hw/s390x/event-facility.c

   1 /*
   2  * SCLP
   3  *    Event Facility
   4  *       handles SCLP event types
   5  *          - Signal Quiesce - system power down
   6  *          - ASCII Console Data - VT220 read and write
   7  *
   8  * Copyright IBM, Corp. 2012
   9  *
  10  * Authors:
  11  *  Heinz Graalfs <[email protected]>
  12  *
  13  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
  14  * option) any later version.  See the COPYING file in the top-level directory.
  15  *
  16  */
  17
  18 #include "sysemu/sysemu.h"
  19
  20 #include "hw/s390x/sclp.h"
  21 #include "hw/s390x/event-facility.h"
  22
  23 typedef struct SCLPEventsBus {
  24     BusState qbus;
  25 } SCLPEventsBus;
  26
  27 struct SCLPEventFacility {
  28     SysBusDevice parent_obj;
  29     SCLPEventsBus sbus;
  30     /* guest' receive mask */
  31     unsigned int receive_mask;
  32 };
  33
  34 /* return true if any child has event pending set */
  35 static bool event_pending(SCLPEventFacility *ef)
  36 {
  37     BusChild *kid;
  38     SCLPEvent *event;
  39     SCLPEventClass *event_class;
  40
  41     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  42         DeviceState *qdev = kid->child;
  43         event = DO_UPCAST(SCLPEvent, qdev, qdev);
  44         event_class = SCLP_EVENT_GET_CLASS(event);
  45         if (event->event_pending &&
  46             event_class->get_send_mask() & ef->receive_mask) {
  47             return true;
  48         }
  49     }
  50     return false;
  51 }
  52
  53 static unsigned int get_host_send_mask(SCLPEventFacility *ef)
  54 {
  55     unsigned int mask;
  56     BusChild *kid;
  57     SCLPEventClass *child;
  58
  59     mask = 0;
  60
  61     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  62         DeviceState *qdev = kid->child;
  63         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  64         mask |= child->get_send_mask();
  65     }
  66     return mask;
  67 }
  68
  69 static unsigned int get_host_receive_mask(SCLPEventFacility *ef)
  70 {
  71     unsigned int mask;
  72     BusChild *kid;
  73     SCLPEventClass *child;
  74
  75     mask = 0;
  76
  77     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
  78         DeviceState *qdev = kid->child;
  79         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
  80         mask |= child->get_receive_mask();
  81     }
  82     return mask;
  83 }
  84
  85 static uint16_t write_event_length_check(SCCB *sccb)
  86 {
  87     int slen;
  88     unsigned elen = 0;
  89     EventBufferHeader *event;
  90     WriteEventData *wed = (WriteEventData *) sccb;
  91
  92     event = (EventBufferHeader *) &wed->ebh;
  93     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
  94         elen = be16_to_cpu(event->length);
  95         if (elen < sizeof(*event) || elen > slen) {
  96             return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
  97         }
  98         event = (void *) event + elen;
  99     }
 100     if (slen) {
 101         return SCLP_RC_INCONSISTENT_LENGTHS;
 102     }
 103     return SCLP_RC_NORMAL_COMPLETION;
 104 }
 105
 106 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
 107                                        EventBufferHeader *event_buf, SCCB *sccb)
 108 {
 109     uint16_t rc;
 110     BusChild *kid;
 111     SCLPEvent *event;
 112     SCLPEventClass *ec;
 113
 114     rc = SCLP_RC_INVALID_FUNCTION;
 115
 116     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 117         DeviceState *qdev = kid->child;
 118         event = (SCLPEvent *) qdev;
 119         ec = SCLP_EVENT_GET_CLASS(event);
 120
 121         if (ec->write_event_data &&
 122             ec->can_handle_event(event_buf->type)) {
 123             rc = ec->write_event_data(event, event_buf);
 124             break;
 125         }
 126     }
 127     return rc;
 128 }
 129
 130 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
 131 {
 132     uint16_t rc;
 133     int slen;
 134     unsigned elen = 0;
 135     EventBufferHeader *event_buf;
 136     WriteEventData *wed = (WriteEventData *) sccb;
 137
 138     event_buf = &wed->ebh;
 139     rc = SCLP_RC_NORMAL_COMPLETION;
 140
 141     /* loop over all contained event buffers */
 142     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
 143         elen = be16_to_cpu(event_buf->length);
 144
 145         /* in case of a previous error mark all trailing buffers
 146          * as not accepted */
 147         if (rc != SCLP_RC_NORMAL_COMPLETION) {
 148             event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 149         } else {
 150             rc = handle_write_event_buf(ef, event_buf, sccb);
 151         }
 152         event_buf = (void *) event_buf + elen;
 153     }
 154     return rc;
 155 }
 156
 157 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
 158 {
 159     if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
 160         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 161         goto out;
 162     }
 163     if (be16_to_cpu(sccb->h.length) < 8) {
 164         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 165         goto out;
 166     }
 167     /* first do a sanity check of the write events */
 168     sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
 169
 170     /* if no early error, then execute */
 171     if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
 172         sccb->h.response_code =
 173                 cpu_to_be16(handle_sccb_write_events(ef, sccb));
 174     }
 175
 176 out:
 177     return;
 178 }
 179
 180 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
 181                                         unsigned int mask)
 182 {
 183     uint16_t rc;
 184     int slen;
 185     unsigned elen;
 186     BusChild *kid;
 187     SCLPEvent *event;
 188     SCLPEventClass *ec;
 189     EventBufferHeader *event_buf;
 190     ReadEventData *red = (ReadEventData *) sccb;
 191
 192     event_buf = &red->ebh;
 193     event_buf->length = 0;
 194     slen = sizeof(sccb->data);
 195
 196     rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
 197
 198     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
 199         DeviceState *qdev = kid->child;
 200         event = (SCLPEvent *) qdev;
 201         ec = SCLP_EVENT_GET_CLASS(event);
 202
 203         if (mask & ec->get_send_mask()) {
 204             if (ec->read_event_data(event, event_buf, &slen)) {
 205                 elen = be16_to_cpu(event_buf->length);
 206                 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
 207                 rc = SCLP_RC_NORMAL_COMPLETION;
 208             }
 209         }
 210     }
 211
 212     if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
 213         /* architecture suggests to reset variable-length-response bit */
 214         sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
 215         /* with a new length value */
 216         sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
 217     }
 218     return rc;
 219 }
 220
 221 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
 222 {
 223     unsigned int sclp_active_selection_mask;
 224     unsigned int sclp_cp_receive_mask;
 225
 226     ReadEventData *red = (ReadEventData *) sccb;
 227
 228     if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
 229         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
 230         goto out;
 231     }
 232
 233     sclp_cp_receive_mask = ef->receive_mask;
 234
 235     /* get active selection mask */
 236     switch (sccb->h.function_code) {
 237     case SCLP_UNCONDITIONAL_READ:
 238         sclp_active_selection_mask = sclp_cp_receive_mask;
 239         break;
 240     case SCLP_SELECTIVE_READ:
 241         sclp_active_selection_mask = be32_to_cpu(red->mask);
 242         if (!sclp_cp_receive_mask ||
 243             (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
 244             sccb->h.response_code =
 245                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
 246             goto out;
 247         }
 248         break;
 249     default:
 250         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
 251         goto out;
 252     }
 253     sccb->h.response_code = cpu_to_be16(
 254             handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
 255
 256 out:
 257     return;
 258 }
 259
 260 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
 261 {
 262     WriteEventMask *we_mask = (WriteEventMask *) sccb;
 263
 264     /* Attention: We assume that Linux uses 4-byte masks, what it actually
 265        does. Architecture allows for masks of variable size, though */
 266     if (be16_to_cpu(we_mask->mask_length) != 4) {
 267         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
 268         goto out;
 269     }
 270
 271     /* keep track of the guest's capability masks */
 272     ef->receive_mask = be32_to_cpu(we_mask->cp_receive_mask);
 273
 274     /* return the SCLP's capability masks to the guest */
 275     we_mask->send_mask = cpu_to_be32(get_host_send_mask(ef));
 276     we_mask->receive_mask = cpu_to_be32(get_host_receive_mask(ef));
 277
 278     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
 279
 280 out:
 281     return;
 282 }
 283
 284 /* qemu object creation and initialization functions */
 285
 286 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
 287
 288 static void sclp_events_bus_realize(BusState *bus, Error **errp)
 289 {
 290     BusChild *kid;
 291
 292     /* TODO: recursive realization has to be done in common code */
 293     QTAILQ_FOREACH(kid, &bus->children, sibling) {
 294         DeviceState *dev = kid->child;
 295
 296         object_property_set_bool(OBJECT(dev), true, "realized", errp);
 297         if (*errp) {
 298             return;
 299         }
 300     }
 301 }
 302
 303 static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
 304 {
 305     BusClass *bc = BUS_CLASS(klass);
 306
 307     bc->realize = sclp_events_bus_realize;
 308 }
 309
 310 static const TypeInfo sclp_events_bus_info = {
 311     .name = TYPE_SCLP_EVENTS_BUS,
 312     .parent = TYPE_BUS,
 313     .class_init = sclp_events_bus_class_init,
 314 };
 315
 316 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
 317 {
 318     switch (code & SCLP_CMD_CODE_MASK) {
 319     case SCLP_CMD_READ_EVENT_DATA:
 320         read_event_data(ef, sccb);
 321         break;
 322     case SCLP_CMD_WRITE_EVENT_DATA:
 323         write_event_data(ef, sccb);
 324         break;
 325     case SCLP_CMD_WRITE_EVENT_MASK:
 326         write_event_mask(ef, sccb);
 327         break;
 328     default:
 329         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
 330         break;
 331     }
 332 }
 333
 334 static const VMStateDescription vmstate_event_facility = {
 335     .name = "vmstate-event-facility",
 336     .version_id = 0,
 337     .minimum_version_id = 0,
 338     .fields = (VMStateField[]) {
 339         VMSTATE_UINT32(receive_mask, SCLPEventFacility),
 340         VMSTATE_END_OF_LIST()
 341      }
 342 };
 343
 344 static void init_event_facility(Object *obj)
 345 {
 346     SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
 347     DeviceState *sdev = DEVICE(obj);
 348     Object *new;
 349
 350     /* Spawn a new bus for SCLP events */
 351     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
 352                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
 353
 354     new = object_new(TYPE_SCLP_QUIESCE);
 355     object_property_add_child(obj, TYPE_SCLP_QUIESCE, new, NULL);
 356     object_unref(new);
 357     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
 358
 359     new = object_new(TYPE_SCLP_CPU_HOTPLUG);
 360     object_property_add_child(obj, TYPE_SCLP_CPU_HOTPLUG, new, NULL);
 361     object_unref(new);
 362     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
 363     /* the facility will automatically realize the devices via the bus */
 364 }
 365
 366 static void reset_event_facility(DeviceState *dev)
 367 {
 368     SCLPEventFacility *sdev = EVENT_FACILITY(dev);
 369
 370     sdev->receive_mask = 0;
 371 }
 372
 373 static void init_event_facility_class(ObjectClass *klass, void *data)
 374 {
 375     SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
 376     DeviceClass *dc = DEVICE_CLASS(sbdc);
 377     SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
 378
 379     dc->reset = reset_event_facility;
 380     dc->vmsd = &vmstate_event_facility;
 381     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 382     k->command_handler = command_handler;
 383     k->event_pending = event_pending;
 384 }
 385
 386 static const TypeInfo sclp_event_facility_info = {
 387     .name          = TYPE_SCLP_EVENT_FACILITY,
 388     .parent        = TYPE_SYS_BUS_DEVICE,
 389     .instance_init = init_event_facility,
 390     .instance_size = sizeof(SCLPEventFacility),
 391     .class_init    = init_event_facility_class,
 392     .class_size    = sizeof(SCLPEventFacilityClass),
 393 };
 394
 395 static void event_realize(DeviceState *qdev, Error **errp)
 396 {
 397     SCLPEvent *event = SCLP_EVENT(qdev);
 398     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 399
 400     if (child->init) {
 401         int rc = child->init(event);
 402         if (rc < 0) {
 403             error_setg(errp, "SCLP event initialization failed.");
 404             return;
 405         }
 406     }
 407 }
 408
 409 static void event_unrealize(DeviceState *qdev, Error **errp)
 410 {
 411     SCLPEvent *event = SCLP_EVENT(qdev);
 412     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
 413     if (child->exit) {
 414         int rc = child->exit(event);
 415         if (rc < 0) {
 416             error_setg(errp, "SCLP event exit failed.");
 417             return;
 418         }
 419     }
 420 }
 421
 422 static void event_class_init(ObjectClass *klass, void *data)
 423 {
 424     DeviceClass *dc = DEVICE_CLASS(klass);
 425
 426     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
 427     dc->realize = event_realize;
 428     dc->unrealize = event_unrealize;
 429 }
 430
 431 static const TypeInfo sclp_event_type_info = {
 432     .name = TYPE_SCLP_EVENT,
 433     .parent = TYPE_DEVICE,
 434     .instance_size = sizeof(SCLPEvent),
 435     .class_init = event_class_init,
 436     .class_size = sizeof(SCLPEventClass),
 437     .abstract = true,
 438 };
 439
 440 static void register_types(void)
 441 {
 442     type_register_static(&sclp_events_bus_info);
 443     type_register_static(&sclp_event_facility_info);
 444     type_register_static(&sclp_event_type_info);
 445 }
 446
 447 type_init(register_types)