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