From patchwork Fri Jul 22 22:37:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Guru Das Srinagesh X-Patchwork-Id: 12926948 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 643D8C433EF for ; Fri, 22 Jul 2022 22:40:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236981AbiGVWkS (ORCPT ); Fri, 22 Jul 2022 18:40:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236994AbiGVWkC (ORCPT ); Fri, 22 Jul 2022 18:40:02 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C80A2220D0; Fri, 22 Jul 2022 15:38:19 -0700 (PDT) Received: from pps.filterd (m0279865.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 26MMQ3c1005708; Fri, 22 Jul 2022 22:37:28 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=qcppdkim1; bh=zXq51b0Xyq3Lda6iIHqPLf1saamJrLBz1i3sB3m9ak0=; b=eBH1p/inZvtKIyQpbvY1ekzkPTRuI1bpihErYgyomdNe4oSxwEZlsyZultHJUoaP6ooi jsxeSk6NijmqTxtU4e46mK06VEACYSGrpH4gXmkwkvkhT17YRMwpa/Njn/5TyRrvZTJR d49oXzbA14KttdKe4sUviY29SgP25pbeJ7Pln3VQ1HJzJ8nIOf2O0u1Ne6/iZqMbEowh sNxB9T+K0xYGA1tKXFFCXOZb737M+3hP2EZeeuBBLUbO75Dz6n2vaBociv9f3wqBrn+6 hKVwnaG6dlxcxpm/mSvUGXM3lDm9ewnjvqaYUokmeRyolAB+rHfVEcibqx1IMj96onrt mg== Received: from nasanppmta01.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3hftv79gd3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 22 Jul 2022 22:37:27 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 26MMbRvT014914 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 22 Jul 2022 22:37:27 GMT Received: from hu-gurus-sd.qualcomm.com (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Fri, 22 Jul 2022 15:37:27 -0700 From: Guru Das Srinagesh To: Andy Gross , Bjorn Andersson , Philipp Zabel , , CC: David Heidelberg , Robert Marko , Rajendra Nayak , Elliot Berman , Guru Das Srinagesh Subject: [PATCH v2 5/5] firmware: qcom: scm: Add wait-queue handling logic Date: Fri, 22 Jul 2022 15:37:18 -0700 Message-ID: <1658529438-9234-6-git-send-email-quic_gurus@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1658529438-9234-1-git-send-email-quic_gurus@quicinc.com> References: <1658529438-9234-1-git-send-email-quic_gurus@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: uX4iJuYFidx_-w8oQM332OQJTZNgvU2V X-Proofpoint-GUID: uX4iJuYFidx_-w8oQM332OQJTZNgvU2V X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-07-22_06,2022-07-21_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 clxscore=1015 suspectscore=0 impostorscore=0 adultscore=0 mlxlogscore=999 spamscore=0 phishscore=0 malwarescore=0 bulkscore=0 priorityscore=1501 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000 definitions=main-2207220091 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Add logic to handle QCOM_SCM_WAITQ_SLEEP or QCOM_SCM_WAITQ_WAKE return codes. Scenario 1: Requests made by 2 different VMs: VM_1 VM_2 Firmware │ │ │ │ │ │ │ │ │ │ │ │ │ REQUEST_1 │ │ ├────────────────────────┼─────────────────────────────────┤ │ │ │ │ │ ┌──┼──┐ │ │ │ │ │ │ │ REQUEST_2 │ │ │ │ ├──────────────────────────────┼──┤ │ │ │ │ │ │Resource │ │ │ │ │is busy │ │ {WQ_SLEEP} │ │ │ │ │◄─────────────────────────────┼──┤ │ │ │ wq_ctx, smc_call_ctx │ │ │ │ │ └──┼──┘ │ REQUEST_1 COMPLETE │ │ │◄───────────────────────┼─────────────────────────────────┤ │ │ │ │ │ IRQ │ │ │◄─-------------------------------│ │ │ │ │ │ get_wq_ctx() │ │ ├────────────────────────────────►│ │ │ │ │ │ │ │ │◄────────────────────────────────┤ │ │ wq_ctx, flags, and │ │ │ more_pending │ │ │ │ │ │ │ │ │ wq_resume(smc_call_ctx) │ │ ├────────────────────────────────►│ │ │ │ │ │ │ │ │ REQUEST_2 COMPLETE │ │ │◄────────────────────────────────┤ │ │ │ │ │ │ Scenario 2: Two Requests coming in from same VM: VM_1 Firmware │ │ │ │ │ │ │ │ │ REQUEST_1 │ ├──────────────────────────────────────────────────────────┤ │ │ │ ┌────┼───┐ │ │ │ │ │ │ │ │ │ │ │ │ │ REQUEST_2 │ │ │ ├─────────────────────────────────────────────────────┼───►│ │ │ │ │ │Resource │ │ │ │is busy │ {WQ_SLEEP} │ │ │ │◄────────────────────────────────────────────────────┼────┤ │ │ wq_ctx, req2_smc_call_ctx │ │ │ │ │ │ │ │ └────┼───┘ │ │ │ {WQ_WAKE} │ │◄─────────────────────────────────────────────────────────┤ │ wq_ctx, req1_smc_call_ctx, flags │ │ │ │ │ │ wq_wake_ack(req1_smc_call_ctx) │ ├─────────────────────────────────────────────────────────►│ │ │ │ REQUEST_1 COMPLETE │ │◄─────────────────────────────────────────────────────────┤ │ │ │ │ │ wq_resume(req_2_smc_call_ctx) │ ├─────────────────────────────────────────────────────────►│ │ │ │ REQUEST_2 COMPLETE │ │◄─────────────────────────────────────────────────────────┤ │ │ With the exception of get_wq_ctx(), the other two newly-introduced SMC calls, wq_ack() and wq_resume() can themselves return WQ_SLEEP (these nested rounds of WQ_SLEEP are not shown in the above diagram for the sake of simplicity). Therefore, introduce a new do-while loop to handle multiple WQ_SLEEP return values for the same parent SCM call. Request Completion in the above diagram refers to either a success return value (zero) or error (and not SMC_WAITQ_SLEEP or SMC_WAITQ_WAKE). Signed-off-by: Guru Das Srinagesh --- [v2] - Combined the error and success cases in scm_smc_do_quirk(). drivers/firmware/qcom_scm-smc.c | 76 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 69 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/qcom_scm-smc.c b/drivers/firmware/qcom_scm-smc.c index 4150da1..09cca48 100644 --- a/drivers/firmware/qcom_scm-smc.c +++ b/drivers/firmware/qcom_scm-smc.c @@ -53,6 +53,9 @@ static void __scm_smc_do_quirk(const struct arm_smccc_args *smc, } while (res->a0 == QCOM_SCM_INTERRUPTED); } +#define IS_WAITQ_SLEEP_OR_WAKE(res) \ + (res->a0 == QCOM_SCM_WAITQ_SLEEP || res->a0 == QCOM_SCM_WAITQ_WAKE) + static void fill_wq_resume_args(struct arm_smccc_args *resume, u32 smc_call_ctx) { memset(resume->args, 0, ARRAY_SIZE(resume->args)); @@ -109,25 +112,77 @@ int scm_get_wq_ctx(u32 *wq_ctx, u32 *flags, u32 *more_pending) return 0; } -static void __scm_smc_do(const struct arm_smccc_args *smc, +static int scm_smc_do_quirk(struct device *dev, struct arm_smccc_args *smc, + struct arm_smccc_res *res) +{ + struct completion *wq = NULL; + struct qcom_scm *qscm; + u32 wq_ctx, smc_call_ctx, flags; + + do { + __scm_smc_do_quirk(smc, res); + + if (IS_WAITQ_SLEEP_OR_WAKE(res)) { + wq_ctx = res->a1; + smc_call_ctx = res->a2; + flags = res->a3; + + if (!dev) + return -EPROBE_DEFER; + + qscm = dev_get_drvdata(dev); + wq = qcom_scm_lookup_wq(qscm, wq_ctx); + if (IS_ERR_OR_NULL(wq)) { + pr_err("No waitqueue found for wq_ctx %d: %ld\n", + wq_ctx, PTR_ERR(wq)); + return PTR_ERR(wq); + } + + if (res->a0 == QCOM_SCM_WAITQ_SLEEP) { + wait_for_completion(wq); + fill_wq_resume_args(smc, smc_call_ctx); + wq = NULL; + continue; + } else { + fill_wq_wake_ack_args(smc, smc_call_ctx); + continue; + } + } else if (!res->a0 || (long)res->a0 < 0) { + /* + * Success, or error. + * wq will be set only if a prior WAKE happened. + * Its value will be the one from the prior WAKE. + */ + if (wq) + scm_waitq_flag_handler(wq, flags); + break; + } + } while (IS_WAITQ_SLEEP_OR_WAKE(res)); + + return 0; +} + +static int __scm_smc_do(struct device *dev, struct arm_smccc_args *smc, struct arm_smccc_res *res, bool atomic) { - int retry_count = 0; + int ret, retry_count = 0; if (atomic) { __scm_smc_do_quirk(smc, res); - return; + return 0; } do { if (!qcom_scm_allow_multicall) mutex_lock(&qcom_scm_lock); - __scm_smc_do_quirk(smc, res); + ret = scm_smc_do_quirk(dev, smc, res); if (!qcom_scm_allow_multicall) mutex_unlock(&qcom_scm_lock); + if (ret) + return ret; if (res->a0 == QCOM_SCM_V2_EBUSY) { if (retry_count++ > QCOM_SCM_EBUSY_MAX_RETRY) @@ -135,6 +190,8 @@ static void __scm_smc_do(const struct arm_smccc_args *smc, msleep(QCOM_SCM_EBUSY_WAIT_MS); } } while (res->a0 == QCOM_SCM_V2_EBUSY); + + return 0; } @@ -143,7 +200,7 @@ int __scm_smc_call(struct device *dev, const struct qcom_scm_desc *desc, struct qcom_scm_res *res, bool atomic) { int arglen = desc->arginfo & 0xf; - int i; + int i, ret; dma_addr_t args_phys = 0; void *args_virt = NULL; size_t alloc_len; @@ -195,19 +252,24 @@ int __scm_smc_call(struct device *dev, const struct qcom_scm_desc *desc, smc.args[SCM_SMC_LAST_REG_IDX] = args_phys; } - __scm_smc_do(&smc, &smc_res, atomic); + ret = __scm_smc_do(dev, &smc, &smc_res, atomic); + /* ret error check follows after args_virt cleanup*/ if (args_virt) { dma_unmap_single(dev, args_phys, alloc_len, DMA_TO_DEVICE); kfree(args_virt); } + if (ret) + return ret; + if (res) { res->result[0] = smc_res.a1; res->result[1] = smc_res.a2; res->result[2] = smc_res.a3; } - return (long)smc_res.a0 ? qcom_scm_remap_error(smc_res.a0) : 0; + ret = (long)smc_res.a0 ? qcom_scm_remap_error(smc_res.a0) : 0; + return ret; }