xref: /titanic_41/usr/src/uts/sun4/os/cpu_states.c (revision 749f21d359d8fbd020c974a1a5227316221bfc9c)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/reboot.h>
30 #include <sys/systm.h>
31 #include <sys/archsystm.h>
32 #include <sys/machsystm.h>
33 #include <sys/promif.h>
34 #include <sys/promimpl.h>
35 #include <sys/prom_plat.h>
36 #include <sys/cpu_sgnblk_defs.h>
37 #include <sys/ivintr.h>
38 #include <sys/kdi.h>
39 #include <sys/callb.h>
40 
41 #ifdef	TRAPTRACE
42 #include <sys/traptrace.h>
43 #endif /* TRAPTRACE */
44 
45 #ifdef C2_AUDIT
46 extern void audit_enterprom();
47 extern void audit_exitprom();
48 #endif /* C2_AUDIT */
49 
50 /*
51  * Platforms that use CPU signatures need to set cpu_sgn_func
52  * to point to a platform specific function.  This needs to
53  * be done in set_platform_defaults() within the platmod.
54  */
55 void (*cpu_sgn_func)(ushort_t, uchar_t, uchar_t, int) = NULL;
56 
57 /*
58  * abort_seq_handler required by sysctrl.
59  */
60 void debug_enter(char *);
61 void (*abort_seq_handler)(char *) = debug_enter;
62 
63 /*
64  * Platform tunable to disable the h/w watchdog timer.
65  */
66 int disable_watchdog_on_exit = 0;
67 extern void clear_watchdog_on_exit(void);
68 
69 
70 /*
71  * On sun4u platform, abort_sequence_enter() can be called at high PIL
72  * and we can't afford to acquire any adaptive mutex or use any
73  * condition variables as we are not allowed to sleep while running
74  * on interrupt stack. We work around this problem by posting a level
75  * 10 soft interrupt and then invoking the "abort_seq_handler" within
76  * that soft interrupt context.
77  *
78  * This has the side effect of not allowing us to drop into debugger
79  * when the kernel is stuck at high PIL (PIL > 10).  It's better to
80  * be able to break into a hung system even if it means crashing the
81  * system.  If a user presses L1-A more than once within a 15 seconds
82  * window, and the previous L1-A soft interrupt is still pending, then
83  * we directly invoke the abort_sequence_enter.
84  *
85  * Since the "msg" argument passed to abort_sequence_enter can refer
86  * to a message anywhere in memory, including stack, it's copied into
87  * abort_seq_msgbuf buffer for processing by the soft interrupt.
88  */
89 
90 #define	ABORT_SEQ_MSGBUFSZ	256
91 #define	FORCE_ABORT_SEQ_INTERVAL ((hrtime_t)15 * NANOSEC)
92 
93 static kmutex_t	abort_seq_lock;
94 static uint_t	abort_seq_inum;		/* abort seq softintr # */
95 static hrtime_t	abort_seq_tstamp;	/* hrtime of last abort seq */
96 static size_t	abort_seq_msglen;	/* abort seq message length */
97 static char	abort_seq_msgbuf[ABORT_SEQ_MSGBUFSZ];
98 
99 /*ARGSUSED0*/
100 static uint_t
101 abort_seq_softintr(caddr_t arg)
102 {
103 	char	*msg;
104 	char	msgbuf[ABORT_SEQ_MSGBUFSZ];
105 
106 	mutex_enter(&abort_seq_lock);
107 	if (abort_enable != 0 && abort_seq_tstamp != 0LL) {
108 		if (abort_seq_msglen > 0) {
109 			bcopy(abort_seq_msgbuf, msgbuf, abort_seq_msglen);
110 			msg = msgbuf;
111 		} else
112 			msg = NULL;
113 		abort_seq_tstamp = 0LL;
114 		mutex_exit(&abort_seq_lock);
115 #ifdef C2_AUDIT
116 		if (audit_active)
117 			audit_enterprom(1);
118 #endif /* C2_AUDIT */
119 		(*abort_seq_handler)(msg);
120 #ifdef C2_AUDIT
121 		if (audit_active)
122 			audit_exitprom(1);
123 #endif /* C2_AUDIT */
124 	} else {
125 		mutex_exit(&abort_seq_lock);
126 #ifdef C2_AUDIT
127 		if (audit_active)
128 			audit_enterprom(0);
129 #endif /* C2_AUDIT */
130 	}
131 	return (1);
132 }
133 
134 void
135 abort_sequence_init(void)
136 {
137 	mutex_init(&abort_seq_lock, NULL, MUTEX_SPIN, (void *)PIL_12);
138 	abort_seq_tstamp = 0LL;
139 	if (abort_seq_inum == 0)
140 		abort_seq_inum = add_softintr(LOCK_LEVEL,
141 		    (softintrfunc)abort_seq_softintr, NULL);
142 }
143 
144 /*
145  *	Machine dependent abort sequence handling
146  */
147 void
148 abort_sequence_enter(char *msg)
149 {
150 	int		s, on_intr;
151 	size_t		msglen;
152 	hrtime_t	tstamp;
153 
154 	if (abort_enable != 0) {
155 		s = splhi();
156 		on_intr = CPU_ON_INTR(CPU) || (spltoipl(s) > LOCK_LEVEL);
157 		splx(s);
158 
159 		tstamp = gethrtime();
160 		mutex_enter(&abort_seq_lock);
161 
162 		/*
163 		 * If we are on an interrupt stack and/or running at
164 		 * PIL > LOCK_LEVEL, then we post a softint and invoke
165 		 * abort_seq_handler from there as we can't afford to
166 		 * acquire any adaptive mutex here. However, if we
167 		 * already have a pending softint, which was posted
168 		 * within FORCE_ABORT_SEQ_INTERVAL duration, then we
169 		 * bypass softint approach as our softint may be blocked
170 		 * and the user really wants to drop into the debugger.
171 		 */
172 		if (on_intr && abort_seq_inum != 0 &&
173 		    (abort_seq_tstamp == 0LL || tstamp >
174 		    (abort_seq_tstamp + FORCE_ABORT_SEQ_INTERVAL))) {
175 			abort_seq_tstamp = tstamp;
176 			if (msg != NULL) {
177 				msglen = strlen(msg);
178 				if (msglen >= ABORT_SEQ_MSGBUFSZ)
179 					msglen = ABORT_SEQ_MSGBUFSZ - 1;
180 				bcopy(msg, abort_seq_msgbuf, msglen);
181 				abort_seq_msgbuf[msglen] = '\0';
182 				abort_seq_msglen = msglen + 1;
183 			} else
184 				abort_seq_msglen = 0;
185 			mutex_exit(&abort_seq_lock);
186 			setsoftint(abort_seq_inum);
187 		} else {
188 			/*
189 			 * Ignore any pending abort sequence softint
190 			 * as we are invoking the abort_seq_handler
191 			 * here.
192 			 */
193 			abort_seq_tstamp = 0LL;
194 			mutex_exit(&abort_seq_lock);
195 #ifdef C2_AUDIT
196 		if (!on_intr && audit_active)
197 			audit_enterprom(1);
198 #endif /* C2_AUDIT */
199 			(*abort_seq_handler)(msg);
200 #ifdef C2_AUDIT
201 		if (!on_intr && audit_active)
202 			audit_exitprom(1);
203 #endif /* C2_AUDIT */
204 		}
205 	} else {
206 #ifdef C2_AUDIT
207 		if (audit_active)
208 			audit_enterprom(0);
209 #endif /* C2_AUDIT */
210 	}
211 }
212 
213 /*
214  * Enter debugger.  Called when the user types L1-A or break or whenever
215  * code wants to enter the debugger and possibly resume later.
216  * If the debugger isn't present, enter the PROM monitor.
217  *
218  * If console is a framebuffer which is powered off, it will be powered up
219  * before jumping to the debugger.  If we are called above lock level, a
220  * softint is triggered to reenter this code and allow the fb to be powered
221  * up as in the less than lock level case.  If this code is entered at greater
222  * than lock level and the fb is not already powered up, the msg argument
223  * will not be displayed.
224  */
225 void
226 debug_enter(char *msg)
227 {
228 	label_t old_pcb;
229 	int s;
230 	extern void pm_cfb_powerup(void);
231 	extern void pm_cfb_rele(void);
232 	extern void pm_cfb_trigger(void);
233 	extern int pm_cfb_check_and_hold(void);
234 
235 	/*
236 	 * For platforms that use CPU signatures, update the signature
237 	 * to indicate that we are entering the debugger if we are in
238 	 * the middle of a panic flow.
239 	 */
240 	if (panicstr)
241 		CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_DEBUG, -1);
242 
243 	if (!panicstr)
244 		(void) callb_execute_class(CB_CL_ENTER_DEBUGGER, 0);
245 
246 	if (pm_cfb_check_and_hold())
247 		if (getpil() > LOCK_LEVEL) {
248 			pm_cfb_trigger();
249 			return;
250 		} else
251 			pm_cfb_powerup();
252 	if (msg)
253 		prom_printf("%s\n", msg);
254 
255 	clear_watchdog_on_exit();
256 
257 	if ((s = getpil()) < ipltospl(12))
258 		s = splzs();
259 
260 	old_pcb = curthread->t_pcb;
261 	(void) setjmp(&curthread->t_pcb);
262 
263 	if (boothowto & RB_DEBUG)
264 		kdi_dvec_enter();
265 	else
266 		prom_enter_mon();
267 
268 	curthread->t_pcb = old_pcb;
269 	splx(s);
270 	pm_cfb_rele();
271 
272 	if (!panicstr)
273 		(void) callb_execute_class(CB_CL_ENTER_DEBUGGER, 1);
274 
275 	if (panicstr)
276 		CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_PANIC_CONT, -1);
277 }
278 
279 /*
280  * Halt the machine and return to the monitor
281  */
282 void
283 halt(char *s)
284 {
285 	flush_windows();
286 	stop_other_cpus();		/* send stop signal to other CPUs */
287 
288 	if (s)
289 		prom_printf("(%s) ", s);
290 
291 	/*
292 	 * For Platforms that use CPU signatures, we
293 	 * need to set the signature block to OS and
294 	 * the state to exiting for all the processors.
295 	 */
296 	CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_HALT, -1);
297 	prom_exit_to_mon();
298 	/*NOTREACHED*/
299 }
300 
301 /*
302  * Halt the machine and power off the system.
303  */
304 void
305 power_down(const char *s)
306 {
307 	flush_windows();
308 	stop_other_cpus();		/* send stop signal to other CPUs */
309 
310 	if (s != NULL)
311 		prom_printf("(%s) ", s);
312 
313 	/*
314 	 * For platforms that use CPU signatures, we need to set up the
315 	 * signature blocks to indicate that we have an environmental
316 	 * interrupt request to power down, and then exit to the prom monitor.
317 	 */
318 	CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_ENVIRON, -1);
319 	prom_power_off();
320 	/*
321 	 * If here is reached, for some reason prom's power-off command failed.
322 	 * Prom should have already printed out error messages. Exit to
323 	 * firmware.
324 	 */
325 	prom_exit_to_mon();
326 	/*NOTREACHED*/
327 }
328 
329 void
330 do_shutdown(void)
331 {
332 	proc_t *initpp;
333 
334 	/*
335 	 * If we're still booting and init(1) isn't set up yet, simply halt.
336 	 */
337 	mutex_enter(&pidlock);
338 	initpp = prfind(P_INITPID);
339 	mutex_exit(&pidlock);
340 	if (initpp == NULL) {
341 		extern void halt(char *);
342 		prom_power_off();
343 		halt("Power off the System");	/* just in case */
344 	}
345 
346 	/*
347 	 * else, graceful shutdown with inittab and all getting involved
348 	 */
349 	psignal(initpp, SIGPWR);
350 }
351