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author | Catalin Marinas <catalin.marinas@arm.com> | 2013-05-01 11:23:05 (GMT) |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2013-06-07 16:58:28 (GMT) |
commit | b5b6c9e9149d8a7c3f1d7b9d0c046c6184e1dd17 (patch) | |
tree | 820998f37abcb6ab846e9c9ec59ec30c5c0b43f4 | |
parent | d25749afc6f2a40471a70c04a35633e30cbe59a5 (diff) | |
download | linux-fsl-qoriq-b5b6c9e9149d8a7c3f1d7b9d0c046c6184e1dd17.tar.xz |
arm64: Avoid cache flushing in flush_dcache_page()
The flush_dcache_page() function is called when the kernel modified a
page cache page. Since the D-cache on AArch64 does not have aliases
this function can simply mark the page as dirty for later flushing via
set_pte_at()/__sync_icache_dcache() if the page is executable (to ensure
the I-D cache coherency).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
-rw-r--r-- | arch/arm64/mm/flush.c | 22 |
1 files changed, 4 insertions, 18 deletions
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index 88611c3..b9cd7a4 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -94,28 +94,14 @@ void __sync_icache_dcache(pte_t pte, unsigned long addr) } /* - * Ensure cache coherency between kernel mapping and userspace mapping of this - * page. + * This function is called when a page has been modified by the kernel. Mark + * it as dirty for later flushing when mapped in user space (if executable, + * see __sync_icache_dcache). */ void flush_dcache_page(struct page *page) { - struct address_space *mapping; - - /* - * The zero page is never written to, so never has any dirty cache - * lines, and therefore never needs to be flushed. - */ - if (page == ZERO_PAGE(0)) - return; - - mapping = page_mapping(page); - if (mapping && mapping_mapped(mapping)) { - __flush_dcache_page(page); - __flush_icache_all(); - set_bit(PG_dcache_clean, &page->flags); - } else { + if (test_bit(PG_dcache_clean, &page->flags)) clear_bit(PG_dcache_clean, &page->flags); - } } EXPORT_SYMBOL(flush_dcache_page); |