blob: c6de48d895032de8d615ee0f1ae8d8b31e13a716 [file] [log] [blame]
* linux/arch/arm/mm/flush.c
* Copyright (C) 1995-2002 Russell King
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <asm/cacheflush.h>
#include <asm/system.h>
static void __flush_dcache_page(struct address_space *mapping, struct page *page)
struct mm_struct *mm = current->active_mm;
struct vm_area_struct *mpnt;
struct prio_tree_iter iter;
pgoff_t pgoff;
* Writeback any data associated with the kernel mapping of this
* page. This ensures that data in the physical page is mutually
* coherent with the kernels mapping.
* If there's no mapping pointer here, then this page isn't
* visible to userspace yet, so there are no cache lines
* associated with any other aliases.
if (!mapping)
* There are possible user space mappings of this page:
* - VIVT cache: we need to also write back and invalidate all user
* data in the current VM view associated with this page.
* - aliasing VIPT: we only need to find one mapping of this page.
pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
unsigned long offset;
* If this VMA is not in our MM, we can ignore it.
if (mpnt->vm_mm != mm)
if (!(mpnt->vm_flags & VM_MAYSHARE))
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page));
if (cache_is_vipt())
* Ensure cache coherency between kernel mapping and userspace mapping
* of this page.
* We have three cases to consider:
* - VIPT non-aliasing cache: fully coherent so nothing required.
* - VIVT: fully aliasing, so we need to handle every alias in our
* current VM view.
* - VIPT aliasing: need to handle one alias in our current VM view.
* If we need to handle aliasing:
* If the page only exists in the page cache and there are no user
* space mappings, we can be lazy and remember that we may have dirty
* kernel cache lines for later. Otherwise, we assume we have
* aliasing mappings.
void flush_dcache_page(struct page *page)
struct address_space *mapping = page_mapping(page);
if (cache_is_vipt_nonaliasing())
if (mapping && !mapping_mapped(mapping))
set_bit(PG_dcache_dirty, &page->flags);
__flush_dcache_page(mapping, page);