openwrt/target/linux/sifiveu/patches-6.1/0006-riscv-sbi-srst-support.patch

From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=S+R5=LD=lists.infradead.org=linux-riscv-bounces+linux-riscv=archiver.kernel.org@kernel.org>
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=-21.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH,
	DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,
	INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,MSGID_FROM_MTA_HEADER,
	SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 9A34CC48BCD
	for <[email protected]>; Wed,  9 Jun 2021 12:50:08 +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 69795611C9
	for <[email protected]>; Wed,  9 Jun 2021 12:50:08 +0000 (UTC)
DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 69795611C9
Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=wdc.com
Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=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.20210309; h=Sender:
	Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post:
	List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:
	Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:
	Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:
	List-Owner; bh=64gRxQ9bX8C6wjLq0KuJ2lv98bQdXijt0LPnNpch3NU=; b=rgeSpoSWQ+Nca2
	9PLsgI7dOYVdTu48CyVJStiizsvIvVFN2rBAgELHF2nRCCtoSiPMxgcpCKtDcm7sh9lC8AblCoBjN
	LXiPRHVYJAcRNiWiQ0qOTqHdTbezFdzSjNOs6drbaiI4B8AZtychw1hP+ubsb5czAaz6510OEVct/
	h5M4Tlljcn/WIyulBd/tnuUOZPT0XL6rb2+TvRQvjXDBFHN+bWqP8OjXKnE1FTvy5MF8OTlUgI6wr
	3f4t/eS/PPbtXRD5raJzEwEQLJ6XY6NJABs40tKpWZNuUaqTfmonNdbP9y1htWhByhsAk+fw5WK/C
	/KocvM6IzPmqGIBWcTdQ==;
Received: from localhost ([::1] helo=bombadil.infradead.org)
	by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux))
	id 1lqxeS-00Do8i-Hj; Wed, 09 Jun 2021 12:49:44 +0000
Received: from esa4.hgst.iphmx.com ([216.71.154.42])
 by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux))
 id 1lqx5h-00DbCQ-K0
 for [email protected]; Wed, 09 Jun 2021 12:13:51 +0000
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple;
 d=wdc.com; [email protected]; q=dns/txt; s=dkim.wdc.com;
 t=1623240829; x=1654776829;
 h=from:to:cc:subject:date:message-id:in-reply-to:
 references:content-transfer-encoding:mime-version;
 bh=s4va/Owvq7MQI8rUsD/e02RmaYfJNzYNcxlXspGRY7g=;
 b=G5GD9eN+rv669E7jyRnRAt0jw83CxhIrSiDIjXuPmhWyMhKeQGD7ACRm
 ii6o0zmOREhGihtwB6X/xpY/2ZvK+cxcHmJXa+Ykyn8QN+/YKFtg3svfj
 eiTN7U/mEozCoGNd1wXu59RQj11Xz60DN/qEUlYFaL6SjukUgifFVgbvG
 uUj8AM8+xf1jKHi3Q/6nVPpJX8uiW/NPFHrwI8hxUwYr9viQwxXvc7FNr
 fR8bH2c/HiGacGYEHosgP0WT//d9Huqn4JNINvjidK4ZSJ74cXlr8KwMG
 8snmfx4UjEWMhK1lCYalJEU7nxXFfih/6DMuFRorETpWQ+424BAKUJdDH Q==;
IronPort-SDR: pYhRsIZkhfmi45K4HfnZj39kxfUGpxs1e+q+Wh8kDE+ySh35HkJaaUcpP04mb7VeIVtPRx/h6Q
 imv6sn8fYo/V8ezHAq4jpd1QadqInKi1ubLnCE3Zy7GnhVBepoV6FbI14Y01V+5QIUwYdFNcGG
 RsxDOTQyU5AljH0Rc6WkrpdVf5jsrXXMddmlDdi6QsfKGy7MwQ/NYojNIqyLhRSgu5w2uTIE7X
 atSbjb8j2a+EJUY0WgYTGfNHKCdQLAhjcsWZgU7Iu0vSaBU6A7seCkqun24dvF/zYuzEj7wedD
 TvE=
X-IronPort-AV: E=Sophos;i="5.83,260,1616428800"; d="scan'208";a="170575129"
Received: from mail-dm6nam12lp2169.outbound.protection.outlook.com (HELO
 NAM12-DM6-obe.outbound.protection.outlook.com) ([104.47.59.169])
 by ob1.hgst.iphmx.com with ESMTP; 09 Jun 2021 20:13:48 +0800
ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none;
 b=hrlr4Qi66FmbQW45zI7QeA9nEYSvxO+tR++vUyFHxjRqnr6WtjKgHM8hPpp8oHXaK82U0+KQUc2+WjLbe8LihexXFQs5zRwBDwuArmkKt85cL3utD3OBzTkr4A9ZhRS5mzztnn9kvTFNplPjSydXPetJQIZ9WKmihJrdeaGQ+zQ//6TdDWVpLyBbqiBVUbUwlKQbpbbfHvzQCHYQbIiUcGn4vaSXYp2Xp1Z5yYVtrfDK+TemKG/8fKQoJjg/tdmDtQ97Cgw7nX6Oc9kdmoTIxFilMy4XjPciPcNOPdLmboGCt6+TMBeftLc1VFNnr7PwuxOogv4I7eJ/P9UaK57k5A==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; 
 s=arcselector9901;
 h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck;
 bh=Ibi36Vj2s7bu56DZaU1uSl4xNA3OB2FHlI/rBKn+8xo=;
 b=CE3o+0GFLPMQuw0AK1IRf/vX00diXsjayn0MmpS7ntSVXgxXIAPT9aDtk7x0NovJBTk2LHI5Mtxvz6SwVnJzUqZmNsXUktEj5Iwdd8EPIIxgCOjugo/6WC0FqaFKNvJB4hQ0tjFxv+J5DexSJ8+mPx6Ucr4DwtUXrCWzOeXyF5YK68mU5FgttbyutW3CGsGkPgaPAdOxXOgJqyYu8X25unmzG12Jq2xC4oVKsbA+RfDiaMKm97q2Bhy+LcgJNS6/ktlFKSOVu1HQ0POYgba3mtldN3vg73wLbxrfsdoe4261aJpkM05GJFDzdTNp4t3rEGhNuLR1+8OmKfLlPeSU9w==
ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass
 smtp.mailfrom=wdc.com; dmarc=pass action=none header.from=wdc.com; dkim=pass
 header.d=wdc.com; arc=none
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=sharedspace.onmicrosoft.com; s=selector2-sharedspace-onmicrosoft-com;
 h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck;
 bh=Ibi36Vj2s7bu56DZaU1uSl4xNA3OB2FHlI/rBKn+8xo=;
 b=Z76YsVxTHK6/ta19C5vwaBPYmtDa2GIM/ml4myQZfIaHFNzXPzZ+PFcYy/Xf1Ixd0GZHcuSZQYgs/SPHWATh+rOWBAislGv1zmSAG/g0tiDckB8WaCwh1e3qGW4ZmUTmAU7dxB0vn0pRSLTnc1hdCUZ73buM78qo9qwsQZv41d0=
Authentication-Results: dabbelt.com; dkim=none (message not signed)
 header.d=none;dabbelt.com; dmarc=none action=none header.from=wdc.com;
Received: from CO6PR04MB7812.namprd04.prod.outlook.com (2603:10b6:303:138::6)
 by CO6PR04MB7794.namprd04.prod.outlook.com (2603:10b6:303:13f::7)
 with Microsoft SMTP Server (version=TLS1_2,
 cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4219.21; Wed, 9 Jun
 2021 12:13:47 +0000
Received: from CO6PR04MB7812.namprd04.prod.outlook.com
 ([fe80::a153:b7f8:c87f:89f8]) by CO6PR04MB7812.namprd04.prod.outlook.com
 ([fe80::a153:b7f8:c87f:89f8%9]) with mapi id 15.20.4219.021; Wed, 9 Jun 2021
 12:13:47 +0000
From: Anup Patel <[email protected]>
To: Palmer Dabbelt <[email protected]>,
 Palmer Dabbelt <[email protected]>,
 Paul Walmsley <[email protected]>, Albert Ou <[email protected]>
Cc: Atish Patra <[email protected]>,
 Alistair Francis <[email protected]>,
 Anup Patel <[email protected]>, [email protected],
 [email protected], Anup Patel <[email protected]>
Subject: [PATCH v7 1/1] RISC-V: Use SBI SRST extension when available
Date: Wed,  9 Jun 2021 17:43:22 +0530
Message-Id: <[email protected]>
X-Mailer: git-send-email 2.25.1
In-Reply-To: <[email protected]>
References: <[email protected]>
X-Originating-IP: [122.172.176.125]
X-ClientProxiedBy: MA1PR0101CA0036.INDPRD01.PROD.OUTLOOK.COM
 (2603:1096:a00:22::22) To CO6PR04MB7812.namprd04.prod.outlook.com
 (2603:10b6:303:138::6)
MIME-Version: 1.0
X-MS-Exchange-MessageSentRepresentingType: 1
Received: from wdc.com (122.172.176.125) by
 MA1PR0101CA0036.INDPRD01.PROD.OUTLOOK.COM (2603:1096:a00:22::22) with
 Microsoft SMTP Server (version=TLS1_2,
 cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4219.21 via Frontend
 Transport; Wed, 9 Jun 2021 12:13:44 +0000
X-MS-PublicTrafficType: Email
X-MS-Office365-Filtering-Correlation-Id: 17406ef0-e8d7-4dc3-eee9-08d92b40085b
X-MS-TrafficTypeDiagnostic: CO6PR04MB7794:
X-MS-Exchange-Transport-Forked: True
X-Microsoft-Antispam-PRVS: <CO6PR04MB77945CDDD1538EFCA060925B8D369@CO6PR04MB7794.namprd04.prod.outlook.com>
WDCIPOUTBOUND: EOP-TRUE
X-MS-Oob-TLC-OOBClassifiers: OLM:2887;
X-MS-Exchange-SenderADCheck: 1
X-Microsoft-Antispam: BCL:0;
X-Microsoft-Antispam-Message-Info: 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
X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:;
 IPV:NLI; SFV:NSPM; H:CO6PR04MB7812.namprd04.prod.outlook.com; PTR:; CAT:NONE;
 SFS:(4636009)(396003)(39860400002)(136003)(346002)(366004)(376002)(8676002)(316002)(55236004)(38100700002)(38350700002)(110136005)(86362001)(54906003)(4326008)(956004)(966005)(478600001)(26005)(186003)(55016002)(8936002)(2616005)(7696005)(52116002)(16526019)(5660300002)(8886007)(6666004)(1076003)(66476007)(66556008)(36756003)(66946007)(83380400001)(2906002)(44832011);
 DIR:OUT; SFP:1102; 
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?2kfiFAcyFkAMcwkoCUqJGxdVnwsuTm5WWTXA4Pq0ZNAjWsfYI4MNugTA9f8C?=
 =?us-ascii?Q?WaQrYEizTkvIlgRDqeKVRS0vaMaeU9XaSzO6UAJMnd0jY3BzkJgKUU9xj1aU?=
 =?us-ascii?Q?vmwXKxCS+vZ2VKgLifaU1JCeemiJqV9aW+6AJEycq722bz9yXmcaJsaHWtX3?=
 =?us-ascii?Q?4sSoLeVPvfzwzDZEEoGsZZi1G7inY2imGEgY/r3m5/qYvavJQ3An4e4sjEqZ?=
 =?us-ascii?Q?Z4a4FAd/6c3X8cjmNwGvgWoAIM5WaJYFQe30MQ79alCUfZyiKB4tR0+5OGFd?=
 =?us-ascii?Q?P/rQ169Z644JNKKcEabikpL7qZZJ6OMPTS7XR9x/7GzWOJ7soV3/3I2tfCdi?=
 =?us-ascii?Q?xVsOK1DRF4y6gi5udvnb+Uu1U5wC1NlT0U/+TrnTSeY/IuLmMgFUysw+fQ+D?=
 =?us-ascii?Q?DIVN44TKrMoEZKx9SKcx4jYpUGYvaCH4sVOAx3zWQC0Oz1Nz3/a/isywpQW9?=
 =?us-ascii?Q?1I1kl/2N97K0EoWIPf6qPjyLVWXg1dOHfk6SjNW64JIIPUNnM3h7k2igDX3o?=
 =?us-ascii?Q?d7lWyFfzoWhNC7opS71uzta+ti8aHxo+xzvYvf2wLb+fdyEP9t+oQVrEQYIW?=
 =?us-ascii?Q?rAUKPqjEfAZOYBB28SaabfVt/QF6hFfV/0yJ/JV/Ie8ivC1t6iO+QZQscV7K?=
 =?us-ascii?Q?d4Pg+xVSE+m+LsgNwO36cTTe6hSLBPnWU1NMOW2cxTRKGm0Lwd2HyjyKTBMD?=
 =?us-ascii?Q?BcnKo9GXAVgOAGCG5cwEBN76q6sXxbWy0pjni3O2bLYBg4CIYCB/JNzOIfE0?=
 =?us-ascii?Q?Toz6Qwc4aw5NxRLqz9IygGT6ZunRVUWUsgJrIt5U20elX+lRmtX1cqrQNTON?=
 =?us-ascii?Q?ZHzuAI587pB0zK4EiS25hc9C8RtwjlY67heuMsYZDww5TU+NV3+0WN1/NrCX?=
 =?us-ascii?Q?3kB7O188tvm1sWVhCaC6hk9s19nKGRgMS5OHXTMxhmyw1Dn/zorMYff3r9ZE?=
 =?us-ascii?Q?sNiBI7fwru/Jsxt2/jNCpFaEYUa9JkrdSse76BXo/UxLALnxO3bzpym3Dq+T?=
 =?us-ascii?Q?s4uEA8UncKM0e+Mhp9hW1c3DR61Qjj8wb+LV3XB0qYK/1rHs8IDdJ97tw1fp?=
 =?us-ascii?Q?Ux9SlgS9YE2bEp6wxcX6TpA5DoYjqdlK50/4/DZ3YTXWlPTaQbt/j36TbEgZ?=
 =?us-ascii?Q?hhIV08WX7EDjBz1QrFRppEtBghOJikHLdvPo6GnZkHNQ9cxaa8Jrk0iypK4d?=
 =?us-ascii?Q?bMj47kiugWCGY+ZW2ioGV1GgH1aZEvAukQgTiAAiyGU83td11Q5Pv2N5ytvk?=
 =?us-ascii?Q?i+Ux/DUoeU4VyqYnb69asjdyKI5RzIxQPdQAQ7x/TBlyPp/Yj2/v31b6lCYT?=
 =?us-ascii?Q?b1iYdeIKK+6I6A+e/EUnPOKC?=
X-OriginatorOrg: wdc.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 17406ef0-e8d7-4dc3-eee9-08d92b40085b
X-MS-Exchange-CrossTenant-AuthSource: CO6PR04MB7812.namprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Jun 2021 12:13:47.1304 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: b61c8803-16f3-4c35-9b17-6f65f441df86
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: rHld9c5jovIZF30ZL04ehEJ81O0isWetsUM3vlp/0cN1LoJ5z8guKzUTANDGVGM0Eua+2cZ1jQGTC49NwWH4hA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO6PR04MB7794
X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 
X-CRM114-CacheID: sfid-20210609_051349_766689_30430D67 
X-CRM114-Status: GOOD (  15.29  )
X-BeenThere: [email protected]
X-Mailman-Version: 2.1.34
Precedence: list
List-Id: <linux-riscv.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-riscv>,
 <mailto:[email protected]?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/linux-riscv/>
List-Post: <mailto:[email protected]>
List-Help: <mailto:[email protected]?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-riscv>,
 <mailto:[email protected]?subject=subscribe>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "linux-riscv" <[email protected]>
Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org

The SBI SRST extension provides a standard way to poweroff and
reboot the system irrespective to whether Linux RISC-V S-mode
is running natively (HS-mode) or inside Guest/VM (VS-mode).

The SBI SRST extension is available in the SBI v0.3 specification.
(Refer, https://github.com/riscv/riscv-sbi-doc/releases/tag/v0.3.0-rc1)

This patch extends Linux RISC-V SBI implementation to detect
and use SBI SRST extension.

Signed-off-by: Anup Patel <[email protected]>
Reviewed-by: Atish Patra <[email protected]>
---
 arch/riscv/include/asm/sbi.h | 24 ++++++++++++++++++++++++
 arch/riscv/kernel/sbi.c      | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)

--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -27,6 +27,7 @@ enum sbi_ext_id {
 	SBI_EXT_IPI = 0x735049,
 	SBI_EXT_RFENCE = 0x52464E43,
 	SBI_EXT_HSM = 0x48534D,
+	SBI_EXT_SRST = 0x53525354,
 };
 
 enum sbi_ext_base_fid {
@@ -70,6 +71,21 @@ enum sbi_hsm_hart_status {
 	SBI_HSM_HART_STATUS_STOP_PENDING,
 };
 
+enum sbi_ext_srst_fid {
+	SBI_EXT_SRST_RESET = 0,
+};
+
+enum sbi_srst_reset_type {
+	SBI_SRST_RESET_TYPE_SHUTDOWN = 0,
+	SBI_SRST_RESET_TYPE_COLD_REBOOT,
+	SBI_SRST_RESET_TYPE_WARM_REBOOT,
+};
+
+enum sbi_srst_reset_reason {
+	SBI_SRST_RESET_REASON_NONE = 0,
+	SBI_SRST_RESET_REASON_SYS_FAILURE,
+};
+
 #define SBI_SPEC_VERSION_DEFAULT	0x1
 #define SBI_SPEC_VERSION_MAJOR_SHIFT	24
 #define SBI_SPEC_VERSION_MAJOR_MASK	0x7f
@@ -148,6 +164,14 @@ static inline unsigned long sbi_minor_ve
 	return sbi_spec_version & SBI_SPEC_VERSION_MINOR_MASK;
 }
 
+/* Make SBI version */
+static inline unsigned long sbi_mk_version(unsigned long major,
+					    unsigned long minor)
+{
+	return ((major & SBI_SPEC_VERSION_MAJOR_MASK) <<
+		SBI_SPEC_VERSION_MAJOR_SHIFT) | minor;
+}
+
 int sbi_err_map_linux_errno(int err);
 #else /* CONFIG_RISCV_SBI */
 static inline int sbi_remote_fence_i(const unsigned long *hart_mask) { return -1; }
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -7,6 +7,7 @@
 
 #include <linux/init.h>
 #include <linux/pm.h>
+#include <linux/reboot.h>
 #include <asm/sbi.h>
 #include <asm/smp.h>
 
@@ -501,6 +502,32 @@ int sbi_remote_hfence_vvma_asid(const un
 }
 EXPORT_SYMBOL(sbi_remote_hfence_vvma_asid);
 
+static void sbi_srst_reset(unsigned long type, unsigned long reason)
+{
+	sbi_ecall(SBI_EXT_SRST, SBI_EXT_SRST_RESET, type, reason,
+		  0, 0, 0, 0);
+	pr_warn("%s: type=0x%lx reason=0x%lx failed\n",
+		__func__, type, reason);
+}
+
+static int sbi_srst_reboot(struct notifier_block *this,
+			   unsigned long mode, void *cmd)
+{
+	sbi_srst_reset((mode == REBOOT_WARM || mode == REBOOT_SOFT) ?
+		       SBI_SRST_RESET_TYPE_WARM_REBOOT :
+		       SBI_SRST_RESET_TYPE_COLD_REBOOT,
+		       SBI_SRST_RESET_REASON_NONE);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block sbi_srst_reboot_nb;
+
+static void sbi_srst_power_off(void)
+{
+	sbi_srst_reset(SBI_SRST_RESET_TYPE_SHUTDOWN,
+		       SBI_SRST_RESET_REASON_NONE);
+}
+
 /**
  * sbi_probe_extension() - Check if an SBI extension ID is supported or not.
  * @extid: The extension ID to be probed.
@@ -608,6 +635,14 @@ void __init sbi_init(void)
 		} else {
 			__sbi_rfence	= __sbi_rfence_v01;
 		}
+		if ((sbi_spec_version >= sbi_mk_version(0, 3)) &&
+		    (sbi_probe_extension(SBI_EXT_SRST) > 0)) {
+			pr_info("SBI SRST extension detected\n");
+			pm_power_off = sbi_srst_power_off;
+			sbi_srst_reboot_nb.notifier_call = sbi_srst_reboot;
+			sbi_srst_reboot_nb.priority = 192;
+			register_restart_handler(&sbi_srst_reboot_nb);
+		}
 	} else {
 		__sbi_set_timer = __sbi_set_timer_v01;
 		__sbi_send_ipi	= __sbi_send_ipi_v01;