arch/arm64/kernel/io.c

   1 /*
   2  * Based on arch/arm/kernel/io.c
   3  *
   4  * Copyright (C) 2012 ARM Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/export.h>
  20 #include <linux/types.h>
  21 #include <linux/io.h>
  22
  23 /*
  24  * Copy data from IO memory space to "real" memory space.
  25  */
  26 void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
  27 {
  28         unsigned char *t = to;
  29         while (count) {
  30                 count--;
  31                 *t = readb(from);
  32                 t++;
  33                 from++;
  34         }
  35 }
  36 EXPORT_SYMBOL(__memcpy_fromio);
  37
  38 /*
  39  * Copy data from "real" memory space to IO memory space.
  40  */
  41 void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
  42 {
  43         const unsigned char *f = from;
  44         while (count) {
  45                 count--;
  46                 writeb(*f, to);
  47                 f++;
  48                 to++;
  49         }
  50 }
  51 EXPORT_SYMBOL(__memcpy_toio);
  52
  53 /*
  54  * "memset" on IO memory space.
  55  */
  56 void __memset_io(volatile void __iomem *dst, int c, size_t count)
  57 {
  58         while (count) {
  59                 count--;
  60                 writeb(c, dst);
  61                 dst++;
  62         }
  63 }
  64 EXPORT_SYMBOL(__memset_io);