xref: /titanic_41/usr/src/uts/sun4/os/cpu_states.c (revision fcf3ce441efd61da9bb2884968af01cb7c1452cc)
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 2007 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/kdi_machimpl.h>
39 #include <sys/callb.h>
40 #include <sys/wdt.h>
41 
42 #ifdef	TRAPTRACE
43 #include <sys/traptrace.h>
44 #endif /* TRAPTRACE */
45 
46 extern void audit_enterprom();
47 extern void audit_exitprom();
48 
49 /*
50  * Platforms that use CPU signatures need to set cpu_sgn_func
51  * to point to a platform specific function.  This needs to
52  * be done in set_platform_defaults() within the platmod.
53  */
54 void (*cpu_sgn_func)(ushort_t, uchar_t, uchar_t, int) = NULL;
55 
56 /*
57  * abort_seq_handler required by sysctrl.
58  */
59 void debug_enter(char *);
60 void (*abort_seq_handler)(char *) = debug_enter;
61 
62 /*
63  * Platform tunable to disable the h/w watchdog timer.
64  */
65 extern void clear_watchdog_on_exit(void);
66 
67 /*
68  * On sun4u platform, abort_sequence_enter() can be called at high PIL
69  * and we can't afford to acquire any adaptive mutex or use any
70  * condition variables as we are not allowed to sleep while running
71  * on interrupt stack. We work around this problem by posting a level
72  * 10 soft interrupt and then invoking the "abort_seq_handler" within
73  * that soft interrupt context.
74  *
75  * This has the side effect of not allowing us to drop into debugger
76  * when the kernel is stuck at high PIL (PIL > 10).  It's better to
77  * be able to break into a hung system even if it means crashing the
78  * system.  If a user presses L1-A more than once within a 15 seconds
79  * window, and the previous L1-A soft interrupt is still pending, then
80  * we directly invoke the abort_sequence_enter.
81  *
82  * Since the "msg" argument passed to abort_sequence_enter can refer
83  * to a message anywhere in memory, including stack, it's copied into
84  * abort_seq_msgbuf buffer for processing by the soft interrupt.
85  */
86 
87 #define	ABORT_SEQ_MSGBUFSZ	256
88 #define	FORCE_ABORT_SEQ_INTERVAL ((hrtime_t)15 * NANOSEC)
89 
90 static kmutex_t	abort_seq_lock;
91 static uint64_t	abort_seq_inum;		/* abort seq softintr # */
92 static hrtime_t	abort_seq_tstamp;	/* hrtime of last abort seq */
93 static size_t	abort_seq_msglen;	/* abort seq message length */
94 static char	abort_seq_msgbuf[ABORT_SEQ_MSGBUFSZ];
95 
96 /*ARGSUSED0*/
97 static uint_t
98 abort_seq_softintr(caddr_t arg)
99 {
100 	char	*msg;
101 	char	msgbuf[ABORT_SEQ_MSGBUFSZ];
102 
103 	mutex_enter(&abort_seq_lock);
104 	if (abort_enable != 0 && abort_seq_tstamp != 0LL) {
105 		if (abort_seq_msglen > 0) {
106 			bcopy(abort_seq_msgbuf, msgbuf, abort_seq_msglen);
107 			msg = msgbuf;
108 		} else
109 			msg = NULL;
110 		abort_seq_tstamp = 0LL;
111 		mutex_exit(&abort_seq_lock);
112 		if (audit_active)
113 			audit_enterprom(1);
114 		(*abort_seq_handler)(msg);
115 		if (audit_active)
116 			audit_exitprom(1);
117 	} else {
118 		mutex_exit(&abort_seq_lock);
119 		if (audit_active)
120 			audit_enterprom(0);
121 	}
122 	return (1);
123 }
124 
125 void
126 abort_sequence_init(void)
127 {
128 	mutex_init(&abort_seq_lock, NULL, MUTEX_SPIN, (void *)PIL_12);
129 	abort_seq_tstamp = 0LL;
130 	if (abort_seq_inum == 0)
131 		abort_seq_inum = add_softintr(LOCK_LEVEL,
132 		    (softintrfunc)abort_seq_softintr, NULL, SOFTINT_ST);
133 }
134 
135 /*
136  *	Machine dependent abort sequence handling
137  */
138 void
139 abort_sequence_enter(char *msg)
140 {
141 	int		s, on_intr;
142 	size_t		msglen;
143 	hrtime_t	tstamp;
144 
145 	if (abort_enable != 0) {
146 		s = splhi();
147 		on_intr = CPU_ON_INTR(CPU) || (spltoipl(s) > LOCK_LEVEL);
148 		splx(s);
149 
150 		tstamp = gethrtime();
151 		mutex_enter(&abort_seq_lock);
152 
153 		/*
154 		 * If we are on an interrupt stack and/or running at
155 		 * PIL > LOCK_LEVEL, then we post a softint and invoke
156 		 * abort_seq_handler from there as we can't afford to
157 		 * acquire any adaptive mutex here. However, if we
158 		 * already have a pending softint, which was posted
159 		 * within FORCE_ABORT_SEQ_INTERVAL duration, then we
160 		 * bypass softint approach as our softint may be blocked
161 		 * and the user really wants to drop into the debugger.
162 		 */
163 		if (on_intr && abort_seq_inum != 0 &&
164 		    (abort_seq_tstamp == 0LL || tstamp >
165 		    (abort_seq_tstamp + FORCE_ABORT_SEQ_INTERVAL))) {
166 			abort_seq_tstamp = tstamp;
167 			if (msg != NULL) {
168 				msglen = strlen(msg);
169 				if (msglen >= ABORT_SEQ_MSGBUFSZ)
170 					msglen = ABORT_SEQ_MSGBUFSZ - 1;
171 				bcopy(msg, abort_seq_msgbuf, msglen);
172 				abort_seq_msgbuf[msglen] = '\0';
173 				abort_seq_msglen = msglen + 1;
174 			} else
175 				abort_seq_msglen = 0;
176 			mutex_exit(&abort_seq_lock);
177 			setsoftint(abort_seq_inum);
178 		} else {
179 			/*
180 			 * Ignore any pending abort sequence softint
181 			 * as we are invoking the abort_seq_handler
182 			 * here.
183 			 */
184 			abort_seq_tstamp = 0LL;
185 			mutex_exit(&abort_seq_lock);
186 		if (!on_intr && audit_active)
187 			audit_enterprom(1);
188 			(*abort_seq_handler)(msg);
189 		if (!on_intr && audit_active)
190 			audit_exitprom(1);
191 		}
192 	} else {
193 		if (audit_active)
194 			audit_enterprom(0);
195 	}
196 }
197 
198 /*
199  * Enter debugger.  Called when the user types L1-A or break or whenever
200  * code wants to enter the debugger and possibly resume later.
201  * If the debugger isn't present, enter the PROM monitor.
202  *
203  * If console is a framebuffer which is powered off, it will be powered up
204  * before jumping to the debugger.  If we are called above lock level, a
205  * softint is triggered to reenter this code and allow the fb to be powered
206  * up as in the less than lock level case.  If this code is entered at greater
207  * than lock level and the fb is not already powered up, the msg argument
208  * will not be displayed.
209  */
210 void
211 debug_enter(char *msg)
212 {
213 	label_t old_pcb;
214 	int s;
215 	extern void pm_cfb_powerup(void);
216 	extern void pm_cfb_rele(void);
217 	extern void pm_cfb_trigger(void);
218 	extern int pm_cfb_check_and_hold(void);
219 
220 	/*
221 	 * For platforms that use CPU signatures, update the signature
222 	 * to indicate that we are entering the debugger if we are in
223 	 * the middle of a panic flow.
224 	 */
225 	if (panicstr)
226 		CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_DEBUG, -1);
227 
228 	if (!panicstr)
229 		(void) callb_execute_class(CB_CL_ENTER_DEBUGGER, 0);
230 
231 	if (pm_cfb_check_and_hold())
232 		if (getpil() > LOCK_LEVEL) {
233 			pm_cfb_trigger();
234 			return;
235 		} else
236 			pm_cfb_powerup();
237 	if (msg)
238 		prom_printf("%s\n", msg);
239 
240 	clear_watchdog_on_exit();
241 
242 	if ((s = getpil()) < ipltospl(12))
243 		s = splzs();
244 
245 	old_pcb = curthread->t_pcb;
246 	(void) setjmp(&curthread->t_pcb);
247 
248 	if (boothowto & RB_DEBUG)
249 		kmdb_enter();
250 	else
251 		prom_enter_mon();
252 
253 	restore_watchdog_on_entry();
254 
255 	curthread->t_pcb = old_pcb;
256 	splx(s);
257 	pm_cfb_rele();
258 
259 	if (!panicstr)
260 		(void) callb_execute_class(CB_CL_ENTER_DEBUGGER, 1);
261 
262 	if (panicstr)
263 		CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_PANIC_CONT, -1);
264 }
265 
266 /*
267  * Halt the machine and return to the monitor
268  */
269 void
270 halt(char *s)
271 {
272 	flush_windows();
273 	stop_other_cpus();		/* send stop signal to other CPUs */
274 
275 	if (s)
276 		prom_printf("(%s) ", s);
277 
278 	/*
279 	 * For Platforms that use CPU signatures, we
280 	 * need to set the signature block to OS and
281 	 * the state to exiting for all the processors.
282 	 */
283 	CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_HALT, -1);
284 	prom_exit_to_mon();
285 	/*NOTREACHED*/
286 }
287 
288 /*
289  * Halt the machine and power off the system.
290  */
291 void
292 power_down(const char *s)
293 {
294 	flush_windows();
295 	stop_other_cpus();		/* send stop signal to other CPUs */
296 
297 	if (s != NULL)
298 		prom_printf("(%s) ", s);
299 
300 	/*
301 	 * For platforms that use CPU signatures, we need to set up the
302 	 * signature blocks to indicate that we have an environmental
303 	 * interrupt request to power down, and then exit to the prom monitor.
304 	 */
305 	CPU_SIGNATURE(OS_SIG, SIGST_EXIT, SIGSUBST_ENVIRON, -1);
306 	prom_power_off();
307 	/*
308 	 * If here is reached, for some reason prom's power-off command failed.
309 	 * Prom should have already printed out error messages. Exit to
310 	 * firmware.
311 	 */
312 	prom_exit_to_mon();
313 	/*NOTREACHED*/
314 }
315 
316 void
317 do_shutdown(void)
318 {
319 	proc_t *initpp;
320 
321 	/*
322 	 * If we're still booting and init(1) isn't set up yet, simply halt.
323 	 */
324 	mutex_enter(&pidlock);
325 	initpp = prfind(P_INITPID);
326 	mutex_exit(&pidlock);
327 	if (initpp == NULL) {
328 		extern void halt(char *);
329 		prom_power_off();
330 		halt("Power off the System");	/* just in case */
331 	}
332 
333 	/*
334 	 * else, graceful shutdown with inittab and all getting involved
335 	 */
336 	psignal(initpp, SIGPWR);
337 }
338