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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/mm/flush.c | |
download | blackbird-op-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz blackbird-op-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/arm/mm/flush.c')
-rw-r--r-- | arch/arm/mm/flush.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c new file mode 100644 index 000000000000..c6de48d89503 --- /dev/null +++ b/arch/arm/mm/flush.c @@ -0,0 +1,94 @@ +/* + * 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. + */ + __cpuc_flush_dcache_page(page_address(page)); + + /* + * 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) + return; + + /* + * 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); + + flush_dcache_mmap_lock(mapping); + 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) + continue; + if (!(mpnt->vm_flags & VM_MAYSHARE)) + continue; + offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT; + flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page)); + if (cache_is_vipt()) + break; + } + flush_dcache_mmap_unlock(mapping); +} + +/* + * 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()) + return; + + if (mapping && !mapping_mapped(mapping)) + set_bit(PG_dcache_dirty, &page->flags); + else + __flush_dcache_page(mapping, page); +} +EXPORT_SYMBOL(flush_dcache_page); |