From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754413AbbETXet (ORCPT ); Wed, 20 May 2015 19:34:49 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:44511 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752759AbbETXeq (ORCPT ); Wed, 20 May 2015 19:34:46 -0400 Date: Wed, 20 May 2015 16:34:16 -0700 From: Sukadev Bhattiprolu To: Michael Ellerman Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH 1/1] powerpc/perf/hv-24x7: Check support before registering Message-ID: <20150520233416.GA10270@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Operating-System: Linux 2.0.32 on an i486 User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15052023-8236-0000-0000-00000BAD64CD Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>From 955102eacf035b19080dc659a15d9b8fbd8fae7f Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Tue, 28 Apr 2015 18:47:58 -0400 Subject: [PATCH 1/1] powerpc/perf/hv-24x7: Check support before registering PMU We currently try to register the 24x7 PMU unconditionally. Not all Power systems support 24x7 counters (eg: Power7). On these systems we get a backtrace during boot when trying to register the 24x7 PMU. Check if the hypervisor supports 24x7 counters before attempting to register the 24x7 PMU. Reported-by: Gustavo Luiz Duarte Signed-off-by: Sukadev Bhattiprolu --- Changelog[v2] - [Michael Ellerman] Simplify check with bogus parameters. --- arch/powerpc/perf/hv-24x7.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c index ec2eb20..c04a332 100644 --- a/arch/powerpc/perf/hv-24x7.c +++ b/arch/powerpc/perf/hv-24x7.c @@ -1268,12 +1268,33 @@ static struct pmu h_24x7_pmu = { .read = h_24x7_event_read, }; +/* + * Return 1 if we can access the 24x7 counter catalog from the hypervisor. + * Return 0 otherwise. + */ +static bool hv_has_24x7(void) +{ + unsigned long hret; + + hret = h_get_24x7_catalog_page(0, 0, 0); + + if (hret != H_FUNCTION) + pr_err("Error %ld reading catalog, disabling 24x7 PMU\n", hret); + + return hret == 0; + +} + + static int hv_24x7_init(void) { int r; unsigned long hret; struct hv_perf_caps caps; + if (!hv_has_24x7()) + return -ENODEV; + if (!firmware_has_feature(FW_FEATURE_LPAR)) { pr_debug("not a virtualized system, not enabling\n"); return -ENODEV; -- 1.7.9.5