From patchwork Mon Apr 22 23:08:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10911705 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8AAC9922 for ; Mon, 22 Apr 2019 23:22:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 79D5E287F9 for ; Mon, 22 Apr 2019 23:22:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6942F287FE; Mon, 22 Apr 2019 23:22:09 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 19805287F9 for ; Mon, 22 Apr 2019 23:22:09 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 0EDE12121794F; Mon, 22 Apr 2019 16:22:09 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.88; helo=mga01.intel.com; envelope-from=dan.j.williams@intel.com; receiver=linux-nvdimm@lists.01.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) (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 509FB2120ADF4 for ; Mon, 22 Apr 2019 16:22:08 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Apr 2019 16:22:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,383,1549958400"; d="scan'208";a="225758970" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga001.jf.intel.com with ESMTP; 22 Apr 2019 16:22:07 -0700 Subject: [4.19, 5.0 stable PATCH 3/4] nfit/ars: Allow root to busy-poll the ARS state machine From: Dan Williams To: stable@vger.kernel.org Date: Mon, 22 Apr 2019 16:08:21 -0700 Message-ID: <155597450168.2675082.12797199567190628607.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <155597449036.2675082.7035380482732870260.stgit@dwillia2-desk3.amr.corp.intel.com> References: <155597449036.2675082.7035380482732870260.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Erwin Tsaur , linux-nvdimm@lists.01.org Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP commit 5479b2757f26fe9908fc341d105b2097fe820b6f upstream. The ARS implementation implements exponential back-off on the poll interval to prevent high-frequency access to the DIMM / platform interface. Depending on when the ARS completes the poll interval may exceed the completion event by minutes. Allow root to reset the timeout each time it probes the status. A one-second timeout is still enforced, but root can otherwise can control the poll interval. Fixes: bc6ba8085842 ("nfit, address-range-scrub: rework and simplify ARS...") Cc: Reported-by: Erwin Tsaur Reviewed-by: Toshi Kani Signed-off-by: Dan Williams --- drivers/acpi/nfit/core.c | 8 ++++++++ drivers/acpi/nfit/nfit.h | 1 + 2 files changed, 9 insertions(+) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 64308e669250..61d3fd65fbe9 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1335,6 +1335,13 @@ static ssize_t scrub_show(struct device *dev, busy = test_bit(ARS_BUSY, &acpi_desc->scrub_flags) && !test_bit(ARS_CANCEL, &acpi_desc->scrub_flags); rc = sprintf(buf, "%d%s", acpi_desc->scrub_count, busy ? "+\n" : "\n"); + /* Allow an admin to poll the busy state at a higher rate */ + if (busy && capable(CAP_SYS_RAWIO) && !test_and_set_bit(ARS_POLL, + &acpi_desc->scrub_flags)) { + acpi_desc->scrub_tmo = 1; + mod_delayed_work(nfit_wq, &acpi_desc->dwork, HZ); + } + mutex_unlock(&acpi_desc->init_mutex); device_unlock(dev); return rc; @@ -3196,6 +3203,7 @@ static void acpi_nfit_scrub(struct work_struct *work) else notify_ars_done(acpi_desc); memset(acpi_desc->ars_status, 0, acpi_desc->max_ars); + clear_bit(ARS_POLL, &acpi_desc->scrub_flags); mutex_unlock(&acpi_desc->init_mutex); } diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h index 897ce10192a0..d14bad687fb8 100644 --- a/drivers/acpi/nfit/nfit.h +++ b/drivers/acpi/nfit/nfit.h @@ -213,6 +213,7 @@ struct nfit_mem { enum scrub_flags { ARS_BUSY, ARS_CANCEL, + ARS_POLL, }; struct acpi_nfit_desc {