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 CC9A0C00A5A for ; Thu, 19 Jan 2023 16:52:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230319AbjASQwp (ORCPT ); Thu, 19 Jan 2023 11:52:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230410AbjASQwO (ORCPT ); Thu, 19 Jan 2023 11:52:14 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 723398CE66; Thu, 19 Jan 2023 08:52:02 -0800 (PST) Received: from pps.filterd (m0279873.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 30JDoehu011854; Thu, 19 Jan 2023 16:51:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=qcppdkim1; bh=bfWor0xqewZyj21QtzzyDo7CaQ3qAeAWgzAps0t0FEc=; b=bcbpjYjdthie7Y2f4Kl1qycrUrkwZOQWn0DRdIGNjVzSuCDmn4G1LwVp0WJ3CfLCe8vV +5VtTsFQ9SUaN52slM15CZtPD2EK2e9lsW3zdyW2iIbpbiXx6BkARlUbEhHeLh0O8i74 tVLdHYaEe+XQz4zBNgsuOmFPdGldpDSSkrL2Du6bxNa68/UJpREmYBs//RJBJn+9WtZj CaHxd081LIbSd6NHUcsF79wAXwyQu5ib6gkCRmqaX6Yye8cSZHgXe1fkLD2vck3ccb8i sihlRY7NFPilddUhnJCg3Syiwofs5pzLQUrr+kjQVn3ZLR+vvFRLMzF5V2PzK4k54ijG 1g== Received: from nalasppmta01.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3n7593rknc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 19 Jan 2023 16:51:51 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 30JGpogD006643 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 19 Jan 2023 16:51:50 GMT Received: from [10.50.23.68] (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Thu, 19 Jan 2023 08:51:48 -0800 Message-ID: Date: Thu, 19 Jan 2023 22:21:27 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH V0 1/1] bootconfig: Increase max size of bootconfig from 32 KB to 256 KB for DCC support Content-Language: en-US To: "Masami Hiramatsu (Google)" CC: , Bjorn Andersson , , , "Sai Prakash Ranjan" , Sibi Sankar , Rajendra Nayak References: <654357bcbfd3974072a558c494a51edafaa73e1a.1673261071.git.quic_schowdhu@quicinc.com> <20230110001820.5ca81344286f614ed4ccec77@kernel.org> <20230110234643.7bbd340ece99c28f25fe7ad7@kernel.org> <9545ca51-ccda-64f0-bdd4-3b53e06785ad@quicinc.com> <20230112160128.600f9e7257d67aa63a5fbcb9@kernel.org> From: Souradeep Chowdhury In-Reply-To: <20230112160128.600f9e7257d67aa63a5fbcb9@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: 43zltKugorCf6LKon1rBTKjhbCvzIXrO X-Proofpoint-ORIG-GUID: 43zltKugorCf6LKon1rBTKjhbCvzIXrO X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.122.1 definitions=2023-01-19_10,2023-01-19_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 mlxlogscore=999 spamscore=0 suspectscore=0 mlxscore=0 adultscore=0 clxscore=1015 impostorscore=0 priorityscore=1501 bulkscore=0 malwarescore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2301190135 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/12/2023 12:31 PM, Masami Hiramatsu (Google) wrote: > On Tue, 10 Jan 2023 20:38:54 +0530 > Souradeep Chowdhury wrote: > >> >> >> On 1/10/2023 8:16 PM, Masami Hiramatsu (Google) wrote: >>> On Tue, 10 Jan 2023 17:26:07 +0530 >>> Souradeep Chowdhury wrote: >>> >>>> >>>> >>>> On 1/9/2023 8:48 PM, Masami Hiramatsu (Google) wrote: >>>>> On Mon, 9 Jan 2023 20:01:05 +0530 >>>>> Souradeep Chowdhury wrote: >>>>> >>>>>> Increasing the memory size of bootconfig to be able to handle a max number of >>>>>> 8192 nodes to be fitted in memory size of 256KB. >>>>> >>>>> Sorry, but you missed the 'xbc_node::data' stores the index of the data and >>>>> that is uint16_t. So the XBC_DATA_MAX is fixed limitation. >>>>> >>>>> The number of nodes (XBC_NODE_MAX) can be expanded because I just decided it >>>>> to keep the pre-compiled array size ~8KB. Maybe expanding it to 64KB just >>>>> increase the size of kernel on init memory (and freed after boot). >>>>> >>>>> Could you tell me why you need such a big data for your DCC? >>>>> >>>>> Thank you, >>>> >>>> DCC is a debugging tool used in qcom which is needed to debug crashes >>>> that can happen at boot-time. For debugging purposes a large number of >>>> registers need to be configured in DCC driver which is to be fed via the >>>> bootconfig file. For that we need to expand the nodes as well as memory >>>> for using bootconfig. >>> >>> Hmm, how many registers does DCC usually use? And how big the bootconfig >>> file is usually? I have no idea about that. >> >> So a typical bootconfig file for consumption of DCC looks like as follows >> >> dcc_config { >> link_list_0 { >> qcom-curr-link-list = 6 >> qcom-link-list = R_0x1781005c_1_apb, >> R_0x1782005c_1_apb >> } >> link_list_1 { >> qcom-curr-link-list = 5 >> qcom-link-list = R_0x1784005c_1_apb >> } >> } >> >> The "qcom-link-list" field can have 1000s of register , based on that >> max nodes is increased to 8192. > > OK, then the number of fields can be larger than 1000. I got it. > >> >>> >>>> Can you let us know the changes that you suggest for doing the same? Is >>>> it fine to just increase the XBC_NODE_MAX, do we also need to >>>> change the uint16_t to u32 for proper storing of index values? >>> >>> Expanding the number of max nodes is easy, just increase the XBC_NODE_MAX >>> (must be less than 64k). That will also increase the memory consumption >>> during the boot time even if the bootconfig is small. Anyway, it will be >>> freed after boot, so it maybe OK. >> >> So since the limit is 64K, 8192 is a valid value for max nodes. > > Yes. Expanding the number of node is OK to me. > >> >>> >>> But expanding the size of max bootconfig needs to change the type of >>> the 'data' field to uint32_t (since that will be used for building >>> bootconfig tool) and you also must confirm that `tools/bootconfig/bootconfig` >>> can be built and pass the test-bootconfig.sh. >>> Hmm, comparing with expanding the max number of XBC node, changing the >>> 'data' type to uint32_t may not have much impact on memory consumption point >>> of view, because it may increase only 20% of memory, but expanding the >>> MAX_XBC_NODE always increases more than double. >>> >>> Thus, if we can accept increasing the number of node, it should be OK to >>> change the 'data' type. >> >> That means from DCC point of view only increasing the max nodes is >> enough as increasing the data size is unrelated to increasing the max nodes? > > Yes, if it is less than 32KB, you just need to increase the XBC_NODE_MAX. > But if you think the size of bootconfig, we have to change the type of > xbc_node::data field. > > Can you check the DCC also need to expand the size of bootconfig limitation? > > Thank you! Yes, I don't think the index needs to be increased from u16 to u32 for dcc. Will be sending out the next version accordingly. Thanks > >> >>> >>> BTW, I think now we don't need the ' __attribute__ ((__packed__))' for >>> struct xbc_node. It was packed for reducing the size of array and able to >>> pass 'compiled' bootconfig, but now it is just passed as a text data for >>> safety. >> >>> >>> Thank you, >>> >>>> >>>> >>>>> >>>>>> >>>>>> Signed-off-by: Souradeep Chowdhury >>>>>> --- >>>>>> include/linux/bootconfig.h | 6 +++--- >>>>>> 1 file changed, 3 insertions(+), 3 deletions(-) >>>>>> >>>>>> diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h >>>>>> index 1611f9d..64d233b 100644 >>>>>> --- a/include/linux/bootconfig.h >>>>>> +++ b/include/linux/bootconfig.h >>>>>> @@ -55,11 +55,11 @@ struct xbc_node { >>>>>> } __attribute__ ((__packed__)); >>>>>> >>>>>> #define XBC_KEY 0 >>>>>> -#define XBC_VALUE (1 << 15) >>>>>> -/* Maximum size of boot config is 32KB - 1 */ >>>>>> +#define XBC_VALUE (1 << 18) >>>>>> +/* Maximum size of boot config is 256KB - 1 */ >>>>>> #define XBC_DATA_MAX (XBC_VALUE - 1) >>>>>> >>>>>> -#define XBC_NODE_MAX 1024 >>>>>> +#define XBC_NODE_MAX 8192 >>>>>> #define XBC_KEYLEN_MAX 256 >>>>>> #define XBC_DEPTH_MAX 16 >>>>>> >>>>>> -- >>>>>> 2.7.4 >>>>>> >>>>> >>>>> >>> >>> > >