summaryrefslogtreecommitdiff
path: root/hw/s390x/sclpconsole.c
blob: fece878e8830b7980b24201b1f888055ba3fa562 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
/*
 * SCLP event type
 *    Ascii Console Data (VT220 Console)
 *
 * Copyright IBM, Corp. 2012
 *
 * Authors:
 *  Heinz Graalfs <graalfs@de.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or (at your
 * option) any later version.  See the COPYING file in the top-level directory.
 *
 */

#include <hw/qdev.h>
#include "qemu-thread.h"

#include "sclp.h"
#include "event-facility.h"

typedef struct ASCIIConsoleData {
    EventBufferHeader ebh;
    char data[0];
} QEMU_PACKED ASCIIConsoleData;

/* max size for ASCII data in 4K SCCB page */
#define SIZE_BUFFER_VT220 4080

typedef struct SCLPConsole {
    SCLPEvent event;
    CharDriverState *chr;
    /* io vector                                                       */
    uint8_t *iov;           /* iov buffer pointer                      */
    uint8_t *iov_sclp;      /* pointer to SCLP read offset             */
    uint8_t *iov_bs;        /* pointer byte stream read offset         */
    uint32_t iov_data_len;  /* length of byte stream in buffer         */
    uint32_t iov_sclp_rest; /* length of byte stream not read via SCLP */
    qemu_irq irq_read_vt220;
} SCLPConsole;

/* character layer call-back functions */

/* Return number of bytes that fit into iov buffer */
static int chr_can_read(void *opaque)
{
    int can_read;
    SCLPConsole *scon = opaque;

    can_read = SIZE_BUFFER_VT220 - scon->iov_data_len;

    return can_read;
}

/* Receive n bytes from character layer, save in iov buffer,
 * and set event pending */
static void receive_from_chr_layer(SCLPConsole *scon, const uint8_t *buf,
                                   int size)
{
    assert(scon->iov);

    /* read data must fit into current buffer */
    assert(size <= SIZE_BUFFER_VT220 - scon->iov_data_len);

    /* put byte-stream from character layer into buffer */
    memcpy(scon->iov_bs, buf, size);
    scon->iov_data_len += size;
    scon->iov_sclp_rest += size;
    scon->iov_bs += size;
    scon->event.event_pending = true;
}

/* Send data from a char device over to the guest */
static void chr_read(void *opaque, const uint8_t *buf, int size)
{
    SCLPConsole *scon = opaque;

    assert(scon);

    receive_from_chr_layer(scon, buf, size);
    /* trigger SCLP read operation */
    qemu_irq_raise(scon->irq_read_vt220);
}

static void chr_event(void *opaque, int event)
{
    SCLPConsole *scon = opaque;

    switch (event) {
    case CHR_EVENT_OPENED:
        if (!scon->iov) {
            scon->iov = g_malloc0(SIZE_BUFFER_VT220);
            scon->iov_sclp = scon->iov;
            scon->iov_bs = scon->iov;
            scon->iov_data_len = 0;
            scon->iov_sclp_rest = 0;
        }
        break;
    case CHR_EVENT_CLOSED:
        if (scon->iov) {
            g_free(scon->iov);
            scon->iov = NULL;
        }
        break;
    }
}

/* functions to be called by event facility */

static int event_type(void)
{
    return SCLP_EVENT_ASCII_CONSOLE_DATA;
}

static unsigned int send_mask(void)
{
    return SCLP_EVENT_MASK_MSG_ASCII;
}

static unsigned int receive_mask(void)
{
    return SCLP_EVENT_MASK_MSG_ASCII;
}

/* triggered by SCLP's read_event_data -
 * copy console data byte-stream into provided (SCLP) buffer
 */
static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
                             int avail)
{
    SCLPConsole *cons = DO_UPCAST(SCLPConsole, event, event);

    /* first byte is hex 0 saying an ascii string follows */
    *buf++ = '\0';
    avail--;
    /* if all data fit into provided SCLP buffer */
    if (avail >= cons->iov_sclp_rest) {
        /* copy character byte-stream to SCLP buffer */
        memcpy(buf, cons->iov_sclp, cons->iov_sclp_rest);
        *size = cons->iov_sclp_rest + 1;
        cons->iov_sclp = cons->iov;
        cons->iov_bs = cons->iov;
        cons->iov_data_len = 0;
        cons->iov_sclp_rest = 0;
        event->event_pending = false;
        /* data provided and no more data pending */
    } else {
        /* if provided buffer is too small, just copy part */
        memcpy(buf, cons->iov_sclp, avail);
        *size = avail + 1;
        cons->iov_sclp_rest -= avail;
        cons->iov_sclp += avail;
        /* more data pending */
    }
}

static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
                           int *slen)
{
    int avail;
    size_t src_len;
    uint8_t *to;
    ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;

    if (!event->event_pending) {
        /* no data pending */
        return 0;
    }

    to = (uint8_t *)&acd->data;
    avail = *slen - sizeof(ASCIIConsoleData);
    get_console_data(event, to, &src_len, avail);

    acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
    acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
    acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
    *slen = avail - src_len;

    return 1;
}

/* triggered by SCLP's write_event_data
 *  - write console data to character layer
 *  returns < 0 if an error occurred
 */
static ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
                                  size_t len)
{
    ssize_t ret = 0;
    const uint8_t *iov_offset;
    SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);

    if (!scon->chr) {
        /* If there's no backend, we can just say we consumed all data. */
        return len;
    }

    iov_offset = buf;
    while (len > 0) {
        ret = qemu_chr_fe_write(scon->chr, buf, len);
        if (ret == 0) {
            /* a pty doesn't seem to be connected - no error */
            len = 0;
        } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
            len -= ret;
            iov_offset += ret;
        } else {
            len = 0;
        }
    }

    return ret;
}

static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
{
    int rc;
    int length;
    ssize_t written;
    ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;

    length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
    written = write_console_data(event, (uint8_t *)acd->data, length);

    rc = SCLP_RC_NORMAL_COMPLETION;
    /* set event buffer accepted flag */
    evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;

    /* written will be zero if a pty is not connected - don't treat as error */
    if (written < 0) {
        /* event buffer not accepted due to error in character layer */
        evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
        rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
    }

    return rc;
}

static void trigger_ascii_console_data(void *env, int n, int level)
{
    sclp_service_interrupt(0);
}

/* qemu object creation and initialization functions */

/* tell character layer our call-back functions */
static int console_init(SCLPEvent *event)
{
    static bool console_available;

    SCLPConsole *scon = DO_UPCAST(SCLPConsole, event, event);

    if (console_available) {
        error_report("Multiple VT220 operator consoles are not supported");
        return -1;
    }
    console_available = true;
    event->event_type = SCLP_EVENT_ASCII_CONSOLE_DATA;
    if (scon->chr) {
        qemu_chr_add_handlers(scon->chr, chr_can_read,
                              chr_read, chr_event, scon);
    }
    scon->irq_read_vt220 = *qemu_allocate_irqs(trigger_ascii_console_data,
                                               NULL, 1);

    return 0;
}

static int console_exit(SCLPEvent *event)
{
    return 0;
}

static Property console_properties[] = {
    DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
    DEFINE_PROP_END_OF_LIST(),
};

static void console_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);

    dc->props = console_properties;
    ec->init = console_init;
    ec->exit = console_exit;
    ec->get_send_mask = send_mask;
    ec->get_receive_mask = receive_mask;
    ec->event_type = event_type;
    ec->read_event_data = read_event_data;
    ec->write_event_data = write_event_data;
}

static TypeInfo sclp_console_info = {
    .name          = "sclpconsole",
    .parent        = TYPE_SCLP_EVENT,
    .instance_size = sizeof(SCLPConsole),
    .class_init    = console_class_init,
    .class_size    = sizeof(SCLPEventClass),
};

static void register_types(void)
{
    type_register_static(&sclp_console_info);
}

type_init(register_types)