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         while (count && (!IS_ALIGNED((unsigned long)from, 8) ||
  29                          !IS_ALIGNED((unsigned long)to, 8))) {
  30                 *(u8 *)to = __raw_readb(from);
  31                 from++;
  32                 to++;
  33                 count--;
  34         }
  35
  36         while (count >= 8) {
  37                 *(u64 *)to = __raw_readq(from);
  38                 from += 8;
  39                 to += 8;
  40                 count -= 8;
  41         }
  42
  43         while (count) {
  44                 *(u8 *)to = __raw_readb(from);
  45                 from++;
  46                 to++;
  47                 count--;
  48         }
  49 }
  50 EXPORT_SYMBOL(__memcpy_fromio);
  51
  52 /*
  53  * Copy data from "real" memory space to IO memory space.
  54  */
  55 void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
  56 {
  57         while (count && (!IS_ALIGNED((unsigned long)to, 8) ||
  58                          !IS_ALIGNED((unsigned long)from, 8))) {
  59                 __raw_writeb(*(volatile u8 *)from, to);
  60                 from++;
  61                 to++;
  62                 count--;
  63         }
  64
  65         while (count >= 8) {
  66                 __raw_writeq(*(volatile u64 *)from, to);
  67                 from += 8;
  68                 to += 8;
  69                 count -= 8;
  70         }
  71
  72         while (count) {
  73                 __raw_writeb(*(volatile u8 *)from, to);
  74                 from++;
  75                 to++;
  76                 count--;
  77         }
  78 }
  79 EXPORT_SYMBOL(__memcpy_toio);
  80
  81 /*
  82  * "memset" on IO memory space.
  83  */
  84 void __memset_io(volatile void __iomem *dst, int c, size_t count)
  85 {
  86         u64 qc = (u8)c;
  87
  88         qc |= qc << 8;
  89         qc |= qc << 16;
  90         qc |= qc << 32;
  91
  92         while (count && !IS_ALIGNED((unsigned long)dst, 8)) {
  93                 __raw_writeb(c, dst);
  94                 dst++;
  95                 count--;
  96         }
  97
  98         while (count >= 8) {
  99                 __raw_writeq(qc, dst);
 100                 dst += 8;
 101                 count -= 8;
 102         }
 103
 104         while (count) {
 105                 __raw_writeb(c, dst);
 106                 dst++;
 107                 count--;
 108         }
 109 }
 110 EXPORT_SYMBOL(__memset_io);