From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E1DCC43219 for ; Thu, 20 Oct 2022 16:04:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231165AbiJTQEr (ORCPT ); Thu, 20 Oct 2022 12:04:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231131AbiJTQEH (ORCPT ); Thu, 20 Oct 2022 12:04:07 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D7AF01BC16C for ; Thu, 20 Oct 2022 09:03:52 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 381E823A; Thu, 20 Oct 2022 09:03:56 -0700 (PDT) Received: from [10.57.68.12] (unknown [10.57.68.12]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AA8A53F792; Thu, 20 Oct 2022 09:03:48 -0700 (PDT) Message-ID: <07c9964b-e074-fe76-8ee1-9b0bdf5d364f@arm.com> Date: Thu, 20 Oct 2022 17:03:47 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.3.3 Subject: Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines To: Xiongfeng Wang Cc: yehaiyang2@hisilicon.com, wanghuiqiang , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.org" , mark.rutland@arm.com, Catalin Marinas , Anshuman Khandual References: <6e85db13-a65f-d4c6-1b6b-660a94cb7060@huawei.com> <9fc5ab20-c7f0-a917-4938-403e3661109f@arm.com> <5c4d3a7f-0dcb-c0e9-0192-2a53d0338078@huawei.com> From: Suzuki K Poulose In-Reply-To: <5c4d3a7f-0dcb-c0e9-0192-2a53d0338078@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi On 19/10/2022 03:04, Xiongfeng Wang wrote: > Hi, Suzuki, Anshuman > > On 2022/10/18 17:18, Suzuki Kuruppassery Poulose wrote: >> Hi, >> >> Cc: Anshuman >> >> On 18/10/2022 03:04, Xiongfeng Wang wrote: >>> Hi, Suzuki >>> >>>     We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory >>> mapped access to ETM and mandates the system registers. The following commit add >>> driver for sysreg only devices, but it only support device tree. >>>    commit 5214b563588e8414193bd7a174c52350256942a6 >>>    coresight: etm4x: Add support for sysreg only devices >>> >>> ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding >>> driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg >>> only device. >> >> That is true. Unfortunately, supporting this requires us to move away from the >> AMBA framework (at least) for ETM4x devices. This is currently >> developed by Anshuman. We can share it as soon as this is complete. > > Thanks a lot. Really appreciate ! > By the way, do we have plan to add ACPI support for TRBE driver? ACPI 6.5 add a Yes, this is again in our pipeline. But, without the ETE support, TRBE is literally unusable. So, this will follow the ETE/ETMv4 sysreg ACPI support. > field 'TRBE Interrupt' in GICC Structure. In the beginning, I plan to add a > platform device when got this IRQ, just like what SPE does in the following commit > commit d24a0c7099b32b6981d7f126c45348e381718350 > arm_pmu: acpi: spe: Add initial MADT/SPE probing > But it seems that TRBE still needs _DSD method to report the links(input port > and output port). Do you have some other advices? Thanks a lot. TRBE doesn't need to specify the input/output ports. It is a per-CPU sink and the TRBE driver registers it as such for each CPU that it probes. Suzuki