From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH 3/7] ARM: perf_event: Add basic support for Krait CPU PMUs Date: Fri, 10 Jan 2014 11:01:14 +0000 Message-ID: <20140110110114.GC10455@mudshark.cambridge.arm.com> References: <1389221984-10973-1-git-send-email-sboyd@codeaurora.org> <1389221984-10973-4-git-send-email-sboyd@codeaurora.org> <20140109110440.GC17838@mudshark.cambridge.arm.com> <52CEFF18.2070501@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <52CEFF18.2070501@codeaurora.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Stephen Boyd Cc: mark.rutland@arm.com, "devicetree@vger.kernel.org" , Ashwin Chaugule , "linux-arm-msm@vger.kernel.org" , Neil Leeder , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org On Thu, Jan 09, 2014 at 07:57:12PM +0000, Stephen Boyd wrote: > (Adding DT reviewers) > > On 01/09/14 03:04, Will Deacon wrote: > > On Wed, Jan 08, 2014 at 10:59:40PM +0000, Stephen Boyd wrote: > > > >> +static int krait_pmu_init(struct arm_pmu *cpu_pmu) > >> +{ > >> + u32 id = read_cpuid_id() & 0xffffff00; > >> + > >> + armv7pmu_init(cpu_pmu); > >> + cpu_pmu->name = "ARMv7 Krait"; > >> + /* Some early versions of Krait don't support PC write events */ > >> + if (id == 0x511f0400 || id == 0x510f0600) > >> + cpu_pmu->map_event = krait_map_event_no_branch; > > Hmm, I'd really rather this information came via the DT. In fact, you could > > just drop the branch event from your main map_event_function and keep things > > simple. It depends how badly you want to advertise it in perf list :) > > > > Not every version of Krait is missing support for this event, so I'd > like to keep it so things like perf stat show branch counts. How about I > add a bool property to the pmu node indicating that this PMU is missing > support for the PC write events? Something like "no-pc-write"? Perhaps, although I think it should be qualcomm-specific, so something like "qcom,krait-no-pc-write"? Again, I'd be glad to hear something from a DT reviewer on this. Will