From patchwork Wed May 3 17:02:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mukesh Ojha X-Patchwork-Id: 13230365 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 7AF82C77B78 for ; Wed, 3 May 2023 17:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230008AbjECRGq (ORCPT ); Wed, 3 May 2023 13:06:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229993AbjECRGW (ORCPT ); Wed, 3 May 2023 13:06:22 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5FCB67A84; Wed, 3 May 2023 10:05:48 -0700 (PDT) Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 343DICht030849; Wed, 3 May 2023 17:04:36 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=qcppdkim1; bh=TcGExpkNVAKfPkIom5yVtMwcamlW4zFdCnQ1qI8g5Cg=; b=QQbDL9gqnDSzsiMazhE6SagRtHuYAMfYfI0wdli5HkaV/nG/kg2fX5EZeKTtsnE9HAAC cqvQUYYILNHgMsClh/qhygo3XNEYXILLU9vu8gURw7NLXMAT5AolCEqr9jGJ96sL73LJ 1+PFYiNoaovsEai3oqekmrSFnrlp26U6dSSpZ0cK82sE+abSFvMgtNfyPQAPdkVmFWj+ VrzlAfiYLHzC828JXhe5Fz5T83Lu8CyQGPZpob6O91qEIyDFXdNl5erWFyWY5EhIweVv LaHTJIoXd3XazGBWKpQQJoiFxrZwE6mVCvASeG3LW/L5SXlDz9uoYG6cNEFfqqWQoKsb pQ== Received: from nasanppmta01.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3qbjwn9971-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 03 May 2023 17:04:35 +0000 Received: from nasanex01c.na.qualcomm.com (nasanex01c.na.qualcomm.com [10.45.79.139]) by NASANPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 343H4Zlo004836 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 3 May 2023 17:04:35 GMT Received: from hu-mojha-hyd.qualcomm.com (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 15.2.986.42; Wed, 3 May 2023 10:04:29 -0700 From: Mukesh Ojha To: , , , , , , , , , , , , , CC: , , , , , , "Mukesh Ojha" Subject: [PATCH v3 17/18] firmware: qcom_scm: Refactor code to support multiple download mode Date: Wed, 3 May 2023 22:32:31 +0530 Message-ID: <1683133352-10046-18-git-send-email-quic_mojha@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1683133352-10046-1-git-send-email-quic_mojha@quicinc.com> References: <1683133352-10046-1-git-send-email-quic_mojha@quicinc.com> MIME-Version: 1.0 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: ReaFtwFdu3iYyzqu5eWcJvSg8A06psLn X-Proofpoint-ORIG-GUID: ReaFtwFdu3iYyzqu5eWcJvSg8A06psLn X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-03_12,2023-05-03_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 impostorscore=0 phishscore=0 suspectscore=0 adultscore=0 mlxlogscore=999 lowpriorityscore=0 priorityscore=1501 clxscore=1015 mlxscore=0 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2305030146 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org 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 --- drivers/firmware/Kconfig | 11 --------- drivers/firmware/qcom_scm.c | 60 +++++++++++++++++++++++++++++++++++++++------ 2 files changed, 52 insertions(+), 19 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 775ac68..4e8fd4e 100644 --- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -20,11 +20,11 @@ #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); +static u32 download_mode; #define SCM_HAS_CORE_CLK BIT(0) #define SCM_HAS_IFACE_CLK BIT(1) @@ -32,6 +32,7 @@ module_param(download_mode, bool, 0); #define QCOM_DOWNLOAD_MODE_MASK 0x30 #define QCOM_DOWNLOAD_FULLDUMP 0x1 +#define QCOM_DOWNLOAD_NODUMP 0x0 struct qcom_scm { struct device *dev; @@ -440,8 +441,9 @@ 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 download_mode) { + bool enable = !!download_mode; bool avail; int ret = 0; @@ -452,8 +454,7 @@ static void qcom_scm_set_download_mode(bool enable) ret = __qcom_scm_set_dload_mode(__scm->dev, enable); } else if (__scm->dload_mode_addr) { ret = qcom_scm_io_update_field(__scm->dload_mode_addr, - QCOM_DOWNLOAD_MODE_MASK, - enable ? QCOM_DOWNLOAD_FULLDUMP : 0); + QCOM_DOWNLOAD_MODE_MASK, download_mode); } else { dev_err(__scm->dev, "No available mechanism for setting download mode\n"); @@ -1421,6 +1422,49 @@ static irqreturn_t qcom_scm_irq_handler(int irq, void *data) return IRQ_HANDLED; } + +static int get_download_mode(char *buffer, const struct kernel_param *kp) +{ + int len = 0; + + if (download_mode == QCOM_DOWNLOAD_FULLDUMP) + len = sysfs_emit(buffer, "full\n"); + else if (download_mode == QCOM_DOWNLOAD_NODUMP) + len = sysfs_emit(buffer, "off\n"); + + return len; +} + +static int set_download_mode(const char *val, const struct kernel_param *kp) +{ + u32 old = download_mode; + + if (sysfs_streq(val, "full")) { + download_mode = QCOM_DOWNLOAD_FULLDUMP; + } else if (sysfs_streq(val, "off")) { + download_mode = QCOM_DOWNLOAD_NODUMP; + } else if (kstrtouint(val, 0, &download_mode) || + !(download_mode == 0 || download_mode == 1)) { + download_mode = old; + pr_err("qcom_scm: unknown download mode: %s\n", val); + return -EINVAL; + } + + if (__scm) + qcom_scm_set_download_mode(download_mode); + + return 0; +} + +static const struct kernel_param_ops download_mode_param_ops = { + .get = get_download_mode, + .set = set_download_mode, +}; + +module_param_cb(download_mode, &download_mode_param_ops, NULL, 0644); +MODULE_PARM_DESC(download_mode, + "Download mode: off/full or 0/1 for existing users"); + static int qcom_scm_probe(struct platform_device *pdev) { struct qcom_scm *scm; @@ -1514,12 +1558,12 @@ 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); + qcom_scm_set_download_mode(download_mode); return 0; } @@ -1527,7 +1571,7 @@ 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[] = {