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

   1/*
   2 * SCLP ASCII access driver
   3 *
   4 * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
   5 *
   6 * This work is licensed under the terms of the GNU GPL, version 2 or (at
   7 * your option) any later version. See the COPYING file in the top-level
   8 * directory.
   9 */
  10
  11#include "s390-ccw.h"
  12#include "sclp.h"
  13
  14static char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
  15
  16/* Perform service call. Return 0 on success, non-zero otherwise. */
  17static int sclp_service_call(unsigned int command, void *sccb)
  18{
  19        int cc;
  20
  21        asm volatile(
  22                "       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
  23                "       ipm     %0\n"
  24                "       srl     %0,28"
  25                : "=&d" (cc) : "d" (command), "a" (__pa(sccb))
  26                : "cc", "memory");
  27        consume_sclp_int();
  28        if (cc == 3)
  29                return -EIO;
  30        if (cc == 2)
  31                return -EBUSY;
  32        return 0;
  33}
  34
  35static void sclp_set_write_mask(void)
  36{
  37    WriteEventMask *sccb = (void *)_sccb;
  38
  39    sccb->h.length = sizeof(WriteEventMask);
  40    sccb->mask_length = sizeof(unsigned int);
  41    sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
  42    sccb->cp_receive_mask = SCLP_EVENT_MASK_MSG_ASCII;
  43    sccb->send_mask = SCLP_EVENT_MASK_MSG_ASCII;
  44    sccb->cp_send_mask = SCLP_EVENT_MASK_MSG_ASCII;
  45
  46    sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
  47}
  48
  49void sclp_setup(void)
  50{
  51    sclp_set_write_mask();
  52}
  53
  54static int _strlen(const char *str)
  55{
  56    int i;
  57    for (i = 0; *str; i++)
  58        str++;
  59    return i;
  60}
  61
  62static void _memcpy(char *dest, const char *src, int len)
  63{
  64    int i;
  65    for (i = 0; i < len; i++)
  66        dest[i] = src[i];
  67}
  68
  69void sclp_print(const char *str)
  70{
  71    int len = _strlen(str);
  72    WriteEventData *sccb = (void *)_sccb;
  73
  74    sccb->h.length = sizeof(WriteEventData) + len;
  75    sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
  76    sccb->ebh.length = sizeof(EventBufferHeader) + len;
  77    sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
  78    sccb->ebh.flags = 0;
  79    _memcpy(sccb->data, str, len);
  80
  81    sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
  82}
  83