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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B434C4724C for ; Fri, 1 May 2020 15:07:51 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2F4C32137B for ; Fri, 1 May 2020 15:07:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Rri5h3sP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F4C32137B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=aT29H9RPBqI84GxUMIKgmjnRS184sYlJXkxp6bSjQOM=; b=Rri5h3sPluoJjk/LrAngpzExq RYgXR7bqSteLqLa/DMNXmUAaC3a4rTcMV37QdVEewwSZ5mqpK8Fyo14CYzCFOmZJ+xCjcWODWnsK5 neaMZPWypScDkZmzdMy2OqGKt6oSyITEDP17xYa13T4xTLtxAI7Ra5mkqrBNGo92yALHdNRJlkG0/ rZTNEKtu5uApOLNmRlzkdVJst82/EAAhF+fs0cX/rlul+FDX9k3Wbr/KmFgopoD6dG0yA1nv6ZDU6 09Ca102uHk1iVZ2uvI4jNUg5u7jROm9g6qaqTj9ip8aVpmvjWmjYKENrB+irYWpgL9qUUTiO+EQH8 qvIF7rPPA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUXGU-00077g-JJ; Fri, 01 May 2020 15:07:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUXGR-00076w-Fq for linux-arm-kernel@lists.infradead.org; Fri, 01 May 2020 15:07:45 +0000 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 96A2230E; Fri, 1 May 2020 08:07:42 -0700 (PDT) Received: from [192.168.1.84] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C66303F68F; Fri, 1 May 2020 08:07:40 -0700 (PDT) Subject: Re: [PATCH 5/5] arm/arm64: smccc: Add ARCH_SOC_ID support To: Sudeep Holla , "linux-arm-kernel@lists.infradead.org" References: <20200430114814.14116-1-sudeep.holla@arm.com> <20200430114814.14116-6-sudeep.holla@arm.com> From: Steven Price Message-ID: <241f0a4b-e5bb-f3d9-40ff-b2f088129a0c@arm.com> Date: Fri, 1 May 2020 16:07:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200430114814.14116-6-sudeep.holla@arm.com> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200501_080743_612100_5E56D02A X-CRM114-Status: GOOD ( 24.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Lorenzo Pieralisi , Catalin Marinas , "linux-kernel@vger.kernel.org" , "Harb Abdulhamid \(harb@amperecomputing.com\)" , Will Deacon Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 30/04/2020 12:48, Sudeep Holla wrote: > SMCCC v1.2 adds a new optional function SMCCC_ARCH_SOC_ID to obtain a > SiP defined SoC identification value. Add support for the same. > > Also using the SoC bus infrastructure, let us expose the platform > specific SoC atrributes under sysfs. We also provide custom sysfs for > the vendor ID as JEP-106 bank and identification code. > > Signed-off-by: Sudeep Holla > --- > drivers/firmware/psci/Makefile | 2 +- > drivers/firmware/psci/soc_id.c | 148 +++++++++++++++++++++++++++++++++ > include/linux/arm-smccc.h | 5 ++ > 3 files changed, 154 insertions(+), 1 deletion(-) > create mode 100644 drivers/firmware/psci/soc_id.c > > diff --git a/drivers/firmware/psci/Makefile b/drivers/firmware/psci/Makefile > index 1956b882470f..c0b0c9ca57e4 100644 > --- a/drivers/firmware/psci/Makefile > +++ b/drivers/firmware/psci/Makefile > @@ -1,4 +1,4 @@ > # SPDX-License-Identifier: GPL-2.0 > # > -obj-$(CONFIG_ARM_PSCI_FW) += psci.o > +obj-$(CONFIG_ARM_PSCI_FW) += psci.o soc_id.o > obj-$(CONFIG_ARM_PSCI_CHECKER) += psci_checker.o > diff --git a/drivers/firmware/psci/soc_id.c b/drivers/firmware/psci/soc_id.c > new file mode 100644 > index 000000000000..820f69dad7f5 > --- /dev/null > +++ b/drivers/firmware/psci/soc_id.c > @@ -0,0 +1,148 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright 2020 Arm Limited > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define SOCID_JEP106_BANK_IDX_MASK GENMASK(30, 24) > +#define SOCID_JEP106_ID_CODE_MASK GENMASK(23, 16) > +#define SOCID_IMP_DEF_SOC_ID_MASK GENMASK(15, 0) > +#define JEP106_BANK_IDX(x) (u8)(FIELD_GET(SOCID_JEP106_BANK_IDX_MASK, (x))) > +#define JEP106_ID_CODE(x) (u8)(FIELD_GET(SOCID_JEP106_ID_CODE_MASK, (x))) > +#define IMP_DEF_SOC_ID(x) (u16)(FIELD_GET(SOCID_IMP_DEF_SOC_ID_MASK, (x))) > + > +static int soc_id_version; > +static struct soc_device *soc_dev; > +static struct soc_device_attribute *soc_dev_attr; > + > +static int smccc_map_error_codes(unsigned long a0) > +{ > + if (a0 == SMCCC_RET_INVALID_PARAMETER) > + return -EINVAL; > + if (a0 == SMCCC_RET_NOT_SUPPORTED) > + return -EOPNOTSUPP; > + return 0; It seems odd to special case just those errors. While they are the only errors we expect, any result with the high bit set is an error (arguably a bug in the firmware) so should really cause an error return. > +} > + > +static int smccc_soc_id_support_check(void) > +{ > + struct arm_smccc_res res; > + > + if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE) { > + pr_err("%s: invalid SMCCC conduit\n", __func__); > + return -EOPNOTSUPP; > + } > + > + arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, > + ARM_SMCCC_ARCH_SOC_ID, &res); > + > + return smccc_map_error_codes(res.a0); > +} > + > +static ssize_t > +jep106_cont_bank_code_show(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + return sprintf(buf, "%02x\n", JEP106_BANK_IDX(soc_id_version) + 1); > +} > + > +static DEVICE_ATTR_RO(jep106_cont_bank_code); > + > +static ssize_t > +jep106_identification_code_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + return sprintf(buf, "%02x\n", JEP106_ID_CODE(soc_id_version) & 0x7F); It seems odd to have the mask defined to include a bit that is then always masked off. From the spec I presume this is a parity bit, but it would be good to have a comment explaining this. > +} > + > +static DEVICE_ATTR_RO(jep106_identification_code); > + > +static struct attribute *jep106_id_attrs[] = { > + &dev_attr_jep106_cont_bank_code.attr, > + &dev_attr_jep106_identification_code.attr, > + NULL > +}; > + > +ATTRIBUTE_GROUPS(jep106_id); > + > +static int __init smccc_soc_init(void) > +{ > + struct device *dev; > + int ret, soc_id_rev; > + struct arm_smccc_res res; > + static char soc_id_str[8], soc_id_rev_str[12]; > + > + if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2) > + return 0; NIT: Do we actually need to check the version here - or would probing ARM_SMCCC_ARCH_FEATURES_FUNC_ID as is done below sufficient? I'm not aware of this relying on any new semantics that v1.2 added. > + > + ret = smccc_soc_id_support_check(); > + if (ret) > + return ret; This seems odd - if the version is =1.2 but doesn't support SOC_ID then it's an error return? > + > + arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res); > + > + ret = smccc_map_error_codes(res.a0); > + if (ret) > + return ret; > + > + soc_id_version = res.a0; > + > + arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res); > + > + ret = smccc_map_error_codes(res.a0); > + if (ret) > + return ret; > + > + soc_id_rev = res.a0; > + > + soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL); > + if (!soc_dev_attr) > + return -ENOMEM; > + > + sprintf(soc_id_str, "0x%04x", IMP_DEF_SOC_ID(soc_id_version)); > + sprintf(soc_id_rev_str, "0x%08x", soc_id_rev); > + > + soc_dev_attr->soc_id = soc_id_str; > + soc_dev_attr->revision = soc_id_rev_str; > + > + soc_dev = soc_device_register(soc_dev_attr); > + if (IS_ERR(soc_dev)) { > + ret = PTR_ERR(soc_dev); > + goto free_soc; > + } > + > + dev = soc_device_to_device(soc_dev); > + > + ret = devm_device_add_groups(dev, jep106_id_groups); > + if (ret) { > + dev_err(dev, "sysfs create failed: %d\n", ret); > + goto unregister_soc; > + } > + > + pr_info("SMCCC SoC ID: %s Revision %s\n", soc_dev_attr->soc_id, > + soc_dev_attr->revision); > + > + return 0; > + > +unregister_soc: > + soc_device_unregister(soc_dev); > +free_soc: > + kfree(soc_dev_attr); > + return ret; > +} > +module_init(smccc_soc_init); > + > +static void __exit smccc_soc_exit(void) > +{ > + if (soc_dev) > + soc_device_unregister(soc_dev); > + kfree(soc_dev_attr); > +} > +module_exit(smccc_soc_exit); > diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h > index d6b0f4acc707..04414fc2000f 100644 > --- a/include/linux/arm-smccc.h > +++ b/include/linux/arm-smccc.h > @@ -68,6 +68,11 @@ > ARM_SMCCC_SMC_32, \ > 0, 1) > > +#define ARM_SMCCC_ARCH_SOC_ID \ > + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ > + ARM_SMCCC_SMC_32, \ > + 0, 2) > + > #define ARM_SMCCC_ARCH_WORKAROUND_1 \ > ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ > ARM_SMCCC_SMC_32, \ > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel