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 7787BC64EC4 for ; Fri, 3 Mar 2023 07:47:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229586AbjCCHrA (ORCPT ); Fri, 3 Mar 2023 02:47:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229534AbjCCHq7 (ORCPT ); Fri, 3 Mar 2023 02:46:59 -0500 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 852A4521EF; Thu, 2 Mar 2023 23:46:58 -0800 (PST) Received: from pps.filterd (m0279862.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 32357uFJ011344; Fri, 3 Mar 2023 07:46:49 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=NIT8nTfoZl7k2Y7KV2J6qVcc307frlqqTymfIe0oI6w=; b=UoTOi4FigknZq+zCecWn+Wv/is2aP4fmLZvFxpo0lZuOvrFb6FMdUtbW+hHFrZR0yKcd vrJKqFj4dHG8fKipomeoUS3F+2nzDa4ppLtQURiaq6ecqZ2yrejfP0eGtsDlhMjNQzam diG8WW9VUGaSft3gaMycrYDlBXT4yGMTjln0Xwu0cT1LG/V5JaNvggxiDPVK1zZAIpEd oMdGmwsbun2Kij/4UxyoKbRsTpaci7o0wfdlSGyyQDebIDagzWQfBZkVqni8efT2S6/Q mjfrrj2wO6CBKfgGDE7Rrj+7O+5IP0bu7AG6880hetnlUXYHofczQqHehCX2hhvvThYl QQ== Received: from nasanppmta05.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3p2ar1572c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 03 Mar 2023 07:46:48 +0000 Received: from nasanex01c.na.qualcomm.com (nasanex01c.na.qualcomm.com [10.45.79.139]) by NASANPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 3237kmo7003991 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 3 Mar 2023 07:46:48 GMT Received: from [10.216.34.86] (10.80.80.8) by nasanex01c.na.qualcomm.com (10.45.79.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.41; Thu, 2 Mar 2023 23:46:45 -0800 Message-ID: Date: Fri, 3 Mar 2023 13:16:41 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH v2 3/4] firmware: qcom_scm: Refactor code to support multiple download mode Content-Language: en-US To: Dmitry Baryshkov , , , CC: , References: <1677664555-30191-1-git-send-email-quic_mojha@quicinc.com> <1677664555-30191-4-git-send-email-quic_mojha@quicinc.com> <469b4a3a-ea40-ad6b-2848-210325b8914c@linaro.org> From: Mukesh Ojha In-Reply-To: <469b4a3a-ea40-ad6b-2848-210325b8914c@linaro.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanex01c.na.qualcomm.com (10.45.79.139) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: 4dfNWHSxzdhU401kYcwlHKg-SFsvvD7p X-Proofpoint-ORIG-GUID: 4dfNWHSxzdhU401kYcwlHKg-SFsvvD7p X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-03_01,2023-03-02_02,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 mlxscore=0 bulkscore=0 impostorscore=0 phishscore=0 lowpriorityscore=0 suspectscore=0 priorityscore=1501 spamscore=0 mlxlogscore=999 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2303030068 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Thanks for your time in checking this.. On 3/1/2023 4:29 PM, Dmitry Baryshkov wrote: > On 01/03/2023 11:55, Mukesh Ojha wrote: >> Currently on Qualcomm SoC, download_mode is enabled if >> CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT is selected. >> >> Refactor the code such that it supports multiple download >> modes and drop CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT config >> instead, give interface to set the download mode from >> module parameter. >> >> Signed-off-by: Mukesh Ojha >> --- >> Changes in v2: >>   - Passed download mode as parameter >>   - Accept human accepatable download mode string. >>   - enable = !!dload_mode >>   - Shifted module param callback to somewhere down in >>     the file so that it no longer need to know the >>     prototype of qcom_scm_set_download_mode() >>   - updated commit text. >> >>   drivers/firmware/Kconfig    | 11 -------- >>   drivers/firmware/qcom_scm.c | 65 >> ++++++++++++++++++++++++++++++++++++++------- >>   2 files changed, 56 insertions(+), 20 deletions(-) >> >> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig >> index b59e304..ff7e9f3 100644 >> --- a/drivers/firmware/Kconfig >> +++ b/drivers/firmware/Kconfig >> @@ -215,17 +215,6 @@ config MTK_ADSP_IPC >>   config QCOM_SCM >>       tristate >> -config QCOM_SCM_DOWNLOAD_MODE_DEFAULT >> -    bool "Qualcomm download mode enabled by default" >> -    depends on QCOM_SCM >> -    help >> -      A device with "download mode" enabled will upon an unexpected >> -      warm-restart enter a special debug mode that allows the user to >> -      "download" memory content over USB for offline postmortem >> analysis. >> -      The feature can be enabled/disabled on the kernel command line. >> - >> -      Say Y here to enable "download mode" by default. >> - >>   config SYSFB >>       bool >>       select BOOT_VESA_SUPPORT >> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c >> index c9f1fad..ca07208 100644 >> --- a/drivers/firmware/qcom_scm.c >> +++ b/drivers/firmware/qcom_scm.c >> @@ -17,17 +17,22 @@ >>   #include >>   #include >>   #include >> +#include >>   #include "qcom_scm.h" >> -static bool download_mode = >> IS_ENABLED(CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT); >> -module_param(download_mode, bool, 0); >> - >>   #define SCM_HAS_CORE_CLK    BIT(0) >>   #define SCM_HAS_IFACE_CLK    BIT(1) >>   #define SCM_HAS_BUS_CLK        BIT(2) >>   #define QCOM_DOWNLOAD_MODE_MASK 0x30 >> +#define QCOM_DOWNLOAD_FULLDUMP    0x10 >> +#define QCOM_DOWNLOAD_NODUMP    0x0 >> + >> +#define MAX_DLOAD_LEN    8 >> + >> +static char download_mode[] = "off"; >> +static u32 dload_mode; >>   struct qcom_scm { >>       struct device *dev; >> @@ -417,8 +422,9 @@ static int __qcom_scm_set_dload_mode(struct device >> *dev, bool enable) >>       return qcom_scm_call_atomic(__scm->dev, &desc, NULL); >>   } >> -static void qcom_scm_set_download_mode(bool enable) >> +static void qcom_scm_set_download_mode(u32 dload_mode) >>   { >> +    bool enable = !!dload_mode; >>       bool avail; >>       int ret = 0; >>       u32 val; >> @@ -438,7 +444,7 @@ static void qcom_scm_set_download_mode(bool enable) >>           val &= ~QCOM_DOWNLOAD_MODE_MASK; >>           if (enable) >> -            val |= QCOM_SCM_BOOT_SET_DLOAD_MODE; >> +            val |= dload_mode; >>           ret = qcom_scm_io_writel(__scm->dload_mode_addr, val); >>       } else { >> @@ -1338,6 +1344,47 @@ bool qcom_scm_is_available(void) >>   } >>   EXPORT_SYMBOL(qcom_scm_is_available); >> +static int set_dload_mode(const char *val, const struct kernel_param >> *kp) >> +{ >> +    int ret; >> + >> +    if (!strncmp(val, "full", strlen("full"))) { >> +        dload_mode = QCOM_DOWNLOAD_FULLDUMP; >> +    } else if (!strncmp(val, "off", strlen("off"))) { >> +        dload_mode = QCOM_DOWNLOAD_NODUMP; >> +    } else { >> +        if (kstrtouint(val, 0, &dload_mode) || >> +             !(dload_mode == 0 || dload_mode == 1)) { >> +            pr_err("unknown download mode\n"); >> +            return -EINVAL; >> +        } >> + >> +    } >> + >> +    ret = param_set_copystring(val, kp); >> +    if (ret) >> +        return ret; >> + >> +    if (__scm) >> +        qcom_scm_set_download_mode(dload_mode); >> + >> +    return 0; >> +} >> + >> +static const struct kernel_param_ops dload_mode_param_ops = { >> +    .set = set_dload_mode, >> +    .get = param_get_string, > > Please follow the param_get_bool approach and return sanitized data > here. In other words, "full" / "none" depending on the dload_mode > instead of storing the passed string and returning it later. > This could be done. >> +}; >> + >> +static struct kparam_string dload_mode_param = { >> +    .string = download_mode, >> +    .maxlen = MAX_DLOAD_LEN, > > I think writing "full" to this param might overwrite some kernel data. > "00000000" should be even worse. There is check in param_set_copystring() which would avoid that. > >> +}; >> + >> +module_param_cb(download_mode, &dload_mode_param_ops, >> &dload_mode_param, 0644); >> +MODULE_PARM_DESC(download_mode, >> +         "Download mode: off/full or 0/1/off/on for existing users"); > > Nit: on is not supported even for existing users. Agree. just 0/1 would do fine there. -Mukesh > >> + >>   static int qcom_scm_probe(struct platform_device *pdev) >>   { >>       struct qcom_scm *scm; >> @@ -1418,12 +1465,12 @@ static int qcom_scm_probe(struct >> platform_device *pdev) >>       __get_convention(); >>       /* >> -     * If requested enable "download mode", from this point on warmboot >> +     * If download mode is requested, from this point on warmboot >>        * will cause the boot stages to enter download mode, unless >>        * disabled below by a clean shutdown/reboot. >>        */ >> -    if (download_mode) >> -        qcom_scm_set_download_mode(true); >> +    if (dload_mode) >> +        qcom_scm_set_download_mode(dload_mode); >>       return 0; >>   } >> @@ -1431,7 +1478,7 @@ static int qcom_scm_probe(struct platform_device >> *pdev) >>   static void qcom_scm_shutdown(struct platform_device *pdev) >>   { >>       /* Clean shutdown, disable download mode to allow normal restart */ >> -    qcom_scm_set_download_mode(false); >> +    qcom_scm_set_download_mode(QCOM_DOWNLOAD_NODUMP); >>   } >>   static const struct of_device_id qcom_scm_dt_match[] = { >