xref: /titanic_41/usr/src/uts/sun4/os/x_call.c (revision 7014882c6a3672fd0e5d60200af8643ae53c5928)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/systm.h>
27 #include <sys/archsystm.h>
28 #include <sys/machsystm.h>
29 #include <sys/cpuvar.h>
30 #include <sys/intreg.h>
31 #include <sys/x_call.h>
32 #include <sys/cmn_err.h>
33 #include <sys/membar.h>
34 #include <sys/disp.h>
35 #include <sys/debug.h>
36 #include <sys/privregs.h>
37 #include <sys/xc_impl.h>
38 #include <sys/ivintr.h>
39 #include <sys/dmv.h>
40 #include <sys/sysmacros.h>
41 
42 #ifdef TRAPTRACE
43 uint_t x_dstat[NCPU][XC_LOOP_EXIT+1];
44 uint_t x_rstat[NCPU][4];
45 #endif /* TRAPTRACE */
46 
47 static uint64_t xc_serv_inum;	/* software interrupt number for xc_serv() */
48 static uint64_t xc_loop_inum;	/* software interrupt number for xc_loop() */
49 kmutex_t xc_sys_mutex;		/* protect xcall session and xc_mbox */
50 int xc_spl_enter[NCPU];		/* protect sending x-call */
51 static int xc_holder = -1; /* the cpu who initiates xc_attention, 0 is valid */
52 
53 /*
54  * Mail box for handshaking and xcall request; protected by xc_sys_mutex
55  */
56 static struct xc_mbox {
57 	xcfunc_t *xc_func;
58 	uint64_t xc_arg1;
59 	uint64_t xc_arg2;
60 	cpuset_t xc_cpuset;
61 	volatile uint_t	xc_state;
62 } xc_mbox[NCPU];
63 
64 uint64_t xc_tick_limit;		/* send_mondo() tick limit value */
65 uint64_t xc_tick_limit_scale = 1;	/* scale used to increase the limit */
66 uint64_t xc_tick_jump_limit;	/* send_mondo() irregular tick jump limit */
67 uint64_t xc_sync_tick_limit;	/* timeout limit for xt_sync() calls */
68 
69 /* timeout value for xcalls to be received by the target CPU */
70 uint64_t xc_mondo_time_limit;
71 
72 /* timeout value for xcall functions to be executed on the target CPU */
73 uint64_t xc_func_time_limit;
74 
75 uint64_t xc_scale = 1;	/* scale used to calculate timeout limits */
76 uint64_t xc_mondo_multiplier = 10;
77 
78 uint_t sendmondo_in_recover;
79 
80 /*
81  * sending x-calls
82  */
83 void	init_mondo(xcfunc_t *func, uint64_t arg1, uint64_t arg2);
84 void	send_one_mondo(int cpuid);
85 void	send_mondo_set(cpuset_t set);
86 
87 /*
88  * Adjust xc_attention timeout if a faster cpu is dynamically added.
89  * Ignore the dynamic removal of a cpu that would lower these timeout
90  * values.
91  */
92 static int
93 xc_func_timeout_adj(cpu_setup_t what, int cpuid) {
94 	uint64_t freq = cpunodes[cpuid].clock_freq;
95 
96 	switch (what) {
97 	case CPU_ON:
98 	case CPU_INIT:
99 	case CPU_CONFIG:
100 	case CPU_CPUPART_IN:
101 		if (freq * xc_scale > xc_mondo_time_limit) {
102 			xc_mondo_time_limit = freq * xc_scale;
103 			xc_func_time_limit = xc_mondo_time_limit *
104 			    xc_mondo_multiplier;
105 		}
106 		break;
107 	case CPU_OFF:
108 	case CPU_UNCONFIG:
109 	case CPU_CPUPART_OUT:
110 	default:
111 		break;
112 	}
113 
114 	return (0);
115 }
116 
117 /*
118  * xc_init - initialize x-call related locks
119  */
120 void
121 xc_init(void)
122 {
123 	int pix;
124 	uint64_t maxfreq = 0;
125 
126 	mutex_init(&xc_sys_mutex, NULL, MUTEX_SPIN,
127 	    (void *)ipltospl(XCALL_PIL));
128 
129 #ifdef TRAPTRACE
130 	/* Initialize for all possible CPUs. */
131 	for (pix = 0; pix < NCPU; pix++) {
132 		XC_STAT_INIT(pix);
133 	}
134 #endif /* TRAPTRACE */
135 
136 	xc_serv_inum = add_softintr(XCALL_PIL, (softintrfunc)xc_serv, 0,
137 	    SOFTINT_MT);
138 	xc_loop_inum = add_softintr(XCALL_PIL, (softintrfunc)xc_loop, 0,
139 	    SOFTINT_MT);
140 
141 	/*
142 	 * Initialize the calibrated tick limit for send_mondo.
143 	 * The value represents the maximum tick count to wait.
144 	 */
145 	xc_tick_limit =
146 	    ((uint64_t)sys_tick_freq * XC_SEND_MONDO_MSEC) / 1000;
147 	xc_tick_jump_limit = xc_tick_limit / 32;
148 	xc_tick_limit *= xc_tick_limit_scale;
149 	xc_sync_tick_limit = xc_tick_limit;
150 
151 	/*
152 	 * Maximum number of loops to wait before timing out in xc_attention.
153 	 */
154 	for (pix = 0; pix < NCPU; pix++) {
155 		maxfreq = MAX(cpunodes[pix].clock_freq, maxfreq);
156 	}
157 	xc_mondo_time_limit = maxfreq * xc_scale;
158 	register_cpu_setup_func((cpu_setup_func_t *)xc_func_timeout_adj, NULL);
159 
160 	/*
161 	 * Maximum number of loops to wait for a xcall function to be
162 	 * executed on the target CPU.
163 	 */
164 	xc_func_time_limit = xc_mondo_time_limit * xc_mondo_multiplier;
165 }
166 
167 /*
168  * The following routines basically provide callers with two kinds of
169  * inter-processor interrupt services:
170  *	1. cross calls (x-calls) - requests are handled at target cpu's TL=0
171  *	2. cross traps (c-traps) - requests are handled at target cpu's TL>0
172  *
173  * Although these routines protect the services from migrating to other cpus
174  * "after" they are called, it is the caller's choice or responsibility to
175  * prevent the cpu migration "before" calling them.
176  *
177  * X-call routines:
178  *
179  *	xc_one()  - send a request to one processor
180  *	xc_some() - send a request to some processors
181  *	xc_all()  - send a request to all processors
182  *
183  *	Their common parameters:
184  *		func - a TL=0 handler address
185  *		arg1 and arg2  - optional
186  *
187  *	The services provided by x-call routines allow callers
188  *	to send a request to target cpus to execute a TL=0
189  *	handler.
190  *	The interface of the registers of the TL=0 handler:
191  *		%o0: arg1
192  *		%o1: arg2
193  *
194  * X-trap routines:
195  *
196  *	xt_one()  - send a request to one processor
197  *	xt_some() - send a request to some processors
198  *	xt_all()  - send a request to all processors
199  *
200  *	Their common parameters:
201  *		func - a TL>0 handler address or an interrupt number
202  *		arg1, arg2
203  *		       optional when "func" is an address;
204  *		       0        when "func" is an interrupt number
205  *
206  *	If the request of "func" is a kernel address, then
207  *	the target cpu will execute the request of "func" with
208  *	args at "TL>0" level.
209  *	The interface of the registers of the TL>0 handler:
210  *		%g1: arg1
211  *		%g2: arg2
212  *
213  *	If the request of "func" is not a kernel address, then it has
214  *	to be an assigned interrupt number through add_softintr().
215  *	An interrupt number is an index to the interrupt vector table,
216  *	which entry contains an interrupt handler address with its
217  *	corresponding interrupt level and argument.
218  *	The target cpu will arrange the request to be serviced according
219  *	to its pre-registered information.
220  *	args are assumed to be zeros in this case.
221  *
222  * In addition, callers are allowed to capture and release cpus by
223  * calling the routines: xc_attention() and xc_dismissed().
224  */
225 
226 /*
227  * spl_xcall - set PIL to xcall level
228  */
229 int
230 spl_xcall(void)
231 {
232 	return (splr(XCALL_PIL));
233 }
234 
235 /*
236  * xt_one - send a "x-trap" to a cpu
237  */
238 void
239 xt_one(int cix, xcfunc_t *func, uint64_t arg1, uint64_t arg2)
240 {
241 	if (!CPU_IN_SET(cpu_ready_set, cix)) {
242 		return;
243 	}
244 	xt_one_unchecked(cix, func, arg1, arg2);
245 }
246 
247 /*
248  * xt_one_unchecked - send a "x-trap" to a cpu without checking for its
249  * existance in cpu_ready_set
250  */
251 void
252 xt_one_unchecked(int cix, xcfunc_t *func, uint64_t arg1, uint64_t arg2)
253 {
254 	int lcx;
255 	int opl;
256 	cpuset_t tset;
257 
258 	/*
259 	 * Make sure the function address will not be interpreted as a
260 	 * dmv interrupt
261 	 */
262 	ASSERT(!DMV_IS_DMV(func));
263 
264 	/*
265 	 * It's illegal to send software inums through the cross-trap
266 	 * interface.
267 	 */
268 	ASSERT((uintptr_t)func >= KERNELBASE);
269 
270 	CPUSET_ZERO(tset);
271 
272 	XC_SPL_ENTER(lcx, opl);			/* lcx set by the macro */
273 
274 	CPUSET_ADD(tset, cix);
275 
276 	if (cix == lcx) {
277 		/*
278 		 * same cpu - use software fast trap
279 		 */
280 		send_self_xcall(CPU, arg1, arg2, func);
281 		XC_STAT_INC(x_dstat[lcx][XT_ONE_SELF]);
282 		XC_TRACE(XT_ONE_SELF, &tset, func, arg1, arg2);
283 	} else {	/* other cpu - send a mondo to the target cpu */
284 		/*
285 		 * other cpu - send a mondo to the target cpu
286 		 */
287 		XC_TRACE(XT_ONE_OTHER, &tset, func, arg1, arg2);
288 		init_mondo(func, arg1, arg2);
289 		send_one_mondo(cix);
290 		XC_STAT_INC(x_dstat[lcx][XT_ONE_OTHER]);
291 	}
292 	XC_SPL_EXIT(lcx, opl);
293 }
294 
295 /*
296  * xt_some - send a "x-trap" to some cpus
297  */
298 void
299 xt_some(cpuset_t cpuset, xcfunc_t *func, uint64_t arg1, uint64_t arg2)
300 {
301 	int lcx;
302 	int opl;
303 	cpuset_t xc_cpuset, tset;
304 
305 	/*
306 	 * Make sure the function address will not be interpreted as a
307 	 * dmv interrupt
308 	 */
309 	ASSERT(!DMV_IS_DMV(func));
310 
311 	/*
312 	 * It's illegal to send software inums through the cross-trap
313 	 * interface.
314 	 */
315 	ASSERT((uintptr_t)func >= KERNELBASE);
316 
317 	CPUSET_ZERO(tset);
318 
319 	XC_SPL_ENTER(lcx, opl);		/* lcx set by the macro */
320 
321 	CPUSET_ADD(tset, lcx);
322 
323 	/*
324 	 * only send to the CPU_READY ones
325 	 */
326 	xc_cpuset = cpu_ready_set;
327 	CPUSET_AND(xc_cpuset, cpuset);
328 
329 	/*
330 	 * send to nobody; just return
331 	 */
332 	if (CPUSET_ISNULL(xc_cpuset)) {
333 		XC_SPL_EXIT(lcx, opl);
334 		return;
335 	}
336 
337 	/*
338 	 * don't send mondo to self
339 	 */
340 	if (CPU_IN_SET(xc_cpuset, lcx)) {
341 		/*
342 		 * same cpu - use software fast trap
343 		 */
344 		send_self_xcall(CPU, arg1, arg2, func);
345 		XC_STAT_INC(x_dstat[lcx][XT_SOME_SELF]);
346 		XC_TRACE(XT_SOME_SELF, &tset, func, arg1, arg2);
347 		CPUSET_DEL(xc_cpuset, lcx);
348 		if (CPUSET_ISNULL(xc_cpuset)) {
349 			XC_SPL_EXIT(lcx, opl);
350 			return;
351 		}
352 	}
353 	XC_TRACE(XT_SOME_OTHER, &xc_cpuset, func, arg1, arg2);
354 	init_mondo(func, arg1, arg2);
355 	send_mondo_set(xc_cpuset);
356 	XC_STAT_INC(x_dstat[lcx][XT_SOME_OTHER]);
357 
358 	XC_SPL_EXIT(lcx, opl);
359 }
360 
361 /*
362  * xt_all - send a "x-trap" to all cpus
363  */
364 void
365 xt_all(xcfunc_t *func, uint64_t arg1, uint64_t arg2)
366 {
367 	int lcx;
368 	int opl;
369 	cpuset_t xc_cpuset, tset;
370 
371 	/*
372 	 * Make sure the function address will not be interpreted as a
373 	 * dmv interrupt
374 	 */
375 	ASSERT(!DMV_IS_DMV(func));
376 
377 	/*
378 	 * It's illegal to send software inums through the cross-trap
379 	 * interface.
380 	 */
381 	ASSERT((uintptr_t)func >= KERNELBASE);
382 
383 	CPUSET_ZERO(tset);
384 
385 	XC_SPL_ENTER(lcx, opl);		/* lcx set by the macro */
386 
387 	CPUSET_ADD(tset, lcx);
388 
389 	/*
390 	 * same cpu - use software fast trap
391 	 */
392 	if (CPU_IN_SET(cpu_ready_set, lcx))
393 		send_self_xcall(CPU, arg1, arg2, func);
394 
395 	XC_TRACE(XT_ALL_OTHER, &cpu_ready_set, func, arg1, arg2);
396 
397 	/*
398 	 * don't send mondo to self
399 	 */
400 	xc_cpuset = cpu_ready_set;
401 	CPUSET_DEL(xc_cpuset, lcx);
402 
403 	if (CPUSET_ISNULL(xc_cpuset)) {
404 		XC_STAT_INC(x_dstat[lcx][XT_ALL_SELF]);
405 		XC_TRACE(XT_ALL_SELF, &tset, func, arg1, arg2);
406 		XC_SPL_EXIT(lcx, opl);
407 		return;
408 	}
409 
410 	init_mondo(func, arg1, arg2);
411 	send_mondo_set(xc_cpuset);
412 
413 	XC_STAT_INC(x_dstat[lcx][XT_ALL_OTHER]);
414 	XC_SPL_EXIT(lcx, opl);
415 }
416 
417 /*
418  * xc_one - send a "x-call" to a cpu
419  */
420 void
421 xc_one(int cix, xcfunc_t *func, uint64_t arg1, uint64_t arg2)
422 {
423 	int lcx;
424 	int opl;
425 	uint64_t loop_cnt = 0;
426 	cpuset_t tset;
427 	int first_time = 1;
428 
429 	/*
430 	 * send to nobody; just return
431 	 */
432 	if (!CPU_IN_SET(cpu_ready_set, cix))
433 		return;
434 
435 	ASSERT((uintptr_t)func > KERNELBASE);
436 	ASSERT(((uintptr_t)func % PC_ALIGN) == 0);
437 
438 	CPUSET_ZERO(tset);
439 
440 	kpreempt_disable();
441 
442 	XC_SPL_ENTER(lcx, opl);		/* lcx set by the macro */
443 
444 	CPUSET_ADD(tset, cix);
445 
446 	if (cix == lcx) {	/* same cpu just do it */
447 		XC_TRACE(XC_ONE_SELF, &tset, func, arg1, arg2);
448 		(*func)(arg1, arg2);
449 		XC_STAT_INC(x_dstat[lcx][XC_ONE_SELF]);
450 		XC_SPL_EXIT(lcx, opl);
451 		kpreempt_enable();
452 		return;
453 	}
454 
455 	if (xc_holder == lcx) {		/* got the xc_sys_mutex already */
456 		ASSERT(MUTEX_HELD(&xc_sys_mutex));
457 		ASSERT(CPU_IN_SET(xc_mbox[lcx].xc_cpuset, lcx));
458 		ASSERT(CPU_IN_SET(xc_mbox[cix].xc_cpuset, cix));
459 		ASSERT(xc_mbox[cix].xc_state == XC_WAIT);
460 		XC_TRACE(XC_ONE_OTHER_H, &tset, func, arg1, arg2);
461 
462 		/*
463 		 * target processor's xc_loop should be waiting
464 		 * for the work to do; just set up the xc_mbox
465 		 */
466 		XC_SETUP(cix, func, arg1, arg2);
467 		membar_stld();
468 
469 		while (xc_mbox[cix].xc_state != XC_WAIT) {
470 			if (loop_cnt++ > xc_func_time_limit) {
471 				if (sendmondo_in_recover) {
472 					drv_usecwait(1);
473 					loop_cnt = 0;
474 					continue;
475 				}
476 				cmn_err(CE_PANIC, "xc_one() timeout, "
477 				    "xc_state[%d] != XC_WAIT", cix);
478 			}
479 		}
480 		XC_STAT_INC(x_dstat[lcx][XC_ONE_OTHER_H]);
481 		XC_SPL_EXIT(lcx, opl);
482 		kpreempt_enable();
483 		return;
484 	}
485 
486 	/*
487 	 * Avoid dead lock if someone has sent us a xc_loop request while
488 	 * we are trying to grab xc_sys_mutex.
489 	 */
490 	XC_SPL_EXIT(lcx, opl);
491 
492 	/*
493 	 * At this point, since we don't own xc_sys_mutex,
494 	 * our pil shouldn't run at or above the XCALL_PIL.
495 	 */
496 	ASSERT(getpil() < XCALL_PIL);
497 
498 	/*
499 	 * Since xc_holder is not owned by us, it could be that
500 	 * no one owns it, or we are not informed to enter into
501 	 * xc_loop(). In either case, we need to grab the
502 	 * xc_sys_mutex before we write to the xc_mbox, and
503 	 * we shouldn't release it until the request is finished.
504 	 */
505 
506 	mutex_enter(&xc_sys_mutex);
507 	xc_spl_enter[lcx] = 1;
508 
509 	/*
510 	 * Since we own xc_sys_mutex now, we are safe to
511 	 * write to the xc_mbox.
512 	 */
513 	ASSERT(xc_mbox[cix].xc_state == XC_IDLE);
514 	XC_TRACE(XC_ONE_OTHER, &tset, func, arg1, arg2);
515 	XC_SETUP(cix, func, arg1, arg2);
516 	init_mondo(setsoftint_tl1, xc_serv_inum, 0);
517 	send_one_mondo(cix);
518 	xc_spl_enter[lcx] = 0;
519 
520 	/* xc_serv does membar_stld */
521 	while (xc_mbox[cix].xc_state != XC_IDLE) {
522 		if (loop_cnt++ > xc_func_time_limit) {
523 			if (sendmondo_in_recover) {
524 				drv_usecwait(1);
525 				loop_cnt = 0;
526 				continue;
527 			}
528 			if (first_time) {
529 				XT_SYNC_ONE(cix);
530 				first_time = 0;
531 				loop_cnt = 0;
532 				continue;
533 			}
534 			cmn_err(CE_PANIC, "xc_one() timeout, "
535 			    "xc_state[%d] != XC_IDLE", cix);
536 		}
537 	}
538 	XC_STAT_INC(x_dstat[lcx][XC_ONE_OTHER]);
539 	mutex_exit(&xc_sys_mutex);
540 
541 	kpreempt_enable();
542 }
543 
544 /*
545  * xc_some - send a "x-call" to some cpus; sending to self is excluded
546  */
547 void
548 xc_some(cpuset_t cpuset, xcfunc_t *func, uint64_t arg1, uint64_t arg2)
549 {
550 	int lcx;
551 	int opl;
552 	cpuset_t xc_cpuset, tset;
553 
554 	ASSERT((uintptr_t)func > KERNELBASE);
555 	ASSERT(((uintptr_t)func % PC_ALIGN) == 0);
556 
557 	CPUSET_ZERO(tset);
558 
559 	kpreempt_disable();
560 	XC_SPL_ENTER(lcx, opl);			/* lcx set by the macro */
561 
562 	CPUSET_ADD(tset, lcx);
563 
564 	/*
565 	 * only send to the CPU_READY ones
566 	 */
567 	xc_cpuset = cpu_ready_set;
568 	CPUSET_AND(xc_cpuset, cpuset);
569 
570 	/*
571 	 * send to nobody; just return
572 	 */
573 	if (CPUSET_ISNULL(xc_cpuset)) {
574 		XC_SPL_EXIT(lcx, opl);
575 		kpreempt_enable();
576 		return;
577 	}
578 
579 	if (CPU_IN_SET(xc_cpuset, lcx)) {
580 		/*
581 		 * same cpu just do it
582 		 */
583 		(*func)(arg1, arg2);
584 		CPUSET_DEL(xc_cpuset, lcx);
585 		if (CPUSET_ISNULL(xc_cpuset)) {
586 			XC_STAT_INC(x_dstat[lcx][XC_SOME_SELF]);
587 			XC_TRACE(XC_SOME_SELF, &tset, func, arg1, arg2);
588 			XC_SPL_EXIT(lcx, opl);
589 			kpreempt_enable();
590 			return;
591 		}
592 	}
593 
594 	if (xc_holder == lcx) {		/* got the xc_sys_mutex already */
595 		cpuset_t mset = xc_mbox[lcx].xc_cpuset;
596 
597 		CPUSET_AND(mset, cpuset);
598 		ASSERT(MUTEX_HELD(&xc_sys_mutex));
599 		ASSERT(CPUSET_ISEQUAL(mset, cpuset));
600 		SEND_MBOX_ONLY(xc_cpuset, func, arg1, arg2, lcx, XC_WAIT);
601 		WAIT_MBOX_DONE(xc_cpuset, lcx, XC_WAIT, 0);
602 		XC_STAT_INC(x_dstat[lcx][XC_SOME_OTHER_H]);
603 		XC_TRACE(XC_SOME_OTHER_H, &xc_cpuset, func, arg1, arg2);
604 		XC_SPL_EXIT(lcx, opl);
605 		kpreempt_enable();
606 		return;
607 	}
608 
609 	/*
610 	 * Avoid dead lock if someone has sent us a xc_loop request while
611 	 * we are trying to grab xc_sys_mutex.
612 	 */
613 	XC_SPL_EXIT(lcx, opl);
614 
615 	/*
616 	 * At this point, since we don't own xc_sys_mutex,
617 	 * our pil shouldn't run at or above the XCALL_PIL.
618 	 */
619 	ASSERT(getpil() < XCALL_PIL);
620 
621 	/*
622 	 * grab xc_sys_mutex before writing to the xc_mbox
623 	 */
624 	mutex_enter(&xc_sys_mutex);
625 	xc_spl_enter[lcx] = 1;
626 
627 	XC_TRACE(XC_SOME_OTHER, &xc_cpuset, func, arg1, arg2);
628 	init_mondo(setsoftint_tl1, xc_serv_inum, 0);
629 	SEND_MBOX_MONDO(xc_cpuset, func, arg1, arg2, XC_IDLE);
630 	WAIT_MBOX_DONE(xc_cpuset, lcx, XC_IDLE, 1);
631 
632 	xc_spl_enter[lcx] = 0;
633 	XC_STAT_INC(x_dstat[lcx][XC_SOME_OTHER]);
634 	mutex_exit(&xc_sys_mutex);
635 	kpreempt_enable();
636 }
637 
638 /*
639  * xc_all - send a "x-call" to all cpus
640  */
641 void
642 xc_all(xcfunc_t *func, uint64_t arg1, uint64_t arg2)
643 {
644 	int lcx;
645 	int opl;
646 	cpuset_t xc_cpuset, tset;
647 
648 	ASSERT((uintptr_t)func > KERNELBASE);
649 	ASSERT(((uintptr_t)func % PC_ALIGN) == 0);
650 
651 	CPUSET_ZERO(tset);
652 
653 	kpreempt_disable();
654 	XC_SPL_ENTER(lcx, opl);			/* lcx set by the macro */
655 
656 	CPUSET_ADD(tset, lcx);
657 
658 	/*
659 	 * same cpu just do it
660 	 */
661 	(*func)(arg1, arg2);
662 	xc_cpuset = cpu_ready_set;
663 	CPUSET_DEL(xc_cpuset, lcx);
664 
665 	if (CPUSET_ISNULL(xc_cpuset)) {
666 		XC_STAT_INC(x_dstat[lcx][XC_ALL_SELF]);
667 		XC_TRACE(XC_ALL_SELF, &tset, func, arg1, arg2);
668 		XC_SPL_EXIT(lcx, opl);
669 		kpreempt_enable();
670 		return;
671 	}
672 
673 	if (xc_holder == lcx) {		/* got the xc_sys_mutex already */
674 		cpuset_t mset = xc_mbox[lcx].xc_cpuset;
675 
676 		CPUSET_AND(mset, xc_cpuset);
677 		ASSERT(MUTEX_HELD(&xc_sys_mutex));
678 		ASSERT(CPUSET_ISEQUAL(mset, xc_cpuset));
679 		XC_TRACE(XC_ALL_OTHER_H, &xc_cpuset, func, arg1, arg2);
680 		SEND_MBOX_ONLY(xc_cpuset, func, arg1, arg2, lcx, XC_WAIT);
681 		WAIT_MBOX_DONE(xc_cpuset, lcx, XC_WAIT, 0);
682 		XC_STAT_INC(x_dstat[lcx][XC_ALL_OTHER_H]);
683 		XC_SPL_EXIT(lcx, opl);
684 		kpreempt_enable();
685 		return;
686 	}
687 
688 	/*
689 	 * Avoid dead lock if someone has sent us a xc_loop request while
690 	 * we are trying to grab xc_sys_mutex.
691 	 */
692 	XC_SPL_EXIT(lcx, opl);
693 
694 	/*
695 	 * At this point, since we don't own xc_sys_mutex,
696 	 * our pil shouldn't run at or above the XCALL_PIL.
697 	 */
698 	ASSERT(getpil() < XCALL_PIL);
699 
700 	/*
701 	 * grab xc_sys_mutex before writing to the xc_mbox
702 	 */
703 	mutex_enter(&xc_sys_mutex);
704 	xc_spl_enter[lcx] = 1;
705 
706 	XC_TRACE(XC_ALL_OTHER, &xc_cpuset, func, arg1, arg2);
707 	init_mondo(setsoftint_tl1, xc_serv_inum, 0);
708 	SEND_MBOX_MONDO(xc_cpuset, func, arg1, arg2, XC_IDLE);
709 	WAIT_MBOX_DONE(xc_cpuset, lcx, XC_IDLE, 1);
710 
711 	xc_spl_enter[lcx] = 0;
712 	XC_STAT_INC(x_dstat[lcx][XC_ALL_OTHER]);
713 	mutex_exit(&xc_sys_mutex);
714 	kpreempt_enable();
715 }
716 
717 /*
718  * xc_attention - paired with xc_dismissed()
719  *
720  * xt_attention() holds the xc_sys_mutex and xc_dismissed() releases it
721  * called when an initiator wants to capture some/all cpus for a critical
722  * session.
723  */
724 void
725 xc_attention(cpuset_t cpuset)
726 {
727 	int pix, lcx;
728 	cpuset_t xc_cpuset, tmpset;
729 	cpuset_t recv_cpuset;
730 	uint64_t loop_cnt = 0;
731 	int first_time = 1;
732 
733 	CPUSET_ZERO(recv_cpuset);
734 
735 	/*
736 	 * don't migrate the cpu until xc_dismissed() is finished
737 	 */
738 	ASSERT(getpil() < XCALL_PIL);
739 	mutex_enter(&xc_sys_mutex);
740 	lcx = (int)(CPU->cpu_id);
741 	ASSERT(x_dstat[lcx][XC_ATTENTION] ==
742 	    x_dstat[lcx][XC_DISMISSED]);
743 	ASSERT(xc_holder == -1);
744 	xc_mbox[lcx].xc_cpuset = cpuset;
745 	xc_holder = lcx; /* no membar; only current cpu needs the right lcx */
746 
747 	/*
748 	 * only send to the CPU_READY ones
749 	 */
750 	xc_cpuset = cpu_ready_set;
751 	CPUSET_AND(xc_cpuset, cpuset);
752 
753 	/*
754 	 * don't send mondo to self
755 	 */
756 	CPUSET_DEL(xc_cpuset, lcx);
757 
758 	XC_STAT_INC(x_dstat[lcx][XC_ATTENTION]);
759 	XC_TRACE(XC_ATTENTION, &xc_cpuset, NULL, NULL, NULL);
760 
761 	if (CPUSET_ISNULL(xc_cpuset))
762 		return;
763 
764 	xc_spl_enter[lcx] = 1;
765 	/*
766 	 * inform the target processors to enter into xc_loop()
767 	 */
768 	init_mondo(setsoftint_tl1, xc_loop_inum, 0);
769 	SEND_MBOX_MONDO_XC_ENTER(xc_cpuset);
770 	xc_spl_enter[lcx] = 0;
771 
772 	/*
773 	 * make sure target processors have entered into xc_loop()
774 	 */
775 	while (!CPUSET_ISEQUAL(recv_cpuset, xc_cpuset)) {
776 		tmpset = xc_cpuset;
777 		for (pix = 0; pix < NCPU; pix++) {
778 			if (CPU_IN_SET(tmpset, pix)) {
779 				/*
780 				 * membar_stld() is done in xc_loop
781 				 */
782 				if (xc_mbox[pix].xc_state == XC_WAIT) {
783 					CPUSET_ADD(recv_cpuset, pix);
784 				}
785 				CPUSET_DEL(tmpset, pix);
786 				if (CPUSET_ISNULL(tmpset)) {
787 					break;
788 				}
789 			}
790 		}
791 		if (loop_cnt++ > xc_mondo_time_limit) {
792 			if (sendmondo_in_recover) {
793 				drv_usecwait(1);
794 				loop_cnt = 0;
795 				continue;
796 			}
797 			if (first_time) {
798 				XT_SYNC_SOME(xc_cpuset);
799 				first_time = 0;
800 				loop_cnt = 0;
801 				continue;
802 			}
803 			cmn_err(CE_PANIC, "xc_attention() timeout");
804 		}
805 	}
806 
807 	/*
808 	 * xc_sys_mutex remains held until xc_dismissed() is finished
809 	 */
810 }
811 
812 /*
813  * xc_dismissed - paired with xc_attention()
814  *
815  * Called after the critical session is finished.
816  */
817 void
818 xc_dismissed(cpuset_t cpuset)
819 {
820 	int pix;
821 	int lcx = (int)(CPU->cpu_id);
822 	cpuset_t xc_cpuset, tmpset;
823 	cpuset_t recv_cpuset;
824 	uint64_t loop_cnt = 0;
825 
826 	ASSERT(lcx == xc_holder);
827 	ASSERT(CPUSET_ISEQUAL(xc_mbox[lcx].xc_cpuset, cpuset));
828 	ASSERT(getpil() >= XCALL_PIL);
829 	CPUSET_ZERO(xc_mbox[lcx].xc_cpuset);
830 	CPUSET_ZERO(recv_cpuset);
831 	membar_stld();
832 
833 	XC_STAT_INC(x_dstat[lcx][XC_DISMISSED]);
834 	ASSERT(x_dstat[lcx][XC_DISMISSED] == x_dstat[lcx][XC_ATTENTION]);
835 
836 	/*
837 	 * only send to the CPU_READY ones
838 	 */
839 	xc_cpuset = cpu_ready_set;
840 	CPUSET_AND(xc_cpuset, cpuset);
841 
842 	/*
843 	 * exclude itself
844 	 */
845 	CPUSET_DEL(xc_cpuset, lcx);
846 	XC_TRACE(XC_DISMISSED, &xc_cpuset, NULL, NULL, NULL);
847 	if (CPUSET_ISNULL(xc_cpuset)) {
848 		xc_holder = -1;
849 		mutex_exit(&xc_sys_mutex);
850 		return;
851 	}
852 
853 	/*
854 	 * inform other processors to get out of xc_loop()
855 	 */
856 	tmpset = xc_cpuset;
857 	for (pix = 0; pix < NCPU; pix++) {
858 		if (CPU_IN_SET(tmpset, pix)) {
859 			xc_mbox[pix].xc_state = XC_EXIT;
860 			membar_stld();
861 			CPUSET_DEL(tmpset, pix);
862 			if (CPUSET_ISNULL(tmpset)) {
863 				break;
864 			}
865 		}
866 	}
867 
868 	/*
869 	 * make sure target processors have exited from xc_loop()
870 	 */
871 	while (!CPUSET_ISEQUAL(recv_cpuset, xc_cpuset)) {
872 		tmpset = xc_cpuset;
873 		for (pix = 0; pix < NCPU; pix++) {
874 			if (CPU_IN_SET(tmpset, pix)) {
875 				/*
876 				 * membar_stld() is done in xc_loop
877 				 */
878 				if (xc_mbox[pix].xc_state == XC_IDLE) {
879 					CPUSET_ADD(recv_cpuset, pix);
880 				}
881 				CPUSET_DEL(tmpset, pix);
882 				if (CPUSET_ISNULL(tmpset)) {
883 					break;
884 				}
885 			}
886 		}
887 		if (loop_cnt++ > xc_func_time_limit) {
888 				if (sendmondo_in_recover) {
889 					drv_usecwait(1);
890 					loop_cnt = 0;
891 					continue;
892 				}
893 			cmn_err(CE_PANIC, "xc_dismissed() timeout");
894 		}
895 	}
896 	xc_holder = -1;
897 	mutex_exit(&xc_sys_mutex);
898 }
899 
900 /*
901  * xc_serv - "x-call" handler at TL=0; serves only one x-call request
902  * runs at XCALL_PIL level.
903  */
904 uint_t
905 xc_serv(void)
906 {
907 	int lcx = (int)(CPU->cpu_id);
908 	struct xc_mbox *xmp;
909 	xcfunc_t *func;
910 	uint64_t arg1, arg2;
911 	cpuset_t tset;
912 
913 	ASSERT(getpil() == XCALL_PIL);
914 	CPUSET_ZERO(tset);
915 	CPUSET_ADD(tset, lcx);
916 	flush_windows();
917 	xmp = &xc_mbox[lcx];
918 	ASSERT(lcx != xc_holder);
919 	ASSERT(xmp->xc_state == XC_DOIT);
920 	func = xmp->xc_func;
921 	XC_TRACE(XC_SERV, &tset, func, xmp->xc_arg1, xmp->xc_arg2);
922 	if (func != NULL) {
923 		arg1 = xmp->xc_arg1;
924 		arg2 = xmp->xc_arg2;
925 		(*func)(arg1, arg2);
926 	}
927 	XC_STAT_INC(x_rstat[lcx][XC_SERV]);
928 	XC_TRACE(XC_SERV, &tset, func, arg1, arg2);
929 	xmp->xc_state = XC_IDLE;
930 	membar_stld();
931 	return (1);
932 }
933 
934 /*
935  * if == 1, an xc_loop timeout will cause a panic
936  * otherwise print a warning
937  */
938 uint_t xc_loop_panic = 0;
939 
940 /*
941  * xc_loop - "x-call" handler at TL=0; capture the cpu for a critial
942  * session, or serve multiple x-call requests runs at XCALL_PIL level.
943  */
944 uint_t
945 xc_loop(void)
946 {
947 	int lcx = (int)(CPU->cpu_id);
948 	struct xc_mbox *xmp;
949 	xcfunc_t *func;
950 	uint64_t arg1, arg2;
951 	uint64_t loop_cnt = 0;
952 	cpuset_t tset;
953 
954 	ASSERT(getpil() == XCALL_PIL);
955 
956 	CPUSET_ZERO(tset);
957 	flush_windows();
958 
959 	/*
960 	 * Some one must have owned the xc_sys_mutex;
961 	 * no further interrupt (at XCALL_PIL or below) can
962 	 * be taken by this processor until xc_loop exits.
963 	 *
964 	 * The owner of xc_sys_mutex (or xc_holder) can expect
965 	 * its xc/xt requests are handled as follows:
966 	 * 	xc requests use xc_mbox's handshaking for their services
967 	 * 	xt requests at TL>0 will be handled immediately
968 	 * 	xt requests at TL=0:
969 	 *		if their handlers'pils are <= XCALL_PIL, then
970 	 *			they will be handled after xc_loop exits
971 	 *			(so, they probably should not be used)
972 	 *		else they will be handled immediately
973 	 *
974 	 * For those who are not informed to enter xc_loop, if they
975 	 * send xc/xt requests to this processor at this moment,
976 	 * the requests will be handled as follows:
977 	 *	xc requests will be handled after they grab xc_sys_mutex
978 	 *	xt requests at TL>0 will be handled immediately
979 	 * 	xt requests at TL=0:
980 	 *		if their handlers'pils are <= XCALL_PIL, then
981 	 *			they will be handled after xc_loop exits
982 	 *		else they will be handled immediately
983 	 */
984 	xmp = &xc_mbox[lcx];
985 	ASSERT(lcx != xc_holder);
986 	ASSERT(xmp->xc_state == XC_ENTER);
987 	xmp->xc_state = XC_WAIT;
988 	CPUSET_ADD(tset, lcx);
989 	membar_stld();
990 	XC_STAT_INC(x_rstat[lcx][XC_LOOP]);
991 	XC_TRACE(XC_LOOP_ENTER, &tset, NULL, NULL, NULL);
992 	while (xmp->xc_state != XC_EXIT) {
993 		if (xmp->xc_state == XC_DOIT) {
994 			func = xmp->xc_func;
995 			arg1 = xmp->xc_arg1;
996 			arg2 = xmp->xc_arg2;
997 			XC_TRACE(XC_LOOP_DOIT, &tset, func, arg1, arg2);
998 			if (func != NULL)
999 				(*func)(arg1, arg2);
1000 			xmp->xc_state = XC_WAIT;
1001 			membar_stld();
1002 			/*
1003 			 * reset the timeout counter
1004 			 * since some work was done
1005 			 */
1006 			loop_cnt = 0;
1007 		} else {
1008 			/* patience is a virtue... */
1009 			loop_cnt++;
1010 		}
1011 
1012 		if (loop_cnt > xc_func_time_limit) {
1013 			if (sendmondo_in_recover) {
1014 				drv_usecwait(1);
1015 				loop_cnt = 0;
1016 				continue;
1017 			}
1018 			cmn_err(xc_loop_panic ? CE_PANIC : CE_WARN,
1019 			    "xc_loop() timeout");
1020 			/*
1021 			 * if the above displayed a warning,
1022 			 * reset the timeout counter and be patient
1023 			 */
1024 			loop_cnt = 0;
1025 		}
1026 	}
1027 	ASSERT(xmp->xc_state == XC_EXIT);
1028 	ASSERT(xc_holder != -1);
1029 	XC_TRACE(XC_LOOP_EXIT, &tset, NULL, NULL, NULL);
1030 	xmp->xc_state = XC_IDLE;
1031 	membar_stld();
1032 	return (1);
1033 }
1034