hw/char/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 #include "qemu/error-report.h"
  18
  19 #include "hw/s390x/sclp.h"
  20 #include "hw/s390x/event-facility.h"
  21 #include "sysemu/char.h"
  22
  23 typedef struct ASCIIConsoleData {
  24     EventBufferHeader ebh;
  25     char data[0];
  26 } QEMU_PACKED ASCIIConsoleData;
  27
  28 /* max size for ASCII data in 4K SCCB page */
  29 #define SIZE_BUFFER_VT220 4080
  30
  31 typedef struct SCLPConsole {
  32     SCLPEvent event;
  33     CharDriverState *chr;
  34     uint8_t iov[SIZE_BUFFER_VT220];
  35     uint32_t iov_sclp;      /* offset in buf for SCLP read operation       */
  36     uint32_t iov_bs;        /* offset in buf for char layer read operation */
  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     bool notify;            /* qemu_notify_event() req'd if true           */
  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     int avail = SIZE_BUFFER_VT220 - scon->iov_data_len;
  49
  50     if (avail == 0) {
  51         scon->notify = true;
  52     }
  53     return avail;
  54 }
  55
  56 /* Send data from a char device over to the guest */
  57 static void chr_read(void *opaque, const uint8_t *buf, int size)
  58 {
  59     SCLPConsole *scon = opaque;
  60
  61     assert(scon);
  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[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     sclp_service_interrupt(0);
  72 }
  73
  74 /* functions to be called by event facility */
  75
  76 static bool can_handle_event(uint8_t type)
  77 {
  78     return type == SCLP_EVENT_ASCII_CONSOLE_DATA;
  79 }
  80
  81 static unsigned int send_mask(void)
  82 {
  83     return SCLP_EVENT_MASK_MSG_ASCII;
  84 }
  85
  86 static unsigned int receive_mask(void)
  87 {
  88     return SCLP_EVENT_MASK_MSG_ASCII;
  89 }
  90
  91 /* triggered by SCLP's read_event_data -
  92  * copy console data byte-stream into provided (SCLP) buffer
  93  */
  94 static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
  95                              int avail)
  96 {
  97     SCLPConsole *cons = DO_UPCAST(SCLPConsole, event, event);
  98
  99     /* first byte is hex 0 saying an ascii string follows */
 100     *buf++ = '\0';
 101     avail--;
 102     /* if all data fit into provided SCLP buffer */
 103     if (avail >= cons->iov_sclp_rest) {
 104         /* copy character byte-stream to SCLP buffer */
 105         memcpy(buf, &cons->iov[cons->iov_sclp], cons->iov_sclp_rest);
 106         *size = cons->iov_sclp_rest + 1;
 107         cons->iov_sclp = 0;
 108         cons->iov_bs = 0;
 109         cons->iov_data_len = 0;
 110         cons->iov_sclp_rest = 0;
 111         event->event_pending = false;
 112         /* data provided and no more data pending */
 113     } else {
 114         /* if provided buffer is too small, just copy part */
 115         memcpy(buf, &cons->iov[cons->iov_sclp], avail);
 116         *size = avail + 1;
 117         cons->iov_sclp_rest -= avail;
 118         cons->iov_sclp += avail;
 119         /* more data pending */
 120     }
 121     if (cons->notify) {
 122         cons->notify = false;
 123         qemu_notify_event();
 124     }
 125 }
 126
 127 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 128                            int *slen)
 129 {
 130     int avail;
 131     size_t src_len;
 132     uint8_t *to;
 133     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 134
 135     if (!event->event_pending) {
 136         /* no data pending */
 137         return 0;
 138     }
 139
 140     to = (uint8_t *)&acd->data;
 141     avail = *slen - sizeof(ASCIIConsoleData);
 142     get_console_data(event, to, &src_len, avail);
 143
 144     acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
 145     acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
 146     acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 147     *slen = avail - src_len;
 148
 149     return 1;
 150 }
 151
 152 /* triggered by SCLP's write_event_data
 153  *  - write console data to character layer
 154  *  returns < 0 if an error occurred
 155  */
 156 static ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
 157                                   size_t len)
 158 {
 159     SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 160
 161     if (!scon->chr) {
 162         /* If there's no backend, we can just say we consumed all data. */
 163         return len;
 164     }
 165
 166     return qemu_chr_fe_write_all(scon->chr, buf, len);
 167 }
 168
 169 static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
 170 {
 171     int rc;
 172     int length;
 173     ssize_t written;
 174     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 175
 176     length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
 177     written = write_console_data(event, (uint8_t *)acd->data, length);
 178
 179     rc = SCLP_RC_NORMAL_COMPLETION;
 180     /* set event buffer accepted flag */
 181     evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 182
 183     /* written will be zero if a pty is not connected - don't treat as error */
 184     if (written < 0) {
 185         /* event buffer not accepted due to error in character layer */
 186         evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 187         rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
 188     }
 189
 190     return rc;
 191 }
 192
 193 static const VMStateDescription vmstate_sclpconsole = {
 194     .name = "sclpconsole",
 195     .version_id = 0,
 196     .minimum_version_id = 0,
 197     .fields = (VMStateField[]) {
 198         VMSTATE_BOOL(event.event_pending, SCLPConsole),
 199         VMSTATE_UINT8_ARRAY(iov, SCLPConsole, SIZE_BUFFER_VT220),
 200         VMSTATE_UINT32(iov_sclp, SCLPConsole),
 201         VMSTATE_UINT32(iov_bs, SCLPConsole),
 202         VMSTATE_UINT32(iov_data_len, SCLPConsole),
 203         VMSTATE_UINT32(iov_sclp_rest, SCLPConsole),
 204         VMSTATE_END_OF_LIST()
 205      }
 206 };
 207
 208 /* qemu object creation and initialization functions */
 209
 210 /* tell character layer our call-back functions */
 211
 212 static int console_init(SCLPEvent *event)
 213 {
 214     static bool console_available;
 215
 216     SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 217
 218     if (console_available) {
 219         error_report("Multiple VT220 operator consoles are not supported");
 220         return -1;
 221     }
 222     console_available = true;
 223     if (scon->chr) {
 224         qemu_chr_add_handlers(scon->chr, chr_can_read,
 225                               chr_read, NULL, scon);
 226     }
 227
 228     return 0;
 229 }
 230
 231 static void console_reset(DeviceState *dev)
 232 {
 233    SCLPEvent *event = SCLP_EVENT(dev);
 234    SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 235
 236    event->event_pending = false;
 237    scon->iov_sclp = 0;
 238    scon->iov_bs = 0;
 239    scon->iov_data_len = 0;
 240    scon->iov_sclp_rest = 0;
 241    scon->notify = false;
 242 }
 243
 244 static int console_exit(SCLPEvent *event)
 245 {
 246     return 0;
 247 }
 248
 249 static Property console_properties[] = {
 250     DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
 251     DEFINE_PROP_END_OF_LIST(),
 252 };
 253
 254 static void console_class_init(ObjectClass *klass, void *data)
 255 {
 256     DeviceClass *dc = DEVICE_CLASS(klass);
 257     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 258
 259     dc->props = console_properties;
 260     dc->reset = console_reset;
 261     dc->vmsd = &vmstate_sclpconsole;
 262     ec->init = console_init;
 263     ec->exit = console_exit;
 264     ec->get_send_mask = send_mask;
 265     ec->get_receive_mask = receive_mask;
 266     ec->can_handle_event = can_handle_event;
 267     ec->read_event_data = read_event_data;
 268     ec->write_event_data = write_event_data;
 269 }
 270
 271 static const TypeInfo sclp_console_info = {
 272     .name          = "sclpconsole",
 273     .parent        = TYPE_SCLP_EVENT,
 274     .instance_size = sizeof(SCLPConsole),
 275     .class_init    = console_class_init,
 276     .class_size    = sizeof(SCLPEventClass),
 277 };
 278
 279 static void register_types(void)
 280 {
 281     type_register_static(&sclp_console_info);
 282 }
 283
 284 type_init(register_types)