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 "qemu/osdep.h"
  16 #include <hw/qdev.h>
  17 #include "qemu/thread.h"
  18 #include "qemu/error-report.h"
  19
  20 #include "hw/s390x/sclp.h"
  21 #include "hw/s390x/event-facility.h"
  22 #include "sysemu/char.h"
  23
  24 typedef struct ASCIIConsoleData {
  25     EventBufferHeader ebh;
  26     char data[0];
  27 } QEMU_PACKED ASCIIConsoleData;
  28
  29 /* max size for ASCII data in 4K SCCB page */
  30 #define SIZE_BUFFER_VT220 4080
  31
  32 typedef struct SCLPConsole {
  33     SCLPEvent event;
  34     CharDriverState *chr;
  35     uint8_t iov[SIZE_BUFFER_VT220];
  36     uint32_t iov_sclp;      /* offset in buf for SCLP read operation       */
  37     uint32_t iov_bs;        /* offset in buf for char layer read operation */
  38     uint32_t iov_data_len;  /* length of byte stream in buffer             */
  39     uint32_t iov_sclp_rest; /* length of byte stream not read via SCLP     */
  40     bool notify;            /* qemu_notify_event() req'd if true           */
  41 } SCLPConsole;
  42
  43 /* character layer call-back functions */
  44
  45 /* Return number of bytes that fit into iov buffer */
  46 static int chr_can_read(void *opaque)
  47 {
  48     SCLPConsole *scon = opaque;
  49     int avail = SIZE_BUFFER_VT220 - scon->iov_data_len;
  50
  51     if (avail == 0) {
  52         scon->notify = true;
  53     }
  54     return avail;
  55 }
  56
  57 /* Send data from a char device over to the guest */
  58 static void chr_read(void *opaque, const uint8_t *buf, int size)
  59 {
  60     SCLPConsole *scon = opaque;
  61
  62     assert(scon);
  63     /* read data must fit into current buffer */
  64     assert(size <= SIZE_BUFFER_VT220 - scon->iov_data_len);
  65
  66     /* put byte-stream from character layer into buffer */
  67     memcpy(&scon->iov[scon->iov_bs], buf, size);
  68     scon->iov_data_len += size;
  69     scon->iov_sclp_rest += size;
  70     scon->iov_bs += size;
  71     scon->event.event_pending = true;
  72     sclp_service_interrupt(0);
  73 }
  74
  75 /* functions to be called by event facility */
  76
  77 static bool can_handle_event(uint8_t type)
  78 {
  79     return type == SCLP_EVENT_ASCII_CONSOLE_DATA;
  80 }
  81
  82 static unsigned int send_mask(void)
  83 {
  84     return SCLP_EVENT_MASK_MSG_ASCII;
  85 }
  86
  87 static unsigned int receive_mask(void)
  88 {
  89     return SCLP_EVENT_MASK_MSG_ASCII;
  90 }
  91
  92 /* triggered by SCLP's read_event_data -
  93  * copy console data byte-stream into provided (SCLP) buffer
  94  */
  95 static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
  96                              int avail)
  97 {
  98     SCLPConsole *cons = DO_UPCAST(SCLPConsole, event, event);
  99
 100     /* first byte is hex 0 saying an ascii string follows */
 101     *buf++ = '\0';
 102     avail--;
 103     /* if all data fit into provided SCLP buffer */
 104     if (avail >= cons->iov_sclp_rest) {
 105         /* copy character byte-stream to SCLP buffer */
 106         memcpy(buf, &cons->iov[cons->iov_sclp], cons->iov_sclp_rest);
 107         *size = cons->iov_sclp_rest + 1;
 108         cons->iov_sclp = 0;
 109         cons->iov_bs = 0;
 110         cons->iov_data_len = 0;
 111         cons->iov_sclp_rest = 0;
 112         event->event_pending = false;
 113         /* data provided and no more data pending */
 114     } else {
 115         /* if provided buffer is too small, just copy part */
 116         memcpy(buf, &cons->iov[cons->iov_sclp], avail);
 117         *size = avail + 1;
 118         cons->iov_sclp_rest -= avail;
 119         cons->iov_sclp += avail;
 120         /* more data pending */
 121     }
 122     if (cons->notify) {
 123         cons->notify = false;
 124         qemu_notify_event();
 125     }
 126 }
 127
 128 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 129                            int *slen)
 130 {
 131     int avail;
 132     size_t src_len;
 133     uint8_t *to;
 134     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 135
 136     if (!event->event_pending) {
 137         /* no data pending */
 138         return 0;
 139     }
 140
 141     to = (uint8_t *)&acd->data;
 142     avail = *slen - sizeof(ASCIIConsoleData);
 143     get_console_data(event, to, &src_len, avail);
 144
 145     acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
 146     acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
 147     acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 148     *slen = avail - src_len;
 149
 150     return 1;
 151 }
 152
 153 /* triggered by SCLP's write_event_data
 154  *  - write console data to character layer
 155  *  returns < 0 if an error occurred
 156  */
 157 static ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
 158                                   size_t len)
 159 {
 160     SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 161
 162     if (!scon->chr) {
 163         /* If there's no backend, we can just say we consumed all data. */
 164         return len;
 165     }
 166
 167     return qemu_chr_fe_write_all(scon->chr, buf, len);
 168 }
 169
 170 static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
 171 {
 172     int rc;
 173     int length;
 174     ssize_t written;
 175     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 176
 177     length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
 178     written = write_console_data(event, (uint8_t *)acd->data, length);
 179
 180     rc = SCLP_RC_NORMAL_COMPLETION;
 181     /* set event buffer accepted flag */
 182     evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 183
 184     /* written will be zero if a pty is not connected - don't treat as error */
 185     if (written < 0) {
 186         /* event buffer not accepted due to error in character layer */
 187         evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 188         rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
 189     }
 190
 191     return rc;
 192 }
 193
 194 static const VMStateDescription vmstate_sclpconsole = {
 195     .name = "sclpconsole",
 196     .version_id = 0,
 197     .minimum_version_id = 0,
 198     .fields = (VMStateField[]) {
 199         VMSTATE_BOOL(event.event_pending, SCLPConsole),
 200         VMSTATE_UINT8_ARRAY(iov, SCLPConsole, SIZE_BUFFER_VT220),
 201         VMSTATE_UINT32(iov_sclp, SCLPConsole),
 202         VMSTATE_UINT32(iov_bs, SCLPConsole),
 203         VMSTATE_UINT32(iov_data_len, SCLPConsole),
 204         VMSTATE_UINT32(iov_sclp_rest, SCLPConsole),
 205         VMSTATE_END_OF_LIST()
 206      }
 207 };
 208
 209 /* qemu object creation and initialization functions */
 210
 211 /* tell character layer our call-back functions */
 212
 213 static int console_init(SCLPEvent *event)
 214 {
 215     static bool console_available;
 216
 217     SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 218
 219     if (console_available) {
 220         error_report("Multiple VT220 operator consoles are not supported");
 221         return -1;
 222     }
 223     console_available = true;
 224     if (scon->chr) {
 225         qemu_chr_add_handlers(scon->chr, chr_can_read,
 226                               chr_read, NULL, scon);
 227     }
 228
 229     return 0;
 230 }
 231
 232 static void console_reset(DeviceState *dev)
 233 {
 234    SCLPEvent *event = SCLP_EVENT(dev);
 235    SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);
 236
 237    event->event_pending = false;
 238    scon->iov_sclp = 0;
 239    scon->iov_bs = 0;
 240    scon->iov_data_len = 0;
 241    scon->iov_sclp_rest = 0;
 242    scon->notify = false;
 243 }
 244
 245 static int console_exit(SCLPEvent *event)
 246 {
 247     return 0;
 248 }
 249
 250 static Property console_properties[] = {
 251     DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
 252     DEFINE_PROP_END_OF_LIST(),
 253 };
 254
 255 static void console_class_init(ObjectClass *klass, void *data)
 256 {
 257     DeviceClass *dc = DEVICE_CLASS(klass);
 258     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 259
 260     dc->props = console_properties;
 261     dc->reset = console_reset;
 262     dc->vmsd = &vmstate_sclpconsole;
 263     ec->init = console_init;
 264     ec->exit = console_exit;
 265     ec->get_send_mask = send_mask;
 266     ec->get_receive_mask = receive_mask;
 267     ec->can_handle_event = can_handle_event;
 268     ec->read_event_data = read_event_data;
 269     ec->write_event_data = write_event_data;
 270     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 271 }
 272
 273 static const TypeInfo sclp_console_info = {
 274     .name          = "sclpconsole",
 275     .parent        = TYPE_SCLP_EVENT,
 276     .instance_size = sizeof(SCLPConsole),
 277     .class_init    = console_class_init,
 278     .class_size    = sizeof(SCLPEventClass),
 279 };
 280
 281 static void register_types(void)
 282 {
 283     type_register_static(&sclp_console_info);
 284 }
 285
 286 type_init(register_types)