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     SCLPConsole *scon = opaque;
  48
  49     return scon->iov ? SIZE_BUFFER_VT220 - scon->iov_data_len : 0;
  50 }
  51
  52 /* Receive n bytes from character layer, save in iov buffer,
  53  * and set event pending */
  54 static void receive_from_chr_layer(SCLPConsole *scon, const uint8_t *buf,
  55                                    int size)
  56 {
  57     assert(scon->iov);
  58
  59     /* read data must fit into current buffer */
  60     assert(size <= SIZE_BUFFER_VT220 - scon->iov_data_len);
  61
  62     /* put byte-stream from character layer into buffer */
  63     memcpy(scon->iov_bs, buf, size);
  64     scon->iov_data_len += size;
  65     scon->iov_sclp_rest += size;
  66     scon->iov_bs += size;
  67     scon->event.event_pending = true;
  68 }
  69
  70 /* Send data from a char device over to the guest */
  71 static void chr_read(void *opaque, const uint8_t *buf, int size)
  72 {
  73     SCLPConsole *scon = opaque;
  74
  75     assert(scon);
  76
  77     receive_from_chr_layer(scon, buf, size);
  78     /* trigger SCLP read operation */
  79     qemu_irq_raise(scon->irq_read_vt220);
  80 }
  81
  82 static void chr_event(void *opaque, int event)
  83 {
  84     SCLPConsole *scon = opaque;
  85
  86     switch (event) {
  87     case CHR_EVENT_OPENED:
  88         if (!scon->iov) {
  89             scon->iov = g_malloc0(SIZE_BUFFER_VT220);
  90             scon->iov_sclp = scon->iov;
  91             scon->iov_bs = scon->iov;
  92             scon->iov_data_len = 0;
  93             scon->iov_sclp_rest = 0;
  94         }
  95         break;
  96     case CHR_EVENT_CLOSED:
  97         if (scon->iov) {
  98             g_free(scon->iov);
  99             scon->iov = NULL;
 100         }
 101         break;
 102     }
 103 }
 104
 105 /* functions to be called by event facility */
 106
 107 static int event_type(void)
 108 {
 109     return SCLP_EVENT_ASCII_CONSOLE_DATA;
 110 }
 111
 112 static unsigned int send_mask(void)
 113 {
 114     return SCLP_EVENT_MASK_MSG_ASCII;
 115 }
 116
 117 static unsigned int receive_mask(void)
 118 {
 119     return SCLP_EVENT_MASK_MSG_ASCII;
 120 }
 121
 122 /* triggered by SCLP's read_event_data -
 123  * copy console data byte-stream into provided (SCLP) buffer
 124  */
 125 static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 126                              int avail)
 127 {
 128     SCLPConsole *cons = DO_UPCAST(SCLPConsole, event, event);
 129
 130     /* first byte is hex 0 saying an ascii string follows */
 131     *buf++ = '\0';
 132     avail--;
 133     /* if all data fit into provided SCLP buffer */
 134     if (avail >= cons->iov_sclp_rest) {
 135         /* copy character byte-stream to SCLP buffer */
 136         memcpy(buf, cons->iov_sclp, cons->iov_sclp_rest);
 137         *size = cons->iov_sclp_rest + 1;
 138         cons->iov_sclp = cons->iov;
 139         cons->iov_bs = cons->iov;
 140         cons->iov_data_len = 0;
 141         cons->iov_sclp_rest = 0;
 142         event->event_pending = false;
 143         /* data provided and no more data pending */
 144     } else {
 145         /* if provided buffer is too small, just copy part */
 146         memcpy(buf, cons->iov_sclp, avail);
 147         *size = avail + 1;
 148         cons->iov_sclp_rest -= avail;
 149         cons->iov_sclp += avail;
 150         /* more data pending */
 151     }
 152 }
 153
 154 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 155                            int *slen)
 156 {
 157     int avail;
 158     size_t src_len;
 159     uint8_t *to;
 160     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 161
 162     if (!event->event_pending) {
 163         /* no data pending */
 164         return 0;
 165     }
 166
 167     to = (uint8_t *)&acd->data;
 168     avail = *slen - sizeof(ASCIIConsoleData);
 169     get_console_data(event, to, &src_len, avail);
 170
 171     acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
 172     acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
 173     acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 174     *slen = avail - src_len;
 175
 176     return 1;
 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 ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
 184                                   size_t len)
 185 {
 186     ssize_t ret = 0;
 187     const uint8_t *iov_offset;
 188     SCLPConsole *scon = DO_UPCAST(SCLPConsole, 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     iov_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             iov_offset += ret;
 204         } else {
 205             len = 0;
 206         }
 207     }
 208
 209     return ret;
 210 }
 211
 212 static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
 213 {
 214     int rc;
 215     int length;
 216     ssize_t written;
 217     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 218
 219     length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
 220     written = write_console_data(event, (uint8_t *)acd->data, length);
 221
 222     rc = SCLP_RC_NORMAL_COMPLETION;
 223     /* set event buffer accepted flag */
 224     evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 225
 226     /* written will be zero if a pty is not connected - don't treat as error */
 227     if (written < 0) {
 228         /* event buffer not accepted due to error in character layer */
 229         evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 230         rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
 231     }
 232
 233     return rc;
 234 }
 235
 236 static void trigger_ascii_console_data(void *env, int n, int level)
 237 {
 238     sclp_service_interrupt(0);
 239 }
 240
 241 /* qemu object creation and initialization functions */
 242
 243 /* tell character layer our call-back functions */
 244 static int console_init(SCLPEvent *event)
 245 {
 246     static bool console_available;
 247
 248     SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 249
 250     if (console_available) {
 251         error_report("Multiple VT220 operator consoles are not supported");
 252         return -1;
 253     }
 254     console_available = true;
 255     event->event_type = SCLP_EVENT_ASCII_CONSOLE_DATA;
 256     if (scon->chr) {
 257         qemu_chr_add_handlers(scon->chr, chr_can_read,
 258                               chr_read, chr_event, scon);
 259     }
 260     scon->irq_read_vt220 = *qemu_allocate_irqs(trigger_ascii_console_data,
 261                                                NULL, 1);
 262
 263     return 0;
 264 }
 265
 266 static int console_exit(SCLPEvent *event)
 267 {
 268     return 0;
 269 }
 270
 271 static Property console_properties[] = {
 272     DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
 273     DEFINE_PROP_END_OF_LIST(),
 274 };
 275
 276 static void console_class_init(ObjectClass *klass, void *data)
 277 {
 278     DeviceClass *dc = DEVICE_CLASS(klass);
 279     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 280
 281     dc->props = console_properties;
 282     ec->init = console_init;
 283     ec->exit = console_exit;
 284     ec->get_send_mask = send_mask;
 285     ec->get_receive_mask = receive_mask;
 286     ec->event_type = event_type;
 287     ec->read_event_data = read_event_data;
 288     ec->write_event_data = write_event_data;
 289 }
 290
 291 static const TypeInfo sclp_console_info = {
 292     .name          = "sclpconsole",
 293     .parent        = TYPE_SCLP_EVENT,
 294     .instance_size = sizeof(SCLPConsole),
 295     .class_init    = console_class_init,
 296     .class_size    = sizeof(SCLPEventClass),
 297 };
 298
 299 static void register_types(void)
 300 {
 301     type_register_static(&sclp_console_info);
 302 }
 303
 304 type_init(register_types)