arch/arm64/lib/uaccess_flushcache.c

   1 /*
   2  * Copyright (C) 2017 ARM Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16
  17 #include <linux/uaccess.h>
  18 #include <asm/barrier.h>
  19 #include <asm/cacheflush.h>
  20
  21 void memcpy_flushcache(void *dst, const void *src, size_t cnt)
  22 {
  23         /*
  24          * We assume this should not be called with @dst pointing to
  25          * non-cacheable memory, such that we don't need an explicit
  26          * barrier to order the cache maintenance against the memcpy.
  27          */
  28         memcpy(dst, src, cnt);
  29         __clean_dcache_area_pop(dst, cnt);
  30 }
  31 EXPORT_SYMBOL_GPL(memcpy_flushcache);
  32
  33 void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
  34                             size_t len)
  35 {
  36         memcpy_flushcache(to, page_address(page) + offset, len);
  37 }
  38
  39 unsigned long __copy_user_flushcache(void *to, const void __user *from,
  40                                      unsigned long n)
  41 {
  42         unsigned long rc = __arch_copy_from_user(to, from, n);
  43
  44         /* See above */
  45         __clean_dcache_area_pop(to, n - rc);
  46         return rc;
  47 }