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/cachetype.h>
  26 #include <asm/tlbflush.h>
  27
  28 #include "mm.h"
  29
  30 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
  31                        unsigned long end)
  32 {
  33         if (vma->vm_flags & VM_EXEC)
  34                 __flush_icache_all();
  35 }
  36
  37 static void sync_icache_aliases(void *kaddr, unsigned long len)
  38 {
  39         unsigned long addr = (unsigned long)kaddr;
  40
  41         if (icache_is_aliasing()) {
  42                 __clean_dcache_area_pou(kaddr, len);
  43                 __flush_icache_all();
  44         } else {
  45                 flush_icache_range(addr, addr + len);
  46         }
  47 }
  48
  49 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
  50                                 unsigned long uaddr, void *kaddr,
  51                                 unsigned long len)
  52 {
  53         if (vma->vm_flags & VM_EXEC)
  54                 sync_icache_aliases(kaddr, len);
  55 }
  56
  57 /*
  58  * Copy user data from/to a page which is mapped into a different processes
  59  * address space.  Really, we want to allow our "user space" model to handle
  60  * this.
  61  *
  62  * Note that this code needs to run on the current CPU.
  63  */
  64 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  65                        unsigned long uaddr, void *dst, const void *src,
  66                        unsigned long len)
  67 {
  68         preempt_disable();
  69         memcpy(dst, src, len);
  70         flush_ptrace_access(vma, page, uaddr, dst, len);
  71         preempt_enable();
  72 }
  73
  74 void __sync_icache_dcache(pte_t pte, unsigned long addr)
  75 {
  76         struct page *page = pte_page(pte);
  77
  78         /* no flushing needed for anonymous pages */
  79         if (!page_mapping(page))
  80                 return;
  81
  82         if (!test_and_set_bit(PG_dcache_clean, &page->flags))
  83                 sync_icache_aliases(page_address(page),
  84                                     PAGE_SIZE << compound_order(page));
  85         else if (icache_is_aivivt())
  86                 __flush_icache_all();
  87 }
  88
  89 /*
  90  * This function is called when a page has been modified by the kernel. Mark
  91  * it as dirty for later flushing when mapped in user space (if executable,
  92  * see __sync_icache_dcache).
  93  */
  94 void flush_dcache_page(struct page *page)
  95 {
  96         if (test_bit(PG_dcache_clean, &page->flags))
  97                 clear_bit(PG_dcache_clean, &page->flags);
  98 }
  99 EXPORT_SYMBOL(flush_dcache_page);
 100
 101 /*
 102  * Additional functions defined in assembly.
 103  */
 104 EXPORT_SYMBOL(flush_icache_range);