From patchwork Thu Sep 23 14:57:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cristian Marussi X-Patchwork-Id: 12513147 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=-18.2 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,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 82381C433F5 for ; Thu, 23 Sep 2021 15:02:38 +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 53415611B0 for ; Thu, 23 Sep 2021 15:02:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 53415611B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=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:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id: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=num6cYPh3czu0uoBHXBxr530uNZ33hnoA4JGao2rY+k=; b=jvYPnO5ERwiENr eI0ScwJ2mfZk+h1oOfXVqVm1thbDCgLt/hJZsQje0So2FzaVBAT8JxP7q9YzNIsn70QIf+91rFAJY zclBrGkFF5gZsrbngiEjZ7fLPmE8lcTYJJpY5QKViadArhJqZmns6arzNpXJP0bLOvYSPtfrsRirL jYS/Xr8Ajr9dFMULRDJ0Zr+D7m6lSytFxSBPZywGLtQExTlgv71RtcGY4u0+Fu2sDneaBYCP14iwZ exOCyGIuFrOj7M20+N5QrRs6jYI7YK6JLhGrdxE2rolgA/qqKpfxQcotYXQ+1YWBqtRCKve0awROI tNgWHc+2icct9RGKJ5DQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTQDY-00Bwuv-0L; Thu, 23 Sep 2021 15:00:56 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTQBS-00Bw1y-Pm for linux-arm-kernel@lists.infradead.org; Thu, 23 Sep 2021 14:58:48 +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 609D6113E; Thu, 23 Sep 2021 07:58:46 -0700 (PDT) Received: from e120937-lin.home (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 904333F718; Thu, 23 Sep 2021 07:58:44 -0700 (PDT) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, peter.hilber@opensynergy.com, igor.skalkin@opensynergy.com, cristian.marussi@arm.com Subject: [PATCH v5 09/13] firmware: arm_scmi: Add atomic mode support to virtio transport Date: Thu, 23 Sep 2021 15:57:58 +0100 Message-Id: <20210923145802.50938-10-cristian.marussi@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210923145802.50938-1-cristian.marussi@arm.com> References: <20210923145802.50938-1-cristian.marussi@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210923_075846_930292_7FEDE006 X-CRM114-Status: GOOD ( 11.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org SCMI virtio transport support does not contain any sleeping pattern, so declare it as .atomic_capable. Add a Kernel configuration option to enable SCMI VirtIO transport atomic mode operation and leave it as default disabled. Signed-off-by: Cristian Marussi --- v4 --> v5 - add CONFIG_ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_ENABLE - reviewed commit message --- drivers/firmware/arm_scmi/Kconfig | 14 ++++++++++++++ drivers/firmware/arm_scmi/virtio.c | 2 ++ 2 files changed, 16 insertions(+) diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig index 62517417848b..0bea0c4d9db1 100644 --- a/drivers/firmware/arm_scmi/Kconfig +++ b/drivers/firmware/arm_scmi/Kconfig @@ -87,6 +87,20 @@ config ARM_SCMI_TRANSPORT_VIRTIO If you want the ARM SCMI PROTOCOL stack to include support for a transport based on VirtIO, answer Y. +config ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_ENABLE + bool "Enable atomic mode for SCMI VirtIO transport" + depends on ARM_SCMI_TRANSPORT_VIRTIO + help + Enable atomic mode of operation for SCMI VirtIO based transport. + + If you want the SCMI VirtIO based transport to operate in atomic + mode, avoiding any kind of sleeping behaviour on the TX path, both + by the transport and by the SCMI core, answer Y. + Enabling atomic mode operations allows any SCMI driver using this + transport to operate in atomic context too, at the price of using + a number of busy-waiting primitives all over instead. + If unsure say N. + endif #ARM_SCMI_PROTOCOL config ARM_SCMI_POWER_DOMAIN diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c index 8941bb40f2df..fb3c2760ed42 100644 --- a/drivers/firmware/arm_scmi/virtio.c +++ b/drivers/firmware/arm_scmi/virtio.c @@ -488,4 +488,6 @@ const struct scmi_desc scmi_virtio_desc = { .max_rx_timeout_ms = 60000, /* for non-realtime virtio devices */ .max_msg = 0, /* overridden by virtio_get_max_msg() */ .max_msg_size = VIRTIO_SCMI_MAX_MSG_SIZE, + .atomic_capable = true, + .atomic_enabled = IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_ENABLE), };