hw/s390x/sclpconsole.c - qemu - Git at Google

 /*
  * 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)
	/*
	* 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)