sound/core/memory.c

   1 /*
   2  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
   3  *
   4  *  Misc memory accessors
   5  *
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation; either version 2 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  *
  21  */
  22
  23 #include <linux/config.h>
  24 #include <asm/io.h>
  25 #include <asm/uaccess.h>
  26
  27 /**
  28  * copy_to_user_fromio - copy data from mmio-space to user-space
  29  * @dst: the destination pointer on user-space
  30  * @src: the source pointer on mmio
  31  * @count: the data size to copy in bytes
  32  *
  33  * Copies the data from mmio-space to user-space.
  34  *
  35  * Returns zero if successful, or non-zero on failure.
  36  */
  37 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
  38 {
  39 #if defined(__i386__) || defined(CONFIG_SPARC32)
  40         return copy_to_user(dst, (const void __force*)src, count) ? -EFAULT : 0;
  41 #else
  42         char buf[256];
  43         while (count) {
  44                 size_t c = count;
  45                 if (c > sizeof(buf))
  46                         c = sizeof(buf);
  47                 memcpy_fromio(buf, (void __iomem *)src, c);
  48                 if (copy_to_user(dst, buf, c))
  49                         return -EFAULT;
  50                 count -= c;
  51                 dst += c;
  52                 src += c;
  53         }
  54         return 0;
  55 #endif
  56 }
  57
  58 /**
  59  * copy_from_user_toio - copy data from user-space to mmio-space
  60  * @dst: the destination pointer on mmio-space
  61  * @src: the source pointer on user-space
  62  * @count: the data size to copy in bytes
  63  *
  64  * Copies the data from user-space to mmio-space.
  65  *
  66  * Returns zero if successful, or non-zero on failure.
  67  */
  68 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
  69 {
  70 #if defined(__i386__) || defined(CONFIG_SPARC32)
  71         return copy_from_user((void __force *)dst, src, count) ? -EFAULT : 0;
  72 #else
  73         char buf[256];
  74         while (count) {
  75                 size_t c = count;
  76                 if (c > sizeof(buf))
  77                         c = sizeof(buf);
  78                 if (copy_from_user(buf, src, c))
  79                         return -EFAULT;
  80                 memcpy_toio(dst, buf, c);
  81                 count -= c;
  82                 dst += c;
  83                 src += c;
  84         }
  85         return 0;
  86 #endif
  87 }