xref: /openbmc/qemu/hw/char/sclpconsole-lm.c (revision 14a650ec) 
1 /*
2  * SCLP event types
3  *    Operations Command - Line Mode input
4  *    Message            - Line Mode output
5  *
6  * Copyright IBM, Corp. 2013
7  *
8  * Authors:
9  *  Heinz Graalfs <graalfs@linux.vnet.ibm.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
12  * option) any later version.  See the COPYING file in the top-level directory.
13  *
14  */
15 
16 #include "hw/qdev.h"
17 #include "qemu/thread.h"
18 #include "qemu/error-report.h"
19 #include "sysemu/char.h"
20 
21 #include "hw/s390x/sclp.h"
22 #include "hw/s390x/event-facility.h"
23 #include "hw/s390x/ebcdic.h"
24 
25 #define SIZE_BUFFER 4096
26 #define NEWLINE     "\n"
27 
28 typedef struct OprtnsCommand {
29     EventBufferHeader header;
30     MDMSU message_unit;
31     char data[0];
32 } QEMU_PACKED OprtnsCommand;
33 
34 /* max size for line-mode data in 4K SCCB page */
35 #define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
36 
37 typedef struct SCLPConsoleLM {
38     SCLPEvent event;
39     CharDriverState *chr;
40     bool echo;                  /* immediate echo of input if true        */
41     uint32_t write_errors;      /* errors writing to char layer           */
42     uint32_t length;            /* length of byte stream in buffer        */
43     uint8_t buf[SIZE_CONSOLE_BUFFER];
44     qemu_irq irq_console_read;
45 } SCLPConsoleLM;
46 
47 /*
48 *  Character layer call-back functions
49  *
50  * Allow 1 character at a time
51  *
52  * Accumulate bytes from character layer in console buffer,
53  * event_pending is set when a newline character is encountered
54  *
55  * The maximum command line length is limited by the maximum
56  * space available in an SCCB
57  */
58 
59 static int chr_can_read(void *opaque)
60 {
61     SCLPConsoleLM *scon = opaque;
62 
63     if (scon->event.event_pending) {
64         return 0;
65     } else if (SIZE_CONSOLE_BUFFER - scon->length) {
66         return 1;
67     }
68     return 0;
69 }
70 
71 static void receive_from_chr_layer(SCLPConsoleLM *scon, const uint8_t *buf,
72                                    int size)
73 {
74     assert(size == 1);
75 
76     if (*buf == '\r' || *buf == '\n') {
77         scon->event.event_pending = true;
78         return;
79     }
80     scon->buf[scon->length] = *buf;
81     scon->length += 1;
82     if (scon->echo) {
83         qemu_chr_fe_write(scon->chr, buf, size);
84     }
85 }
86 
87 /*
88  * Send data from a char device over to the guest
89  */
90 static void chr_read(void *opaque, const uint8_t *buf, int size)
91 {
92     SCLPConsoleLM *scon = opaque;
93 
94     receive_from_chr_layer(scon, buf, size);
95     if (scon->event.event_pending) {
96         /* trigger SCLP read operation */
97         qemu_irq_raise(scon->irq_console_read);
98     }
99 }
100 
101 /* functions to be called by event facility */
102 
103 static bool can_handle_event(uint8_t type)
104 {
105     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
106 }
107 
108 static unsigned int send_mask(void)
109 {
110     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
111 }
112 
113 static unsigned int receive_mask(void)
114 {
115     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
116 }
117 
118 /*
119  * Triggered by SCLP's read_event_data
120  * - convert ASCII byte stream to EBCDIC and
121  * - copy converted data into provided (SCLP) buffer
122  */
123 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
124                             int avail)
125 {
126     int len;
127 
128     SCLPConsoleLM *cons = DO_UPCAST(SCLPConsoleLM, event, event);
129 
130     len = cons->length;
131     /* data need to fit into provided SCLP buffer */
132     if (len > avail) {
133         return 1;
134     }
135 
136     ebcdic_put(buf, (char *)&cons->buf, len);
137     *size = len;
138     cons->length = 0;
139     /* data provided and no more data pending */
140     event->event_pending = false;
141     return 0;
142 }
143 
144 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
145                            int *slen)
146 {
147     int avail, rc;
148     size_t src_len;
149     uint8_t *to;
150     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
151 
152     if (!event->event_pending) {
153         /* no data pending */
154         return 0;
155     }
156 
157     to = (uint8_t *)&oc->data;
158     avail = *slen - sizeof(OprtnsCommand);
159     rc = get_console_data(event, to, &src_len, avail);
160     if (rc) {
161         /* data didn't fit, try next SCCB */
162         return 1;
163     }
164 
165     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
166     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
167 
168     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
169     oc->message_unit.cpmsu.length =
170         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
171 
172     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
173     oc->message_unit.text_command.length =
174         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
175 
176     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
177     oc->message_unit.self_def_text_message.length =
178         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
179 
180     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
181     oc->message_unit.text_message.length =
182         cpu_to_be16(sizeof(GdsSubvector) + src_len);
183 
184     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
185     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
186     *slen = avail - src_len;
187 
188     return 1;
189 }
190 
191 /*
192  * Triggered by SCLP's write_event_data
193  *  - write console data to character layer
194  *  returns < 0 if an error occurred
195  */
196 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
197 {
198     int ret = 0;
199     const uint8_t *buf_offset;
200 
201     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
202 
203     if (!scon->chr) {
204         /* If there's no backend, we can just say we consumed all data. */
205         return len;
206     }
207 
208     buf_offset = buf;
209     while (len > 0) {
210         ret = qemu_chr_fe_write(scon->chr, buf, len);
211         if (ret == 0) {
212             /* a pty doesn't seem to be connected - no error */
213             len = 0;
214         } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
215             len -= ret;
216             buf_offset += ret;
217         } else {
218             len = 0;
219         }
220     }
221 
222     return ret;
223 }
224 
225 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
226 {
227     int rc;
228     int len;
229     uint8_t buffer[SIZE_BUFFER];
230 
231     len = be16_to_cpu(mdbo->length);
232     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
233             + sizeof(mdbo->mto.line_type_flags)
234             + sizeof(mdbo->mto.alarm_control)
235             + sizeof(mdbo->mto._reserved);
236 
237     assert(len <= SIZE_BUFFER);
238 
239     /* convert EBCDIC SCLP contents to ASCII console message */
240     ascii_put(buffer, mdbo->mto.message, len);
241     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
242     if (rc < 0) {
243         return rc;
244     }
245     return write_console_data(event, buffer, len);
246 }
247 
248 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
249 {
250     int len;
251     int written;
252     int errors = 0;
253     MDBO *mdbo;
254     SclpMsg *data = (SclpMsg *) ebh;
255     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
256 
257     len = be16_to_cpu(data->mdb.header.length);
258     if (len < sizeof(data->mdb.header)) {
259         return SCLP_RC_INCONSISTENT_LENGTHS;
260     }
261     len -= sizeof(data->mdb.header);
262 
263     /* first check message buffers */
264     mdbo = data->mdb.mdbo;
265     while (len > 0) {
266         if (be16_to_cpu(mdbo->length) > len
267                 || be16_to_cpu(mdbo->length) == 0) {
268             return SCLP_RC_INCONSISTENT_LENGTHS;
269         }
270         len -= be16_to_cpu(mdbo->length);
271         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
272     }
273 
274     /* then execute */
275     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
276     mdbo = data->mdb.mdbo;
277     while (len > 0) {
278         switch (be16_to_cpu(mdbo->type)) {
279         case MESSAGE_TEXT:
280             /* message text object */
281             written = process_mdb(event, mdbo);
282             if (written < 0) {
283                 /* character layer error */
284                 errors++;
285             }
286             break;
287         default: /* ignore */
288             break;
289         }
290         len -= be16_to_cpu(mdbo->length);
291         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
292     }
293     if (errors) {
294         scon->write_errors += errors;
295     }
296     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
297 
298     return SCLP_RC_NORMAL_COMPLETION;
299 }
300 
301 static void trigger_console_data(void *opaque, int n, int level)
302 {
303     sclp_service_interrupt(0);
304 }
305 
306 /* functions for live migration */
307 
308 static const VMStateDescription vmstate_sclplmconsole = {
309     .name = "sclplmconsole",
310     .version_id = 0,
311     .minimum_version_id = 0,
312     .minimum_version_id_old = 0,
313     .fields      = (VMStateField[]) {
314         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
315         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
316         VMSTATE_UINT32(length, SCLPConsoleLM),
317         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
318         VMSTATE_END_OF_LIST()
319      }
320 };
321 
322 /* qemu object creation and initialization functions */
323 
324 /* tell character layer our call-back functions */
325 
326 static int console_init(SCLPEvent *event)
327 {
328     static bool console_available;
329 
330     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
331 
332     if (console_available) {
333         error_report("Multiple line-mode operator consoles are not supported");
334         return -1;
335     }
336     console_available = true;
337 
338     if (scon->chr) {
339         qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
340     }
341     scon->irq_console_read = *qemu_allocate_irqs(trigger_console_data, NULL, 1);
342 
343     return 0;
344 }
345 
346 static int console_exit(SCLPEvent *event)
347 {
348     return 0;
349 }
350 
351 static void console_reset(DeviceState *dev)
352 {
353    SCLPEvent *event = SCLP_EVENT(dev);
354    SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
355 
356    event->event_pending = false;
357    scon->length = 0;
358    scon->write_errors = 0;
359 }
360 
361 static Property console_properties[] = {
362     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
363     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
364     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
365     DEFINE_PROP_END_OF_LIST(),
366 };
367 
368 static void console_class_init(ObjectClass *klass, void *data)
369 {
370     DeviceClass *dc = DEVICE_CLASS(klass);
371     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
372 
373     dc->props = console_properties;
374     dc->reset = console_reset;
375     dc->vmsd = &vmstate_sclplmconsole;
376     ec->init = console_init;
377     ec->exit = console_exit;
378     ec->get_send_mask = send_mask;
379     ec->get_receive_mask = receive_mask;
380     ec->can_handle_event = can_handle_event;
381     ec->read_event_data = read_event_data;
382     ec->write_event_data = write_event_data;
383 }
384 
385 static const TypeInfo sclp_console_info = {
386     .name          = "sclplmconsole",
387     .parent        = TYPE_SCLP_EVENT,
388     .instance_size = sizeof(SCLPConsoleLM),
389     .class_init    = console_class_init,
390     .class_size    = sizeof(SCLPEventClass),
391 };
392 
393 static void register_types(void)
394 {
395     type_register_static(&sclp_console_info);
396 }
397 
398 type_init(register_types)
399