qemu/hw/char/sclpconsole.c

290 lines
7.9 KiB
C

/*
* 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 "qemu/error-report.h"
#include "hw/s390x/sclp.h"
#include "hw/s390x/event-facility.h"
#include "sysemu/char.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)
{
SCLPConsole *scon = opaque;
return scon->iov ? SIZE_BUFFER_VT220 - scon->iov_data_len : 0;
}
/* 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)
{
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;
}
return qemu_chr_fe_write_all(scon->chr, buf, len);
}
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 *opaque, 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 const 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)