From patchwork Fri Sep 30 23:19:30 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 9359007 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4EAC96086A for ; Fri, 30 Sep 2016 23:20:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 33703288A7 for ; Fri, 30 Sep 2016 23:20:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 27C8D29EB5; Fri, 30 Sep 2016 23:20:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B44FB288A7 for ; Fri, 30 Sep 2016 23:20:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752423AbcI3XUV (ORCPT ); Fri, 30 Sep 2016 19:20:21 -0400 Received: from mga03.intel.com ([134.134.136.65]:60543 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751677AbcI3XUU (ORCPT ); Fri, 30 Sep 2016 19:20:20 -0400 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP; 30 Sep 2016 16:20:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,423,1473145200"; d="scan'208";a="1064666185" Received: from omniknight.lm.intel.com ([10.232.112.53]) by fmsmga002.fm.intel.com with ESMTP; 30 Sep 2016 16:20:19 -0700 From: Vishal Verma To: Cc: Dan Williams , Ross Zwisler , Linda Knippers , , "Rafael J. Wysocki" , Vishal Verma Subject: [PATCH 2/3] pmem: reduce kmap_atomic sections to the memcpys only Date: Fri, 30 Sep 2016 17:19:30 -0600 Message-Id: <1475277571-10152-3-git-send-email-vishal.l.verma@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1475277571-10152-1-git-send-email-vishal.l.verma@intel.com> References: <1475277571-10152-1-git-send-email-vishal.l.verma@intel.com> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP pmem_do_bvec used to kmap_atomic at the begin, and only unmap at the end. Things like nvdimm_clear_poison may want to do nvdimm subsystem bookkeeping operations that may involve taking locks or doing memory allocations, and we can't do that from the atomic context. Reduce the atomic context to just what needs it - the memcpy to/from pmem. Cc: Ross Zwisler Signed-off-by: Vishal Verma --- drivers/nvdimm/pmem.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 571a6c7..42b3a82 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -66,13 +66,32 @@ static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, invalidate_pmem(pmem->virt_addr + offset, len); } +static void write_pmem(void *pmem_addr, struct page *page, + unsigned int off, unsigned int len) +{ + void *mem = kmap_atomic(page); + + memcpy_to_pmem(pmem_addr, mem + off, len); + kunmap_atomic(mem); +} + +static int read_pmem(struct page *page, unsigned int off, + void *pmem_addr, unsigned int len) +{ + int rc; + void *mem = kmap_atomic(page); + + rc = memcpy_from_pmem(mem + off, pmem_addr, len); + kunmap_atomic(mem); + return rc; +} + static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, unsigned int len, unsigned int off, bool is_write, sector_t sector) { int rc = 0; bool bad_pmem = false; - void *mem = kmap_atomic(page); phys_addr_t pmem_off = sector * 512 + pmem->data_offset; void *pmem_addr = pmem->virt_addr + pmem_off; @@ -83,7 +102,7 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, if (unlikely(bad_pmem)) rc = -EIO; else { - rc = memcpy_from_pmem(mem + off, pmem_addr, len); + rc = read_pmem(page, off, pmem_addr, len); flush_dcache_page(page); } } else { @@ -102,14 +121,13 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, * after clear poison. */ flush_dcache_page(page); - memcpy_to_pmem(pmem_addr, mem + off, len); + write_pmem(pmem_addr, page, off, len); if (unlikely(bad_pmem)) { pmem_clear_poison(pmem, pmem_off, len); - memcpy_to_pmem(pmem_addr, mem + off, len); + write_pmem(pmem_addr, page, off, len); } } - kunmap_atomic(mem); return rc; }