From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755864Ab3GAUXy (ORCPT ); Mon, 1 Jul 2013 16:23:54 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48963 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755264Ab3GAUKZ (ORCPT ); Mon, 1 Jul 2013 16:10:25 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Simon Baatz , Catalin Marinas , Russell King Subject: [ 02/26] ARM: 7755/1: handle user space mapped pages in flush_kernel_dcache_page Date: Mon, 1 Jul 2013 13:09:57 -0700 Message-Id: <20130701200730.186193645@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130701200729.872850414@linuxfoundation.org> References: <20130701200729.872850414@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Simon Baatz commit 1bc39742aab09248169ef9d3727c9def3528b3f3 upstream. Commit f8b63c1 made flush_kernel_dcache_page a no-op assuming that the pages it needs to handle are kernel mapped only. However, for example when doing direct I/O, pages with user space mappings may occur. Thus, continue to do lazy flushing if there are no user space mappings. Otherwise, flush the kernel cache lines directly. Signed-off-by: Simon Baatz Reviewed-by: Catalin Marinas Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/cacheflush.h | 4 +--- arch/arm/mm/flush.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 3 deletions(-) --- a/arch/arm/include/asm/cacheflush.h +++ b/arch/arm/include/asm/cacheflush.h @@ -320,9 +320,7 @@ static inline void flush_anon_page(struc } #define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE -static inline void flush_kernel_dcache_page(struct page *page) -{ -} +extern void flush_kernel_dcache_page(struct page *); #define flush_dcache_mmap_lock(mapping) \ spin_lock_irq(&(mapping)->tree_lock) --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -298,6 +298,39 @@ void flush_dcache_page(struct page *page EXPORT_SYMBOL(flush_dcache_page); /* + * Ensure cache coherency for the kernel mapping of this page. We can + * assume that the page is pinned via kmap. + * + * If the page only exists in the page cache and there are no user + * space mappings, this is a no-op since the page was already marked + * dirty at creation. Otherwise, we need to flush the dirty kernel + * cache lines directly. + */ +void flush_kernel_dcache_page(struct page *page) +{ + if (cache_is_vivt() || cache_is_vipt_aliasing()) { + struct address_space *mapping; + + mapping = page_mapping(page); + + if (!mapping || mapping_mapped(mapping)) { + void *addr; + + addr = page_address(page); + /* + * kmap_atomic() doesn't set the page virtual + * address for highmem pages, and + * kunmap_atomic() takes care of cache + * flushing already. + */ + if (!IS_ENABLED(CONFIG_HIGHMEM) || addr) + __cpuc_flush_dcache_area(addr, PAGE_SIZE); + } + } +} +EXPORT_SYMBOL(flush_kernel_dcache_page); + +/* * Flush an anonymous page so that users of get_user_pages() * can safely access the data. The expected sequence is: *