sound/core/memory.c

   1 /*
   2  *  Copyright (c) by Jaroslav Kysela <perex@perex.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/export.h>
  24 #include <linux/io.h>
  25 #include <linux/uaccess.h>
  26 #include <sound/core.h>
  27
  28 /**
  29  * copy_to_user_fromio - copy data from mmio-space to user-space
  30  * @dst: the destination pointer on user-space
  31  * @src: the source pointer on mmio
  32  * @count: the data size to copy in bytes
  33  *
  34  * Copies the data from mmio-space to user-space.
  35  *
  36  * Return: Zero if successful, or non-zero on failure.
  37  */
  38 int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
  39 {
  40 #if defined(__i386__) || defined(CONFIG_SPARC32)
  41         return copy_to_user(dst, (const void __force*)src, count) ? -EFAULT : 0;
  42 #else
  43         char buf[256];
  44         while (count) {
  45                 size_t c = count;
  46                 if (c > sizeof(buf))
  47                         c = sizeof(buf);
  48                 memcpy_fromio(buf, (void __iomem *)src, c);
  49                 if (copy_to_user(dst, buf, c))
  50                         return -EFAULT;
  51                 count -= c;
  52                 dst += c;
  53                 src += c;
  54         }
  55         return 0;
  56 #endif
  57 }
  58 EXPORT_SYMBOL(copy_to_user_fromio);
  59
  60 /**
  61  * copy_from_user_toio - copy data from user-space to mmio-space
  62  * @dst: the destination pointer on mmio-space
  63  * @src: the source pointer on user-space
  64  * @count: the data size to copy in bytes
  65  *
  66  * Copies the data from user-space to mmio-space.
  67  *
  68  * Return: Zero if successful, or non-zero on failure.
  69  */
  70 int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
  71 {
  72 #if defined(__i386__) || defined(CONFIG_SPARC32)
  73         return copy_from_user((void __force *)dst, src, count) ? -EFAULT : 0;
  74 #else
  75         char buf[256];
  76         while (count) {
  77                 size_t c = count;
  78                 if (c > sizeof(buf))
  79                         c = sizeof(buf);
  80                 if (copy_from_user(buf, src, c))
  81                         return -EFAULT;
  82                 memcpy_toio(dst, buf, c);
  83                 count -= c;
  84                 dst += c;
  85                 src += c;
  86         }
  87         return 0;
  88 #endif
  89 }
  90 EXPORT_SYMBOL(copy_from_user_toio);