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=-16.9 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,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 96AF6C48BD1 for ; Fri, 11 Jun 2021 17:12:31 +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 6E0E0613CF for ; Fri, 11 Jun 2021 17:12:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E0E0613CF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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.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=8NuHpnIVlySI9020yXlw7D/npBkLifYR1dIw6xI+pmg=; b=fJ+xvWUXNmu9CK WS8dJnuAL9cPkPOq4Sp14J3bH+OWu2aDZavaKQrztuYkpsHs+5XfPKNi/eJgcDX1j22HY1IQaDvRW /j14sak/84xhiLYJ8QIViFVw9RlNjLjjv9bw66VRzGsPmntj3FmELSwe4UtrKgRb3wcRVISO8KT3v PC4qkK7xM6Mh/CB2FVSnc+rr83RV3O2T4+8W9grEv2tGnxwxjiUkRlY5IRONH8ybFnZP3T9HXeo5n eEhS/k20snJUKcdmEWMewu5OAida4zjzozDntUKkHTmaEgX7tYOkTx85ddsnntqiQ5biPVV9O3JvP hQvzJlR7p2wT5QP/+Ctw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lrkfp-006G0g-GK; Fri, 11 Jun 2021 17:10:26 +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 1lrkX7-006Bxr-BE for linux-arm-kernel@lists.infradead.org; Fri, 11 Jun 2021 17:01:26 +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 D0CE4143D; Fri, 11 Jun 2021 10:01:24 -0700 (PDT) Received: from e120937-lin.home (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9DE6D3F719; Fri, 11 Jun 2021 10:01:19 -0700 (PDT) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.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, cristian.marussi@arm.com, igor.skalkin@opensynergy.com, peter.hilber@opensynergy.com, alex.bennee@linaro.org, jean-philippe@linaro.org, mikhail.golubev@opensynergy.com, anton.yakovlev@opensynergy.com, Vasyl.Vavrychuk@opensynergy.com, Andriy.Tryshnivskyy@opensynergy.com Subject: [PATCH v4 16/16] firmware: arm_scmi: Add polling mode to virtio transport Date: Fri, 11 Jun 2021 17:59:37 +0100 Message-Id: <20210611165937.701-17-cristian.marussi@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210611165937.701-1-cristian.marussi@arm.com> References: <20210611165937.701-1-cristian.marussi@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210611_100125_469041_8F9F492E X-CRM114-Status: GOOD ( 11.40 ) 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Enable polling mode support to virtio transport. Upon reception of a synchronous command response for a transfer that has the hdr.poll_completion flag set, virtio transport now simply completes the same completion which .poll_done() is spinning on. Signed-off-by: Cristian Marussi --- Note that as of now in order to test this you have to forcibly enable hdr.poll_completion in the core and increase SCMI_MAX_POLL_TO_NS. These workarounds won't be needed anymore once addressed by a distinct series currently under review. --- drivers/firmware/arm_scmi/virtio.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c index 4412bc590ca7..f77c7f288d4c 100644 --- a/drivers/firmware/arm_scmi/virtio.c +++ b/drivers/firmware/arm_scmi/virtio.c @@ -158,12 +158,12 @@ static void scmi_process_vqueue_input(struct scmi_vio_channel *vioch, /* Drop processed virtio message anyway */ scmi_finalize_message(vioch, msg); + /* Deliver DRESP, NOTIF and non-polled RESP */ if (vioch->is_rx || !xfer->hdr.poll_completion) scmi_rx_callback(vioch->cinfo, msg_hdr); else - dev_warn(vioch->cinfo->dev, - "Polling mode NOT supported. Dropped hdr:0X%X\n", - msg_hdr); + /* poll_done() is busy-waiting on this */ + complete(&xfer->done); scmi_transfer_release(vioch->cinfo, xfer); } @@ -414,10 +414,16 @@ static void dummy_clear_channel(struct scmi_chan_info *cinfo) { } -static bool dummy_poll_done(struct scmi_chan_info *cinfo, - struct scmi_xfer *xfer) +static bool virtio_poll_done(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) { - return false; + /* + * In polling mode SCMI core does not use xfer->done completion, + * so we can busy-wait on this same completion without adding + * a new flag: this is completed properly upon msg reception in + * scmi_process_vqueue_input(). + */ + return try_wait_for_completion(&xfer->done); } static const struct scmi_transport_ops scmi_virtio_ops = { @@ -430,7 +436,7 @@ static const struct scmi_transport_ops scmi_virtio_ops = { .fetch_response = virtio_fetch_response, .fetch_notification = virtio_fetch_notification, .clear_channel = dummy_clear_channel, - .poll_done = dummy_poll_done, + .poll_done = virtio_poll_done, }; static int scmi_vio_probe(struct virtio_device *vdev) -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel