xref: /titanic_41/usr/src/uts/sun4/os/cpu_states.c (revision 3173664e967186de0a5f0e61548c25996fa6d37f)
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 2006 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/reboot.h>
29 #include <sys/systm.h>
30 #include <sys/archsystm.h>
31 #include <sys/machsystm.h>
32 #include <sys/promif.h>
33 #include <sys/promimpl.h>
34 #include <sys/prom_plat.h>
35 #include <sys/cpu_sgnblk_defs.h>
36 #include <sys/ivintr.h>
37 #include <sys/kdi.h>
38 #include <sys/callb.h>
39 #include <sys/wdt.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 extern void clear_watchdog_on_exit(void);
67 
68 /*
69  * On sun4u platform, abort_sequence_enter() can be called at high PIL
70  * and we can't afford to acquire any adaptive mutex or use any
71  * condition variables as we are not allowed to sleep while running
72  * on interrupt stack. We work around this problem by posting a level
73  * 10 soft interrupt and then invoking the "abort_seq_handler" within
74  * that soft interrupt context.
75  *
76  * This has the side effect of not allowing us to drop into debugger
77  * when the kernel is stuck at high PIL (PIL > 10).  It's better to
78  * be able to break into a hung system even if it means crashing the
79  * system.  If a user presses L1-A more than once within a 15 seconds
80  * window, and the previous L1-A soft interrupt is still pending, then
81  * we directly invoke the abort_sequence_enter.
82  *
83  * Since the "msg" argument passed to abort_sequence_enter can refer
84  * to a message anywhere in memory, including stack, it's copied into
85  * abort_seq_msgbuf buffer for processing by the soft interrupt.
86  */
87 
88 #define	ABORT_SEQ_MSGBUFSZ	256
89 #define	FORCE_ABORT_SEQ_INTERVAL ((hrtime_t)15 * NANOSEC)
90 
91 static kmutex_t	abort_seq_lock;
92 static uint64_t	abort_seq_inum;		/* abort seq softintr # */
93 static hrtime_t	abort_seq_tstamp;	/* hrtime of last abort seq */
94 static size_t	abort_seq_msglen;	/* abort seq message length */
95 static char	abort_seq_msgbuf[ABORT_SEQ_MSGBUFSZ];
96 
97 /*ARGSUSED0*/
98 static uint_t
99 abort_seq_softintr(caddr_t arg)
100 {
101 	char	*msg;
102 	char	msgbuf[ABORT_SEQ_MSGBUFSZ];
103 
104 	mutex_enter(&abort_seq_lock);
105 	if (abort_enable != 0 && abort_seq_tstamp != 0LL) {
106 		if (abort_seq_msglen > 0) {
107 			bcopy(abort_seq_msgbuf, msgbuf, abort_seq_msglen);
108 			msg = msgbuf;
109 		} else
110 			msg = NULL;
111 		abort_seq_tstamp = 0LL;
112 		mutex_exit(&abort_seq_lock);
113 #ifdef C2_AUDIT
114 		if (audit_active)
115 			audit_enterprom(1);
116 #endif /* C2_AUDIT */
117 		(*abort_seq_handler)(msg);
118 #ifdef C2_AUDIT
119 		if (audit_active)
120 			audit_exitprom(1);
121 #endif /* C2_AUDIT */
122 	} else {
123 		mutex_exit(&abort_seq_lock);
124 #ifdef C2_AUDIT
125 		if (audit_active)
126 			audit_enterprom(0);
127 #endif /* C2_AUDIT */
128 	}
129 	return (1);
130 }
131 
132 void
133 abort_sequence_init(void)
134 {
135 	mutex_init(&abort_seq_lock, NULL, MUTEX_SPIN, (void *)PIL_12);
136 	abort_seq_tstamp = 0LL;
137 	if (abort_seq_inum == 0)
138 		abort_seq_inum = add_softintr(LOCK_LEVEL,
139 		    (softintrfunc)abort_seq_softintr, NULL, SOFTINT_ST);
140 }
141 
142 /*
143  *	Machine dependent abort sequence handling
144  */
145 void
146 abort_sequence_enter(char *msg)
147 {
148 	int		s, on_intr;
149 	size_t		msglen;
150 	hrtime_t	tstamp;
151 
152 	if (abort_enable != 0) {
153 		s = splhi();
154 		on_intr = CPU_ON_INTR(CPU) || (spltoipl(s) > LOCK_LEVEL);
155 		splx(s);
156 
157 		tstamp = gethrtime();
158 		mutex_enter(&abort_seq_lock);
159 
160 		/*
161 		 * If we are on an interrupt stack and/or running at
162 		 * PIL > LOCK_LEVEL, then we post a softint and invoke
163 		 * abort_seq_handler from there as we can't afford to
164 		 * acquire any adaptive mutex here. However, if we
165 		 * already have a pending softint, which was posted
166 		 * within FORCE_ABORT_SEQ_INTERVAL duration, then we
167 		 * bypass softint approach as our softint may be blocked
168 		 * and the user really wants to drop into the debugger.
169 		 */
170 		if (on_intr && abort_seq_inum != 0 &&
171 		    (abort_seq_tstamp == 0LL || tstamp >
172 		    (abort_seq_tstamp + FORCE_ABORT_SEQ_INTERVAL))) {
173 			abort_seq_tstamp = tstamp;
174 			if (msg != NULL) {
175 				msglen = strlen(msg);
176 				if (msglen >= ABORT_SEQ_MSGBUFSZ)
177 					msglen = ABORT_SEQ_MSGBUFSZ - 1;
178 				bcopy(msg, abort_seq_msgbuf, msglen);
179 				abort_seq_msgbuf[msglen] = '\0';
180 				abort_seq_msglen = msglen + 1;
181 			} else
182 				abort_seq_msglen = 0;
183 			mutex_exit(&abort_seq_lock);
184 			setsoftint(abort_seq_inum);
185 		} else {
186 			/*
187 			 * Ignore any pending abort sequence softint
188 			 * as we are invoking the abort_seq_handler
189 			 * here.
190 			 */
191 			abort_seq_tstamp = 0LL;
192 			mutex_exit(&abort_seq_lock);
193 #ifdef C2_AUDIT
194 		if (!on_intr && audit_active)
195 			audit_enterprom(1);
196 #endif /* C2_AUDIT */
197 			(*abort_seq_handler)(msg);
198 #ifdef C2_AUDIT
199 		if (!on_intr && audit_active)
200 			audit_exitprom(1);
201 #endif /* C2_AUDIT */
202 		}
203 	} else {
204 #ifdef C2_AUDIT
205 		if (audit_active)
206 			audit_enterprom(0);
207 #endif /* C2_AUDIT */
208 	}
209 }
210 
211 /*
212  * Enter debugger.  Called when the user types L1-A or break or whenever
213  * code wants to enter the debugger and possibly resume later.
214  * If the debugger isn't present, enter the PROM monitor.
215  *
216  * If console is a framebuffer which is powered off, it will be powered up
217  * before jumping to the debugger.  If we are called above lock level, a
218  * softint is triggered to reenter this code and allow the fb to be powered
219  * up as in the less than lock level case.  If this code is entered at greater
220  * than lock level and the fb is not already powered up, the msg argument
221  * will not be displayed.
222  */
223 void
224 debug_enter(char *msg)
225 {
226 	label_t old_pcb;
227 	int s;
228 	extern void pm_cfb_powerup(void);
229 	extern void pm_cfb_rele(void);
230 	extern void pm_cfb_trigger(void);
231 	extern int pm_cfb_check_and_hold(void);
232 
233 	/*
234 	 * For platforms that use CPU signatures, update the signature
235 	 * to indicate that we are entering the debugger if we are in
236 	 * the middle of a panic flow.
237 	 */
238 	if (panicstr)
239 		CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_DEBUG, -1);
240 
241 	if (!panicstr)
242 		(void) callb_execute_class(CB_CL_ENTER_DEBUGGER, 0);
243 
244 	if (pm_cfb_check_and_hold())
245 		if (getpil() > LOCK_LEVEL) {
246 			pm_cfb_trigger();
247 			return;
248 		} else
249 			pm_cfb_powerup();
250 	if (msg)
251 		prom_printf("%s\n", msg);
252 
253 	clear_watchdog_on_exit();
254 
255 	if ((s = getpil()) < ipltospl(12))
256 		s = splzs();
257 
258 	old_pcb = curthread->t_pcb;
259 	(void) setjmp(&curthread->t_pcb);
260 
261 	if (boothowto & RB_DEBUG)
262 		kdi_dvec_enter();
263 	else
264 		prom_enter_mon();
265 
266 	restore_watchdog_on_entry();
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