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 51F05C43334 for ; Mon, 6 Jun 2022 15:16:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240396AbiFFPQQ (ORCPT ); Mon, 6 Jun 2022 11:16:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240346AbiFFPQO (ORCPT ); Mon, 6 Jun 2022 11:16:14 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4BA5655499 for ; Mon, 6 Jun 2022 08:16:13 -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 28595D6E; Mon, 6 Jun 2022 08:16:13 -0700 (PDT) Received: from [10.57.82.168] (unknown [10.57.82.168]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 03ACB3F73B; Mon, 6 Jun 2022 08:16:11 -0700 (PDT) Message-ID: <367f8d3d-7890-12bd-6caf-c470b0b4c614@arm.com> Date: Mon, 6 Jun 2022 16:16:10 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH v6 2/2] Documentation: Add document for UltraSoc SMB drivers To: Qi Liu , mathieu.poirier@linaro.org, mike.leach@linaro.org Cc: coresight@lists.linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxarm@huawei.com References: <20220606130223.57354-1-liuqi115@huawei.com> <20220606130223.57354-3-liuqi115@huawei.com> From: Suzuki K Poulose In-Reply-To: <20220606130223.57354-3-liuqi115@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Qi Please find my comments below. On 06/06/2022 14:02, Qi Liu wrote: > This patch bring in a documentation for UltraSoc SMB drivers. > It simple descripts the device, sysfs interface and the > firmware bindings. > > Signed-off-by: Qi Liu > --- > .../trace/coresight/ultrasoc-smb.rst | 80 +++++++++++++++++++ > 1 file changed, 80 insertions(+) > create mode 100644 Documentation/trace/coresight/ultrasoc-smb.rst > > diff --git a/Documentation/trace/coresight/ultrasoc-smb.rst b/Documentation/trace/coresight/ultrasoc-smb.rst > new file mode 100644 > index 000000000000..b4cfea82deb8 > --- /dev/null > +++ b/Documentation/trace/coresight/ultrasoc-smb.rst > @@ -0,0 +1,80 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +====================================== > +UltraSoc - HW Assisted Tracing on SoC > +====================================== > + :Author: Qi Liu > + :Date: March 2022 > + > +Introduction > +------------ > + > +UltraSoc SMB is a per SCCL(Super CPU Cluster) hardware, and it provides a way to buffer and store minor nit: alignment. > +CPU trace messages in a region of shared system memory. SMB is plugged as > +a coresight sink device and the corresponding trace generators (ETM) are > +plugged in as source devices. > + --8>--- > +Sysfs files and directories > +--------------------------- > + > +The SMB devices appear on the existing coresight bus alongside the other > +coresight devices:: > + > + $# ls /sys/bus/coresight/devices/ > + ultra_smb0 ultra_smb1 ultra_smb2 ultra_smb3 > + > +The ``ultra_smb`` named SMB associated with SCCL.:: > + > + $# ls /sys/bus/coresight/devices/ultra_smb0 > + enable_sink mgmt > + $# ls /sys/bus/coresight/devices/ultra_smb0/mgmt > + buf_size buf_status read_pos write_pos > + These should also be placed in, with the appropriate format. Documentation/ABI/testing/sysfs-bus-coresight-devices-ultra_smb > +*Key file items are:-* > + * ``read_pos``: Shows the value held by UltraSoc SMB Read Pointer register. > + * ``write_pos``: Shows the value held by UltraSoc SMB Write Pointer register. > + * ``buf_status``: Shows the value held by UltraSoc SMB status register. > + BIT(0) is zero means buffer is empty. > + * ``buf_size``: Shows the buffer size of each UltraSoc SMB device. > + > +Firmware Bindings > +--------------------------- > + > +Firmware binding of SMB device describes SMB device indentifier, resource > +information and graph structure. Please could you mention that this is only supported with ACPI here ? > + > +SMB is platform device and device id is "HISI03A1", resource of device is > +declared using the _CRS method. Each SMB must present two base address, Simply say, the device is identified by ACPI HID "HISI03A1". > +the first one is the configuration base address of SMB device, the second > +one is the base address of shared system memory. > + > +examples:: > + > + Device(USMB) { \ > + Name(_HID, "HISI03A1") \ > + Name(_CRS, ResourceTemplate() { \ > + MEM_RESRC(0x95100000, 0x951FFFFF, 0x100000) \ > + MEM_RESRC(0x50000000, 0x53FFFFFF, 0x4000000) \ > + }) \ > + Name(_DSD, Package() { \ > + ToUUID("ab02a46b-74c7-45a2-bd68-f7d344ef2153"), \ > + /* Use CoreSight Graph ACPI bindings to describe connections topology */ > + Package() { \ > + 0, \ > + 1, \ > + Package() { \ > + 1, \ > + ToUUID("3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd"), \ > + 8, \ > + Package() {0x8, 0, \_SB.S00.SL11.CL28.F008, 0}, \ > + Package() {0x9, 0, \_SB.S00.SL11.CL29.F009, 0}, \ > + Package() {0xa, 0, \_SB.S00.SL11.CL2A.F010, 0}, \ > + Package() {0xb, 0, \_SB.S00.SL11.CL2B.F011, 0}, \ > + Package() {0xc, 0, \_SB.S00.SL11.CL2C.F012, 0}, \ > + Package() {0xd, 0, \_SB.S00.SL11.CL2D.F013, 0}, \ > + Package() {0xe, 0, \_SB.S00.SL11.CL2E.F014, 0}, \ > + Package() {0xf, 0, \_SB.S00.SL11.CL2F.F015, 0}, \ > + } \ > + } \ > + }) \ > + } Rest looks fine to me Suzuki