qemu/pc-bios/s390-ccw/sclp-ascii.c

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/*
* SCLP ASCII access driver
*
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
*
* 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 "s390-ccw.h"
#include "sclp.h"
static char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
/* Perform service call. Return 0 on success, non-zero otherwise. */
static int sclp_service_call(unsigned int command, void *sccb)
{
int cc;
asm volatile(
" .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */
" ipm %0\n"
" srl %0,28"
: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
: "cc", "memory");
if (cc == 3)
return -EIO;
if (cc == 2)
return -EBUSY;
return 0;
}
static void sclp_set_write_mask(void)
{
WriteEventMask *sccb = (void*)_sccb;
sccb->h.length = sizeof(WriteEventMask);
sccb->mask_length = sizeof(unsigned int);
sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
sccb->cp_receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
sccb->send_mask = SCLP_EVENT_MASK_MSG_ASCII;
sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII;
sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
}
void sclp_setup(void)
{
sclp_set_write_mask();
}
static int _strlen(const char *str)
{
int i;
for (i = 0; *str; i++)
str++;
return i;
}
static void _memcpy(char *dest, const char *src, int len)
{
int i;
for (i = 0; i < len; i++)
dest[i] = src[i];
}
void sclp_print(const char *str)
{
int len = _strlen(str);
WriteEventData *sccb = (void*)_sccb;
sccb->h.length = sizeof(WriteEventData) + len;
sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
sccb->ebh.length = sizeof(EventBufferHeader) + len;
sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
sccb->ebh.flags = 0;
_memcpy(sccb->data, str, len);
sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
}