From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935441AbcA1SOz (ORCPT ); Thu, 28 Jan 2016 13:14:55 -0500 Received: from g4t3425.houston.hp.com ([15.201.208.53]:38370 "EHLO g4t3425.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934695AbcA1SN7 (ORCPT ); Thu, 28 Jan 2016 13:13:59 -0500 From: Toshi Kani To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, bp@suse.de, dan.j.williams@intel.com Cc: ross.zwisler@linux.intel.com, vishal.l.verma@intel.com, micah.parrish@hpe.com, brian.boylston@hpe.com, x86@kernel.org, linux-nvdimm@ml01.01.org, linux-kernel@vger.kernel.org, Toshi Kani Subject: [PATCH 2/2] pmem: Flush cache on unaligned request Date: Thu, 28 Jan 2016 11:12:50 -0700 Message-Id: <1454004770-6318-3-git-send-email-toshi.kani@hpe.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1454004770-6318-1-git-send-email-toshi.kani@hpe.com> References: <1454004770-6318-1-git-send-email-toshi.kani@hpe.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org arch_memcpy_to_pmem() calls __copy_user_nocache() to copy data via non-temporal stores. However, __copy_user_nocache() still performs cached copy when a request is not naturally aligned or is less then 4 bytes. Call clflush_cache_range() to flush destination when a request leads to cached copy. Signed-off-by: Toshi Kani Cc: Thomas Gleixner Cc: Ingo Molnar Cc: H. Peter Anvin Cc: Borislav Petkov Cc: Dan Williams Cc: Ross Zwisler Cc: Vishal Verma --- arch/x86/include/asm/pmem.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h index c57fd1e..f135064 100644 --- a/arch/x86/include/asm/pmem.h +++ b/arch/x86/include/asm/pmem.h @@ -45,6 +45,17 @@ static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src, if (WARN(unwritten, "%s: fault copying %p <- %p unwritten: %d\n", __func__, dst, src, unwritten)) BUG(); + + /* + * Flush the caches when the request is not naturally aligned. + * Non-temporal stores are not used for unaligned copy. + */ + if (((n >= 8) && + (!IS_ALIGNED((unsigned long)dst, 8) || !IS_ALIGNED(n, 8))) || + ((n < 8) && + (!IS_ALIGNED((unsigned long)dst, 4) || (n != 4)))) { + clflush_cache_range(dst, n); + } } /**