LXR linux/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 */
  38int 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
  59EXPORT_SYMBOL(copy_to_user_fromio);
  60
  61/**
  62 * copy_from_user_toio - copy data from user-space to mmio-space
  63 * @dst: the destination pointer on mmio-space
  64 * @src: the source pointer on user-space
  65 * @count: the data size to copy in bytes
  66 *
  67 * Copies the data from user-space to mmio-space.
  68 *
  69 * Return: Zero if successful, or non-zero on failure.
  70 */
  71int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
  72{
  73#if defined(__i386__) || defined(CONFIG_SPARC32)
  74        return copy_from_user((void __force *)dst, src, count) ? -EFAULT : 0;
  75#else
  76        char buf[256];
  77        while (count) {
  78                size_t c = count;
  79                if (c > sizeof(buf))
  80                        c = sizeof(buf);
  81                if (copy_from_user(buf, src, c))
  82                        return -EFAULT;
  83                memcpy_toio(dst, buf, c);
  84                count -= c;
  85                dst += c;
  86                src += c;
  87        }
  88        return 0;
  89#endif
  90}
  91
  92EXPORT_SYMBOL(copy_from_user_toio);
  93