From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752281AbdAMQEd (ORCPT ); Fri, 13 Jan 2017 11:04:33 -0500 Received: from foss.arm.com ([217.140.101.70]:49144 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751830AbdAMQEN (ORCPT ); Fri, 13 Jan 2017 11:04:13 -0500 From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: marc.zyngier@arm.com, mark.rutland@arm.com, kim.phillips@arm.com, alex.bennee@linaro.org, christoffer.dall@linaro.org, tglx@linutronix.de, peterz@infradead.org, alexander.shishkin@linux.intel.com, robh@kernel.org, suzuki.poulose@arm.com, pawel.moll@arm.com, mathieu.poirier@linaro.org, mingo@redhat.com, linux-kernel@vger.kernel.org, Will Deacon Subject: [RFC PATCH v2 01/10] arm64: cpufeature: allow for version discrepancy in PMU implementations Date: Fri, 13 Jan 2017 16:03:40 +0000 Message-Id: <1484323429-15231-2-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1484323429-15231-1-git-send-email-will.deacon@arm.com> References: <1484323429-15231-1-git-send-email-will.deacon@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Perf already supports multiple PMU instances for heterogeneous systems, so there's no need to be strict in the cpufeature checking, particularly as the PMU extension is optional in the architecture. Acked-by: Mark Rutland Reviewed-by: Suzuki K Poulose Signed-off-by: Will Deacon --- arch/arm64/kernel/cpufeature.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index fdf8f045929f..47d0226620e8 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -184,7 +184,11 @@ static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = { ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0), - S_ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0), + /* + * We can instantiate multiple PMU instances with different levels + * of support. + * */ + S_ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6), ARM64_FTR_END, -- 2.1.4