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