From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756257AbdJJJbp (ORCPT ); Tue, 10 Oct 2017 05:31:45 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:40818 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755531AbdJJJbn (ORCPT ); Tue, 10 Oct 2017 05:31:43 -0400 Date: Tue, 10 Oct 2017 10:30:11 +0100 From: Mark Rutland To: Thor Thayer Cc: linux-kernel@vger.kernel.org, Borislav Petkov Subject: Re: [PATCH 02/13] EDAC, altera: kill off ACCESS_ONCE() Message-ID: <20171010093010.GC27659@leverpostej> References: <1507573730-8083-1-git-send-email-mark.rutland@arm.com> <1507573730-8083-3-git-send-email-mark.rutland@arm.com> <0b61c449-4aa9-095d-fd83-b177670f3fbb@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0b61c449-4aa9-095d-fd83-b177670f3fbb@linux.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 09, 2017 at 06:12:10PM -0500, Thor Thayer wrote: > On 10/09/2017 01:28 PM, Mark Rutland wrote: > >diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c > >index 346c498..11d6419 100644 > >--- a/drivers/edac/altera_edac.c > >+++ b/drivers/edac/altera_edac.c > >@@ -175,11 +175,11 @@ static ssize_t altr_sdr_mc_err_inject_write(struct file *file, > > /* > > * To trigger the error, we need to read the data back > > * (the data was written with errors above). > >- * The ACCESS_ONCE macros and printk are used to prevent the > >+ * The READ_ONCE macros and printk are used to prevent the > > * the compiler optimizing these reads out. > > */ > >- reg = ACCESS_ONCE(ptemp[0]); > >- read_reg = ACCESS_ONCE(ptemp[1]); > >+ reg = READ_ONCE(ptemp[0]); > >+ read_reg = READ_ONCE(ptemp[1]); > > /* Force Read */ > > rmb(); > >@@ -618,7 +618,7 @@ static ssize_t altr_edac_device_trig(struct file *file, > > for (i = 0; i < (priv->trig_alloc_sz / sizeof(*ptemp)); i++) { > > /* Read data so we're in the correct state */ > > rmb(); > >- if (ACCESS_ONCE(ptemp[i])) > >+ if (READ_ONCE(ptemp[i])) > > result = -1; > > /* Toggle Error bit (it is latched), leave ECC enabled */ > > writel(error_mask, (drvdata->base + priv->set_err_ofst)); > >@@ -635,7 +635,7 @@ static ssize_t altr_edac_device_trig(struct file *file, > > /* Read out written data. ECC error caused here */ > > for (i = 0; i < ALTR_TRIGGER_READ_WRD_CNT; i++) > >- if (ACCESS_ONCE(ptemp[i]) != i) > >+ if (READ_ONCE(ptemp[i]) != i) > > edac_printk(KERN_ERR, EDAC_DEVICE, > > "Read doesn't match written data\n"); > > > > Tested on Cyclone5 and Arria10. Thanks! > Acked-by: Thor Thayer Thanks, that's much appreciated! Mark.