hw/s390x/sclpconsole.c

   1 /*
   2  * SCLP event type
   3  *    Ascii Console Data (VT220 Console)
   4  *
   5  * Copyright IBM, Corp. 2012
   6  *
   7  * Authors:
   8  *  Heinz Graalfs <graalfs@de.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
  11  * option) any later version.  See the COPYING file in the top-level directory.
  12  *
  13  */
  14
  15 #include <hw/qdev.h>
  16 #include "qemu/thread.h"
  17
  18 #include "sclp.h"
  19 #include "event-facility.h"
  20 #include "char/char.h"
  21
  22 typedef struct ASCIIConsoleData {
  23     EventBufferHeader ebh;
  24     char data[0];
  25 } QEMU_PACKED ASCIIConsoleData;
  26
  27 /* max size for ASCII data in 4K SCCB page */
  28 #define SIZE_BUFFER_VT220 4080
  29
  30 typedef struct SCLPConsole {
  31     SCLPEvent event;
  32     CharDriverState *chr;
  33     /* io vector                                                       */
  34     uint8_t *iov;           /* iov buffer pointer                      */
  35     uint8_t *iov_sclp;      /* pointer to SCLP read offset             */
  36     uint8_t *iov_bs;        /* pointer byte stream read offset         */
  37     uint32_t iov_data_len;  /* length of byte stream in buffer         */
  38     uint32_t iov_sclp_rest; /* length of byte stream not read via SCLP */
  39     qemu_irq irq_read_vt220;
  40 } SCLPConsole;
  41
  42 /* character layer call-back functions */
  43
  44 /* Return number of bytes that fit into iov buffer */
  45 static int chr_can_read(void *opaque)
  46 {
  47     int can_read;
  48     SCLPConsole *scon = opaque;
  49
  50     can_read = SIZE_BUFFER_VT220 - scon->iov_data_len;
  51
  52     return can_read;
  53 }
  54
  55 /* Receive n bytes from character layer, save in iov buffer,
  56  * and set event pending */
  57 static void receive_from_chr_layer(SCLPConsole *scon, const uint8_t *buf,
  58                                    int size)
  59 {
  60     assert(scon->iov);
  61
  62     /* read data must fit into current buffer */
  63     assert(size <= SIZE_BUFFER_VT220 - scon->iov_data_len);
  64
  65     /* put byte-stream from character layer into buffer */
  66     memcpy(scon->iov_bs, buf, size);
  67     scon->iov_data_len += size;
  68     scon->iov_sclp_rest += size;
  69     scon->iov_bs += size;
  70     scon->event.event_pending = true;
  71 }
  72
  73 /* Send data from a char device over to the guest */
  74 static void chr_read(void *opaque, const uint8_t *buf, int size)
  75 {
  76     SCLPConsole *scon = opaque;
  77
  78     assert(scon);
  79
  80     receive_from_chr_layer(scon, buf, size);
  81     /* trigger SCLP read operation */
  82     qemu_irq_raise(scon->irq_read_vt220);
  83 }
  84
  85 static void chr_event(void *opaque, int event)
  86 {
  87     SCLPConsole *scon = opaque;
  88
  89     switch (event) {
  90     case CHR_EVENT_OPENED:
  91         if (!scon->iov) {
  92             scon->iov = g_malloc0(SIZE_BUFFER_VT220);
  93             scon->iov_sclp = scon->iov;
  94             scon->iov_bs = scon->iov;
  95             scon->iov_data_len = 0;
  96             scon->iov_sclp_rest = 0;
  97         }
  98         break;
  99     case CHR_EVENT_CLOSED:
 100         if (scon->iov) {
 101             g_free(scon->iov);
 102             scon->iov = NULL;
 103         }
 104         break;
 105     }
 106 }
 107
 108 /* functions to be called by event facility */
 109
 110 static int event_type(void)
 111 {
 112     return SCLP_EVENT_ASCII_CONSOLE_DATA;
 113 }
 114
 115 static unsigned int send_mask(void)
 116 {
 117     return SCLP_EVENT_MASK_MSG_ASCII;
 118 }
 119
 120 static unsigned int receive_mask(void)
 121 {
 122     return SCLP_EVENT_MASK_MSG_ASCII;
 123 }
 124
 125 /* triggered by SCLP's read_event_data -
 126  * copy console data byte-stream into provided (SCLP) buffer
 127  */
 128 static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 129                              int avail)
 130 {
 131     SCLPConsole *cons = DO_UPCAST(SCLPConsole, event, event);
 132
 133     /* first byte is hex 0 saying an ascii string follows */
 134     *buf++ = '\0';
 135     avail--;
 136     /* if all data fit into provided SCLP buffer */
 137     if (avail >= cons->iov_sclp_rest) {
 138         /* copy character byte-stream to SCLP buffer */
 139         memcpy(buf, cons->iov_sclp, cons->iov_sclp_rest);
 140         *size = cons->iov_sclp_rest + 1;
 141         cons->iov_sclp = cons->iov;
 142         cons->iov_bs = cons->iov;
 143         cons->iov_data_len = 0;
 144         cons->iov_sclp_rest = 0;
 145         event->event_pending = false;
 146         /* data provided and no more data pending */
 147     } else {
 148         /* if provided buffer is too small, just copy part */
 149         memcpy(buf, cons->iov_sclp, avail);
 150         *size = avail + 1;
 151         cons->iov_sclp_rest -= avail;
 152         cons->iov_sclp += avail;
 153         /* more data pending */
 154     }
 155 }
 156
 157 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 158                            int *slen)
 159 {
 160     int avail;
 161     size_t src_len;
 162     uint8_t *to;
 163     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 164
 165     if (!event->event_pending) {
 166         /* no data pending */
 167         return 0;
 168     }
 169
 170     to = (uint8_t *)&acd->data;
 171     avail = *slen - sizeof(ASCIIConsoleData);
 172     get_console_data(event, to, &src_len, avail);
 173
 174     acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
 175     acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
 176     acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 177     *slen = avail - src_len;
 178
 179     return 1;
 180 }
 181
 182 /* triggered by SCLP's write_event_data
 183  *  - write console data to character layer
 184  *  returns < 0 if an error occurred
 185  */
 186 static ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
 187                                   size_t len)
 188 {
 189     ssize_t ret = 0;
 190     const uint8_t *iov_offset;
 191     SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 192
 193     if (!scon->chr) {
 194         /* If there's no backend, we can just say we consumed all data. */
 195         return len;
 196     }
 197
 198     iov_offset = buf;
 199     while (len > 0) {
 200         ret = qemu_chr_fe_write(scon->chr, buf, len);
 201         if (ret == 0) {
 202             /* a pty doesn't seem to be connected - no error */
 203             len = 0;
 204         } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
 205             len -= ret;
 206             iov_offset += ret;
 207         } else {
 208             len = 0;
 209         }
 210     }
 211
 212     return ret;
 213 }
 214
 215 static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
 216 {
 217     int rc;
 218     int length;
 219     ssize_t written;
 220     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 221
 222     length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
 223     written = write_console_data(event, (uint8_t *)acd->data, length);
 224
 225     rc = SCLP_RC_NORMAL_COMPLETION;
 226     /* set event buffer accepted flag */
 227     evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 228
 229     /* written will be zero if a pty is not connected - don't treat as error */
 230     if (written < 0) {
 231         /* event buffer not accepted due to error in character layer */
 232         evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 233         rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
 234     }
 235
 236     return rc;
 237 }
 238
 239 static void trigger_ascii_console_data(void *env, int n, int level)
 240 {
 241     sclp_service_interrupt(0);
 242 }
 243
 244 /* qemu object creation and initialization functions */
 245
 246 /* tell character layer our call-back functions */
 247 static int console_init(SCLPEvent *event)
 248 {
 249     static bool console_available;
 250
 251     SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 252
 253     if (console_available) {
 254         error_report("Multiple VT220 operator consoles are not supported");
 255         return -1;
 256     }
 257     console_available = true;
 258     event->event_type = SCLP_EVENT_ASCII_CONSOLE_DATA;
 259     if (scon->chr) {
 260         qemu_chr_add_handlers(scon->chr, chr_can_read,
 261                               chr_read, chr_event, scon);
 262     }
 263     scon->irq_read_vt220 = *qemu_allocate_irqs(trigger_ascii_console_data,
 264                                                NULL, 1);
 265
 266     return 0;
 267 }
 268
 269 static int console_exit(SCLPEvent *event)
 270 {
 271     return 0;
 272 }
 273
 274 static Property console_properties[] = {
 275     DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
 276     DEFINE_PROP_END_OF_LIST(),
 277 };
 278
 279 static void console_class_init(ObjectClass *klass, void *data)
 280 {
 281     DeviceClass *dc = DEVICE_CLASS(klass);
 282     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 283
 284     dc->props = console_properties;
 285     ec->init = console_init;
 286     ec->exit = console_exit;
 287     ec->get_send_mask = send_mask;
 288     ec->get_receive_mask = receive_mask;
 289     ec->event_type = event_type;
 290     ec->read_event_data = read_event_data;
 291     ec->write_event_data = write_event_data;
 292 }
 293
 294 static const TypeInfo sclp_console_info = {
 295     .name          = "sclpconsole",
 296     .parent        = TYPE_SCLP_EVENT,
 297     .instance_size = sizeof(SCLPConsole),
 298     .class_init    = console_class_init,
 299     .class_size    = sizeof(SCLPEventClass),
 300 };
 301
 302 static void register_types(void)
 303 {
 304     type_register_static(&sclp_console_info);
 305 }
 306
 307 type_init(register_types)