From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp05.in.ibm.com (e28smtp05.in.ibm.com [125.16.236.5]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 1BDE01A02D7 for ; Tue, 16 Feb 2016 17:38:11 +1100 (AEDT) Received: from localhost by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 16 Feb 2016 12:08:09 +0530 Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay03.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u1G6c4Ih1769972 for ; Tue, 16 Feb 2016 12:08:04 +0530 Received: from d28av03.in.ibm.com (localhost [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u1G6c35f031138 for ; Tue, 16 Feb 2016 12:08:04 +0530 From: Anshuman Khandual To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH V11_RESEND 08/10] powerpc/perf: Change POWER8 PMU configuration to work with SW filters Date: Tue, 16 Feb 2016 12:07:08 +0530 Message-Id: <1455604630-16214-9-git-send-email-khandual@linux.vnet.ibm.com> In-Reply-To: <1455604630-16214-1-git-send-email-khandual@linux.vnet.ibm.com> References: <1455604630-16214-1-git-send-email-khandual@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The kernel now supports SW based branch filters for book3s systems with some specific requirements while dealing with HW supported branch filters in order to achieve overall OR semantics prevailing in perf branch stack sampling framework. This patch adapts the BHRB branch filter configuration to meet those protocols. POWER8 PMU can only handle one HW based branch filter request at any point of time. For all other combinations PMU will pass it on to the SW. Signed-off-by: Anshuman Khandual --- arch/powerpc/perf/power8-pmu.c | 51 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 44 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c index 3d819cb..ee8a68a 100644 --- a/arch/powerpc/perf/power8-pmu.c +++ b/arch/powerpc/perf/power8-pmu.c @@ -656,6 +656,16 @@ static int power8_generic_events[] = { static u64 power8_bhrb_filter_map(u64 branch_sample_type, u64 *bhrb_filter) { + u64 x, pmu_bhrb_filter; + + pmu_bhrb_filter = 0; + *bhrb_filter = 0; + + if (branch_sample_type & PERF_SAMPLE_BRANCH_ANY) { + *bhrb_filter = PERF_SAMPLE_BRANCH_ANY; + return pmu_bhrb_filter; + } + /* BHRB and regular PMU events share the same privilege state * filter configuration. BHRB is always recorded along with a * regular PMU event. As the privilege state filter is handled @@ -666,18 +676,45 @@ static u64 power8_bhrb_filter_map(u64 branch_sample_type, u64 *bhrb_filter) /* Ignore user, kernel, hv bits */ branch_sample_type &= ~PERF_SAMPLE_BRANCH_PLM_ALL; - /* No branch filter requested */ - if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY) - return 0; + /* + * POWER8 does not support ORing of PMU HW branch filters. Hence + * if multiple branch filters are requested which may include filters + * supported in PMU, still go ahead and clear the PMU based HW branch + * filter component as in this case all the filters will be processed + * in SW. + */ if (branch_sample_type & PERF_SAMPLE_BRANCH_CALL) return -1; - if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY_CALL) - return POWER8_MMCRA_IFM1; + for_each_branch_sample_type(x) { + /* Ignore privilege branch filters */ + if ((x == PERF_SAMPLE_BRANCH_USER) + || (x == PERF_SAMPLE_BRANCH_KERNEL) + || (x == PERF_SAMPLE_BRANCH_HV)) + continue; + + if (!(branch_sample_type & x)) + continue; + + /* Supported individual PMU branch filters */ + if (branch_sample_type & PERF_SAMPLE_BRANCH_ANY_CALL) { + branch_sample_type &= ~PERF_SAMPLE_BRANCH_ANY_CALL; + if (branch_sample_type) { + /* Multiple filters will be processed in SW */ + pmu_bhrb_filter = 0; + *bhrb_filter = 0; + return pmu_bhrb_filter; + } else { + /* Individual filter will be processed in HW */ + pmu_bhrb_filter |= POWER8_MMCRA_IFM1; + *bhrb_filter |= PERF_SAMPLE_BRANCH_ANY_CALL; + return pmu_bhrb_filter; + } + } + } - /* Every thing else is unsupported */ - return -1; + return pmu_bhrb_filter; } static void power8_config_bhrb(u64 pmu_bhrb_filter) -- 2.1.0