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) 2004-2006 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         static int snsc_shutting_down = 0;
 191         int code, esp_code, src, class;
 192         char desc[CHUNKSIZE];
 193         char *severity;
 194
 195         if (scdrv_parse_event(event, &src, &code, &esp_code, desc) < 0) {
 196                 /* ignore uninterpretible event */
 197                 return;
 198         }
 199
 200         /* how urgent is the message? */
 201         severity = scdrv_event_severity(code);
 202
 203         class = (code & EV_CLASS_MASK);
 204
 205         if (class == EV_CLASS_PWRD_NOTIFY || code == ENV_PWRDN_PEND) {
 206                 struct task_struct *p;
 207
 208                 if (snsc_shutting_down)
 209                         return;
 210
 211                 snsc_shutting_down = 1;
 212
 213                 /* give a message for each type of event */
 214                 if (class == EV_CLASS_PWRD_NOTIFY)
 215                         printk(KERN_NOTICE "Power off indication received."
 216                                " Sending SIGPWR to init...\n");
 217                 else if (code == ENV_PWRDN_PEND)
 218                         printk(KERN_CRIT "WARNING: Shutting down the system"
 219                                " due to a critical environmental condition."
 220                                " Sending SIGPWR to init...\n");
 221
 222                 /* give a SIGPWR signal to init proc */
 223
 224                 /* first find init's task */
 225                 read_lock(&tasklist_lock);
 226                 for_each_process(p) {
 227                         if (p->pid == 1)
 228                                 break;
 229                 }
 230                 if (p) {
 231                         force_sig(SIGPWR, p);
 232                 } else {
 233                         printk(KERN_ERR "Failed to signal init!\n");
 234                         snsc_shutting_down = 0; /* so can try again (?) */
 235                 }
 236                 read_unlock(&tasklist_lock);
 237         } else {
 238                 /* print to system log */
 239                 printk("%s|$(0x%x)%s\n", severity, esp_code, desc);
 240         }
 241 }
 242
 243
 244 /*
 245  * scdrv_event
 246  *
 247  * Called as a tasklet when an event arrives from the L1.  Read the event
 248  * from where it's temporarily stored in SAL and call scdrv_dispatch_event()
 249  * to send it on its way.  Keep trying to read events until SAL indicates
 250  * that there are no more immediately available.
 251  */
 252 void
 253 scdrv_event(unsigned long dummy)
 254 {
 255         int status;
 256         int len;
 257         unsigned long flags;
 258         struct subch_data_s *sd = event_sd;
 259
 260         /* anything to read? */
 261         len = CHUNKSIZE;
 262         spin_lock_irqsave(&sd->sd_rlock, flags);
 263         status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
 264                                    sd->sd_rb, &len);
 265
 266         while (!(status < 0)) {
 267                 spin_unlock_irqrestore(&sd->sd_rlock, flags);
 268                 scdrv_dispatch_event(sd->sd_rb, len);
 269                 len = CHUNKSIZE;
 270                 spin_lock_irqsave(&sd->sd_rlock, flags);
 271                 status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
 272                                            sd->sd_rb, &len);
 273         }
 274         spin_unlock_irqrestore(&sd->sd_rlock, flags);
 275 }
 276
 277
 278 /*
 279  * scdrv_event_init
 280  *
 281  * Sets up a system controller subchannel to begin receiving event
 282  * messages. This is sort of a specialized version of scdrv_open()
 283  * in drivers/char/sn_sysctl.c.
 284  */
 285 void
 286 scdrv_event_init(struct sysctl_data_s *scd)
 287 {
 288         int rv;
 289
 290         event_sd = kzalloc(sizeof (struct subch_data_s), GFP_KERNEL);
 291         if (event_sd == NULL) {
 292                 printk(KERN_WARNING "%s: couldn't allocate subchannel info"
 293                        " for event monitoring\n", __FUNCTION__);
 294                 return;
 295         }
 296
 297         /* initialize subch_data_s fields */
 298         event_sd->sd_nasid = scd->scd_nasid;
 299         spin_lock_init(&event_sd->sd_rlock);
 300
 301         /* ask the system controllers to send events to this node */
 302         event_sd->sd_subch = ia64_sn_sysctl_event_init(scd->scd_nasid);
 303
 304         if (event_sd->sd_subch < 0) {
 305                 kfree(event_sd);
 306                 printk(KERN_WARNING "%s: couldn't open event subchannel\n",
 307                        __FUNCTION__);
 308                 return;
 309         }
 310
 311         /* hook event subchannel up to the system controller interrupt */
 312         rv = request_irq(SGI_UART_VECTOR, scdrv_event_interrupt,
 313                          IRQF_SHARED | IRQF_DISABLED,
 314                          "system controller events", event_sd);
 315         if (rv) {
 316                 printk(KERN_WARNING "%s: irq request failed (%d)\n",
 317                        __FUNCTION__, rv);
 318                 ia64_sn_irtr_close(event_sd->sd_nasid, event_sd->sd_subch);
 319                 kfree(event_sd);
 320                 return;
 321         }
 322 }