xref: /openbmc/qemu/hw/s390x/event-facility.c (revision c39f95dc) 
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 <graalfs@de.ibm.com>
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 "qemu/osdep.h"
19 #include "qapi/error.h"
20 #include "sysemu/sysemu.h"
21 
22 #include "hw/s390x/sclp.h"
23 #include "hw/s390x/event-facility.h"
24 
25 typedef struct SCLPEventsBus {
26     BusState qbus;
27 } SCLPEventsBus;
28 
29 struct SCLPEventFacility {
30     SysBusDevice parent_obj;
31     SCLPEventsBus sbus;
32     /* guest' receive mask */
33     unsigned int receive_mask;
34 };
35 
36 /* return true if any child has event pending set */
37 static bool event_pending(SCLPEventFacility *ef)
38 {
39     BusChild *kid;
40     SCLPEvent *event;
41     SCLPEventClass *event_class;
42 
43     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
44         DeviceState *qdev = kid->child;
45         event = DO_UPCAST(SCLPEvent, qdev, qdev);
46         event_class = SCLP_EVENT_GET_CLASS(event);
47         if (event->event_pending &&
48             event_class->get_send_mask() & ef->receive_mask) {
49             return true;
50         }
51     }
52     return false;
53 }
54 
55 static unsigned int get_host_send_mask(SCLPEventFacility *ef)
56 {
57     unsigned int mask;
58     BusChild *kid;
59     SCLPEventClass *child;
60 
61     mask = 0;
62 
63     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
64         DeviceState *qdev = kid->child;
65         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
66         mask |= child->get_send_mask();
67     }
68     return mask;
69 }
70 
71 static unsigned int get_host_receive_mask(SCLPEventFacility *ef)
72 {
73     unsigned int mask;
74     BusChild *kid;
75     SCLPEventClass *child;
76 
77     mask = 0;
78 
79     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
80         DeviceState *qdev = kid->child;
81         child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
82         mask |= child->get_receive_mask();
83     }
84     return mask;
85 }
86 
87 static uint16_t write_event_length_check(SCCB *sccb)
88 {
89     int slen;
90     unsigned elen = 0;
91     EventBufferHeader *event;
92     WriteEventData *wed = (WriteEventData *) sccb;
93 
94     event = (EventBufferHeader *) &wed->ebh;
95     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
96         elen = be16_to_cpu(event->length);
97         if (elen < sizeof(*event) || elen > slen) {
98             return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
99         }
100         event = (void *) event + elen;
101     }
102     if (slen) {
103         return SCLP_RC_INCONSISTENT_LENGTHS;
104     }
105     return SCLP_RC_NORMAL_COMPLETION;
106 }
107 
108 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
109                                        EventBufferHeader *event_buf, SCCB *sccb)
110 {
111     uint16_t rc;
112     BusChild *kid;
113     SCLPEvent *event;
114     SCLPEventClass *ec;
115 
116     rc = SCLP_RC_INVALID_FUNCTION;
117 
118     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
119         DeviceState *qdev = kid->child;
120         event = (SCLPEvent *) qdev;
121         ec = SCLP_EVENT_GET_CLASS(event);
122 
123         if (ec->write_event_data &&
124             ec->can_handle_event(event_buf->type)) {
125             rc = ec->write_event_data(event, event_buf);
126             break;
127         }
128     }
129     return rc;
130 }
131 
132 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
133 {
134     uint16_t rc;
135     int slen;
136     unsigned elen = 0;
137     EventBufferHeader *event_buf;
138     WriteEventData *wed = (WriteEventData *) sccb;
139 
140     event_buf = &wed->ebh;
141     rc = SCLP_RC_NORMAL_COMPLETION;
142 
143     /* loop over all contained event buffers */
144     for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
145         elen = be16_to_cpu(event_buf->length);
146 
147         /* in case of a previous error mark all trailing buffers
148          * as not accepted */
149         if (rc != SCLP_RC_NORMAL_COMPLETION) {
150             event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
151         } else {
152             rc = handle_write_event_buf(ef, event_buf, sccb);
153         }
154         event_buf = (void *) event_buf + elen;
155     }
156     return rc;
157 }
158 
159 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
160 {
161     if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
162         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
163         goto out;
164     }
165     if (be16_to_cpu(sccb->h.length) < 8) {
166         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
167         goto out;
168     }
169     /* first do a sanity check of the write events */
170     sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
171 
172     /* if no early error, then execute */
173     if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
174         sccb->h.response_code =
175                 cpu_to_be16(handle_sccb_write_events(ef, sccb));
176     }
177 
178 out:
179     return;
180 }
181 
182 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
183                                         unsigned int mask)
184 {
185     uint16_t rc;
186     int slen;
187     unsigned elen;
188     BusChild *kid;
189     SCLPEvent *event;
190     SCLPEventClass *ec;
191     EventBufferHeader *event_buf;
192     ReadEventData *red = (ReadEventData *) sccb;
193 
194     event_buf = &red->ebh;
195     event_buf->length = 0;
196     slen = sizeof(sccb->data);
197 
198     rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
199 
200     QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
201         DeviceState *qdev = kid->child;
202         event = (SCLPEvent *) qdev;
203         ec = SCLP_EVENT_GET_CLASS(event);
204 
205         if (mask & ec->get_send_mask()) {
206             if (ec->read_event_data(event, event_buf, &slen)) {
207                 elen = be16_to_cpu(event_buf->length);
208                 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
209                 rc = SCLP_RC_NORMAL_COMPLETION;
210             }
211         }
212     }
213 
214     if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
215         /* architecture suggests to reset variable-length-response bit */
216         sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
217         /* with a new length value */
218         sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
219     }
220     return rc;
221 }
222 
223 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
224 {
225     unsigned int sclp_active_selection_mask;
226     unsigned int sclp_cp_receive_mask;
227 
228     ReadEventData *red = (ReadEventData *) sccb;
229 
230     if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
231         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
232         goto out;
233     }
234 
235     sclp_cp_receive_mask = ef->receive_mask;
236 
237     /* get active selection mask */
238     switch (sccb->h.function_code) {
239     case SCLP_UNCONDITIONAL_READ:
240         sclp_active_selection_mask = sclp_cp_receive_mask;
241         break;
242     case SCLP_SELECTIVE_READ:
243         sclp_active_selection_mask = be32_to_cpu(red->mask);
244         if (!sclp_cp_receive_mask ||
245             (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
246             sccb->h.response_code =
247                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
248             goto out;
249         }
250         break;
251     default:
252         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
253         goto out;
254     }
255     sccb->h.response_code = cpu_to_be16(
256             handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
257 
258 out:
259     return;
260 }
261 
262 /* copy up to dst_len bytes and fill the rest of dst with zeroes */
263 static void copy_mask(uint8_t *dst, uint8_t *src, uint16_t dst_len,
264                       uint16_t src_len)
265 {
266     int i;
267 
268     for (i = 0; i < dst_len; i++) {
269         dst[i] = i < src_len ? src[i] : 0;
270     }
271 }
272 
273 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
274 {
275     WriteEventMask *we_mask = (WriteEventMask *) sccb;
276     uint16_t mask_length = be16_to_cpu(we_mask->mask_length);
277     uint32_t tmp_mask;
278 
279     if (!mask_length || (mask_length > SCLP_EVENT_MASK_LEN_MAX)) {
280         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
281         goto out;
282     }
283 
284     /*
285      * Note: We currently only support masks up to 4 byte length;
286      *       the remainder is filled up with zeroes. Linux uses
287      *       a 4 byte mask length.
288      */
289 
290     /* keep track of the guest's capability masks */
291     copy_mask((uint8_t *)&tmp_mask, WEM_CP_RECEIVE_MASK(we_mask, mask_length),
292               sizeof(tmp_mask), mask_length);
293     ef->receive_mask = be32_to_cpu(tmp_mask);
294 
295     /* return the SCLP's capability masks to the guest */
296     tmp_mask = cpu_to_be32(get_host_send_mask(ef));
297     copy_mask(WEM_RECEIVE_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
298               mask_length, sizeof(tmp_mask));
299     tmp_mask = cpu_to_be32(get_host_receive_mask(ef));
300     copy_mask(WEM_SEND_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
301               mask_length, sizeof(tmp_mask));
302 
303     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
304 
305 out:
306     return;
307 }
308 
309 /* qemu object creation and initialization functions */
310 
311 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
312 
313 static void sclp_events_bus_realize(BusState *bus, Error **errp)
314 {
315     BusChild *kid;
316 
317     /* TODO: recursive realization has to be done in common code */
318     QTAILQ_FOREACH(kid, &bus->children, sibling) {
319         DeviceState *dev = kid->child;
320 
321         object_property_set_bool(OBJECT(dev), true, "realized", errp);
322         if (*errp) {
323             return;
324         }
325     }
326 }
327 
328 static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
329 {
330     BusClass *bc = BUS_CLASS(klass);
331 
332     bc->realize = sclp_events_bus_realize;
333 }
334 
335 static const TypeInfo sclp_events_bus_info = {
336     .name = TYPE_SCLP_EVENTS_BUS,
337     .parent = TYPE_BUS,
338     .class_init = sclp_events_bus_class_init,
339 };
340 
341 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
342 {
343     switch (code & SCLP_CMD_CODE_MASK) {
344     case SCLP_CMD_READ_EVENT_DATA:
345         read_event_data(ef, sccb);
346         break;
347     case SCLP_CMD_WRITE_EVENT_DATA:
348         write_event_data(ef, sccb);
349         break;
350     case SCLP_CMD_WRITE_EVENT_MASK:
351         write_event_mask(ef, sccb);
352         break;
353     default:
354         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
355         break;
356     }
357 }
358 
359 static const VMStateDescription vmstate_event_facility = {
360     .name = "vmstate-event-facility",
361     .version_id = 0,
362     .minimum_version_id = 0,
363     .fields = (VMStateField[]) {
364         VMSTATE_UINT32(receive_mask, SCLPEventFacility),
365         VMSTATE_END_OF_LIST()
366      }
367 };
368 
369 static void init_event_facility(Object *obj)
370 {
371     SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
372     DeviceState *sdev = DEVICE(obj);
373     Object *new;
374 
375     /* Spawn a new bus for SCLP events */
376     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
377                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
378 
379     new = object_new(TYPE_SCLP_QUIESCE);
380     object_property_add_child(obj, TYPE_SCLP_QUIESCE, new, NULL);
381     object_unref(new);
382     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
383 
384     new = object_new(TYPE_SCLP_CPU_HOTPLUG);
385     object_property_add_child(obj, TYPE_SCLP_CPU_HOTPLUG, new, NULL);
386     object_unref(new);
387     qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
388     /* the facility will automatically realize the devices via the bus */
389 }
390 
391 static void reset_event_facility(DeviceState *dev)
392 {
393     SCLPEventFacility *sdev = EVENT_FACILITY(dev);
394 
395     sdev->receive_mask = 0;
396 }
397 
398 static void init_event_facility_class(ObjectClass *klass, void *data)
399 {
400     SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
401     DeviceClass *dc = DEVICE_CLASS(sbdc);
402     SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
403 
404     dc->reset = reset_event_facility;
405     dc->vmsd = &vmstate_event_facility;
406     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
407     k->command_handler = command_handler;
408     k->event_pending = event_pending;
409 }
410 
411 static const TypeInfo sclp_event_facility_info = {
412     .name          = TYPE_SCLP_EVENT_FACILITY,
413     .parent        = TYPE_SYS_BUS_DEVICE,
414     .instance_init = init_event_facility,
415     .instance_size = sizeof(SCLPEventFacility),
416     .class_init    = init_event_facility_class,
417     .class_size    = sizeof(SCLPEventFacilityClass),
418 };
419 
420 static void event_realize(DeviceState *qdev, Error **errp)
421 {
422     SCLPEvent *event = SCLP_EVENT(qdev);
423     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
424 
425     if (child->init) {
426         int rc = child->init(event);
427         if (rc < 0) {
428             error_setg(errp, "SCLP event initialization failed.");
429             return;
430         }
431     }
432 }
433 
434 static void event_unrealize(DeviceState *qdev, Error **errp)
435 {
436     SCLPEvent *event = SCLP_EVENT(qdev);
437     SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
438     if (child->exit) {
439         int rc = child->exit(event);
440         if (rc < 0) {
441             error_setg(errp, "SCLP event exit failed.");
442             return;
443         }
444     }
445 }
446 
447 static void event_class_init(ObjectClass *klass, void *data)
448 {
449     DeviceClass *dc = DEVICE_CLASS(klass);
450 
451     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
452     dc->realize = event_realize;
453     dc->unrealize = event_unrealize;
454 }
455 
456 static const TypeInfo sclp_event_type_info = {
457     .name = TYPE_SCLP_EVENT,
458     .parent = TYPE_DEVICE,
459     .instance_size = sizeof(SCLPEvent),
460     .class_init = event_class_init,
461     .class_size = sizeof(SCLPEventClass),
462     .abstract = true,
463 };
464 
465 static void register_types(void)
466 {
467     type_register_static(&sclp_events_bus_info);
468     type_register_static(&sclp_event_facility_info);
469     type_register_static(&sclp_event_type_info);
470 }
471 
472 type_init(register_types)
473