From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D64DC3A5A2 for ; Sun, 22 Sep 2019 18:50:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67DD821D7B for ; Sun, 22 Sep 2019 18:50:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569178236; bh=5+4+EyeHu/Ui4dWZQbgh+L+4DfByRKwtCBXnWaSYN9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AzlNOeBxUZ8XesIP8MEiuGOigExlj/I4T66z/A+KlYCzhXqxyHwhp9JBnQV8OLVkD YHU+HXCyRBxWiV0m8WbweqWMuoCjUFggPodSSCxHQJp41I8nTmK3Rby9FkVdfmMpRH pQrjPNHqR64UIBYNtZJ1PWSRAMfVdwG4ql/F7X0I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403965AbfIVSuf (ORCPT ); Sun, 22 Sep 2019 14:50:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:47780 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403906AbfIVSuf (ORCPT ); Sun, 22 Sep 2019 14:50:35 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5D60821D6C; Sun, 22 Sep 2019 18:50:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569178234; bh=5+4+EyeHu/Ui4dWZQbgh+L+4DfByRKwtCBXnWaSYN9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IaCt5icOhXAMtQv10BKDl2E8fe+MMNSL9fis6NesxhGilVDhmD38U1cyozR6yk4OY HlT/KjtcYFSJXxW3kJGG/Z4g2QnaJnDIexRZJheWOVbO2P11Fvap83nruBjnoFOW2x GwQRTqM+Nsd/iRcSJKmyUo6G0//3PrLyH+PyzFYs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Robert Richter , Borislav Petkov , "linux-edac@vger.kernel.org" , James Morse , Mauro Carvalho Chehab , Tony Luck , Sasha Levin Subject: [PATCH AUTOSEL 5.2 031/185] EDAC/mc: Fix grain_bits calculation Date: Sun, 22 Sep 2019 14:46:49 -0400 Message-Id: <20190922184924.32534-31-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190922184924.32534-1-sashal@kernel.org> References: <20190922184924.32534-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-edac-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org From: Robert Richter [ Upstream commit 3724ace582d9f675134985727fd5e9811f23c059 ] The grain in EDAC is defined as "minimum granularity for an error report, in bytes". The following calculation of the grain_bits in edac_mc is wrong: grain_bits = fls_long(e->grain) + 1; Where grain_bits is defined as: grain = 1 << grain_bits Example: grain = 8 # 64 bit (8 bytes) grain_bits = fls_long(8) + 1 grain_bits = 4 + 1 = 5 grain = 1 << grain_bits grain = 1 << 5 = 32 Replace it with the correct calculation: grain_bits = fls_long(e->grain - 1); The example gives now: grain_bits = fls_long(8 - 1) grain_bits = fls_long(7) grain_bits = 3 grain = 1 << 3 = 8 Also, check if the hardware reports a reasonable grain != 0 and fallback with a warning to 1 byte granularity otherwise. [ bp: massage a bit. ] Signed-off-by: Robert Richter Signed-off-by: Borislav Petkov Cc: "linux-edac@vger.kernel.org" Cc: James Morse Cc: Mauro Carvalho Chehab Cc: Tony Luck Link: https://lkml.kernel.org/r/20190624150758.6695-2-rrichter@marvell.com Signed-off-by: Sasha Levin --- drivers/edac/edac_mc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index 64922c8fa7e3b..d899d86897d06 100644 --- a/drivers/edac/edac_mc.c +++ b/drivers/edac/edac_mc.c @@ -1235,9 +1235,13 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type, if (p > e->location) *(p - 1) = '\0'; - /* Report the error via the trace interface */ - grain_bits = fls_long(e->grain) + 1; + /* Sanity-check driver-supplied grain value. */ + if (WARN_ON_ONCE(!e->grain)) + e->grain = 1; + + grain_bits = fls_long(e->grain - 1); + /* Report the error via the trace interface */ if (IS_ENABLED(CONFIG_RAS)) trace_mc_event(type, e->msg, e->label, e->error_count, mci->mc_idx, e->top_layer, e->mid_layer, -- 2.20.1