From patchwork Wed Jan 11 10:17:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sibi Sankar X-Patchwork-Id: 13096371 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 5BEFFC54EBE for ; Wed, 11 Jan 2023 10:18:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229636AbjAKKSo (ORCPT ); Wed, 11 Jan 2023 05:18:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232062AbjAKKR7 (ORCPT ); Wed, 11 Jan 2023 05:17:59 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A33DDDA; Wed, 11 Jan 2023 02:17:56 -0800 (PST) Received: from pps.filterd (m0279868.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 30B7UU7w024925; Wed, 11 Jan 2023 10:17:50 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=J4Lov1mdMDLpfAf1DIEnzXirjpeXZYs01KPgNOPMj5M=; b=Ob9W4rCQTsjP0QTVgxDznapelPRPZpSILCbpUSw+2ibplYs63K2q7EUIVY+o8YfRSyBm id3ClKTGn1SpbDiBEjR8/2WZ/vsZomiff9zMNCgAh0a/BQD1Job2EPXxO99IKqm2/zMW rA/G5jfyWhIyLuAdTW4Eq/ur6TlYDi+/vK6KGesqvpMM+0CXrLbsrelmTnXxqlPLCWCn H+ENSEl1bjei4oPHyOr+j3frjZhcjs3pAjJEa8Q0m8XB+UCceWJe5qeVSn4Pl7G1V7X2 mQjRlNcgulGXCHGh/4umYkhYasYYFd8uZi+JhBsQkYAGSBfXjso6zedNyK/9Y/Gfdc33 UA== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3n1k6a0xkh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 11 Jan 2023 10:17:49 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 30BAHmQ5029706 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 11 Jan 2023 10:17:48 GMT Received: from blr-ubuntu-87.ap.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 15.2.986.36; Wed, 11 Jan 2023 02:17:44 -0800 From: Sibi Sankar To: , CC: , , , , , , , , , Sibi Sankar Subject: [PATCH V8 0/2] SCM: Add support for wait-queue aware firmware Date: Wed, 11 Jan 2023 15:47:16 +0530 Message-ID: <20230111101718.9225-1-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: nasanex01b.na.qualcomm.com (10.46.141.250) 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: n3Ag30uiyrkGFjttsHeS-JVMqB9uSlMZ X-Proofpoint-GUID: n3Ag30uiyrkGFjttsHeS-JVMqB9uSlMZ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2023-01-11_04,2023-01-11_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 adultscore=0 lowpriorityscore=0 impostorscore=0 phishscore=0 clxscore=1015 malwarescore=0 mlxscore=0 priorityscore=1501 spamscore=0 bulkscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2301110078 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. v8: - Rename qcom_scm_lookup_wq to qcom_scm_assert_valid_wq_ctx [Bjorn] - Document wq_ctx limitations [Guru] - Drop dev check and add include completion header [Srini] - Rename qcom_scm_lookup_completion to qcom_scm_wait_for_wq_completion. v7: - Move lookup + wait_for_completion into a single function in qcom_scm [Bjorn] - Simplify completion retrieval [Bjorn] v6: - Fix subject of bindings [Krzysztof] - Update commit message to include the SoC supporting the feature [Krzysztof] - Make the interrupt property valid on SM8450 SoC [Krzysztof] - Fix misc. nits in the scm driver [Krzysztof] - Rebased on Krzysztof's narrow clocks and interconnect series. v5: - Pick up R-b - Handle the wake_one/wake_all flags [Guru] - Rename flag handler to qcom_scm_waitq_wakeup [Bjorn] - Resume scm call can return ebusy as well handle that scenario by retrying the original smc call and not the resume call v4: - platform_set_drvdata will be used by __scm_smc_do_quirk_handle_waitq to get access to scm struct from device so retain it - Use a single completion as it satisfies all of the current usecases [Bjorn] - Inline scm_get_wq_ctx [Bjorn] - Convert all pr_err to dev_err [Bjorn] - Handle idr_destroy in a thread safe manner [Bjorn] - Misc. 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]. 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 | 18 ++++ drivers/firmware/qcom_scm-smc.c | 87 +++++++++++++++-- drivers/firmware/qcom_scm.c | 93 ++++++++++++++++++- drivers/firmware/qcom_scm.h | 8 ++ 4 files changed, 198 insertions(+), 8 deletions(-)