to_wait > 0) {
469 			/* busy wait */
470 			drv_usecwait(usecs_to_wait);
471 		}
472 	}
473 }
474 
475 static void
476 log_internal_errors(uint64_t hverr, char *fname)
477 {
478 	switch (hverr) {
479 	case H_EBADALIGN:
480 		cmn_err(CE_WARN,
481 		    "n2rng: internal alignment "
482 		    "problem");
483 		break;
484 	case H_ENORADDR:
485 		cmn_err(CE_WARN, "n2rng: internal "
486 		    "invalid address");
487 		break;
488 	case H_ENOACCESS:
489 		cmn_err(CE_WARN, "n2rng: access failure");
490 		break;
491 	case H_EWOULDBLOCK:
492 		cmn_err(CE_WARN, "n2rng: hardware busy");
493 		break;
494 	default:
495 		cmn_err(CE_NOTE,
496 		    "n2rng: %s "
497 		    "unexpectedly "
498 		    "returned hverr %ld", fname, hverr);
499 		break;
500 	}
501 }
502 
503 /*
504  * Collects a buffer full of bits, using the specified setup. numbytes
505  * must be a multiple of 8. If a sub-operation fails with EIO (handle
506  * mismatch), returns EIO.  If collect_setupp is NULL, the current
507  * setup is used.  If exit_setupp is NULL, the control configuratin
508  * and state are not set at exit.  WARNING: the buffer must be 8-byte
509  * aligned and in contiguous physical addresses.  Contiguousness is
510  * not checked!
511  */
512 int
513 n2rng_collect_diag_bits(n2rng_t *n2rng, int rngid,
514     n2rng_setup_t *collect_setupp, void *buffer, int numbytes,
515     n2rng_setup_t *exit_setupp, uint64_t exitstate)
516 {
517 	int		rv;
518 	int		override_rv = 0;
519 	uint64_t	hverr;
520 	int		i;
521 	uint64_t	tdelta;
522 	n2rng_setup_t	setupbuffer[2];
523 	n2rng_setup_t	*setupcontigp;
524 	uint64_t	setupphys;
525 	int		numchunks;
526 	boolean_t	rnglooping;
527 	int		busycount = 0;
528 	int		blockcount = 0;
529 
530 	if (numbytes % sizeof (uint64_t)) {
531 		return (EINVAL);
532 	}
533 
534 	if ((uint64_t)buffer % sizeof (uint64_t) != 0) {
535 		return (EINVAL);
536 	}
537 
538 	numchunks = ((numbytes / sizeof (uint64_t)) + RNG_DIAG_CHUNK_SIZE - 1)
539 	    / RNG_DIAG_CHUNK_SIZE;
540 	/*
541 	 * Use setupbuffer[0] if it is contiguous, otherwise
542 	 * setupbuffer[1].
543 	 */
544 	setupcontigp = &setupbuffer[
545 	    CONTIGUOUS(&setupbuffer[0], n2rng_setup_t) ? 0 : 1];
546 	setupphys = va_to_pa(setupcontigp);
547 
548 	/*
549 	 * If a non-null collect_setupp pointer has been provided,
550 	 * push the specified setup into the hardware.
551 	 */
552 	if (collect_setupp != NULL) {
553 		/* copy the specified state to the aligned buffer */
554 		*setupcontigp = *collect_setupp;
555 		rnglooping = B_TRUE;
556 		while (rnglooping) {
557 			hverr = n2rng_ctl_write(n2rng, rngid, setupphys,
558 			    CTL_STATE_HEALTHCHECK,
559 			    n2rng->n_ctl_data->n_watchdog_cycles, &tdelta);
560 			rv = n2rng_herr2kerr(hverr);
561 			switch (hverr) {
562 			case H_EOK:
563 				rnglooping = B_FALSE;
564 				break;
565 			case H_EIO: /* control yanked from us */
566 			case H_ENOACCESS: /* We are not control domain */
567 				return (rv);
568 			case H_EWOULDBLOCK:
569 				/* Data currently not available, try again */
570 				if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
571 					DBG1(n2rng, DHEALTH,
572 					    "n2rng_collect_diag_bits(1) : "
573 					    "exceeded block count of %d",
574 					    RNG_MAX_BLOCK_ATTEMPTS);
575 					return (rv);
576 				} else {
577 					cyclesleep(n2rng, tdelta);
578 				}
579 				break;
580 			case H_EBUSY:
581 				/*
582 				 * A control write is already in progress.
583 				 * Note: This shouldn't happen since
584 				 * n2rng_ctl_write() waits for the
585 				 * write to complete.
586 				 */
587 				if (++busycount > RNG_MAX_BUSY_ATTEMPTS) {
588 					DBG1(n2rng, DHEALTH,
589 					    "n2rng_collect_diag_bits(1): "
590 					    "exceeded busy count of %d",
591 					    RNG_MAX_BUSY_ATTEMPTS);
592 					return (rv);
593 				} else {
594 					delay(RNG_RETRY_BUSY_DELAY);
595 				}
596 				break;
597 			default:
598 				log_internal_errors(hverr, "hv_rng_ctl_write");
599 				override_rv = rv;
600 				goto restore_state;
601 			}
602 		} /* while (rnglooping) */
603 	} /* if (collect_setupp != NULL) */
604 
605 	/* If the caller asks for some bytes, collect the data */
606 	if (numbytes > 0) {
607 		for (i = 0; i < numchunks; i++) {
608 			size_t thisnumbytes = (i == numchunks - 1) ?
609 			    numbytes - i * (RNG_DIAG_CHUNK_SIZE *
610 			    sizeof (uint64_t)) :
611 			    RNG_DIAG_CHUNK_SIZE * sizeof (uint64_t);
612 
613 			/* try until we successfully read a word of data */
614 			rnglooping = B_TRUE;
615 			busycount = 0;
616 			blockcount = 0;
617 			while (rnglooping) {
618 				hverr = n2rng_data_read_diag(n2rng, rngid,
619 				    va_to_pa((uint64_t *)buffer +
620 				    RNG_DIAG_CHUNK_SIZE * i),
621 				    thisnumbytes, &tdelta);
622 				rv = n2rng_herr2kerr(hverr);
623 				switch (hverr) {
624 				case H_EOK:
625 					rnglooping = B_FALSE;
626 					break;
627 				case H_EIO:
628 				case H_ENOACCESS:
629 					return (rv);
630 				case H_EWOULDBLOCK:
631 					/* Data not available, try again */
632 					if (++blockcount >
633 					    RNG_MAX_BLOCK_ATTEMPTS) {
634 						DBG1(n2rng, DHEALTH,
635 						    "n2rng_collect_diag_bits"
636 						    "(2): exceeded block count"
637 						    " of %d",
638 						    RNG_MAX_BLOCK_ATTEMPTS);
639 						return (rv);
640 					} else {
641 						cyclesleep(n2rng, tdelta);
642 					}
643 					break;
644 				default:
645 					log_internal_errors(hverr,
646 					    "hv_rng_data_read_diag");
647 					override_rv = rv;
648 					goto restore_state;
649 				}
650 			} /* while (!rnglooping) */
651 		} /* for */
652 	}
653 
654 restore_state:
655 
656 	/* restore the preferred configuration and set exit state */
657 	if (exit_setupp != NULL) {
658 
659 		*setupcontigp = *exit_setupp;
660 		rnglooping = B_TRUE;
661 		busycount = 0;
662 		blockcount = 0;
663 		while (rnglooping) {
664 			hverr = n2rng_ctl_write(n2rng, rngid, setupphys,
665 			    exitstate, n2rng->n_ctl_data->n_watchdog_cycles,
666 			    &tdelta);
667 			rv = n2rng_herr2kerr(hverr);
668 			switch (hverr) {
669 			case H_EOK:
670 			case H_EIO: /* control yanked from us */
671 			case H_EINVAL: /* some external error, probably */
672 			case H_ENOACCESS: /* We are not control domain */
673 				rnglooping = B_FALSE;
674 				break;
675 			case H_EWOULDBLOCK:
676 				/* Data currently not available, try again */
677 				if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
678 					DBG1(n2rng, DHEALTH,
679 					    "n2rng_collect_diag_bits(3): "
680 					    "exceeded block count of %d",
681 					    RNG_MAX_BLOCK_ATTEMPTS);
682 					return (rv);
683 				} else {
684 					cyclesleep(n2rng, tdelta);
685 				}
686 				break;
687 			case H_EBUSY:
688 				/*
689 				 * A control write is already in progress.
690 				 * Note: This shouldn't happen since
691 				 * n2rng_ctl_write() waits for the
692 				 * write to complete.
693 				 */
694 				if (++busycount > RNG_MAX_BUSY_ATTEMPTS) {
695 					DBG1(n2rng, DHEALTH,
696 					    "n2rng_collect_diag_bits(3): "
697 					    "exceeded busy count of %d",
698 					    RNG_MAX_BUSY_ATTEMPTS);
699 					return (rv);
700 				} else {
701 					delay(RNG_RETRY_BUSY_DELAY);
702 				}
703 				break;
704 			default:
705 				rnglooping = B_FALSE;
706 				log_internal_errors(hverr, "hv_rng_ctl_write");
707 				break;
708 			}
709 		} /* while */
710 	} /* if */
711 
712 	/*
713 	 * override_rv takes care of the case where we abort becuase
714 	 * of some error, but still want to restore the peferred state
715 	 * and return the first error, even if other error occur.
716 	 */
717 	return (override_rv ? override_rv : rv);
718 }
719 
720 int
721 n2rng_getentropy(n2rng_t *n2rng, void *buffer, size_t size)
722 {
723 	int		i, rv = 0;  /* so it works if size is zero */
724 	uint64_t	hverr;
725 	uint64_t	*buffer_w = (uint64_t *)buffer;
726 	int		num_w = size / sizeof (uint64_t);
727 	uint64_t	randval;
728 	uint64_t	randvalphys = va_to_pa(&randval);
729 	uint64_t	tdelta;
730 	int		failcount = 0;
731 	int		blockcount = 0;
732 	boolean_t	rnglooping;
733 
734 	for (i = 0; i < num_w; i++) {
735 		rnglooping = B_TRUE;
736 		while (rnglooping) {
737 			hverr = hv_rng_data_read(randvalphys, &tdelta);
738 			rv = n2rng_herr2kerr(hverr);
739 			switch (hverr) {
740 			case H_EOK:
741 				buffer_w[i] = randval;
742 				failcount = 0;
743 				rnglooping = B_FALSE;
744 				break;
745 			case H_EIO:
746 				/*
747 				 * Either a health check is in progress, or
748 				 * the watchdog timer has expired while running
749 				 * hv api version 2.0 or higher with health
750 				 * checks enabled.
751 				 */
752 				if (n2rng->n_hvapi_major_version < 2) {
753 					/*
754 					 * A health check is in progress.
755 					 * Wait RNG_RETRY_HLCHK_USECS and fail
756 					 * after RNG_MAX_DATA_READ_ATTEMPTS
757 					 * failures.
758 					 */
759 					if (++failcount >
760 					    RNG_MAX_DATA_READ_ATTEMPTS) {
761 						DBG2(n2rng, DHEALTH,
762 						    "n2rng_getentropy: exceeded"
763 						    "EIO count of %d on cpu %d",
764 						    RNG_MAX_DATA_READ_ATTEMPTS,
765 						    CPU->cpu_id);
766 						goto exitpoint;
767 					} else {
768 						delay(drv_usectohz
769 						    (RNG_RETRY_HLCHK_USECS));
770 					}
771 				} else {
772 					/*
773 					 * Just return the error. If a flurry of
774 					 * random data requests happen to occur
775 					 * during a health check, there are
776 					 * multiple levels of defense:
777 					 * - 2.0 HV provides random data pool
778 					 * - FIPS algorithm tolerates failures
779 					 * - Software failover
780 					 * - Automatic configuration retries
781 					 * - Hardware failover on some systems
782 					 */
783 					goto exitpoint;
784 				}
785 				break;
786 			case H_EWOULDBLOCK:
787 				/* Data currently not available, try again */
788 				if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
789 					DBG1(n2rng, DHEALTH,
790 					    "n2rng_getentropy: "
791 					    "exceeded block count of %d",
792 					    RNG_MAX_BLOCK_ATTEMPTS);
793 					goto exitpoint;
794 				} else {
795 					cyclesleep(n2rng, tdelta);
796 				}
797 				break;
798 			default:
799 				log_internal_errors(hverr, "hv_rng_data_read");
800 				goto exitpoint;
801 			}
802 		} /* while */
803 	} /* for */
804 
805 exitpoint:
806 	return (rv);
807 }
808 
809 uint64_t
810 n2rng_ctl_read(n2rng_t *n2rng, int rngid, uint64_t ctlregs_pa, uint64_t *state,
811     uint64_t *tdelta, uint64_t *wdelta)
812 {
813 	uint64_t	rv;
814 	uint64_t	wstatus;
815 
816 	/* Call correct hv function based on api version */
817 	if (n2rng->n_hvapi_major_version == 2) {
818 		rv = hv_rng_ctl_read_v2(ctlregs_pa, (uint64_t)rngid, state,
819 		    tdelta, wdelta, &wstatus);
820 		if (rv == 0) {
821 			rv = wstatus;
822 		}
823 	} else {
824 		rv = hv_rng_ctl_read(ctlregs_pa, state, tdelta);
825 		*wdelta = 0;
826 	}
827 
828 	return (rv);
829 }
830 
831 uint64_t
832 n2rng_ctl_wait(n2rng_t *n2rng, int rngid)
833 {
834 	uint64_t	state;
835 	uint64_t	tdelta;
836 	uint64_t	wdelta;
837 	uint64_t	wstatus;
838 	boolean_t	rnglooping = B_TRUE;
839 	uint64_t	rv;
840 	n2rng_setup_t	setupbuffer[2];
841 	n2rng_setup_t	*setupcontigp;
842 	uint64_t	setupphys;
843 	int		busycount = 0;
844 	int		blockcount = 0;
845 
846 	/*
847 	 * Use setupbuffer[0] if it is contiguous, otherwise
848 	 * setupbuffer[1].
849 	 */
850 	setupcontigp = &setupbuffer[
851 	    CONTIGUOUS(&setupbuffer[0], n2rng_setup_t) ? 0 : 1];
852 	setupphys = va_to_pa(setupcontigp);
853 
854 	while (rnglooping) {
855 		rv = hv_rng_ctl_read_v2(setupphys, (uint64_t)rngid, &state,
856 		    &tdelta, &wdelta, &wstatus);
857 		switch (rv) {
858 		case H_EOK:
859 			rv = wstatus;
860 			rnglooping = B_FALSE;
861 			break;
862 		case H_EWOULDBLOCK:
863 			/* Data currently not available, try again */
864 			if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
865 				DBG1(n2rng, DHEALTH, "n2rng_ctl_wait: "
866 				    "exceeded block count of %d",
867 				    RNG_MAX_BLOCK_ATTEMPTS);
868 				return (rv);
869 			} else {
870 				cyclesleep(n2rng, tdelta);
871 			}
872 			break;
873 		case H_EBUSY:
874 			/* Control write still pending, try again */
875 			if (++busycount > RNG_MAX_BUSY_ATTEMPTS) {
876 				DBG1(n2rng, DHEALTH, "n2rng_ctl_wait: "
877 				    "exceeded busy count of %d",
878 				    RNG_MAX_BUSY_ATTEMPTS);
879 				return (rv);
880 			} else {
881 				delay(RNG_RETRY_BUSY_DELAY);
882 			}
883 			break;
884 		default:
885 			log_internal_errors(rv, "n2rng_ctl_wait");
886 			rnglooping = B_FALSE;
887 		}
888 	} /* while (rnglooping) */
889 
890 	return (rv);
891 }
892 
893 uint64_t
894 n2rng_ctl_write(n2rng_t *n2rng, int rngid, uint64_t ctlregs_pa,
895     uint64_t newstate, uint64_t wtimeout, uint64_t *tdelta)
896 {
897 	uint64_t	rv;
898 
899 	/* Call correct hv function based on api version */
900 	if (n2rng->n_hvapi_major_version == 2) {
901 		rv = hv_rng_ctl_write_v2(ctlregs_pa, newstate, wtimeout,
902 		    (uint64_t)rngid);
903 		if (rv == H_EOK) {
904 			/* Wait for control registers to be written */
905 			rv = n2rng_ctl_wait(n2rng, rngid);
906 		}
907 		*tdelta = RNG_DEFAULT_ACCUMULATE_CYCLES;
908 	} else {
909 		rv = hv_rng_ctl_write(ctlregs_pa, newstate, wtimeout, tdelta);
910 	}
911 
912 	return (rv);
913 }
914 
915 uint64_t
916 n2rng_data_read_diag(n2rng_t *n2rng, int rngid, uint64_t data_pa,
917     size_t  datalen, uint64_t *tdelta)
918 {
919 	uint64_t	rv;
920 
921 	/* Call correct hv function based on api version */
922 	if (n2rng->n_hvapi_major_version == 2) {
923 		rv = hv_rng_data_read_diag_v2(data_pa, datalen,
924 		    (uint64_t)rngid, tdelta);
925 		if (*tdelta == 0) {
926 			*tdelta = RNG_DEFAULT_ACCUMULATE_CYCLES;
927 		}
928 	} else {
929 		rv = hv_rng_data_read_diag(data_pa, datalen, tdelta);
930 	}
931 
932 	return (rv);
933 }
934 
935 uint64_t
936 n2rng_check_ctl_access(n2rng_t *n2rng)
937 {
938 	uint64_t	rv;
939 	uint64_t	unused_64;
940 
941 	/* Call correct hv function based on api version */
942 	if (n2rng->n_hvapi_major_version == 2) {
943 		/*
944 		 * Attempt to read control registers with invalid ID and data
945 		 * just to see if we get an access error
946 		 */
947 		rv = hv_rng_ctl_read_v2(NULL, N2RNG_INVALID_ID,
948 		    &unused_64, &unused_64, &unused_64, &unused_64);
949 	} else {
950 		rv = hv_rng_get_diag_control();
951 	}
952 
953 	return (rv);
954 }
955 
956 /*
957  * n2rng_config_retry()
958  *
959  * Schedule a timed call to n2rng_config() if one is not already pending
960  */
961 void
962 n2rng_config_retry(n2rng_t *n2rng, clock_t seconds)
963 {
964 	mutex_enter(&n2rng->n_lock);
965 	/* Check if a config retry is already pending */
966 	if (n2rng->n_timeout_id) {
967 		DBG1(n2rng, DCFG, "n2rng_config_retry: retry pending "
968 		    "id = %x", n2rng->n_timeout_id);
969 	} else {
970 		n2rng->n_timeout_id = timeout(n2rng_config_task,
971 		    (void *)n2rng, drv_usectohz(seconds * SECOND));
972 		DBG2(n2rng, DCFG, "n2rng_config_retry: retry scheduled in "
973 		    "%d seconds, id = %x", seconds, n2rng->n_timeout_id);
974 	}
975 	mutex_exit(&n2rng->n_lock);
976 }
977 
978 static uint64_t
979 sticks_per_usec(void)
980 {
981 	uint64_t starttick = gettick();
982 	hrtime_t starttime = gethrtime();
983 	uint64_t endtick;
984 	hrtime_t endtime;
985 
986 	delay(2);
987 
988 	endtick = gettick();
989 	endtime = gethrtime();
990 
991 	return ((1000 * (endtick - starttick)) / (endtime - starttime));
992 }
993 
994 static int
995 n2rng_init_ctl(n2rng_t *n2rng)
996 {
997 	int		rv;
998 	int		hverr;
999 	rng_entry_t	*rng;
1000 	int		rngid;
1001 	int		blockcount = 0;
1002 
1003 	n2rng->n_ctl_data = NULL;
1004 
1005 	/* Attempt to gain diagnostic control */
1006 	do {
1007 		hverr = n2rng_check_ctl_access(n2rng);
1008 		rv = n2rng_herr2kerr(hverr);
1009 		if ((hverr == H_EWOULDBLOCK) &&
1010 		    (++blockcount > RNG_MAX_BUSY_ATTEMPTS)) {
1011 			DBG1(n2rng, DHEALTH, "n2rng_int_ctl: exceeded busy "
1012 			    "count of %d", RNG_MAX_BUSY_ATTEMPTS);
1013 			return (rv);
1014 		} else {
1015 			delay(RNG_RETRY_BUSY_DELAY);
1016 		}
1017 	} while (hverr == H_EWOULDBLOCK);
1018 
1019 	/*
1020 	 * If attempt fails with EPERM, the driver is not running in the
1021 	 * control domain
1022 	 */
1023 	if (rv == EPERM) {
1024 		DBG0(n2rng, DATTACH,
1025 		    "n2rng_init_ctl: Running in guest domain");
1026 		return (DDI_SUCCESS);
1027 	}
1028 
1029 	/* Allocate control stucture only used in control domain */
1030 	n2rng->n_ctl_data = kmem_alloc(sizeof (rng_ctl_data_t), KM_SLEEP);
1031 	n2rng->n_ctl_data->n_num_rngs_online = 0;
1032 
1033 	/*
1034 	 * If running with an API version less than 2.0 default to one rng.
1035 	 * Otherwise get number of rngs from device properties.
1036 	 */
1037 	if (n2rng->n_hvapi_major_version < 2) {
1038 		n2rng->n_ctl_data->n_num_rngs = 1;
1039 	} else {
1040 		n2rng->n_ctl_data->n_num_rngs =
1041 		    ddi_getprop(DDI_DEV_T_ANY, n2rng->n_dip,
1042 		    DDI_PROP_CANSLEEP | DDI_PROP_DONTPASS,
1043 		    N2RNG_PROP_NUM_UNITS, 0);
1044 		if (n2rng->n_ctl_data->n_num_rngs == 0) {
1045 			cmn_err(CE_WARN, "n2rng: %s property not found",
1046 			    N2RNG_PROP_NUM_UNITS);
1047 			return (DDI_FAILURE);
1048 		}
1049 	}
1050 
1051 	/* Allocate space for all rng entries */
1052 	n2rng->n_ctl_data->n_rngs =
1053 	    kmem_zalloc(n2rng->n_ctl_data->n_num_rngs *
1054 	    sizeof (rng_entry_t), KM_SLEEP);
1055 
1056 	/* Get accumulate cycles from .conf file. */
1057 	n2rng->n_ctl_data->n_accumulate_cycles =
1058 	    ddi_getprop(DDI_DEV_T_ANY, n2rng->n_dip,
1059 	    DDI_PROP_CANSLEEP | DDI_PROP_DONTPASS, "acc_cycles",
1060 	    RNG_DEFAULT_ACCUMULATE_CYCLES);
1061 
1062 	/* Get health check frequency from .conf file */
1063 	n2rng->n_ctl_data->n_hc_secs = ddi_getprop(DDI_DEV_T_ANY, n2rng->n_dip,
1064 	    DDI_PROP_CANSLEEP | DDI_PROP_DONTPASS, "hc_seconds",
1065 	    RNG_DEFAULT_HC_SECS);
1066 
1067 	/* API versions prior to 2.0 do not support health checks */
1068 	if ((n2rng->n_hvapi_major_version < 2) &&
1069 	    (n2rng->n_ctl_data->n_hc_secs > 0)) {
1070 		cmn_err(CE_WARN, "n2rng: Hyperviser api "
1071 		    "version %d.%d does not support health checks",
1072 		    n2rng->n_hvapi_major_version,
1073 		    n2rng->n_hvapi_minor_version);
1074 		n2rng->n_ctl_data->n_hc_secs = 0;
1075 	}
1076 
1077 
1078 	/* Calculate watchdog timeout value */
1079 	if (n2rng->n_ctl_data->n_hc_secs <= 0) {
1080 		n2rng->n_ctl_data->n_watchdog_cycles = 0;
1081 	} else {
1082 		n2rng->n_ctl_data->n_watchdog_cycles =
1083 		    ((uint64_t)(RNG_EXTRA_WATCHDOG_SECS) +
1084 		    n2rng->n_ctl_data->n_hc_secs) *
1085 		    n2rng->n_sticks_per_usec * 1000000;
1086 	}
1087 
1088 	/*
1089 	 * Set some plausible state into the preferred configuration.
1090 	 * The intent is that the health check will immediately overwrite it.
1091 	 */
1092 	for (rngid = 0; rngid < n2rng->n_ctl_data->n_num_rngs; rngid++) {
1093 
1094 		rng = &n2rng->n_ctl_data->n_rngs[rngid];
1095 
1096 		rng->n_preferred_config.ctlwds[0].word = 0;
1097 		rng->n_preferred_config.ctlwds[0].fields.rnc_anlg_sel =
1098 		    N2RNG_NOANALOGOUT;
1099 		rng->n_preferred_config.ctlwds[0].fields.rnc_cnt =
1100 		    RNG_DEFAULT_ACCUMULATE_CYCLES;
1101 		rng->n_preferred_config.ctlwds[0].fields.rnc_mode =
1102 		    RNG_MODE_NORMAL;
1103 		rng->n_preferred_config.ctlwds[1].word =
1104 		    rng->n_preferred_config.ctlwds[0].word;
1105 		rng->n_preferred_config.ctlwds[2].word =
1106 		    rng->n_preferred_config.ctlwds[0].word;
1107 		rng->n_preferred_config.ctlwds[3].word =
1108 		    rng->n_preferred_config.ctlwds[0].word;
1109 		rng->n_preferred_config.ctlwds[0].fields.rnc_vcoctl = 1;
1110 		rng->n_preferred_config.ctlwds[0].fields.rnc_selbits = 1;
1111 		rng->n_preferred_config.ctlwds[1].fields.rnc_vcoctl = 2;
1112 		rng->n_preferred_config.ctlwds[1].fields.rnc_selbits = 2;
1113 		rng->n_preferred_config.ctlwds[2].fields.rnc_vcoctl = 3;
1114 		rng->n_preferred_config.ctlwds[2].fields.rnc_selbits = 4;
1115 		rng->n_preferred_config.ctlwds[3].fields.rnc_vcoctl = 0;
1116 		rng->n_preferred_config.ctlwds[3].fields.rnc_selbits = 7;
1117 	}
1118 
1119 	n2rng_setcontrol(n2rng);
1120 	DBG2(n2rng, DATTACH,
1121 	    "n2rng_init_ctl: Running in control domain with %d rng device%s",
1122 	    n2rng->n_ctl_data->n_num_rngs,
1123 	    (n2rng->n_ctl_data->n_num_rngs == 1) ? "" : "s");
1124 	DBG2(n2rng, DCFG,
1125 	    "n2rng_init_ctl: n_sticks_per_usec = %ld, n_hc_secs = %d",
1126 	    n2rng->n_sticks_per_usec,
1127 	    n2rng->n_ctl_data->n_hc_secs);
1128 	DBG2(n2rng, DCFG,
1129 	    "n2rng_init_ctl: n_watchdog_cycles = %ld, "
1130 	    "n_accumulate_cycles = %ld", n2rng->n_ctl_data->n_watchdog_cycles,
1131 	    n2rng->n_ctl_data->n_accumulate_cycles);
1132 
1133 	return (DDI_SUCCESS);
1134 }
1135 
1136 static void
1137 n2rng_uninit_ctl(n2rng_t *n2rng)
1138 {
1139 	if (n2rng->n_ctl_data) {
1140 		if (n2rng->n_ctl_data->n_num_rngs) {
1141 			kmem_free(n2rng->n_ctl_data->n_rngs,
1142 			    n2rng->n_ctl_data->n_num_rngs *
1143 			    sizeof (rng_entry_t));
1144 			n2rng->n_ctl_data->n_rngs = NULL;
1145 			n2rng->n_ctl_data->n_num_rngs = 0;
1146 		}
1147 		kmem_free(n2rng->n_ctl_data, sizeof (rng_ctl_data_t));
1148 		n2rng->n_ctl_data = NULL;
1149 	}
1150 }
1151 
1152 
1153 /*
1154  * n2rng_config_test()
1155  *
1156  * Attempt read random data to see if the rng is configured.
1157  */
1158 int
1159 n2rng_config_test(n2rng_t *n2rng)
1160 {
1161 	int		rv = 0;
1162 	uint64_t	hverr;
1163 	uint64_t	randval = 0;
1164 	uint64_t	randvalphys = va_to_pa(&randval);
1165 	uint64_t	tdelta;
1166 	int		failcount = 0;
1167 	int		blockcount = 0;
1168 	boolean_t	rnglooping = B_TRUE;
1169 
1170 	while (rnglooping) {
1171 		hverr = hv_rng_data_read(randvalphys, &tdelta);
1172 		rv = n2rng_herr2kerr(hverr);
1173 		switch (hverr) {
1174 		case H_EOK:
1175 			failcount = 0;
1176 			rnglooping = B_FALSE;
1177 			break;
1178 		case H_EIO:
1179 			/*
1180 			 * A health check is in progress.
1181 			 * Wait RNG_RETRY_HLCHK_USECS and fail
1182 			 * after RNG_MAX_DATA_READ_ATTEMPTS
1183 			 * failures.
1184 			 */
1185 			if (++failcount > RNG_MAX_DATA_READ_ATTEMPTS) {
1186 				goto exitpoint;
1187 			} else {
1188 				delay(drv_usectohz(RNG_RETRY_HLCHK_USECS));
1189 			}
1190 			break;
1191 		case H_EWOULDBLOCK:
1192 			/* Data currently not available, try again */
1193 			if (++blockcount > RNG_MAX_BLOCK_ATTEMPTS) {
1194 				DBG1(n2rng, DHEALTH, "n2rng_config_test: "
1195 				    "exceeded block count of %d",
1196 				    RNG_MAX_BLOCK_ATTEMPTS);
1197 				goto exitpoint;
1198 			} else {
1199 				cyclesleep(n2rng, tdelta);
1200 			}
1201 			break;
1202 		case H_ENOACCESS:
1203 			/* An rng error has occured during health check */
1204 			goto exitpoint;
1205 		default:
1206 			log_internal_errors(hverr, "hv_rng_data_read");
1207 			goto exitpoint;
1208 		}
1209 	} /* while */
1210 
1211 exitpoint:
1212 	return (rv);
1213 }
1214 
1215 /*
1216  * n2rng_config()
1217  *
1218  * Run health check on the RNG hardware
1219  * Configure the RNG hardware
1220  * Register with crypto framework
1221  */
1222 static int
1223 n2rng_config(n2rng_t *n2rng)
1224 {
1225 	int		rv;
1226 	rng_entry_t	*rng;
1227 	int		rngid;
1228 
1229 	/*
1230 	 * Run health checks and configure rngs if running in control domain,
1231 	 * otherwise just check if at least one rng is available.
1232 	 */
1233 	if (n2rng_iscontrol(n2rng)) {
1234 
1235 		for (rngid = 0; rngid < n2rng->n_ctl_data->n_num_rngs;
1236 		    rngid++) {
1237 
1238 			rng = &n2rng->n_ctl_data->n_rngs[rngid];
1239 
1240 			/* Only test rngs that have not already failed */
1241 			if (rng->n_rng_state == CTL_STATE_ERROR) {
1242 				continue;
1243 			}
1244 
1245 			if ((n2rng->n_binding == N2RNG_CPU_VF) &&
1246 			    (n2rng->n_hvapi_major_version < 2)) {
1247 				/*
1248 				 * Since api versions prior to 2.0 do not
1249 				 * support multiple rngs, bind to the current
1250 				 * processor for the entire health check
1251 				 * process.
1252 				 */
1253 				thread_affinity_set(curthread, CPU_CURRENT);
1254 				DBG1(n2rng, DCFG, "n2rng_config: "
1255 				    "Configuring single rng from cpu %d",
1256 				    CPU->cpu_id);
1257 				rv = n2rng_do_health_check(n2rng, rngid);
1258 				thread_affinity_clear(curthread);
1259 			} else {
1260 				rv = n2rng_do_health_check(n2rng, rngid);
1261 			}
1262 
1263 			switch (rv) {
1264 			case 0:
1265 				/*
1266 				 * Successful, increment online count if
1267 				 * necessary
1268 				 */
1269 				DBG1(n2rng, DCFG, "n2rng_config: rng(%d) "
1270 				    "passed health checks", rngid);
1271 				if (rng->n_rng_state != CTL_STATE_CONFIGURED) {
1272 					rng->n_rng_state =
1273 					    CTL_STATE_CONFIGURED;
1274 					n2rng->n_ctl_data->n_num_rngs_online++;
1275 				}
1276 				break;
1277 			default:
1278 				/*
1279 				 * Health checks failed, decrement online
1280 				 * count if necessary
1281 				 */
1282 				cmn_err(CE_WARN, "n2rng: rng(%d) "
1283 				    "failed health checks", rngid);
1284 				if (rng->n_rng_state == CTL_STATE_CONFIGURED) {
1285 					n2rng->n_ctl_data->n_num_rngs_online--;
1286 				}
1287 				rng->n_rng_state = CTL_STATE_ERROR;
1288 				break;
1289 			}
1290 		}
1291 		DBG2(n2rng, DCFG, "n2rng_config: %d rng%s online",
1292 		    n2rng->n_ctl_data->n_num_rngs_online,
1293 		    (n2rng->n_ctl_data->n_num_rngs_online == 1) ? "" : "s");
1294 
1295 		/* Check if all rngs have failed */
1296 		if (n2rng->n_ctl_data->n_num_rngs_online == 0) {
1297 			cmn_err(CE_WARN, "n2rng: %d RNG device%s failed",
1298 			    n2rng->n_ctl_data->n_num_rngs,
1299 			    (n2rng->n_ctl_data->n_num_rngs == 1) ? "" : "s");
1300 			goto errorexit;
1301 		} else {
1302 			n2rng_setconfigured(n2rng);
1303 		}
1304 	} else {
1305 		/* Running in guest domain, just check if rng is configured */
1306 		rv = n2rng_config_test(n2rng);
1307 		switch (rv) {
1308 		case 0:
1309 			n2rng_setconfigured(n2rng);
1310 			break;
1311 		case EIO:
1312 			/* Don't set configured to force a retry */
1313 			break;
1314 		default:
1315 			goto errorexit;
1316 		}
1317 	}
1318 
1319 	/*
1320 	 * Initialize FIPS state and register with KCF if we have at least one
1321 	 * RNG configured.  Otherwise schedule a retry if all rngs have not
1322 	 * failed.
1323 	 */
1324 	if (n2rng_isconfigured(n2rng)) {
1325 
1326 		if (n2rng_init(n2rng) != DDI_SUCCESS) {
1327 			cmn_err(CE_WARN, "n2rng: unable to register with KCF");
1328 			goto errorexit;
1329 		}
1330 
1331 		/*
1332 		 * Schedule a retry if running in the control domain and a
1333 		 * health check time has been specified.
1334 		 */
1335 		if (n2rng_iscontrol(n2rng) &&
1336 		    (n2rng->n_ctl_data->n_hc_secs > 0)) {
1337 			n2rng_config_retry(n2rng,
1338 			    n2rng->n_ctl_data->n_hc_secs);
1339 		}
1340 	} else if (!n2rng_isfailed(n2rng)) {
1341 		/* Schedule a retry if one is not already pending */
1342 		n2rng_config_retry(n2rng, RNG_CFG_RETRY_SECS);
1343 	}
1344 	return (DDI_SUCCESS);
1345 
1346 errorexit:
1347 	/* Unregister from kCF if we are registered */
1348 	(void) n2rng_unregister_provider(n2rng);
1349 	n2rng_setfailed(n2rng);
1350 	cmn_err(CE_WARN, "n2rng: hardware failure detected");
1351 	return (DDI_FAILURE);
1352 }
1353 
1354 /*
1355  * n2rng_config_task()
1356  *
1357  * Call n2rng_config() from the task queue or after a timeout, ignore result.
1358  */
1359 static void
1360 n2rng_config_task(void *targ)
1361 {
1362 	n2rng_t *n2rng = (n2rng_t *)targ;
1363 
1364 	mutex_enter(&n2rng->n_lock);
1365 	n2rng->n_timeout_id = 0;
1366 	mutex_exit(&n2rng->n_lock);
1367 	(void) n2rng_config(n2rng);
1368 }
1369