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         preempt_disable();
  64         memcpy(dst, src, len);
  65         flush_ptrace_access(vma, page, uaddr, dst, len);
  66         preempt_enable();
  67 }
  68
  69 void __sync_icache_dcache(pte_t pte, unsigned long addr)
  70 {
  71         struct page *page = pte_page(pte);
  72
  73         /* no flushing needed for anonymous pages */
  74         if (!page_mapping(page))
  75                 return;
  76
  77         if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
  78                 __flush_dcache_area(page_address(page),
  79                                 PAGE_SIZE << compound_order(page));
  80                 __flush_icache_all();
  81         } else if (icache_is_aivivt()) {
  82                 __flush_icache_all();
  83         }
  84 }
  85
  86 /*
  87  * This function is called when a page has been modified by the kernel. Mark
  88  * it as dirty for later flushing when mapped in user space (if executable,
  89  * see __sync_icache_dcache).
  90  */
  91 void flush_dcache_page(struct page *page)
  92 {
  93         if (test_bit(PG_dcache_clean, &page->flags))
  94                 clear_bit(PG_dcache_clean, &page->flags);
  95 }
  96 EXPORT_SYMBOL(flush_dcache_page);
  97
  98 /*
  99  * Additional functions defined in assembly.
 100  */
 101 EXPORT_SYMBOL(flush_icache_range);
 102
 103 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 104 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
 105 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 106                           pmd_t *pmdp)
 107 {
 108         pmd_t pmd = pmd_mksplitting(*pmdp);
 109
 110         VM_BUG_ON(address & ~PMD_MASK);
 111         set_pmd_at(vma->vm_mm, address, pmdp, pmd);
 112
 113         /* dummy IPI to serialise against fast_gup */
 114         kick_all_cpus_sync();
 115 }
 116 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */
 117 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */