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intr.c revision 1.36.14.1 
      1 /*	$NetBSD: intr.c,v 1.36.14.1 2013/06/23 06:20:28 tls Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2008-2010 Antti Kantee.  All Rights Reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     25  * SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __KERNEL_RCSID(0, "$NetBSD: intr.c,v 1.36.14.1 2013/06/23 06:20:28 tls Exp $");
     30 
     31 #include <sys/param.h>
     32 #include <sys/atomic.h>
     33 #include <sys/cpu.h>
     34 #include <sys/kernel.h>
     35 #include <sys/kmem.h>
     36 #include <sys/kthread.h>
     37 #include <sys/malloc.h>
     38 #include <sys/intr.h>
     39 #include <sys/timetc.h>
     40 
     41 #include <rump/rumpuser.h>
     42 
     43 #include "rump_private.h"
     44 
     45 /*
     46  * Interrupt simulator.  It executes hardclock() and softintrs.
     47  */
     48 
     49 #define SI_MPSAFE 0x01
     50 #define SI_KILLME 0x02
     51 
     52 struct softint_percpu;
     53 struct softint {
     54 	void (*si_func)(void *);
     55 	void *si_arg;
     56 	int si_flags;
     57 	int si_level;
     58 
     59 	struct softint_percpu *si_entry; /* [0,ncpu-1] */
     60 };
     61 
     62 struct softint_percpu {
     63 	struct softint *sip_parent;
     64 	bool sip_onlist;
     65 
     66 	LIST_ENTRY(softint_percpu) sip_entries;
     67 };
     68 
     69 struct softint_lev {
     70 	struct rumpuser_cv *si_cv;
     71 	LIST_HEAD(, softint_percpu) si_pending;
     72 };
     73 
     74 kcondvar_t lbolt; /* Oh Kath Ra */
     75 
     76 static u_int ticks;
     77 static int ncpu_final;
     78 
     79 static u_int
     80 rumptc_get(struct timecounter *tc)
     81 {
     82 
     83 	KASSERT(rump_threads);
     84 	return ticks;
     85 }
     86 
     87 static struct timecounter rumptc = {
     88 	.tc_get_timecount	= rumptc_get,
     89 	.tc_poll_pps 		= NULL,
     90 	.tc_counter_mask	= ~0,
     91 	.tc_frequency		= 0,
     92 	.tc_name		= "rumpclk",
     93 	.tc_quality		= 0,
     94 };
     95 
     96 /*
     97  * clock "interrupt"
     98  */
     99 static void
    100 doclock(void *noarg)
    101 {
    102 	struct timespec thetick, curclock;
    103 	int64_t sec;
    104 	long nsec;
    105 	int error;
    106 	extern int hz;
    107 
    108 	error = rumpuser_clock_gettime(RUMPUSER_CLOCK_ABSMONO, &sec, &nsec);
    109 	if (error)
    110 		panic("clock: cannot get monotonic time");
    111 
    112 	curclock.tv_sec = sec;
    113 	curclock.tv_nsec = nsec;
    114 	thetick.tv_sec = 0;
    115 	thetick.tv_nsec = 1000000000/hz;
    116 
    117 	for (;;) {
    118 		callout_hardclock();
    119 
    120 		error = rumpuser_clock_sleep(RUMPUSER_CLOCK_ABSMONO,
    121 		    curclock.tv_sec, curclock.tv_nsec);
    122 		KASSERT(!error);
    123 		timespecadd(&curclock, &thetick, &curclock);
    124 
    125 #if 0
    126 		/* CPU_IS_PRIMARY is MD and hence unreliably correct here */
    127 		if (!CPU_IS_PRIMARY(curcpu()))
    128 			continue;
    129 #else
    130 		if (curcpu()->ci_index != 0)
    131 			continue;
    132 #endif
    133 
    134 		if ((++ticks % hz) == 0) {
    135 			cv_broadcast(&lbolt);
    136 		}
    137 		tc_ticktock();
    138 	}
    139 }
    140 
    141 /*
    142  * Soft interrupt execution thread.  This thread is pinned to the
    143  * same CPU that scheduled the interrupt, so we don't need to do
    144  * lock against si_lvl.
    145  */
    146 static void
    147 sithread(void *arg)
    148 {
    149 	struct softint_percpu *sip;
    150 	struct softint *si;
    151 	void (*func)(void *) = NULL;
    152 	void *funarg;
    153 	bool mpsafe;
    154 	int mylevel = (uintptr_t)arg;
    155 	struct softint_lev *si_lvlp, *si_lvl;
    156 	struct cpu_data *cd = &curcpu()->ci_data;
    157 
    158 	si_lvlp = cd->cpu_softcpu;
    159 	si_lvl = &si_lvlp[mylevel];
    160 
    161 	for (;;) {
    162 		if (!LIST_EMPTY(&si_lvl->si_pending)) {
    163 			sip = LIST_FIRST(&si_lvl->si_pending);
    164 			si = sip->sip_parent;
    165 
    166 			func = si->si_func;
    167 			funarg = si->si_arg;
    168 			mpsafe = si->si_flags & SI_MPSAFE;
    169 
    170 			sip->sip_onlist = false;
    171 			LIST_REMOVE(sip, sip_entries);
    172 			if (si->si_flags & SI_KILLME) {
    173 				softint_disestablish(si);
    174 				continue;
    175 			}
    176 		} else {
    177 			rump_schedlock_cv_wait(si_lvl->si_cv);
    178 			continue;
    179 		}
    180 
    181 		if (!mpsafe)
    182 			KERNEL_LOCK(1, curlwp);
    183 		func(funarg);
    184 		if (!mpsafe)
    185 			KERNEL_UNLOCK_ONE(curlwp);
    186 	}
    187 
    188 	panic("sithread unreachable");
    189 }
    190 
    191 void
    192 rump_intr_init(int numcpu)
    193 {
    194 
    195 	cv_init(&lbolt, "oh kath ra");
    196 	ncpu_final = numcpu;
    197 }
    198 
    199 void
    200 softint_init(struct cpu_info *ci)
    201 {
    202 	struct cpu_data *cd = &ci->ci_data;
    203 	struct softint_lev *slev;
    204 	int rv, i;
    205 
    206 	if (!rump_threads)
    207 		return;
    208 
    209 	/* XXX */
    210 	if (ci->ci_index == 0) {
    211 		rumptc.tc_frequency = hz;
    212 		tc_init(&rumptc);
    213 	}
    214 
    215 	slev = kmem_alloc(sizeof(struct softint_lev) * SOFTINT_COUNT, KM_SLEEP);
    216 	for (i = 0; i < SOFTINT_COUNT; i++) {
    217 		rumpuser_cv_init(&slev[i].si_cv);
    218 		LIST_INIT(&slev[i].si_pending);
    219 	}
    220 	cd->cpu_softcpu = slev;
    221 
    222 	/* softint might run on different physical CPU */
    223 	membar_sync();
    224 
    225 	for (i = 0; i < SOFTINT_COUNT; i++) {
    226 		rv = kthread_create(PRI_NONE,
    227 		    KTHREAD_MPSAFE | KTHREAD_INTR, ci,
    228 		    sithread, (void *)(uintptr_t)i,
    229 		    NULL, "rsi%d/%d", ci->ci_index, i);
    230 	}
    231 
    232 	rv = kthread_create(PRI_NONE, KTHREAD_MPSAFE,
    233 	    ci, doclock, NULL, NULL, "rumpclk%d", ci->ci_index);
    234 	if (rv)
    235 		panic("clock thread creation failed: %d", rv);
    236 }
    237 
    238 void *
    239 softint_establish(u_int flags, void (*func)(void *), void *arg)
    240 {
    241 	struct softint *si;
    242 	struct softint_percpu *sip;
    243 	int i;
    244 
    245 	si = malloc(sizeof(*si), M_TEMP, M_WAITOK);
    246 	si->si_func = func;
    247 	si->si_arg = arg;
    248 	si->si_flags = flags & SOFTINT_MPSAFE ? SI_MPSAFE : 0;
    249 	si->si_level = flags & SOFTINT_LVLMASK;
    250 	KASSERT(si->si_level < SOFTINT_COUNT);
    251 	si->si_entry = malloc(sizeof(*si->si_entry) * ncpu_final,
    252 	    M_TEMP, M_WAITOK | M_ZERO);
    253 	for (i = 0; i < ncpu_final; i++) {
    254 		sip = &si->si_entry[i];
    255 		sip->sip_parent = si;
    256 	}
    257 
    258 	return si;
    259 }
    260 
    261 /*
    262  * Soft interrupts bring two choices.  If we are running with thread
    263  * support enabled, defer execution, otherwise execute in place.
    264  */
    265 
    266 void
    267 softint_schedule(void *arg)
    268 {
    269 	struct softint *si = arg;
    270 	struct softint_percpu *sip = &si->si_entry[curcpu()->ci_index];
    271 	struct cpu_data *cd = &curcpu()->ci_data;
    272 	struct softint_lev *si_lvl = cd->cpu_softcpu;
    273 
    274 	if (!rump_threads) {
    275 		si->si_func(si->si_arg);
    276 	} else {
    277 		if (!sip->sip_onlist) {
    278 			LIST_INSERT_HEAD(&si_lvl[si->si_level].si_pending,
    279 			    sip, sip_entries);
    280 			sip->sip_onlist = true;
    281 		}
    282 	}
    283 }
    284 
    285 /*
    286  * flimsy disestablish: should wait for softints to finish.
    287  */
    288 void
    289 softint_disestablish(void *cook)
    290 {
    291 	struct softint *si = cook;
    292 	int i;
    293 
    294 	for (i = 0; i < ncpu_final; i++) {
    295 		struct softint_percpu *sip;
    296 
    297 		sip = &si->si_entry[i];
    298 		if (sip->sip_onlist) {
    299 			si->si_flags |= SI_KILLME;
    300 			return;
    301 		}
    302 	}
    303 	free(si->si_entry, M_TEMP);
    304 	free(si, M_TEMP);
    305 }
    306 
    307 void
    308 rump_softint_run(struct cpu_info *ci)
    309 {
    310 	struct cpu_data *cd = &ci->ci_data;
    311 	struct softint_lev *si_lvl = cd->cpu_softcpu;
    312 	int i;
    313 
    314 	if (!rump_threads)
    315 		return;
    316 
    317 	for (i = 0; i < SOFTINT_COUNT; i++) {
    318 		if (!LIST_EMPTY(&si_lvl[i].si_pending))
    319 			rumpuser_cv_signal(si_lvl[i].si_cv);
    320 	}
    321 }
    322 
    323 bool
    324 cpu_intr_p(void)
    325 {
    326 
    327 	return false;
    328 }
    329 
    330 bool
    331 cpu_softintr_p(void)
    332 {
    333 
    334 	return curlwp->l_pflag & LP_INTR;
    335 }
    336