arch/arm64/mm/flush.c

   1 /*
   2  * Based on arch/arm/mm/flush.c
   3  *
   4  * Copyright (C) 1995-2002 Russell King
   5  * Copyright (C) 2012 ARM Ltd.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/export.h>
  21 #include <linux/mm.h>
  22 #include <linux/pagemap.h>
  23
  24 #include <asm/cacheflush.h>
  25 #include <asm/cache.h>
  26 #include <asm/tlbflush.h>
  27
  28 void sync_icache_aliases(void *kaddr, unsigned long len)
  29 {
  30         unsigned long addr = (unsigned long)kaddr;
  31
  32         if (icache_is_aliasing()) {
  33                 __clean_dcache_area_pou(kaddr, len);
  34                 __flush_icache_all();
  35         } else {
  36                 flush_icache_range(addr, addr + len);
  37         }
  38 }
  39
  40 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
  41                                 unsigned long uaddr, void *kaddr,
  42                                 unsigned long len)
  43 {
  44         if (vma->vm_flags & VM_EXEC)
  45                 sync_icache_aliases(kaddr, len);
  46 }
  47
  48 /*
  49  * Copy user data from/to a page which is mapped into a different processes
  50  * address space.  Really, we want to allow our "user space" model to handle
  51  * this.
  52  */
  53 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  54                        unsigned long uaddr, void *dst, const void *src,
  55                        unsigned long len)
  56 {
  57         memcpy(dst, src, len);
  58         flush_ptrace_access(vma, page, uaddr, dst, len);
  59 }
  60
  61 void __sync_icache_dcache(pte_t pte, unsigned long addr)
  62 {
  63         struct page *page = pte_page(pte);
  64
  65         if (!test_and_set_bit(PG_dcache_clean, &page->flags))
  66                 sync_icache_aliases(page_address(page),
  67                                     PAGE_SIZE << compound_order(page));
  68 }
  69
  70 /*
  71  * This function is called when a page has been modified by the kernel. Mark
  72  * it as dirty for later flushing when mapped in user space (if executable,
  73  * see __sync_icache_dcache).
  74  */
  75 void flush_dcache_page(struct page *page)
  76 {
  77         if (test_bit(PG_dcache_clean, &page->flags))
  78                 clear_bit(PG_dcache_clean, &page->flags);
  79 }
  80 EXPORT_SYMBOL(flush_dcache_page);
  81
  82 /*
  83  * Additional functions defined in assembly.
  84  */
  85 EXPORT_SYMBOL(flush_icache_range);