xref: /openbmc/qemu/hw/char/sclpconsole-lm.c (revision acb0ef58) 
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 } SCLPConsoleLM;
45 
46 /*
47 *  Character layer call-back functions
48  *
49  * Allow 1 character at a time
50  *
51  * Accumulate bytes from character layer in console buffer,
52  * event_pending is set when a newline character is encountered
53  *
54  * The maximum command line length is limited by the maximum
55  * space available in an SCCB
56  */
57 
58 static int chr_can_read(void *opaque)
59 {
60     SCLPConsoleLM *scon = opaque;
61 
62     if (scon->event.event_pending) {
63         return 0;
64     } else if (SIZE_CONSOLE_BUFFER - scon->length) {
65         return 1;
66     }
67     return 0;
68 }
69 
70 static void chr_read(void *opaque, const uint8_t *buf, int size)
71 {
72     SCLPConsoleLM *scon = opaque;
73 
74     assert(size == 1);
75 
76     if (*buf == '\r' || *buf == '\n') {
77         scon->event.event_pending = true;
78         sclp_service_interrupt(0);
79         return;
80     }
81     scon->buf[scon->length] = *buf;
82     scon->length += 1;
83     if (scon->echo) {
84         qemu_chr_fe_write(scon->chr, buf, size);
85     }
86 }
87 
88 /* functions to be called by event facility */
89 
90 static bool can_handle_event(uint8_t type)
91 {
92     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
93 }
94 
95 static unsigned int send_mask(void)
96 {
97     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
98 }
99 
100 static unsigned int receive_mask(void)
101 {
102     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
103 }
104 
105 /*
106  * Triggered by SCLP's read_event_data
107  * - convert ASCII byte stream to EBCDIC and
108  * - copy converted data into provided (SCLP) buffer
109  */
110 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
111                             int avail)
112 {
113     int len;
114 
115     SCLPConsoleLM *cons = DO_UPCAST(SCLPConsoleLM, event, event);
116 
117     len = cons->length;
118     /* data need to fit into provided SCLP buffer */
119     if (len > avail) {
120         return 1;
121     }
122 
123     ebcdic_put(buf, (char *)&cons->buf, len);
124     *size = len;
125     cons->length = 0;
126     /* data provided and no more data pending */
127     event->event_pending = false;
128     return 0;
129 }
130 
131 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
132                            int *slen)
133 {
134     int avail, rc;
135     size_t src_len;
136     uint8_t *to;
137     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
138 
139     if (!event->event_pending) {
140         /* no data pending */
141         return 0;
142     }
143 
144     to = (uint8_t *)&oc->data;
145     avail = *slen - sizeof(OprtnsCommand);
146     rc = get_console_data(event, to, &src_len, avail);
147     if (rc) {
148         /* data didn't fit, try next SCCB */
149         return 1;
150     }
151 
152     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
153     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
154 
155     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
156     oc->message_unit.cpmsu.length =
157         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
158 
159     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
160     oc->message_unit.text_command.length =
161         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
162 
163     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
164     oc->message_unit.self_def_text_message.length =
165         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
166 
167     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
168     oc->message_unit.text_message.length =
169         cpu_to_be16(sizeof(GdsSubvector) + src_len);
170 
171     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
172     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
173     *slen = avail - src_len;
174 
175     return 1;
176 }
177 
178 /*
179  * Triggered by SCLP's write_event_data
180  *  - write console data to character layer
181  *  returns < 0 if an error occurred
182  */
183 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
184 {
185     int ret = 0;
186     const uint8_t *buf_offset;
187 
188     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
189 
190     if (!scon->chr) {
191         /* If there's no backend, we can just say we consumed all data. */
192         return len;
193     }
194 
195     buf_offset = buf;
196     while (len > 0) {
197         ret = qemu_chr_fe_write(scon->chr, buf, len);
198         if (ret == 0) {
199             /* a pty doesn't seem to be connected - no error */
200             len = 0;
201         } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
202             len -= ret;
203             buf_offset += ret;
204         } else {
205             len = 0;
206         }
207     }
208 
209     return ret;
210 }
211 
212 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
213 {
214     int rc;
215     int len;
216     uint8_t buffer[SIZE_BUFFER];
217 
218     len = be16_to_cpu(mdbo->length);
219     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
220             + sizeof(mdbo->mto.line_type_flags)
221             + sizeof(mdbo->mto.alarm_control)
222             + sizeof(mdbo->mto._reserved);
223 
224     assert(len <= SIZE_BUFFER);
225 
226     /* convert EBCDIC SCLP contents to ASCII console message */
227     ascii_put(buffer, mdbo->mto.message, len);
228     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
229     if (rc < 0) {
230         return rc;
231     }
232     return write_console_data(event, buffer, len);
233 }
234 
235 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
236 {
237     int len;
238     int written;
239     int errors = 0;
240     MDBO *mdbo;
241     SclpMsg *data = (SclpMsg *) ebh;
242     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
243 
244     len = be16_to_cpu(data->mdb.header.length);
245     if (len < sizeof(data->mdb.header)) {
246         return SCLP_RC_INCONSISTENT_LENGTHS;
247     }
248     len -= sizeof(data->mdb.header);
249 
250     /* first check message buffers */
251     mdbo = data->mdb.mdbo;
252     while (len > 0) {
253         if (be16_to_cpu(mdbo->length) > len
254                 || be16_to_cpu(mdbo->length) == 0) {
255             return SCLP_RC_INCONSISTENT_LENGTHS;
256         }
257         len -= be16_to_cpu(mdbo->length);
258         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
259     }
260 
261     /* then execute */
262     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
263     mdbo = data->mdb.mdbo;
264     while (len > 0) {
265         switch (be16_to_cpu(mdbo->type)) {
266         case MESSAGE_TEXT:
267             /* message text object */
268             written = process_mdb(event, mdbo);
269             if (written < 0) {
270                 /* character layer error */
271                 errors++;
272             }
273             break;
274         default: /* ignore */
275             break;
276         }
277         len -= be16_to_cpu(mdbo->length);
278         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
279     }
280     if (errors) {
281         scon->write_errors += errors;
282     }
283     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
284 
285     return SCLP_RC_NORMAL_COMPLETION;
286 }
287 
288 /* functions for live migration */
289 
290 static const VMStateDescription vmstate_sclplmconsole = {
291     .name = "sclplmconsole",
292     .version_id = 0,
293     .minimum_version_id = 0,
294     .fields = (VMStateField[]) {
295         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
296         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
297         VMSTATE_UINT32(length, SCLPConsoleLM),
298         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
299         VMSTATE_END_OF_LIST()
300      }
301 };
302 
303 /* qemu object creation and initialization functions */
304 
305 /* tell character layer our call-back functions */
306 
307 static int console_init(SCLPEvent *event)
308 {
309     static bool console_available;
310 
311     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
312 
313     if (console_available) {
314         error_report("Multiple line-mode operator consoles are not supported");
315         return -1;
316     }
317     console_available = true;
318 
319     if (scon->chr) {
320         qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
321     }
322 
323     return 0;
324 }
325 
326 static int console_exit(SCLPEvent *event)
327 {
328     return 0;
329 }
330 
331 static void console_reset(DeviceState *dev)
332 {
333    SCLPEvent *event = SCLP_EVENT(dev);
334    SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
335 
336    event->event_pending = false;
337    scon->length = 0;
338    scon->write_errors = 0;
339 }
340 
341 static Property console_properties[] = {
342     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
343     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
344     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
345     DEFINE_PROP_END_OF_LIST(),
346 };
347 
348 static void console_class_init(ObjectClass *klass, void *data)
349 {
350     DeviceClass *dc = DEVICE_CLASS(klass);
351     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
352 
353     dc->props = console_properties;
354     dc->reset = console_reset;
355     dc->vmsd = &vmstate_sclplmconsole;
356     ec->init = console_init;
357     ec->exit = console_exit;
358     ec->get_send_mask = send_mask;
359     ec->get_receive_mask = receive_mask;
360     ec->can_handle_event = can_handle_event;
361     ec->read_event_data = read_event_data;
362     ec->write_event_data = write_event_data;
363 }
364 
365 static const TypeInfo sclp_console_info = {
366     .name          = "sclplmconsole",
367     .parent        = TYPE_SCLP_EVENT,
368     .instance_size = sizeof(SCLPConsoleLM),
369     .class_init    = console_class_init,
370     .class_size    = sizeof(SCLPEventClass),
371 };
372 
373 static void register_types(void)
374 {
375     type_register_static(&sclp_console_info);
376 }
377 
378 type_init(register_types)
379