LXR linux/arch/powerpc/platforms/pseries/hvconsole.c

   1/*
   2 * hvconsole.c
   3 * Copyright (C) 2004 Hollis Blanchard, IBM Corporation
   4 * Copyright (C) 2004 IBM Corporation
   5 *
   6 * Additional Author(s):
   7 *  Ryan S. Arnold <rsa@us.ibm.com>
   8 *
   9 * LPAR console support.
  10 * 
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2 of the License, or
  14 * (at your option) any later version.
  15 * 
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 * 
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  24 */
  25
  26#include <linux/kernel.h>
  27#include <linux/export.h>
  28#include <linux/errno.h>
  29#include <asm/hvcall.h>
  30#include <asm/hvconsole.h>
  31#include <asm/plpar_wrappers.h>
  32
  33/**
  34 * hvc_get_chars - retrieve characters from firmware for denoted vterm adatper
  35 * @vtermno: The vtermno or unit_address of the adapter from which to fetch the
  36 *      data.
  37 * @buf: The character buffer into which to put the character data fetched from
  38 *      firmware.
  39 * @count: not used?
  40 */
  41int hvc_get_chars(uint32_t vtermno, char *buf, int count)
  42{
  43        long ret;
  44        unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
  45        unsigned long *lbuf = (unsigned long *)buf;
  46
  47        ret = plpar_hcall(H_GET_TERM_CHAR, retbuf, vtermno);
  48        lbuf[0] = be64_to_cpu(retbuf[1]);
  49        lbuf[1] = be64_to_cpu(retbuf[2]);
  50
  51        if (ret == H_SUCCESS)
  52                return retbuf[0];
  53
  54        return 0;
  55}
  56
  57EXPORT_SYMBOL(hvc_get_chars);
  58
  59
  60/**
  61 * hvc_put_chars: send characters to firmware for denoted vterm adapter
  62 * @vtermno: The vtermno or unit_address of the adapter from which the data
  63 *      originated.
  64 * @buf: The character buffer that contains the character data to send to
  65 *      firmware.
  66 * @count: Send this number of characters.
  67 */
  68int hvc_put_chars(uint32_t vtermno, const char *buf, int count)
  69{
  70        unsigned long *lbuf = (unsigned long *) buf;
  71        long ret;
  72
  73
  74        /* hcall will ret H_PARAMETER if 'count' exceeds firmware max.*/
  75        if (count > MAX_VIO_PUT_CHARS)
  76                count = MAX_VIO_PUT_CHARS;
  77
  78        ret = plpar_hcall_norets(H_PUT_TERM_CHAR, vtermno, count,
  79                                 cpu_to_be64(lbuf[0]),
  80                                 cpu_to_be64(lbuf[1]));
  81        if (ret == H_SUCCESS)
  82                return count;
  83        if (ret == H_BUSY)
  84                return -EAGAIN;
  85        return -EIO;
  86}
  87
  88EXPORT_SYMBOL(hvc_put_chars);
  89