drivers/s390/cio/eadm_sch.c

   1 /*
   2  * Driver for s390 eadm subchannels
   3  *
   4  * Copyright IBM Corp. 2012
   5  * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
   6  */
   7
   8 #include <linux/kernel_stat.h>
   9 #include <linux/completion.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/device.h>
  13 #include <linux/module.h>
  14 #include <linux/timer.h>
  15 #include <linux/slab.h>
  16 #include <linux/list.h>
  17
  18 #include <asm/css_chars.h>
  19 #include <asm/debug.h>
  20 #include <asm/isc.h>
  21 #include <asm/cio.h>
  22 #include <asm/scsw.h>
  23 #include <asm/eadm.h>
  24
  25 #include "eadm_sch.h"
  26 #include "ioasm.h"
  27 #include "cio.h"
  28 #include "css.h"
  29 #include "orb.h"
  30
  31 MODULE_DESCRIPTION("driver for s390 eadm subchannels");
  32 MODULE_LICENSE("GPL");
  33
  34 #define EADM_TIMEOUT (7 * HZ)
  35 static DEFINE_SPINLOCK(list_lock);
  36 static LIST_HEAD(eadm_list);
  37
  38 static debug_info_t *eadm_debug;
  39
  40 #define EADM_LOG(imp, txt) do {                                 \
  41                 debug_text_event(eadm_debug, imp, txt);         \
  42         } while (0)
  43
  44 static void EADM_LOG_HEX(int level, void *data, int length)
  45 {
  46         debug_event(eadm_debug, level, data, length);
  47 }
  48
  49 static void orb_init(union orb *orb)
  50 {
  51         memset(orb, 0, sizeof(union orb));
  52         orb->eadm.compat1 = 1;
  53         orb->eadm.compat2 = 1;
  54         orb->eadm.fmt = 1;
  55         orb->eadm.x = 1;
  56 }
  57
  58 static int eadm_subchannel_start(struct subchannel *sch, struct aob *aob)
  59 {
  60         union orb *orb = &get_eadm_private(sch)->orb;
  61         int cc;
  62
  63         orb_init(orb);
  64         orb->eadm.aob = (u32)__pa(aob);
  65         orb->eadm.intparm = (u32)(addr_t)sch;
  66         orb->eadm.key = PAGE_DEFAULT_KEY >> 4;
  67
  68         EADM_LOG(6, "start");
  69         EADM_LOG_HEX(6, &sch->schid, sizeof(sch->schid));
  70
  71         cc = ssch(sch->schid, orb);
  72         switch (cc) {
  73         case 0:
  74                 sch->schib.scsw.eadm.actl |= SCSW_ACTL_START_PEND;
  75                 break;
  76         case 1:         /* status pending */
  77         case 2:         /* busy */
  78                 return -EBUSY;
  79         case 3:         /* not operational */
  80                 return -ENODEV;
  81         }
  82         return 0;
  83 }
  84
  85 static int eadm_subchannel_clear(struct subchannel *sch)
  86 {
  87         int cc;
  88
  89         cc = csch(sch->schid);
  90         if (cc)
  91                 return -ENODEV;
  92
  93         sch->schib.scsw.eadm.actl |= SCSW_ACTL_CLEAR_PEND;
  94         return 0;
  95 }
  96
  97 static void eadm_subchannel_timeout(struct timer_list *t)
  98 {
  99         struct eadm_private *private = from_timer(private, t, timer);
 100         struct subchannel *sch = private->sch;
 101
 102         spin_lock_irq(sch->lock);
 103         EADM_LOG(1, "timeout");
 104         EADM_LOG_HEX(1, &sch->schid, sizeof(sch->schid));
 105         if (eadm_subchannel_clear(sch))
 106                 EADM_LOG(0, "clear failed");
 107         spin_unlock_irq(sch->lock);
 108 }
 109
 110 static void eadm_subchannel_set_timeout(struct subchannel *sch, int expires)
 111 {
 112         struct eadm_private *private = get_eadm_private(sch);
 113
 114         if (expires == 0) {
 115                 del_timer(&private->timer);
 116                 return;
 117         }
 118         if (timer_pending(&private->timer)) {
 119                 if (mod_timer(&private->timer, jiffies + expires))
 120                         return;
 121         }
 122         private->timer.expires = jiffies + expires;
 123         add_timer(&private->timer);
 124 }
 125
 126 static void eadm_subchannel_irq(struct subchannel *sch)
 127 {
 128         struct eadm_private *private = get_eadm_private(sch);
 129         struct eadm_scsw *scsw = &sch->schib.scsw.eadm;
 130         struct irb *irb = this_cpu_ptr(&cio_irb);
 131         blk_status_t error = BLK_STS_OK;
 132
 133         EADM_LOG(6, "irq");
 134         EADM_LOG_HEX(6, irb, sizeof(*irb));
 135
 136         inc_irq_stat(IRQIO_ADM);
 137
 138         if ((scsw->stctl & (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))
 139             && scsw->eswf == 1 && irb->esw.eadm.erw.r)
 140                 error = BLK_STS_IOERR;
 141
 142         if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC)
 143                 error = BLK_STS_TIMEOUT;
 144
 145         eadm_subchannel_set_timeout(sch, 0);
 146
 147         if (private->state != EADM_BUSY) {
 148                 EADM_LOG(1, "irq unsol");
 149                 EADM_LOG_HEX(1, irb, sizeof(*irb));
 150                 private->state = EADM_NOT_OPER;
 151                 css_sched_sch_todo(sch, SCH_TODO_EVAL);
 152                 return;
 153         }
 154         scm_irq_handler((struct aob *)(unsigned long)scsw->aob, error);
 155         private->state = EADM_IDLE;
 156
 157         if (private->completion)
 158                 complete(private->completion);
 159 }
 160
 161 static struct subchannel *eadm_get_idle_sch(void)
 162 {
 163         struct eadm_private *private;
 164         struct subchannel *sch;
 165         unsigned long flags;
 166
 167         spin_lock_irqsave(&list_lock, flags);
 168         list_for_each_entry(private, &eadm_list, head) {
 169                 sch = private->sch;
 170                 spin_lock(sch->lock);
 171                 if (private->state == EADM_IDLE) {
 172                         private->state = EADM_BUSY;
 173                         list_move_tail(&private->head, &eadm_list);
 174                         spin_unlock(sch->lock);
 175                         spin_unlock_irqrestore(&list_lock, flags);
 176
 177                         return sch;
 178                 }
 179                 spin_unlock(sch->lock);
 180         }
 181         spin_unlock_irqrestore(&list_lock, flags);
 182
 183         return NULL;
 184 }
 185
 186 int eadm_start_aob(struct aob *aob)
 187 {
 188         struct eadm_private *private;
 189         struct subchannel *sch;
 190         unsigned long flags;
 191         int ret;
 192
 193         sch = eadm_get_idle_sch();
 194         if (!sch)
 195                 return -EBUSY;
 196
 197         spin_lock_irqsave(sch->lock, flags);
 198         eadm_subchannel_set_timeout(sch, EADM_TIMEOUT);
 199         ret = eadm_subchannel_start(sch, aob);
 200         if (!ret)
 201                 goto out_unlock;
 202
 203         /* Handle start subchannel failure. */
 204         eadm_subchannel_set_timeout(sch, 0);
 205         private = get_eadm_private(sch);
 206         private->state = EADM_NOT_OPER;
 207         css_sched_sch_todo(sch, SCH_TODO_EVAL);
 208
 209 out_unlock:
 210         spin_unlock_irqrestore(sch->lock, flags);
 211
 212         return ret;
 213 }
 214 EXPORT_SYMBOL_GPL(eadm_start_aob);
 215
 216 static int eadm_subchannel_probe(struct subchannel *sch)
 217 {
 218         struct eadm_private *private;
 219         int ret;
 220
 221         private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
 222         if (!private)
 223                 return -ENOMEM;
 224
 225         INIT_LIST_HEAD(&private->head);
 226         timer_setup(&private->timer, eadm_subchannel_timeout, 0);
 227
 228         spin_lock_irq(sch->lock);
 229         set_eadm_private(sch, private);
 230         private->state = EADM_IDLE;
 231         private->sch = sch;
 232         sch->isc = EADM_SCH_ISC;
 233         ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
 234         if (ret) {
 235                 set_eadm_private(sch, NULL);
 236                 spin_unlock_irq(sch->lock);
 237                 kfree(private);
 238                 goto out;
 239         }
 240         spin_unlock_irq(sch->lock);
 241
 242         spin_lock_irq(&list_lock);
 243         list_add(&private->head, &eadm_list);
 244         spin_unlock_irq(&list_lock);
 245
 246         if (dev_get_uevent_suppress(&sch->dev)) {
 247                 dev_set_uevent_suppress(&sch->dev, 0);
 248                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 249         }
 250 out:
 251         return ret;
 252 }
 253
 254 static void eadm_quiesce(struct subchannel *sch)
 255 {
 256         struct eadm_private *private = get_eadm_private(sch);
 257         DECLARE_COMPLETION_ONSTACK(completion);
 258         int ret;
 259
 260         spin_lock_irq(sch->lock);
 261         if (private->state != EADM_BUSY)
 262                 goto disable;
 263
 264         if (eadm_subchannel_clear(sch))
 265                 goto disable;
 266
 267         private->completion = &completion;
 268         spin_unlock_irq(sch->lock);
 269
 270         wait_for_completion_io(&completion);
 271
 272         spin_lock_irq(sch->lock);
 273         private->completion = NULL;
 274
 275 disable:
 276         eadm_subchannel_set_timeout(sch, 0);
 277         do {
 278                 ret = cio_disable_subchannel(sch);
 279         } while (ret == -EBUSY);
 280
 281         spin_unlock_irq(sch->lock);
 282 }
 283
 284 static int eadm_subchannel_remove(struct subchannel *sch)
 285 {
 286         struct eadm_private *private = get_eadm_private(sch);
 287
 288         spin_lock_irq(&list_lock);
 289         list_del(&private->head);
 290         spin_unlock_irq(&list_lock);
 291
 292         eadm_quiesce(sch);
 293
 294         spin_lock_irq(sch->lock);
 295         set_eadm_private(sch, NULL);
 296         spin_unlock_irq(sch->lock);
 297
 298         kfree(private);
 299
 300         return 0;
 301 }
 302
 303 static void eadm_subchannel_shutdown(struct subchannel *sch)
 304 {
 305         eadm_quiesce(sch);
 306 }
 307
 308 static int eadm_subchannel_freeze(struct subchannel *sch)
 309 {
 310         return cio_disable_subchannel(sch);
 311 }
 312
 313 static int eadm_subchannel_restore(struct subchannel *sch)
 314 {
 315         return cio_enable_subchannel(sch, (u32)(unsigned long)sch);
 316 }
 317
 318 /**
 319  * eadm_subchannel_sch_event - process subchannel event
 320  * @sch: subchannel
 321  * @process: non-zero if function is called in process context
 322  *
 323  * An unspecified event occurred for this subchannel. Adjust data according
 324  * to the current operational state of the subchannel. Return zero when the
 325  * event has been handled sufficiently or -EAGAIN when this function should
 326  * be called again in process context.
 327  */
 328 static int eadm_subchannel_sch_event(struct subchannel *sch, int process)
 329 {
 330         struct eadm_private *private;
 331         unsigned long flags;
 332
 333         spin_lock_irqsave(sch->lock, flags);
 334         if (!device_is_registered(&sch->dev))
 335                 goto out_unlock;
 336
 337         if (work_pending(&sch->todo_work))
 338                 goto out_unlock;
 339
 340         if (cio_update_schib(sch)) {
 341                 css_sched_sch_todo(sch, SCH_TODO_UNREG);
 342                 goto out_unlock;
 343         }
 344         private = get_eadm_private(sch);
 345         if (private->state == EADM_NOT_OPER)
 346                 private->state = EADM_IDLE;
 347
 348 out_unlock:
 349         spin_unlock_irqrestore(sch->lock, flags);
 350
 351         return 0;
 352 }
 353
 354 static struct css_device_id eadm_subchannel_ids[] = {
 355         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_ADM, },
 356         { /* end of list */ },
 357 };
 358 MODULE_DEVICE_TABLE(css, eadm_subchannel_ids);
 359
 360 static struct css_driver eadm_subchannel_driver = {
 361         .drv = {
 362                 .name = "eadm_subchannel",
 363                 .owner = THIS_MODULE,
 364         },
 365         .subchannel_type = eadm_subchannel_ids,
 366         .irq = eadm_subchannel_irq,
 367         .probe = eadm_subchannel_probe,
 368         .remove = eadm_subchannel_remove,
 369         .shutdown = eadm_subchannel_shutdown,
 370         .sch_event = eadm_subchannel_sch_event,
 371         .freeze = eadm_subchannel_freeze,
 372         .thaw = eadm_subchannel_restore,
 373         .restore = eadm_subchannel_restore,
 374 };
 375
 376 static int __init eadm_sch_init(void)
 377 {
 378         int ret;
 379
 380         if (!css_general_characteristics.eadm)
 381                 return -ENXIO;
 382
 383         eadm_debug = debug_register("eadm_log", 16, 1, 16);
 384         if (!eadm_debug)
 385                 return -ENOMEM;
 386
 387         debug_register_view(eadm_debug, &debug_hex_ascii_view);
 388         debug_set_level(eadm_debug, 2);
 389
 390         isc_register(EADM_SCH_ISC);
 391         ret = css_driver_register(&eadm_subchannel_driver);
 392         if (ret)
 393                 goto cleanup;
 394
 395         return ret;
 396
 397 cleanup:
 398         isc_unregister(EADM_SCH_ISC);
 399         debug_unregister(eadm_debug);
 400         return ret;
 401 }
 402
 403 static void __exit eadm_sch_exit(void)
 404 {
 405         css_driver_unregister(&eadm_subchannel_driver);
 406         isc_unregister(EADM_SCH_ISC);
 407         debug_unregister(eadm_debug);
 408 }
 409 module_init(eadm_sch_init);
 410 module_exit(eadm_sch_exit);