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 C8204C433FE for ; Wed, 19 Oct 2022 02:05:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229885AbiJSCFM (ORCPT ); Tue, 18 Oct 2022 22:05:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229756AbiJSCFJ (ORCPT ); Tue, 18 Oct 2022 22:05:09 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3414A4CA1E for ; Tue, 18 Oct 2022 19:04:55 -0700 (PDT) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MsYp362NLzVhvP; Wed, 19 Oct 2022 09:59:55 +0800 (CST) Received: from dggpemm500002.china.huawei.com (7.185.36.229) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 19 Oct 2022 10:04:32 +0800 Received: from [10.174.179.5] (10.174.179.5) by dggpemm500002.china.huawei.com (7.185.36.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 19 Oct 2022 10:04:31 +0800 Subject: Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines To: Suzuki Kuruppassery Poulose CC: , wanghuiqiang , "Linux Kernel Mailing List" , "linux-arm-kernel@lists.infradead.org" , , "Catalin Marinas" , Anshuman Khandual References: <6e85db13-a65f-d4c6-1b6b-660a94cb7060@huawei.com> <9fc5ab20-c7f0-a917-4938-403e3661109f@arm.com> From: Xiongfeng Wang Message-ID: <5c4d3a7f-0dcb-c0e9-0192-2a53d0338078@huawei.com> Date: Wed, 19 Oct 2022 10:04:31 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <9fc5ab20-c7f0-a917-4938-403e3661109f@arm.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.5] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500002.china.huawei.com (7.185.36.229) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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. Thanks Xiongfeng > > Thanks > Suzuki > >> >> Do we have some other way to use CoreSight ETMv4.4 on ACPI machines. Thanks a >> lot. >> >> Thanks, >> Xiongfeng > > > .