Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935425AbaBDWDE (ORCPT ); Tue, 4 Feb 2014 17:03:04 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56901 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933582AbaBDVJR (ORCPT ); Tue, 4 Feb 2014 16:09:17 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Helge Deller , John David Anglin Subject: [PATCH 3.12 118/133] parisc: fix cache-flushing Date: Tue, 4 Feb 2014 13:08:39 -0800 Message-Id: <20140204210740.364449733@linuxfoundation.org> X-Mailer: git-send-email 1.8.5.1.163.gd7aced9 In-Reply-To: <20140204210737.008598235@linuxfoundation.org> References: <20140204210737.008598235@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Helge Deller commit 57737c49dd72c96cfbcd4f66559f3ffc399aeb4f upstream. This commit: f8dae00684d678afa13041ef170cecfd1297ed40: parisc: Ensure full cache coherency for kmap/kunmap caused negative caching side-effects, e.g. hanging processes with expect and too many inequivalent alias messages from flush_dcache_page() on Debian 5 systems. This patch now partly reverts it and has been in production use on our debian buildd makeservers since a week without any major problems. Signed-off-by: Helge Deller Signed-off-by: John David Anglin Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman --- arch/parisc/include/asm/cacheflush.h | 2 -- arch/parisc/include/asm/page.h | 3 ++- arch/parisc/kernel/cache.c | 14 ++++++++++++++ 3 files changed, 16 insertions(+), 3 deletions(-) --- a/arch/parisc/include/asm/cacheflush.h +++ b/arch/parisc/include/asm/cacheflush.h @@ -132,7 +132,6 @@ void mark_rodata_ro(void); static inline void *kmap(struct page *page) { might_sleep(); - flush_dcache_page(page); return page_address(page); } @@ -144,7 +143,6 @@ static inline void kunmap(struct page *p static inline void *kmap_atomic(struct page *page) { pagefault_disable(); - flush_dcache_page(page); return page_address(page); } --- a/arch/parisc/include/asm/page.h +++ b/arch/parisc/include/asm/page.h @@ -29,7 +29,8 @@ struct page; void clear_page_asm(void *page); void copy_page_asm(void *to, void *from); #define clear_user_page(vto, vaddr, page) clear_page_asm(vto) -#define copy_user_page(vto, vfrom, vaddr, page) copy_page_asm(vto, vfrom) +void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, + struct page *pg); /* #define CONFIG_PARISC_TMPALIAS */ --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -388,6 +388,20 @@ void flush_kernel_dcache_page_addr(void } EXPORT_SYMBOL(flush_kernel_dcache_page_addr); +void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, + struct page *pg) +{ + /* Copy using kernel mapping. No coherency is needed (all in + kunmap) for the `to' page. However, the `from' page needs to + be flushed through a mapping equivalent to the user mapping + before it can be accessed through the kernel mapping. */ + preempt_disable(); + flush_dcache_page_asm(__pa(vfrom), vaddr); + preempt_enable(); + copy_page_asm(vto, vfrom); +} +EXPORT_SYMBOL(copy_user_page); + void purge_tlb_entries(struct mm_struct *mm, unsigned long addr) { unsigned long flags; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/