intr.c revision 1.34 
1/*	$NetBSD: intr.c,v 1.34 2010/09/07 18:25:38 pooka Exp $	*/
2
3/*
4 * Copyright (c) 2008 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 1.34 2010/09/07 18:25:38 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
52struct softint_percpu;
53struct 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
62struct softint_percpu {
63	struct softint *sip_parent;
64	bool sip_onlist;
65
66	LIST_ENTRY(softint_percpu) sip_entries;
67};
68
69struct softint_lev {
70	struct rumpuser_cv *si_cv;
71	LIST_HEAD(, softint_percpu) si_pending;
72};
73
74kcondvar_t lbolt; /* Oh Kath Ra */
75
76static u_int ticks;
77static int ncpu_final;
78
79static u_int
80rumptc_get(struct timecounter *tc)
81{
82
83	KASSERT(rump_threads);
84	return ticks;
85}
86
87static 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 */
99static void
100doclock(void *noarg)
101{
102	struct timespec clockbase, clockup;
103	struct timespec thetick, curtime;
104	struct rumpuser_cv *clockcv;
105	struct rumpuser_mtx *clockmtx;
106	uint64_t sec, nsec;
107	int error;
108	extern int hz;
109
110	memset(&clockup, 0, sizeof(clockup));
111	rumpuser_gettime(&sec, &nsec, &error);
112	clockbase.tv_sec = sec;
113	clockbase.tv_nsec = nsec;
114	curtime = clockbase;
115	thetick.tv_sec = 0;
116	thetick.tv_nsec = 1000000000/hz;
117
118	/* XXX: dummies */
119	rumpuser_cv_init(&clockcv);
120	rumpuser_mutex_init(&clockmtx);
121
122	rumpuser_mutex_enter(clockmtx);
123	for (;;) {
124		callout_hardclock();
125
126		/* wait until the next tick. XXX: what if the clock changes? */
127		while (rumpuser_cv_timedwait(clockcv, clockmtx,
128		    curtime.tv_sec, curtime.tv_nsec) == 0)
129			continue;
130
131		/* XXX: sync with a) virtual clock b) host clock */
132		timespecadd(&clockup, &clockbase, &curtime);
133		timespecadd(&clockup, &thetick, &clockup);
134
135#if 0
136		/* CPU_IS_PRIMARY is MD and hence unreliably correct here */
137		if (!CPU_IS_PRIMARY(curcpu()))
138			continue;
139#else
140		if (curcpu()->ci_index != 0)
141			continue;
142#endif
143
144		if ((++ticks % hz) == 0) {
145			cv_broadcast(&lbolt);
146		}
147		tc_ticktock();
148	}
149}
150
151/*
152 * Soft interrupt execution thread.  This thread is pinned to the
153 * same CPU that scheduled the interrupt, so we don't need to do
154 * lock against si_lvl.
155 */
156static void
157sithread(void *arg)
158{
159	struct softint_percpu *sip;
160	struct softint *si;
161	void (*func)(void *) = NULL;
162	void *funarg;
163	bool mpsafe;
164	int mylevel = (uintptr_t)arg;
165	struct softint_lev *si_lvlp, *si_lvl;
166	struct cpu_data *cd = &curcpu()->ci_data;
167
168	si_lvlp = cd->cpu_softcpu;
169	si_lvl = &si_lvlp[mylevel];
170
171	for (;;) {
172		if (!LIST_EMPTY(&si_lvl->si_pending)) {
173			sip = LIST_FIRST(&si_lvl->si_pending);
174			si = sip->sip_parent;
175
176			func = si->si_func;
177			funarg = si->si_arg;
178			mpsafe = si->si_flags & SI_MPSAFE;
179
180			sip->sip_onlist = false;
181			LIST_REMOVE(sip, sip_entries);
182			if (si->si_flags & SI_KILLME) {
183				softint_disestablish(si);
184				continue;
185			}
186		} else {
187			rump_schedlock_cv_wait(si_lvl->si_cv);
188			continue;
189		}
190
191		if (!mpsafe)
192			KERNEL_LOCK(1, curlwp);
193		func(funarg);
194		if (!mpsafe)
195			KERNEL_UNLOCK_ONE(curlwp);
196	}
197
198	panic("sithread unreachable");
199}
200
201void
202rump_intr_init(int numcpu)
203{
204
205	cv_init(&lbolt, "oh kath ra");
206	ncpu_final = numcpu;
207}
208
209void
210softint_init(struct cpu_info *ci)
211{
212	struct cpu_data *cd = &ci->ci_data;
213	struct softint_lev *slev;
214	int rv, i;
215
216	if (!rump_threads)
217		return;
218
219	/* XXX */
220	if (ci->ci_index == 0) {
221		rumptc.tc_frequency = hz;
222		tc_init(&rumptc);
223	}
224
225	slev = kmem_alloc(sizeof(struct softint_lev) * SOFTINT_COUNT, KM_SLEEP);
226	for (i = 0; i < SOFTINT_COUNT; i++) {
227		rumpuser_cv_init(&slev[i].si_cv);
228		LIST_INIT(&slev[i].si_pending);
229	}
230	cd->cpu_softcpu = slev;
231
232	/* softint might run on different physical CPU */
233	membar_sync();
234
235	for (i = 0; i < SOFTINT_COUNT; i++) {
236		rv = kthread_create(PRI_NONE,
237		    KTHREAD_MPSAFE | KTHREAD_INTR, ci,
238		    sithread, (void *)(uintptr_t)i,
239		    NULL, "rsi%d/%d", ci->ci_index, i);
240	}
241
242	rv = kthread_create(PRI_NONE, KTHREAD_MPSAFE,
243	    ci, doclock, NULL, NULL, "rumpclk%d", ci->ci_index);
244	if (rv)
245		panic("clock thread creation failed: %d", rv);
246}
247
248void *
249softint_establish(u_int flags, void (*func)(void *), void *arg)
250{
251	struct softint *si;
252	struct softint_percpu *sip;
253	int i;
254
255	si = malloc(sizeof(*si), M_TEMP, M_WAITOK);
256	si->si_func = func;
257	si->si_arg = arg;
258	si->si_flags = flags & SOFTINT_MPSAFE ? SI_MPSAFE : 0;
259	si->si_level = flags & SOFTINT_LVLMASK;
260	KASSERT(si->si_level < SOFTINT_COUNT);
261	si->si_entry = malloc(sizeof(*si->si_entry) * ncpu_final,
262	    M_TEMP, M_WAITOK | M_ZERO);
263	for (i = 0; i < ncpu_final; i++) {
264		sip = &si->si_entry[i];
265		sip->sip_parent = si;
266	}
267
268	return si;
269}
270
271/*
272 * Soft interrupts bring two choices.  If we are running with thread
273 * support enabled, defer execution, otherwise execute in place.
274 */
275
276void
277softint_schedule(void *arg)
278{
279	struct softint *si = arg;
280	struct softint_percpu *sip = &si->si_entry[curcpu()->ci_index];
281	struct cpu_data *cd = &curcpu()->ci_data;
282	struct softint_lev *si_lvl = cd->cpu_softcpu;
283
284	if (!rump_threads) {
285		si->si_func(si->si_arg);
286	} else {
287		if (!sip->sip_onlist) {
288			LIST_INSERT_HEAD(&si_lvl[si->si_level].si_pending,
289			    sip, sip_entries);
290			sip->sip_onlist = true;
291		}
292	}
293}
294
295/*
296 * flimsy disestablish: should wait for softints to finish.
297 */
298void
299softint_disestablish(void *cook)
300{
301	struct softint *si = cook;
302	int i;
303
304	for (i = 0; i < ncpu_final; i++) {
305		struct softint_percpu *sip;
306
307		sip = &si->si_entry[i];
308		if (sip->sip_onlist) {
309			si->si_flags |= SI_KILLME;
310			return;
311		}
312	}
313	free(si->si_entry, M_TEMP);
314	free(si, M_TEMP);
315}
316
317void
318rump_softint_run(struct cpu_info *ci)
319{
320	struct cpu_data *cd = &ci->ci_data;
321	struct softint_lev *si_lvl = cd->cpu_softcpu;
322	int i;
323
324	if (!rump_threads)
325		return;
326
327	for (i = 0; i < SOFTINT_COUNT; i++) {
328		if (!LIST_EMPTY(&si_lvl[i].si_pending))
329			rumpuser_cv_signal(si_lvl[i].si_cv);
330	}
331}
332
333bool
334cpu_intr_p(void)
335{
336
337	return false;
338}
339
340bool
341cpu_softintr_p(void)
342{
343
344	return curlwp->l_pflag & LP_INTR;
345}
346