Pull unaligned-snsc_event into release branch
[linux-2.6] / drivers / char / snsc_event.c
1 /*
2  * SN Platform system controller communication support
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 2004 Silicon Graphics, Inc. All rights reserved.
9  */
10
11 /*
12  * System controller event handler
13  *
14  * These routines deal with environmental events arriving from the
15  * system controllers.
16  */
17
18 #include <linux/interrupt.h>
19 #include <linux/sched.h>
20 #include <linux/byteorder/generic.h>
21 #include <asm/sn/sn_sal.h>
22 #include <asm/unaligned.h>
23 #include "snsc.h"
24
25 static struct subch_data_s *event_sd;
26
27 void scdrv_event(unsigned long);
28 DECLARE_TASKLET(sn_sysctl_event, scdrv_event, 0);
29
30 /*
31  * scdrv_event_interrupt
32  *
33  * Pull incoming environmental events off the physical link to the
34  * system controller and put them in a temporary holding area in SAL.
35  * Schedule scdrv_event() to move them along to their ultimate
36  * destination.
37  */
38 static irqreturn_t
39 scdrv_event_interrupt(int irq, void *subch_data, struct pt_regs *regs)
40 {
41         struct subch_data_s *sd = subch_data;
42         unsigned long flags;
43         int status;
44
45         spin_lock_irqsave(&sd->sd_rlock, flags);
46         status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
47
48         if ((status > 0) && (status & SAL_IROUTER_INTR_RECV)) {
49                 tasklet_schedule(&sn_sysctl_event);
50         }
51         spin_unlock_irqrestore(&sd->sd_rlock, flags);
52         return IRQ_HANDLED;
53 }
54
55
56 /*
57  * scdrv_parse_event
58  *
59  * Break an event (as read from SAL) into useful pieces so we can decide
60  * what to do with it.
61  */
62 static int
63 scdrv_parse_event(char *event, int *src, int *code, int *esp_code, char *desc)
64 {
65         char *desc_end;
66         __be32 from_buf;
67
68         /* record event source address */
69         from_buf = get_unaligned((__be32 *)event);
70         *src = be32_to_cpup(&from_buf);
71         event += 4;                     /* move on to event code */
72
73         /* record the system controller's event code */
74         from_buf = get_unaligned((__be32 *)event);
75         *code = be32_to_cpup(&from_buf);
76         event += 4;                     /* move on to event arguments */
77
78         /* how many arguments are in the packet? */
79         if (*event++ != 2) {
80                 /* if not 2, give up */
81                 return -1;
82         }
83
84         /* parse out the ESP code */
85         if (*event++ != IR_ARG_INT) {
86                 /* not an integer argument, so give up */
87                 return -1;
88         }
89         from_buf = get_unaligned((__be32 *)event);
90         *esp_code = be32_to_cpup(&from_buf);
91         event += 4;
92
93         /* parse out the event description */
94         if (*event++ != IR_ARG_ASCII) {
95                 /* not an ASCII string, so give up */
96                 return -1;
97         }
98         event[CHUNKSIZE-1] = '\0';      /* ensure this string ends! */
99         event += 2;                     /* skip leading CR/LF */
100         desc_end = desc + sprintf(desc, "%s", event);
101
102         /* strip trailing CR/LF (if any) */
103         for (desc_end--;
104              (desc_end != desc) && ((*desc_end == 0xd) || (*desc_end == 0xa));
105              desc_end--) {
106                 *desc_end = '\0';
107         }
108
109         return 0;
110 }
111
112
113 /*
114  * scdrv_event_severity
115  *
116  * Figure out how urgent a message we should write to the console/syslog
117  * via printk.
118  */
119 static char *
120 scdrv_event_severity(int code)
121 {
122         int ev_class = (code & EV_CLASS_MASK);
123         int ev_severity = (code & EV_SEVERITY_MASK);
124         char *pk_severity = KERN_NOTICE;
125
126         switch (ev_class) {
127         case EV_CLASS_POWER:
128                 switch (ev_severity) {
129                 case EV_SEVERITY_POWER_LOW_WARNING:
130                 case EV_SEVERITY_POWER_HIGH_WARNING:
131                         pk_severity = KERN_WARNING;
132                         break;
133                 case EV_SEVERITY_POWER_HIGH_FAULT:
134                 case EV_SEVERITY_POWER_LOW_FAULT:
135                         pk_severity = KERN_ALERT;
136                         break;
137                 }
138                 break;
139         case EV_CLASS_FAN:
140                 switch (ev_severity) {
141                 case EV_SEVERITY_FAN_WARNING:
142                         pk_severity = KERN_WARNING;
143                         break;
144                 case EV_SEVERITY_FAN_FAULT:
145                         pk_severity = KERN_CRIT;
146                         break;
147                 }
148                 break;
149         case EV_CLASS_TEMP:
150                 switch (ev_severity) {
151                 case EV_SEVERITY_TEMP_ADVISORY:
152                         pk_severity = KERN_WARNING;
153                         break;
154                 case EV_SEVERITY_TEMP_CRITICAL:
155                         pk_severity = KERN_CRIT;
156                         break;
157                 case EV_SEVERITY_TEMP_FAULT:
158                         pk_severity = KERN_ALERT;
159                         break;
160                 }
161                 break;
162         case EV_CLASS_ENV:
163                 pk_severity = KERN_ALERT;
164                 break;
165         case EV_CLASS_TEST_FAULT:
166                 pk_severity = KERN_ALERT;
167                 break;
168         case EV_CLASS_TEST_WARNING:
169                 pk_severity = KERN_WARNING;
170                 break;
171         case EV_CLASS_PWRD_NOTIFY:
172                 pk_severity = KERN_ALERT;
173                 break;
174         }
175
176         return pk_severity;
177 }
178
179
180 /*
181  * scdrv_dispatch_event
182  *
183  * Do the right thing with an incoming event.  That's often nothing
184  * more than printing it to the system log.  For power-down notifications
185  * we start a graceful shutdown.
186  */
187 static void
188 scdrv_dispatch_event(char *event, int len)
189 {
190         int code, esp_code, src;
191         char desc[CHUNKSIZE];
192         char *severity;
193
194         if (scdrv_parse_event(event, &src, &code, &esp_code, desc) < 0) {
195                 /* ignore uninterpretible event */
196                 return;
197         }
198
199         /* how urgent is the message? */
200         severity = scdrv_event_severity(code);
201
202         if ((code & EV_CLASS_MASK) == EV_CLASS_PWRD_NOTIFY) {
203                 struct task_struct *p;
204
205                 /* give a SIGPWR signal to init proc */
206
207                 /* first find init's task */
208                 read_lock(&tasklist_lock);
209                 for_each_process(p) {
210                         if (p->pid == 1)
211                                 break;
212                 }
213                 if (p) { /* we found init's task */
214                         printk(KERN_EMERG "Power off indication received. Initiating power fail sequence...\n");
215                         force_sig(SIGPWR, p);
216                 } else { /* failed to find init's task - just give message(s) */
217                         printk(KERN_WARNING "Failed to find init proc to handle power off!\n");
218                         printk("%s|$(0x%x)%s\n", severity, esp_code, desc);
219                 }
220                 read_unlock(&tasklist_lock);
221         } else {
222                 /* print to system log */
223                 printk("%s|$(0x%x)%s\n", severity, esp_code, desc);
224         }
225 }
226
227
228 /*
229  * scdrv_event
230  *
231  * Called as a tasklet when an event arrives from the L1.  Read the event
232  * from where it's temporarily stored in SAL and call scdrv_dispatch_event()
233  * to send it on its way.  Keep trying to read events until SAL indicates
234  * that there are no more immediately available.
235  */
236 void
237 scdrv_event(unsigned long dummy)
238 {
239         int status;
240         int len;
241         unsigned long flags;
242         struct subch_data_s *sd = event_sd;
243
244         /* anything to read? */
245         len = CHUNKSIZE;
246         spin_lock_irqsave(&sd->sd_rlock, flags);
247         status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
248                                    sd->sd_rb, &len);
249
250         while (!(status < 0)) {
251                 spin_unlock_irqrestore(&sd->sd_rlock, flags);
252                 scdrv_dispatch_event(sd->sd_rb, len);
253                 len = CHUNKSIZE;
254                 spin_lock_irqsave(&sd->sd_rlock, flags);
255                 status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
256                                            sd->sd_rb, &len);
257         }
258         spin_unlock_irqrestore(&sd->sd_rlock, flags);
259 }
260
261
262 /*
263  * scdrv_event_init
264  *
265  * Sets up a system controller subchannel to begin receiving event
266  * messages. This is sort of a specialized version of scdrv_open()
267  * in drivers/char/sn_sysctl.c.
268  */
269 void
270 scdrv_event_init(struct sysctl_data_s *scd)
271 {
272         int rv;
273
274         event_sd = kmalloc(sizeof (struct subch_data_s), GFP_KERNEL);
275         if (event_sd == NULL) {
276                 printk(KERN_WARNING "%s: couldn't allocate subchannel info"
277                        " for event monitoring\n", __FUNCTION__);
278                 return;
279         }
280
281         /* initialize subch_data_s fields */
282         memset(event_sd, 0, sizeof (struct subch_data_s));
283         event_sd->sd_nasid = scd->scd_nasid;
284         spin_lock_init(&event_sd->sd_rlock);
285
286         /* ask the system controllers to send events to this node */
287         event_sd->sd_subch = ia64_sn_sysctl_event_init(scd->scd_nasid);
288
289         if (event_sd->sd_subch < 0) {
290                 kfree(event_sd);
291                 printk(KERN_WARNING "%s: couldn't open event subchannel\n",
292                        __FUNCTION__);
293                 return;
294         }
295
296         /* hook event subchannel up to the system controller interrupt */
297         rv = request_irq(SGI_UART_VECTOR, scdrv_event_interrupt,
298                          SA_SHIRQ | SA_INTERRUPT,
299                          "system controller events", event_sd);
300         if (rv) {
301                 printk(KERN_WARNING "%s: irq request failed (%d)\n",
302                        __FUNCTION__, rv);
303                 ia64_sn_irtr_close(event_sd->sd_nasid, event_sd->sd_subch);
304                 kfree(event_sd);
305                 return;
306         }
307 }
308
309