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