From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757529AbbE2XTh (ORCPT ); Fri, 29 May 2015 19:19:37 -0400 Received: from g4t3427.houston.hp.com ([15.201.208.55]:52603 "EHLO g4t3427.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757447AbbE2XTN (ORCPT ); Fri, 29 May 2015 19:19:13 -0400 From: Toshi Kani To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-nvdimm@ml01.01.org, jgross@suse.com, stefan.bader@canonical.com, luto@amacapital.net, hmh@hmh.eng.br, yigal@plexistor.com, konrad.wilk@oracle.com, Elliott@hp.com, mcgrof@suse.com, hch@lst.de, Toshi Kani Subject: [PATCH v11 12/12] drivers/block/pmem: Map NVDIMM with ioremap_wt() Date: Fri, 29 May 2015 16:59:10 -0600 Message-Id: <1432940350-1802-13-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1432940350-1802-1-git-send-email-toshi.kani@hp.com> References: <1432940350-1802-1-git-send-email-toshi.kani@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Toshi Kani The pmem driver maps NVDIMM with ioremap_nocache() as we cannot write back the contents of the CPU caches in case of a crash. This patch changes to use ioremap_wt(), which provides uncached writes but cached reads, for improving read performance. Signed-off-by: Toshi Kani --- drivers/block/pmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c index eabf4a8..095dfaa 100644 --- a/drivers/block/pmem.c +++ b/drivers/block/pmem.c @@ -139,11 +139,11 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res) } /* - * Map the memory as non-cachable, as we can't write back the contents + * Map the memory as write-through, as we can't write back the contents * of the CPU caches in case of a crash. */ err = -ENOMEM; - pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size); + pmem->virt_addr = ioremap_wt(pmem->phys_addr, pmem->size); if (!pmem->virt_addr) goto out_release_region;