From patchwork Mon Nov 14 08:26:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sibi Sankar X-Patchwork-Id: 13041953 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 69FE6C4332F for ; Mon, 14 Nov 2022 08:27:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236472AbiKNI1a (ORCPT ); Mon, 14 Nov 2022 03:27:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236434AbiKNI1U (ORCPT ); Mon, 14 Nov 2022 03:27:20 -0500 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EB5E1B7A6; Mon, 14 Nov 2022 00:27:17 -0800 (PST) Received: from pps.filterd (m0279862.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2AE84Nf0007838; Mon, 14 Nov 2022 08:27:04 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : mime-version : content-type : content-transfer-encoding; s=qcppdkim1; bh=7+J08TV+0Iia79MFT0vTqGM4PT7GfAZUdItBGmxImpE=; b=XQLgNTCUl6yvrclkz2TY5VeAHGxZmRLdX/zwcT5kZOlBq5OuOL+dqJ5RQRkC7UNh9H+Z q0x2r5Q9jjTB99t9+t55abneCRtcUA6bB2LmyHHKMj91YI+lS5ZgL9QzNsgDGe0yNnyW tBgQngjbQK5PxQASVmWw1HvtE+kcnjXStYi6m5ofBxm7kWnJI/lBOkvnyAJyQ66rs5ux SWcVgVQwwfxm2fy4UaNSvyeVw9C3bJFAKMOIS2+YaD1qtZlGpqN5sH9jfwdjmFInS6yq Xmwm3awXvZKcrAUxKiijB1pbo8fSsPodz/4w4WYsNF+Wh/bxndlYx/mYXagmoDQacFon jg== Received: from nalasppmta05.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3kufk20cnt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 14 Nov 2022 08:27:04 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 2AE8R3Hw028145 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 14 Nov 2022 08:27:03 GMT Received: from blr-ubuntu-311.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.29; Mon, 14 Nov 2022 00:27:00 -0800 From: Sibi Sankar To: , , CC: , , , , , , , , Sibi Sankar Subject: [PATCH V4 0/2] SCM: Add support for wait-queue aware firmware Date: Mon, 14 Nov 2022 13:56:42 +0530 Message-ID: <20221114082644.28739-1-quic_sibis@quicinc.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: x6J54nauQurWYnwkqqXXG7E3pDWajQK3 X-Proofpoint-GUID: x6J54nauQurWYnwkqqXXG7E3pDWajQK3 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-11-14_07,2022-11-11_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 mlxlogscore=999 suspectscore=0 bulkscore=0 clxscore=1015 impostorscore=0 malwarescore=0 priorityscore=1501 adultscore=0 spamscore=0 lowpriorityscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2211140061 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org This patch series enables the QCOM SCM driver to support firmware (FW) versions that expect the high-level OS (HLOS) to be tolerant of SCM call requests not being processed right away and, instead, being placed on a wait-queue in FW and processed accordingly. The problem this feature is fixing is as follows. In a scenario where there is a VM in addition to HLOS (and an underlying hypervisor): 1. HLOS makes an SMC call on core 5 2. The hypervisor scheduling interrupt interrupts this SMC call. 3. The hypervisor schedules the VM on core 5. 4. The VM makes an SMC call on core 5. 5. The SMC call is non-interruptibly stuck on FW spinlock on core 5. 6. HLOS cannot reschedule since core 5 is not responding to Reschedule IPIs. 7. Watchdog timer expires waiting for core 5. This problem is solved by FW returning a new return code SCM_WAITQ_SLEEP to HLOS right away when it is overwhelmed by the VM's SMC call. HLOS then places the call on a wait-queue and wakes it up when it receives an interrupt that signifies "all-clear". There are two new SMC calls also being defined in this design that, together with one new return code, form the handshake protocol between Linux and FW. This design is also backwards-compatible with existing firmware versions that do not support this feature. v4: - Use a single completion as it satisfies all of the current usecases [Bjorn] - Misc. logic/style fixes [Bjorn] - Qualify bindings [Krzysztoff] v3: - Drop allow-multi-call property since HLOS doesn't completely support it yet. - Fixup irq handling so as not to affect SoCs without the interrupt. - Fix warnings reported by kernel test-bot. v2: - Changes made to patches 4 and 5 are listed therein. - Rebased dt-bindings on top of the YAML conversion patch [1]. Older version of the series: [v2] https://patchwork.kernel.org/project/linux-arm-msm/cover/1661898311-30126-1-git-send-email-quic_gurus@quicinc.com/ [v1] https://patchwork.kernel.org/project/linux-arm-msm/cover/1656359076-13018-1-git-send-email-quic_gurus@quicinc.com/ Guru Das Srinagesh (2): dt-bindings: firmware: qcom-scm: Add optional interrupt firmware: qcom: scm: Add wait-queue handling logic .../bindings/firmware/qcom,scm.yaml | 6 ++ drivers/firmware/qcom_scm-smc.c | 94 ++++++++++++++-- drivers/firmware/qcom_scm.c | 102 +++++++++++++++++- drivers/firmware/qcom_scm.h | 9 ++ 4 files changed, 203 insertions(+), 8 deletions(-)