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 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  */
  59 void 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
  73 void __flush_dcache_page(struct page *page)
  74 {
  75         __flush_dcache_area(page_address(page), PAGE_SIZE);
  76 }
  77
  78 void __sync_icache_dcache(pte_t pte, unsigned long addr)
  79 {
  80         unsigned long pfn;
  81         struct page *page;
  82
  83         pfn = pte_pfn(pte);
  84         if (!pfn_valid(pfn))
  85                 return;
  86
  87         page = pfn_to_page(pfn);
  88         if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
  89                 __flush_dcache_page(page);
  90                 __flush_icache_all();
  91         } else if (icache_is_aivivt()) {
  92                 __flush_icache_all();
  93         }
  94 }
  95
  96 /*
  97  * Ensure cache coherency between kernel mapping and userspace mapping of this
  98  * page.
  99  */
 100 void flush_dcache_page(struct page *page)
 101 {
 102         struct address_space *mapping;
 103
 104         /*
 105          * The zero page is never written to, so never has any dirty cache
 106          * lines, and therefore never needs to be flushed.
 107          */
 108         if (page == ZERO_PAGE(0))
 109                 return;
 110
 111         mapping = page_mapping(page);
 112         if (mapping && mapping_mapped(mapping)) {
 113                 __flush_dcache_page(page);
 114                 __flush_icache_all();
 115                 set_bit(PG_dcache_clean, &page->flags);
 116         } else {
 117                 clear_bit(PG_dcache_clean, &page->flags);
 118         }
 119 }
 120 EXPORT_SYMBOL(flush_dcache_page);
 121
 122 /*
 123  * Additional functions defined in assembly.
 124  */
 125 EXPORT_SYMBOL(flush_cache_all);
 126 EXPORT_SYMBOL(flush_icache_range);