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   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