xref: /openbmc/qemu/hw/char/sclpconsole-lm.c (revision 9c4218e9) 
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 "qemu/osdep.h"
17 #include "hw/qdev.h"
18 #include "qemu/thread.h"
19 #include "qemu/error-report.h"
20 #include "sysemu/char.h"
21 
22 #include "hw/s390x/sclp.h"
23 #include "hw/s390x/event-facility.h"
24 #include "hw/s390x/ebcdic.h"
25 
26 #define SIZE_BUFFER 4096
27 #define NEWLINE     "\n"
28 
29 typedef struct OprtnsCommand {
30     EventBufferHeader header;
31     MDMSU message_unit;
32     char data[0];
33 } QEMU_PACKED OprtnsCommand;
34 
35 /* max size for line-mode data in 4K SCCB page */
36 #define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
37 
38 typedef struct SCLPConsoleLM {
39     SCLPEvent event;
40     CharDriverState *chr;
41     bool echo;                  /* immediate echo of input if true        */
42     uint32_t write_errors;      /* errors writing to char layer           */
43     uint32_t length;            /* length of byte stream in buffer        */
44     uint8_t buf[SIZE_CONSOLE_BUFFER];
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. Line mode console input is sent
57  * truncated to the guest in case it doesn't fit into the SCCB.
58  */
59 
60 static int chr_can_read(void *opaque)
61 {
62     SCLPConsoleLM *scon = opaque;
63 
64     if (scon->event.event_pending) {
65         return 0;
66     }
67     return 1;
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     if (scon->length == SIZE_CONSOLE_BUFFER) {
82         /* Eat the character, but still process CR and LF.  */
83         return;
84     }
85     scon->buf[scon->length] = *buf;
86     scon->length += 1;
87     if (scon->echo) {
88         qemu_chr_fe_write(scon->chr, buf, size);
89     }
90 }
91 
92 /* functions to be called by event facility */
93 
94 static bool can_handle_event(uint8_t type)
95 {
96     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
97 }
98 
99 static unsigned int send_mask(void)
100 {
101     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
102 }
103 
104 static unsigned int receive_mask(void)
105 {
106     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
107 }
108 
109 /*
110  * Triggered by SCLP's read_event_data
111  * - convert ASCII byte stream to EBCDIC and
112  * - copy converted data into provided (SCLP) buffer
113  */
114 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
115                             int avail)
116 {
117     int len;
118 
119     SCLPConsoleLM *cons = DO_UPCAST(SCLPConsoleLM, event, event);
120 
121     len = cons->length;
122     /* data need to fit into provided SCLP buffer */
123     if (len > avail) {
124         return 1;
125     }
126 
127     ebcdic_put(buf, (char *)&cons->buf, len);
128     *size = len;
129     cons->length = 0;
130     /* data provided and no more data pending */
131     event->event_pending = false;
132     qemu_notify_event();
133     return 0;
134 }
135 
136 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
137                            int *slen)
138 {
139     int avail, rc;
140     size_t src_len;
141     uint8_t *to;
142     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
143 
144     if (!event->event_pending) {
145         /* no data pending */
146         return 0;
147     }
148 
149     to = (uint8_t *)&oc->data;
150     avail = *slen - sizeof(OprtnsCommand);
151     rc = get_console_data(event, to, &src_len, avail);
152     if (rc) {
153         /* data didn't fit, try next SCCB */
154         return 1;
155     }
156 
157     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
158     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
159 
160     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
161     oc->message_unit.cpmsu.length =
162         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
163 
164     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
165     oc->message_unit.text_command.length =
166         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
167 
168     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
169     oc->message_unit.self_def_text_message.length =
170         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
171 
172     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
173     oc->message_unit.text_message.length =
174         cpu_to_be16(sizeof(GdsSubvector) + src_len);
175 
176     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
177     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
178     *slen = avail - src_len;
179 
180     return 1;
181 }
182 
183 /*
184  * Triggered by SCLP's write_event_data
185  *  - write console data to character layer
186  *  returns < 0 if an error occurred
187  */
188 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
189 {
190     int ret = 0;
191     const uint8_t *buf_offset;
192 
193     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
194 
195     if (!scon->chr) {
196         /* If there's no backend, we can just say we consumed all data. */
197         return len;
198     }
199 
200     buf_offset = buf;
201     while (len > 0) {
202         ret = qemu_chr_fe_write(scon->chr, buf, len);
203         if (ret == 0) {
204             /* a pty doesn't seem to be connected - no error */
205             len = 0;
206         } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
207             len -= ret;
208             buf_offset += ret;
209         } else {
210             len = 0;
211         }
212     }
213 
214     return ret;
215 }
216 
217 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
218 {
219     int rc;
220     int len;
221     uint8_t buffer[SIZE_BUFFER];
222 
223     len = be16_to_cpu(mdbo->length);
224     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
225             + sizeof(mdbo->mto.line_type_flags)
226             + sizeof(mdbo->mto.alarm_control)
227             + sizeof(mdbo->mto._reserved);
228 
229     assert(len <= SIZE_BUFFER);
230 
231     /* convert EBCDIC SCLP contents to ASCII console message */
232     ascii_put(buffer, mdbo->mto.message, len);
233     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
234     if (rc < 0) {
235         return rc;
236     }
237     return write_console_data(event, buffer, len);
238 }
239 
240 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
241 {
242     int len;
243     int written;
244     int errors = 0;
245     MDBO *mdbo;
246     SclpMsg *data = (SclpMsg *) ebh;
247     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
248 
249     len = be16_to_cpu(data->mdb.header.length);
250     if (len < sizeof(data->mdb.header)) {
251         return SCLP_RC_INCONSISTENT_LENGTHS;
252     }
253     len -= sizeof(data->mdb.header);
254 
255     /* first check message buffers */
256     mdbo = data->mdb.mdbo;
257     while (len > 0) {
258         if (be16_to_cpu(mdbo->length) > len
259                 || be16_to_cpu(mdbo->length) == 0) {
260             return SCLP_RC_INCONSISTENT_LENGTHS;
261         }
262         len -= be16_to_cpu(mdbo->length);
263         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
264     }
265 
266     /* then execute */
267     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
268     mdbo = data->mdb.mdbo;
269     while (len > 0) {
270         switch (be16_to_cpu(mdbo->type)) {
271         case MESSAGE_TEXT:
272             /* message text object */
273             written = process_mdb(event, mdbo);
274             if (written < 0) {
275                 /* character layer error */
276                 errors++;
277             }
278             break;
279         default: /* ignore */
280             break;
281         }
282         len -= be16_to_cpu(mdbo->length);
283         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
284     }
285     if (errors) {
286         scon->write_errors += errors;
287     }
288     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
289 
290     return SCLP_RC_NORMAL_COMPLETION;
291 }
292 
293 /* functions for live migration */
294 
295 static const VMStateDescription vmstate_sclplmconsole = {
296     .name = "sclplmconsole",
297     .version_id = 0,
298     .minimum_version_id = 0,
299     .fields = (VMStateField[]) {
300         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
301         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
302         VMSTATE_UINT32(length, SCLPConsoleLM),
303         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
304         VMSTATE_END_OF_LIST()
305      }
306 };
307 
308 /* qemu object creation and initialization functions */
309 
310 /* tell character layer our call-back functions */
311 
312 static int console_init(SCLPEvent *event)
313 {
314     static bool console_available;
315 
316     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
317 
318     if (console_available) {
319         error_report("Multiple line-mode operator consoles are not supported");
320         return -1;
321     }
322     console_available = true;
323 
324     if (scon->chr) {
325         qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
326     }
327 
328     return 0;
329 }
330 
331 static int console_exit(SCLPEvent *event)
332 {
333     return 0;
334 }
335 
336 static void console_reset(DeviceState *dev)
337 {
338    SCLPEvent *event = SCLP_EVENT(dev);
339    SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
340 
341    event->event_pending = false;
342    scon->length = 0;
343    scon->write_errors = 0;
344 }
345 
346 static Property console_properties[] = {
347     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
348     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
349     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
350     DEFINE_PROP_END_OF_LIST(),
351 };
352 
353 static void console_class_init(ObjectClass *klass, void *data)
354 {
355     DeviceClass *dc = DEVICE_CLASS(klass);
356     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
357 
358     dc->props = console_properties;
359     dc->reset = console_reset;
360     dc->vmsd = &vmstate_sclplmconsole;
361     ec->init = console_init;
362     ec->exit = console_exit;
363     ec->get_send_mask = send_mask;
364     ec->get_receive_mask = receive_mask;
365     ec->can_handle_event = can_handle_event;
366     ec->read_event_data = read_event_data;
367     ec->write_event_data = write_event_data;
368     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
369 }
370 
371 static const TypeInfo sclp_console_info = {
372     .name          = "sclplmconsole",
373     .parent        = TYPE_SCLP_EVENT,
374     .instance_size = sizeof(SCLPConsoleLM),
375     .class_init    = console_class_init,
376     .class_size    = sizeof(SCLPEventClass),
377 };
378 
379 static void register_types(void)
380 {
381     type_register_static(&sclp_console_info);
382 }
383 
384 type_init(register_types)
385