xref: /netbsd-src/sys/rump/librump/rumpkern/intr.c (revision 7788a0781fe6ff2cce37368b4578a7ade0850cb1)
1 /*	$NetBSD: intr.c,v 1.40 2013/05/02 21:45:28 pooka 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 1.40 2013/05/02 21:45:28 pooka 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