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/slab.h>
  21 #include <asm/byteorder.h>
  22 #include <asm/sn/sn_sal.h>
  23 #include <asm/unaligned.h>
  24 #include "snsc.h"
  25
  26 static struct subch_data_s *event_sd;
  27
  28 void scdrv_event(unsigned long);
  29 DECLARE_TASKLET(sn_sysctl_event, scdrv_event, 0);
  30
  31 /*
  32  * scdrv_event_interrupt
  33  *
  34  * Pull incoming environmental events off the physical link to the
  35  * system controller and put them in a temporary holding area in SAL.
  36  * Schedule scdrv_event() to move them along to their ultimate
  37  * destination.
  38  */
  39 static irqreturn_t
  40 scdrv_event_interrupt(int irq, void *subch_data)
  41 {
  42         struct subch_data_s *sd = subch_data;
  43         unsigned long flags;
  44         int status;
  45
  46         spin_lock_irqsave(&sd->sd_rlock, flags);
  47         status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
  48
  49         if ((status > 0) && (status & SAL_IROUTER_INTR_RECV)) {
  50                 tasklet_schedule(&sn_sysctl_event);
  51         }
  52         spin_unlock_irqrestore(&sd->sd_rlock, flags);
  53         return IRQ_HANDLED;
  54 }
  55
  56
  57 /*
  58  * scdrv_parse_event
  59  *
  60  * Break an event (as read from SAL) into useful pieces so we can decide
  61  * what to do with it.
  62  */
  63 static int
  64 scdrv_parse_event(char *event, int *src, int *code, int *esp_code, char *desc)
  65 {
  66         char *desc_end;
  67
  68         /* record event source address */
  69         *src = get_unaligned_be32(event);
  70         event += 4;                     /* move on to event code */
  71
  72         /* record the system controller's event code */
  73         *code = get_unaligned_be32(event);
  74         event += 4;                     /* move on to event arguments */
  75
  76         /* how many arguments are in the packet? */
  77         if (*event++ != 2) {
  78                 /* if not 2, give up */
  79                 return -1;
  80         }
  81
  82         /* parse out the ESP code */
  83         if (*event++ != IR_ARG_INT) {
  84                 /* not an integer argument, so give up */
  85                 return -1;
  86         }
  87         *esp_code = get_unaligned_be32(event);
  88         event += 4;
  89
  90         /* parse out the event description */
  91         if (*event++ != IR_ARG_ASCII) {
  92                 /* not an ASCII string, so give up */
  93                 return -1;
  94         }
  95         event[CHUNKSIZE-1] = '\0';      /* ensure this string ends! */
  96         event += 2;                     /* skip leading CR/LF */
  97         desc_end = desc + sprintf(desc, "%s", event);
  98
  99         /* strip trailing CR/LF (if any) */
 100         for (desc_end--;
 101              (desc_end != desc) && ((*desc_end == 0xd) || (*desc_end == 0xa));
 102              desc_end--) {
 103                 *desc_end = '\0';
 104         }
 105
 106         return 0;
 107 }
 108
 109
 110 /*
 111  * scdrv_event_severity
 112  *
 113  * Figure out how urgent a message we should write to the console/syslog
 114  * via printk.
 115  */
 116 static char *
 117 scdrv_event_severity(int code)
 118 {
 119         int ev_class = (code & EV_CLASS_MASK);
 120         int ev_severity = (code & EV_SEVERITY_MASK);
 121         char *pk_severity = KERN_NOTICE;
 122
 123         switch (ev_class) {
 124         case EV_CLASS_POWER:
 125                 switch (ev_severity) {
 126                 case EV_SEVERITY_POWER_LOW_WARNING:
 127                 case EV_SEVERITY_POWER_HIGH_WARNING:
 128                         pk_severity = KERN_WARNING;
 129                         break;
 130                 case EV_SEVERITY_POWER_HIGH_FAULT:
 131                 case EV_SEVERITY_POWER_LOW_FAULT:
 132                         pk_severity = KERN_ALERT;
 133                         break;
 134                 }
 135                 break;
 136         case EV_CLASS_FAN:
 137                 switch (ev_severity) {
 138                 case EV_SEVERITY_FAN_WARNING:
 139                         pk_severity = KERN_WARNING;
 140                         break;
 141                 case EV_SEVERITY_FAN_FAULT:
 142                         pk_severity = KERN_CRIT;
 143                         break;
 144                 }
 145                 break;
 146         case EV_CLASS_TEMP:
 147                 switch (ev_severity) {
 148                 case EV_SEVERITY_TEMP_ADVISORY:
 149                         pk_severity = KERN_WARNING;
 150                         break;
 151                 case EV_SEVERITY_TEMP_CRITICAL:
 152                         pk_severity = KERN_CRIT;
 153                         break;
 154                 case EV_SEVERITY_TEMP_FAULT:
 155                         pk_severity = KERN_ALERT;
 156                         break;
 157                 }
 158                 break;
 159         case EV_CLASS_ENV:
 160                 pk_severity = KERN_ALERT;
 161                 break;
 162         case EV_CLASS_TEST_FAULT:
 163                 pk_severity = KERN_ALERT;
 164                 break;
 165         case EV_CLASS_TEST_WARNING:
 166                 pk_severity = KERN_WARNING;
 167                 break;
 168         case EV_CLASS_PWRD_NOTIFY:
 169                 pk_severity = KERN_ALERT;
 170                 break;
 171         }
 172
 173         return pk_severity;
 174 }
 175
 176
 177 /*
 178  * scdrv_dispatch_event
 179  *
 180  * Do the right thing with an incoming event.  That's often nothing
 181  * more than printing it to the system log.  For power-down notifications
 182  * we start a graceful shutdown.
 183  */
 184 static void
 185 scdrv_dispatch_event(char *event, int len)
 186 {
 187         static int snsc_shutting_down = 0;
 188         int code, esp_code, src, class;
 189         char desc[CHUNKSIZE];
 190         char *severity;
 191
 192         if (scdrv_parse_event(event, &src, &code, &esp_code, desc) < 0) {
 193                 /* ignore uninterpretible event */
 194                 return;
 195         }
 196
 197         /* how urgent is the message? */
 198         severity = scdrv_event_severity(code);
 199
 200         class = (code & EV_CLASS_MASK);
 201
 202         if (class == EV_CLASS_PWRD_NOTIFY || code == ENV_PWRDN_PEND) {
 203                 if (snsc_shutting_down)
 204                         return;
 205
 206                 snsc_shutting_down = 1;
 207
 208                 /* give a message for each type of event */
 209                 if (class == EV_CLASS_PWRD_NOTIFY)
 210                         printk(KERN_NOTICE "Power off indication received."
 211                                " Sending SIGPWR to init...\n");
 212                 else if (code == ENV_PWRDN_PEND)
 213                         printk(KERN_CRIT "WARNING: Shutting down the system"
 214                                " due to a critical environmental condition."
 215                                " Sending SIGPWR to init...\n");
 216
 217                 /* give a SIGPWR signal to init proc */
 218                 kill_cad_pid(SIGPWR, 0);
 219         } else {
 220                 /* print to system log */
 221                 printk("%s|$(0x%x)%s\n", severity, esp_code, desc);
 222         }
 223 }
 224
 225
 226 /*
 227  * scdrv_event
 228  *
 229  * Called as a tasklet when an event arrives from the L1.  Read the event
 230  * from where it's temporarily stored in SAL and call scdrv_dispatch_event()
 231  * to send it on its way.  Keep trying to read events until SAL indicates
 232  * that there are no more immediately available.
 233  */
 234 void
 235 scdrv_event(unsigned long dummy)
 236 {
 237         int status;
 238         int len;
 239         unsigned long flags;
 240         struct subch_data_s *sd = event_sd;
 241
 242         /* anything to read? */
 243         len = CHUNKSIZE;
 244         spin_lock_irqsave(&sd->sd_rlock, flags);
 245         status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
 246                                    sd->sd_rb, &len);
 247
 248         while (!(status < 0)) {
 249                 spin_unlock_irqrestore(&sd->sd_rlock, flags);
 250                 scdrv_dispatch_event(sd->sd_rb, len);
 251                 len = CHUNKSIZE;
 252                 spin_lock_irqsave(&sd->sd_rlock, flags);
 253                 status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
 254                                            sd->sd_rb, &len);
 255         }
 256         spin_unlock_irqrestore(&sd->sd_rlock, flags);
 257 }
 258
 259
 260 /*
 261  * scdrv_event_init
 262  *
 263  * Sets up a system controller subchannel to begin receiving event
 264  * messages. This is sort of a specialized version of scdrv_open()
 265  * in drivers/char/sn_sysctl.c.
 266  */
 267 void
 268 scdrv_event_init(struct sysctl_data_s *scd)
 269 {
 270         int rv;
 271
 272         event_sd = kzalloc(sizeof (struct subch_data_s), GFP_KERNEL);
 273         if (event_sd == NULL) {
 274                 printk(KERN_WARNING "%s: couldn't allocate subchannel info"
 275                        " for event monitoring\n", __func__);
 276                 return;
 277         }
 278
 279         /* initialize subch_data_s fields */
 280         event_sd->sd_nasid = scd->scd_nasid;
 281         spin_lock_init(&event_sd->sd_rlock);
 282
 283         /* ask the system controllers to send events to this node */
 284         event_sd->sd_subch = ia64_sn_sysctl_event_init(scd->scd_nasid);
 285
 286         if (event_sd->sd_subch < 0) {
 287                 kfree(event_sd);
 288                 printk(KERN_WARNING "%s: couldn't open event subchannel\n",
 289                        __func__);
 290                 return;
 291         }
 292
 293         /* hook event subchannel up to the system controller interrupt */
 294         rv = request_irq(SGI_UART_VECTOR, scdrv_event_interrupt,
 295                          IRQF_SHARED | IRQF_DISABLED,
 296                          "system controller events", event_sd);
 297         if (rv) {
 298                 printk(KERN_WARNING "%s: irq request failed (%d)\n",
 299                        __func__, rv);
 300                 ia64_sn_irtr_close(event_sd->sd_nasid, event_sd->sd_subch);
 301                 kfree(event_sd);
 302                 return;
 303         }
 304 }