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/workqueue.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/device.h>
  12 #include <linux/module.h>
  13 #include <linux/timer.h>
  14 #include <linux/slab.h>
  15 #include <linux/list.h>
  16
  17 #include <asm/css_chars.h>
  18 #include <asm/debug.h>
  19 #include <asm/isc.h>
  20 #include <asm/cio.h>
  21 #include <asm/scsw.h>
  22 #include <asm/eadm.h>
  23
  24 #include "eadm_sch.h"
  25 #include "ioasm.h"
  26 #include "cio.h"
  27 #include "css.h"
  28 #include "orb.h"
  29
  30 MODULE_DESCRIPTION("driver for s390 eadm subchannels");
  31 MODULE_LICENSE("GPL");
  32
  33 #define EADM_TIMEOUT (5 * HZ)
  34 static DEFINE_SPINLOCK(list_lock);
  35 static LIST_HEAD(eadm_list);
  36
  37 static debug_info_t *eadm_debug;
  38
  39 #define EADM_LOG(imp, txt) do {                                 \
  40                 debug_text_event(eadm_debug, imp, txt);         \
  41         } while (0)
  42
  43 static void EADM_LOG_HEX(int level, void *data, int length)
  44 {
  45         if (level > eadm_debug->level)
  46                 return;
  47         while (length > 0) {
  48                 debug_event(eadm_debug, level, data, length);
  49                 length -= eadm_debug->buf_size;
  50                 data += eadm_debug->buf_size;
  51         }
  52 }
  53
  54 static void orb_init(union orb *orb)
  55 {
  56         memset(orb, 0, sizeof(union orb));
  57         orb->eadm.compat1 = 1;
  58         orb->eadm.compat2 = 1;
  59         orb->eadm.fmt = 1;
  60         orb->eadm.x = 1;
  61 }
  62
  63 static int eadm_subchannel_start(struct subchannel *sch, struct aob *aob)
  64 {
  65         union orb *orb = &get_eadm_private(sch)->orb;
  66         int cc;
  67
  68         orb_init(orb);
  69         orb->eadm.aob = (u32)__pa(aob);
  70         orb->eadm.intparm = (u32)(addr_t)sch;
  71         orb->eadm.key = PAGE_DEFAULT_KEY >> 4;
  72
  73         EADM_LOG(6, "start");
  74         EADM_LOG_HEX(6, &sch->schid, sizeof(sch->schid));
  75
  76         cc = ssch(sch->schid, orb);
  77         switch (cc) {
  78         case 0:
  79                 sch->schib.scsw.eadm.actl |= SCSW_ACTL_START_PEND;
  80                 break;
  81         case 1:         /* status pending */
  82         case 2:         /* busy */
  83                 return -EBUSY;
  84         case 3:         /* not operational */
  85                 return -ENODEV;
  86         }
  87         return 0;
  88 }
  89
  90 static int eadm_subchannel_clear(struct subchannel *sch)
  91 {
  92         int cc;
  93
  94         cc = csch(sch->schid);
  95         if (cc)
  96                 return -ENODEV;
  97
  98         sch->schib.scsw.eadm.actl |= SCSW_ACTL_CLEAR_PEND;
  99         return 0;
 100 }
 101
 102 static void eadm_subchannel_timeout(unsigned long data)
 103 {
 104         struct subchannel *sch = (struct subchannel *) data;
 105
 106         spin_lock_irq(sch->lock);
 107         EADM_LOG(1, "timeout");
 108         EADM_LOG_HEX(1, &sch->schid, sizeof(sch->schid));
 109         if (eadm_subchannel_clear(sch))
 110                 EADM_LOG(0, "clear failed");
 111         spin_unlock_irq(sch->lock);
 112 }
 113
 114 static void eadm_subchannel_set_timeout(struct subchannel *sch, int expires)
 115 {
 116         struct eadm_private *private = get_eadm_private(sch);
 117
 118         if (expires == 0) {
 119                 del_timer(&private->timer);
 120                 return;
 121         }
 122         if (timer_pending(&private->timer)) {
 123                 if (mod_timer(&private->timer, jiffies + expires))
 124                         return;
 125         }
 126         private->timer.function = eadm_subchannel_timeout;
 127         private->timer.data = (unsigned long) sch;
 128         private->timer.expires = jiffies + expires;
 129         add_timer(&private->timer);
 130 }
 131
 132 static void eadm_subchannel_irq(struct subchannel *sch)
 133 {
 134         struct eadm_private *private = get_eadm_private(sch);
 135         struct eadm_scsw *scsw = &sch->schib.scsw.eadm;
 136         struct irb *irb = (struct irb *)&S390_lowcore.irb;
 137         int error = 0;
 138
 139         EADM_LOG(6, "irq");
 140         EADM_LOG_HEX(6, irb, sizeof(*irb));
 141
 142         inc_irq_stat(IRQIO_ADM);
 143
 144         if ((scsw->stctl & (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))
 145             && scsw->eswf == 1 && irb->esw.eadm.erw.r)
 146                 error = -EIO;
 147
 148         if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC)
 149                 error = -ETIMEDOUT;
 150
 151         eadm_subchannel_set_timeout(sch, 0);
 152
 153         if (private->state != EADM_BUSY) {
 154                 EADM_LOG(1, "irq unsol");
 155                 EADM_LOG_HEX(1, irb, sizeof(*irb));
 156                 private->state = EADM_NOT_OPER;
 157                 css_sched_sch_todo(sch, SCH_TODO_EVAL);
 158                 return;
 159         }
 160         scm_irq_handler((struct aob *)(unsigned long)scsw->aob, error);
 161         private->state = EADM_IDLE;
 162 }
 163
 164 static struct subchannel *eadm_get_idle_sch(void)
 165 {
 166         struct eadm_private *private;
 167         struct subchannel *sch;
 168         unsigned long flags;
 169
 170         spin_lock_irqsave(&list_lock, flags);
 171         list_for_each_entry(private, &eadm_list, head) {
 172                 sch = private->sch;
 173                 spin_lock(sch->lock);
 174                 if (private->state == EADM_IDLE) {
 175                         private->state = EADM_BUSY;
 176                         list_move_tail(&private->head, &eadm_list);
 177                         spin_unlock(sch->lock);
 178                         spin_unlock_irqrestore(&list_lock, flags);
 179
 180                         return sch;
 181                 }
 182                 spin_unlock(sch->lock);
 183         }
 184         spin_unlock_irqrestore(&list_lock, flags);
 185
 186         return NULL;
 187 }
 188
 189 static int eadm_start_aob(struct aob *aob)
 190 {
 191         struct eadm_private *private;
 192         struct subchannel *sch;
 193         unsigned long flags;
 194         int ret;
 195
 196         sch = eadm_get_idle_sch();
 197         if (!sch)
 198                 return -EBUSY;
 199
 200         spin_lock_irqsave(sch->lock, flags);
 201         eadm_subchannel_set_timeout(sch, EADM_TIMEOUT);
 202         ret = eadm_subchannel_start(sch, aob);
 203         if (!ret)
 204                 goto out_unlock;
 205
 206         /* Handle start subchannel failure. */
 207         eadm_subchannel_set_timeout(sch, 0);
 208         private = get_eadm_private(sch);
 209         private->state = EADM_NOT_OPER;
 210         css_sched_sch_todo(sch, SCH_TODO_EVAL);
 211
 212 out_unlock:
 213         spin_unlock_irqrestore(sch->lock, flags);
 214
 215         return ret;
 216 }
 217
 218 static int eadm_subchannel_probe(struct subchannel *sch)
 219 {
 220         struct eadm_private *private;
 221         int ret;
 222
 223         private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
 224         if (!private)
 225                 return -ENOMEM;
 226
 227         INIT_LIST_HEAD(&private->head);
 228         init_timer(&private->timer);
 229
 230         spin_lock_irq(sch->lock);
 231         set_eadm_private(sch, private);
 232         private->state = EADM_IDLE;
 233         private->sch = sch;
 234         sch->isc = EADM_SCH_ISC;
 235         ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
 236         if (ret) {
 237                 set_eadm_private(sch, NULL);
 238                 spin_unlock_irq(sch->lock);
 239                 kfree(private);
 240                 goto out;
 241         }
 242         spin_unlock_irq(sch->lock);
 243
 244         spin_lock_irq(&list_lock);
 245         list_add(&private->head, &eadm_list);
 246         spin_unlock_irq(&list_lock);
 247
 248         if (dev_get_uevent_suppress(&sch->dev)) {
 249                 dev_set_uevent_suppress(&sch->dev, 0);
 250                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 251         }
 252 out:
 253         return ret;
 254 }
 255
 256 static void eadm_quiesce(struct subchannel *sch)
 257 {
 258         int ret;
 259
 260         do {
 261                 spin_lock_irq(sch->lock);
 262                 ret = cio_disable_subchannel(sch);
 263                 spin_unlock_irq(sch->lock);
 264         } while (ret == -EBUSY);
 265 }
 266
 267 static int eadm_subchannel_remove(struct subchannel *sch)
 268 {
 269         struct eadm_private *private = get_eadm_private(sch);
 270
 271         spin_lock_irq(&list_lock);
 272         list_del(&private->head);
 273         spin_unlock_irq(&list_lock);
 274
 275         eadm_quiesce(sch);
 276
 277         spin_lock_irq(sch->lock);
 278         set_eadm_private(sch, NULL);
 279         spin_unlock_irq(sch->lock);
 280
 281         kfree(private);
 282
 283         return 0;
 284 }
 285
 286 static void eadm_subchannel_shutdown(struct subchannel *sch)
 287 {
 288         eadm_quiesce(sch);
 289 }
 290
 291 static int eadm_subchannel_freeze(struct subchannel *sch)
 292 {
 293         return cio_disable_subchannel(sch);
 294 }
 295
 296 static int eadm_subchannel_restore(struct subchannel *sch)
 297 {
 298         return cio_enable_subchannel(sch, (u32)(unsigned long)sch);
 299 }
 300
 301 /**
 302  * eadm_subchannel_sch_event - process subchannel event
 303  * @sch: subchannel
 304  * @process: non-zero if function is called in process context
 305  *
 306  * An unspecified event occurred for this subchannel. Adjust data according
 307  * to the current operational state of the subchannel. Return zero when the
 308  * event has been handled sufficiently or -EAGAIN when this function should
 309  * be called again in process context.
 310  */
 311 static int eadm_subchannel_sch_event(struct subchannel *sch, int process)
 312 {
 313         struct eadm_private *private;
 314         unsigned long flags;
 315         int ret = 0;
 316
 317         spin_lock_irqsave(sch->lock, flags);
 318         if (!device_is_registered(&sch->dev))
 319                 goto out_unlock;
 320
 321         if (work_pending(&sch->todo_work))
 322                 goto out_unlock;
 323
 324         if (cio_update_schib(sch)) {
 325                 css_sched_sch_todo(sch, SCH_TODO_UNREG);
 326                 goto out_unlock;
 327         }
 328         private = get_eadm_private(sch);
 329         if (private->state == EADM_NOT_OPER)
 330                 private->state = EADM_IDLE;
 331
 332 out_unlock:
 333         spin_unlock_irqrestore(sch->lock, flags);
 334
 335         return ret;
 336 }
 337
 338 static struct css_device_id eadm_subchannel_ids[] = {
 339         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_ADM, },
 340         { /* end of list */ },
 341 };
 342 MODULE_DEVICE_TABLE(css, eadm_subchannel_ids);
 343
 344 static struct css_driver eadm_subchannel_driver = {
 345         .drv = {
 346                 .name = "eadm_subchannel",
 347                 .owner = THIS_MODULE,
 348         },
 349         .subchannel_type = eadm_subchannel_ids,
 350         .irq = eadm_subchannel_irq,
 351         .probe = eadm_subchannel_probe,
 352         .remove = eadm_subchannel_remove,
 353         .shutdown = eadm_subchannel_shutdown,
 354         .sch_event = eadm_subchannel_sch_event,
 355         .freeze = eadm_subchannel_freeze,
 356         .thaw = eadm_subchannel_restore,
 357         .restore = eadm_subchannel_restore,
 358 };
 359
 360 static struct eadm_ops eadm_ops = {
 361         .eadm_start = eadm_start_aob,
 362         .owner = THIS_MODULE,
 363 };
 364
 365 static int __init eadm_sch_init(void)
 366 {
 367         int ret;
 368
 369         if (!css_general_characteristics.eadm)
 370                 return -ENXIO;
 371
 372         eadm_debug = debug_register("eadm_log", 16, 1, 16);
 373         if (!eadm_debug)
 374                 return -ENOMEM;
 375
 376         debug_register_view(eadm_debug, &debug_hex_ascii_view);
 377         debug_set_level(eadm_debug, 2);
 378
 379         isc_register(EADM_SCH_ISC);
 380         ret = css_driver_register(&eadm_subchannel_driver);
 381         if (ret)
 382                 goto cleanup;
 383
 384         register_eadm_ops(&eadm_ops);
 385         return ret;
 386
 387 cleanup:
 388         isc_unregister(EADM_SCH_ISC);
 389         debug_unregister(eadm_debug);
 390         return ret;
 391 }
 392
 393 static void __exit eadm_sch_exit(void)
 394 {
 395         unregister_eadm_ops(&eadm_ops);
 396         css_driver_unregister(&eadm_subchannel_driver);
 397         isc_unregister(EADM_SCH_ISC);
 398         debug_unregister(eadm_debug);
 399 }
 400 module_init(eadm_sch_init);
 401 module_exit(eadm_sch_exit);