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 adapter
  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  */
  41 int 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
  57 EXPORT_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  */
  68 int 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
  88 EXPORT_SYMBOL(hvc_put_chars);