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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 ED6AAC4320A for ; Mon, 30 Aug 2021 12:01:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D40226115C for ; Mon, 30 Aug 2021 12:01:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236981AbhH3MCI (ORCPT ); Mon, 30 Aug 2021 08:02:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:50264 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236974AbhH3MBn (ORCPT ); Mon, 30 Aug 2021 08:01:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9677461159; Mon, 30 Aug 2021 12:00:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1630324850; bh=azX6HPHRCwzj4NaEWidL0BFd7dzgOdWj38vLO5cN6vE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m6lylMFyZhfMWiKJhrhtHHV0QxYsV0f7THO0fRCxmmZf1baNpAqObC7VSN2nBxnTg HZ62h9m6ljDO2trn5QzYg3KGeeICk2iJON0Ygoz+z0wqe+2Kz0kHpbEuNVPp7LbucF cdJ8bXt+zZ8zBcIiO+19Xj29b5AOF/E3hIXsJ+J0pLOFpB0XgkOyOSVojgmlzfpy0Q cNjR56UGKaUrR2YrSR8y1U2+aXsyYerGfkeGiz8J5Tc+ZbDNV/ha6tga0P5vNzLya+ SZFACR7sxgJ0+i/WSH+Pt4CWfIv23UolGh4ENDwZV76RIBjlT2l1l7ip04Q94uzHuY D40GZDICcDKOw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kim Phillips , Peter Zijlstra , Ingo Molnar , Sasha Levin , linux-perf-users@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 5/7] perf/x86/amd/ibs: Work around erratum #1197 Date: Mon, 30 Aug 2021 08:00:41 -0400 Message-Id: <20210830120043.1018096-5-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210830120043.1018096-1-sashal@kernel.org> References: <20210830120043.1018096-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org From: Kim Phillips [ Upstream commit 26db2e0c51fe83e1dd852c1321407835b481806e ] Erratum #1197 "IBS (Instruction Based Sampling) Register State May be Incorrect After Restore From CC6" is published in a document: "Revision Guide for AMD Family 19h Models 00h-0Fh Processors" 56683 Rev. 1.04 July 2021 https://bugzilla.kernel.org/show_bug.cgi?id=206537 Implement the erratum's suggested workaround and ignore IBS samples if MSRC001_1031 == 0. Signed-off-by: Kim Phillips Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210817221048.88063-3-kim.phillips@amd.com Signed-off-by: Sasha Levin --- arch/x86/events/amd/ibs.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c index 3fe68f7f9d5e..5043425ced6b 100644 --- a/arch/x86/events/amd/ibs.c +++ b/arch/x86/events/amd/ibs.c @@ -90,6 +90,7 @@ struct perf_ibs { unsigned long offset_mask[1]; int offset_max; unsigned int fetch_count_reset_broken : 1; + unsigned int fetch_ignore_if_zero_rip : 1; struct cpu_perf_ibs __percpu *pcpu; struct attribute **format_attrs; @@ -674,6 +675,10 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs) if (check_rip && (ibs_data.regs[2] & IBS_RIP_INVALID)) { regs.flags &= ~PERF_EFLAGS_EXACT; } else { + /* Workaround for erratum #1197 */ + if (perf_ibs->fetch_ignore_if_zero_rip && !(ibs_data.regs[1])) + goto out; + set_linear_ip(®s, ibs_data.regs[1]); regs.flags |= PERF_EFLAGS_EXACT; } @@ -767,6 +772,9 @@ static __init void perf_event_ibs_init(void) if (boot_cpu_data.x86 >= 0x16 && boot_cpu_data.x86 <= 0x18) perf_ibs_fetch.fetch_count_reset_broken = 1; + if (boot_cpu_data.x86 == 0x19 && boot_cpu_data.x86_model < 0x10) + perf_ibs_fetch.fetch_ignore_if_zero_rip = 1; + perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch"); if (ibs_caps & IBS_CAPS_OPCNT) { -- 2.30.2