arch/arm64/kernel/io.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Based on arch/arm/kernel/io.c
   4  *
   5  * Copyright (C) 2012 ARM Ltd.
   6  */
   7
   8 #include <linux/export.h>
   9 #include <linux/types.h>
  10 #include <linux/io.h>
  11
  12 /*
  13  * This generates a memcpy that works on a from/to address which is aligned to
  14  * bits. Count is in terms of the number of bits sized quantities to copy. It
  15  * optimizes to use the STR groupings when possible so that it is WC friendly.
  16  */
  17 #define memcpy_toio_aligned(to, from, count, bits)                        \
  18         ({                                                                \
  19                 volatile u##bits __iomem *_to = to;                       \
  20                 const u##bits *_from = from;                              \
  21                 size_t _count = count;                                    \
  22                 const u##bits *_end_from = _from + ALIGN_DOWN(_count, 8); \
  23                                                                           \
  24                 for (; _from < _end_from; _from += 8, _to += 8)           \
  25                         __const_memcpy_toio_aligned##bits(_to, _from, 8); \
  26                 if ((_count % 8) >= 4) {                                  \
  27                         __const_memcpy_toio_aligned##bits(_to, _from, 4); \
  28                         _from += 4;                                       \
  29                         _to += 4;                                         \
  30                 }                                                         \
  31                 if ((_count % 4) >= 2) {                                  \
  32                         __const_memcpy_toio_aligned##bits(_to, _from, 2); \
  33                         _from += 2;                                       \
  34                         _to += 2;                                         \
  35                 }                                                         \
  36                 if (_count % 2)                                           \
  37                         __const_memcpy_toio_aligned##bits(_to, _from, 1); \
  38         })
  39
  40 void __iowrite64_copy_full(void __iomem *to, const void *from, size_t count)
  41 {
  42         memcpy_toio_aligned(to, from, count, 64);
  43         dgh();
  44 }
  45 EXPORT_SYMBOL(__iowrite64_copy_full);
  46
  47 void __iowrite32_copy_full(void __iomem *to, const void *from, size_t count)
  48 {
  49         memcpy_toio_aligned(to, from, count, 32);
  50         dgh();
  51 }
  52 EXPORT_SYMBOL(__iowrite32_copy_full);