LXR linux/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
  30void 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
  37static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
  38                                unsigned long uaddr, void *kaddr,
  39                                unsigned long len)
  40{
  41        if (vma->vm_flags & VM_EXEC) {
  42                unsigned long addr = (unsigned long)kaddr;
  43                if (icache_is_aliasing()) {
  44                        __flush_dcache_area(kaddr, len);
  45                        __flush_icache_all();
  46                } else {
  47                        flush_icache_range(addr, addr + len);
  48                }
  49        }
  50}
  51
  52/*
  53 * Copy user data from/to a page which is mapped into a different processes
  54 * address space.  Really, we want to allow our "user space" model to handle
  55 * this.
  56 *
  57 * Note that this code needs to run on the current CPU.
  58 */
  59void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  60                       unsigned long uaddr, void *dst, const void *src,
  61                       unsigned long len)
  62{
  63#ifdef CONFIG_SMP
  64        preempt_disable();
  65#endif
  66        memcpy(dst, src, len);
  67        flush_ptrace_access(vma, page, uaddr, dst, len);
  68#ifdef CONFIG_SMP
  69        preempt_enable();
  70#endif
  71}
  72
  73void __sync_icache_dcache(pte_t pte, unsigned long addr)
  74{
  75        struct page *page = pte_page(pte);
  76
  77        /* no flushing needed for anonymous pages */
  78        if (!page_mapping(page))
  79                return;
  80
  81        if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
  82                __flush_dcache_area(page_address(page), PAGE_SIZE);
  83                __flush_icache_all();
  84        } else if (icache_is_aivivt()) {
  85                __flush_icache_all();
  86        }
  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 */
  94void 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}
  99EXPORT_SYMBOL(flush_dcache_page);
 100
 101/*
 102 * Additional functions defined in assembly.
 103 */
 104EXPORT_SYMBOL(flush_cache_all);
 105EXPORT_SYMBOL(flush_icache_range);
 106