From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934173AbcKJPcR (ORCPT ); Thu, 10 Nov 2016 10:32:17 -0500 Received: from foss.arm.com ([217.140.101.70]:51356 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932553AbcKJPcQ (ORCPT ); Thu, 10 Nov 2016 10:32:16 -0500 Subject: Re: [PATCH 1/2] arm64: perf: Move ARMv8 PMU perf event definitions to asm/perf_event.h To: Wei Huang , kvmarm@lists.cs.columbia.edu References: <1478721480-24852-1-git-send-email-wei@redhat.com> Cc: linux-arm-kernel@lists.infradead.org, shannon.zhao@linaro.org, kvm@vger.kernel.org, christoffer.dall@linaro.org, drjones@redhat.com, cov@codeaurora.org, will.deacon@arm.com, mark.rutland@arm.com, catalin.marinas@arm.com, linux-kernel@vger.kernel.org From: Marc Zyngier Organization: ARM Ltd Message-ID: <733f067d-7f3b-df28-eab7-a15abba947fc@arm.com> Date: Thu, 10 Nov 2016 15:32:12 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/11/16 15:12, Wei Huang wrote: > > > On 11/10/2016 03:10 AM, Marc Zyngier wrote: >> Hi Wei, >> >> On 09/11/16 19:57, Wei Huang wrote: >>> This patch moves ARMv8-related perf event definitions from perf_event.c >>> to asm/perf_event.h; so KVM code can use them directly. This also help >>> remove a duplicated definition of SW_INCR in perf_event.h. >>> >>> Signed-off-by: Wei Huang >>> --- >>> arch/arm64/include/asm/perf_event.h | 161 +++++++++++++++++++++++++++++++++++- >>> arch/arm64/kernel/perf_event.c | 161 ------------------------------------ >>> 2 files changed, 160 insertions(+), 162 deletions(-) >>> >>> diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h >>> index 2065f46..6c7b18b 100644 >>> --- a/arch/arm64/include/asm/perf_event.h >>> +++ b/arch/arm64/include/asm/perf_event.h >>> @@ -46,7 +46,166 @@ >>> #define ARMV8_PMU_EVTYPE_MASK 0xc800ffff /* Mask for writable bits */ >>> #define ARMV8_PMU_EVTYPE_EVENT 0xffff /* Mask for EVENT bits */ >>> >>> -#define ARMV8_PMU_EVTYPE_EVENT_SW_INCR 0 /* Software increment event */ >>> +/* >>> + * ARMv8 PMUv3 Performance Events handling code. >>> + * Common event types. >>> + */ >>> + >>> +/* Required events. */ >>> +#define ARMV8_PMUV3_PERFCTR_SW_INCR 0x00 >>> +#define ARMV8_PMUV3_PERFCTR_L1D_CACHE_REFILL 0x03 >>> +#define ARMV8_PMUV3_PERFCTR_L1D_CACHE 0x04 >>> +#define ARMV8_PMUV3_PERFCTR_BR_MIS_PRED 0x10 >>> +#define ARMV8_PMUV3_PERFCTR_CPU_CYCLES 0x11 >>> +#define ARMV8_PMUV3_PERFCTR_BR_PRED 0x12 >> >> In my initial review, I asked for the "required" events to be moved to a >> shared location. What's the rational for moving absolutely everything? > > I did notice the phrase "required" in the original email. However I > think it is weird to have two places for a same set of PMU definitions. > Other developers might think these two are missing if they don't search > kernel files carefully. > > If Will Deacon and you insist, I can move only two defs to perf_event.h, > consolidated with the 2nd patch into a single one. My personal feeling is that only architected events should be in a public header. The CPU-specific ones are probably better kept private, as it is doubtful that other users would appear). I'll leave it up to Will to decide, as all I want to avoid is the duplication of constants between the PMU and KVM code bases. Thanks, M. -- Jazz is not dead. It just smells funny...