From patchwork Tue Jul 14 07:02:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 11661707 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0A7D014DD for ; Tue, 14 Jul 2020 07:04:32 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E712D2220F for ; Tue, 14 Jul 2020 07:04:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E712D2220F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id CF84510056B17; Tue, 14 Jul 2020 00:04:31 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=192.55.52.136; helo=mga12.intel.com; envelope-from=ira.weiny@intel.com; receiver= Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 703F810056AFD for ; Tue, 14 Jul 2020 00:04:28 -0700 (PDT) IronPort-SDR: QVkV/IMKVcqz0zmy+u9RvwR8hWCnM5g6U9vy9/1bKHcbq440vuG866xVAL0aYHjy/Qj/oawWzc 3SJSxl5/O0Xw== X-IronPort-AV: E=McAfee;i="6000,8403,9681"; a="128391978" X-IronPort-AV: E=Sophos;i="5.75,350,1589266800"; d="scan'208";a="128391978" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2020 00:04:28 -0700 IronPort-SDR: 2GlF4QiJnNhoGgMJ5XMp7xdyQ0iPfyqW+HUR8m12RTg7zWuuTG19TEkAYr8cw+FwjIa2w1Dc3M MV33WpvpzAfw== X-IronPort-AV: E=Sophos;i="5.75,350,1589266800"; d="scan'208";a="269934896" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2020 00:04:28 -0700 From: ira.weiny@intel.com To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra Subject: [RFC PATCH 14/15] nvdimm/pmem: Stray write protection for pmem->virt_addr Date: Tue, 14 Jul 2020 00:02:19 -0700 Message-Id: <20200714070220.3500839-15-ira.weiny@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200714070220.3500839-1-ira.weiny@intel.com> References: <20200714070220.3500839-1-ira.weiny@intel.com> MIME-Version: 1.0 Message-ID-Hash: NKA2VIRRDGBUBDKSK5CQC3KWSI2TGXE3 X-Message-ID-Hash: NKA2VIRRDGBUBDKSK5CQC3KWSI2TGXE3 X-MailFrom: ira.weiny@intel.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: x86@kernel.org, Dave Hansen , Andrew Morton , Fenghua Yu , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: From: Ira Weiny The pmem driver uses a cached virtual address to access its memory directly. Because the nvdimm driver is well aware of the special protections it has mapped memory with, we call dev_access_[en|dis]able() around the direct pmem->virt_addr (pmem_addr) usage instead of the unnecessary overhead of trying to get a page to kmap. Signed-off-by: Ira Weiny --- drivers/nvdimm/pmem.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index d25e66fd942d..46c11a09b813 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -148,7 +148,9 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem, if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) return BLK_STS_IOERR; + dev_access_enable(); rc = read_pmem(page, page_off, pmem_addr, len); + dev_access_disable(); flush_dcache_page(page); return rc; } @@ -180,11 +182,13 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem, * after clear poison. */ flush_dcache_page(page); + dev_access_enable(); write_pmem(pmem_addr, page, page_off, len); if (unlikely(bad_pmem)) { rc = pmem_clear_poison(pmem, pmem_off, len); write_pmem(pmem_addr, page, page_off, len); } + dev_access_disable(); return rc; }