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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97887C77B6C for ; Mon, 3 Apr 2023 20:16:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232847AbjDCUQG (ORCPT ); Mon, 3 Apr 2023 16:16:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231336AbjDCUQE (ORCPT ); Mon, 3 Apr 2023 16:16:04 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F4B92738; Mon, 3 Apr 2023 13:16:02 -0700 (PDT) Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 333Ju43I000927; Mon, 3 Apr 2023 20:15:47 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=qcppdkim1; bh=xe8Qdz0/ye8j2kRzlr57fCVQvK34/mM9zLANVX4x+fk=; b=O+hhI+XKsqh8UuGmvtXWMO+sSseAtMXZ9ehohfMk/TzPM2JOe3I3r3bu6GsmHpKyopT0 TfAiXNzQu4k/VK4hpQnxr5QKj0+nP3yIeyY4KhfHsAEuPdgadph6yM9LGLw3FyfQTA2U wu8zZ43gb7x1mCPSJj+Nysg9Wxd1kOJVTghBENyIIHamAGLcKesfrtwoSWXw8bmjauDR dqhrTKRZCidKKjrfg7501Y86ABoJ8tYfwfTacdME5urt2zH6dnpY4FN4eqbHrsdJwyhx R+G/XuqSIU3BKLpYoTpWFwc5JH/nD9KfEpWdTaw34N1Uog5i3X8HWkiJU2bFVC2bCzOu 8A== Received: from nasanppmta05.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3pqy6211tq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 03 Apr 2023 20:15:47 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 333KFk79032508 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 3 Apr 2023 20:15:46 GMT Received: from [10.134.65.165] (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 15.2.986.42; Mon, 3 Apr 2023 13:15:43 -0700 Message-ID: Date: Mon, 3 Apr 2023 13:15:42 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH v11 07/26] mailbox: Add Gunyah message queue mailbox Content-Language: en-US To: Alex Elder , Srinivas Kandagatla , Prakruthi Deepak Heragu , Jonathan Corbet , Jassi Brar CC: Murali Nalajala , Trilok Soni , Srivatsa Vaddagiri , Carl van Schaik , Dmitry Baryshkov , Bjorn Andersson , "Konrad Dybcio" , Arnd Bergmann , "Greg Kroah-Hartman" , Rob Herring , Krzysztof Kozlowski , Bagas Sanjaya , Will Deacon , Andy Gross , Catalin Marinas , , , , , References: <20230304010632.2127470-1-quic_eberman@quicinc.com> <20230304010632.2127470-8-quic_eberman@quicinc.com> <01f2f8a2-15e6-66e8-a5a0-eb9f511a1121@linaro.org> From: Elliot Berman In-Reply-To: <01f2f8a2-15e6-66e8-a5a0-eb9f511a1121@linaro.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) 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-GUID: AVte1V2yz1fQolIEmfHixMe1j3NHv3Hw X-Proofpoint-ORIG-GUID: AVte1V2yz1fQolIEmfHixMe1j3NHv3Hw X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-03_16,2023-04-03_03,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 suspectscore=0 bulkscore=0 mlxlogscore=826 phishscore=0 mlxscore=0 adultscore=0 impostorscore=0 clxscore=1015 malwarescore=0 lowpriorityscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304030157 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/31/2023 7:25 AM, Alex Elder wrote: > On 3/3/23 7:06 PM, Elliot Berman wrote: >> Gunyah message queues are a unidirectional inter-VM pipe for messages up >> to 1024 bytes. This driver supports pairing a receiver message queue and >> a transmitter message queue to expose a single mailbox channel. > > I think it's good to reuse existing frameworks, for example, using > the mailbox abstraction to implement your messaging code.  But I > find there are some minor mismatches between what you need and > the way the mailbox code works. > > I'm not really suggesting you change anything, but I'll just say > it seemed like there were a few spots you needed to do things > that were slightly awkward in order to satisfy mailbox requirements. > > I'll point out in a few comments what I mean below. > > I'll take one more look at it again next time, but I assume this > works and I have no other new comments today. > >                     -Alex > >> Signed-off-by: Elliot Berman >> --- >>   Documentation/virt/gunyah/message-queue.rst |   8 + >>   drivers/mailbox/Makefile                    |   2 + >>   drivers/mailbox/gunyah-msgq.c               | 209 ++++++++++++++++++++ >>   include/linux/gunyah.h                      |  57 ++++++ >>   4 files changed, 276 insertions(+) >>   create mode 100644 drivers/mailbox/gunyah-msgq.c >> >> diff --git a/Documentation/virt/gunyah/message-queue.rst >> b/Documentation/virt/gunyah/message-queue.rst >> index b352918ae54b..70d82a4ef32d 100644 >> --- a/Documentation/virt/gunyah/message-queue.rst >> +++ b/Documentation/virt/gunyah/message-queue.rst >> @@ -61,3 +61,11 @@ vIRQ: two TX message queues will have two vIRQs >> (and two capability IDs). >>         |               |         |                 | >> |               | >>         |               |         |                 | >> |               | >>         +---------------+         +-----------------+ >> +---------------+ >> + >> +Gunyah message queues are exposed as mailboxes. To create the >> mailbox, create >> +a mbox_client and call `gh_msgq_init()`. On receipt of the RX_READY >> interrupt, >> +all messages in the RX message queue are read and pushed via the >> `rx_callback` >> +of the registered mbox_client. >> + >> +.. kernel-doc:: drivers/mailbox/gunyah-msgq.c >> +   :identifiers: gh_msgq_init >> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile >> index fc9376117111..5f929bb55e9a 100644 >> --- a/drivers/mailbox/Makefile >> +++ b/drivers/mailbox/Makefile >> @@ -55,6 +55,8 @@ obj-$(CONFIG_MTK_CMDQ_MBOX)    += mtk-cmdq-mailbox.o >>   obj-$(CONFIG_ZYNQMP_IPI_MBOX)    += zynqmp-ipi-mailbox.o >> +obj-$(CONFIG_GUNYAH)        += gunyah-msgq.o >> + >>   obj-$(CONFIG_SUN6I_MSGBOX)    += sun6i-msgbox.o >>   obj-$(CONFIG_SPRD_MBOX)        += sprd-mailbox.o >> diff --git a/drivers/mailbox/gunyah-msgq.c >> b/drivers/mailbox/gunyah-msgq.c >> new file mode 100644 >> index 000000000000..1989298653f9 >> --- /dev/null >> +++ b/drivers/mailbox/gunyah-msgq.c >> @@ -0,0 +1,209 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All >> rights reserved. >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#define mbox_chan_to_msgq(chan) (container_of(chan->mbox, struct >> gh_msgq, mbox)) >> + >> +static irqreturn_t gh_msgq_rx_irq_handler(int irq, void *data) >> +{ >> +    struct gh_msgq *msgq = data; >> +    struct gh_msgq_rx_data rx_data; >> +    enum gh_error gh_error; >> +    bool ready = true; >> + >> +    while (ready) { >> +        gh_error = gh_hypercall_msgq_recv(msgq->rx_ghrsc->capid, >> +                &rx_data.data, sizeof(rx_data.data), >> +                &rx_data.length, &ready); >> +        if (gh_error != GH_ERROR_OK) { >> +            if (gh_error != GH_ERROR_MSGQUEUE_EMPTY) >> +                dev_warn(msgq->mbox.dev, "Failed to receive data: >> %d\n", gh_error); >> +            break; >> +        } >> +        mbox_chan_received_data(gh_msgq_chan(msgq), &rx_data); >> +    } >> + >> +    return IRQ_HANDLED; >> +} >> + >> +/* Fired when message queue transitions from "full" to "space >> available" to send messages */ >> +static irqreturn_t gh_msgq_tx_irq_handler(int irq, void *data) >> +{ >> +    struct gh_msgq *msgq = data; >> + >> +    mbox_chan_txdone(gh_msgq_chan(msgq), 0); >> + >> +    return IRQ_HANDLED; >> +} >> + >> +/* Fired after sending message and hypercall told us there was more >> space available. */ >> +static void gh_msgq_txdone_tasklet(struct tasklet_struct *tasklet) >> +{ >> +    struct gh_msgq *msgq = container_of(tasklet, struct gh_msgq, >> txdone_tasklet); >> + >> +    mbox_chan_txdone(gh_msgq_chan(msgq), msgq->last_ret); >> +} >> + >> +static int gh_msgq_send_data(struct mbox_chan *chan, void *data) >> +{ >> +    struct gh_msgq *msgq = mbox_chan_to_msgq(chan); >> +    struct gh_msgq_tx_data *msgq_data = data; >> +    u64 tx_flags = 0; >> +    enum gh_error gh_error; >> +    bool ready; >> + >> +    if (msgq_data->push) >> +        tx_flags |= GH_HYPERCALL_MSGQ_TX_FLAGS_PUSH; >> + >> +    gh_error = gh_hypercall_msgq_send(msgq->tx_ghrsc->capid, >> msgq_data->length, msgq_data->data, >> +                        tx_flags, &ready); >> + >> +    /** >> +     * unlikely because Linux tracks state of msgq and should not try to >> +     * send message when msgq is full. >> +     */ >> +    if (unlikely(gh_error == GH_ERROR_MSGQUEUE_FULL)) >> +        return -EAGAIN; >> + >> +    /** >> +     * Propagate all other errors to client. If we return error to >> mailbox >> +     * framework, then no other messages can be sent and nobody will >> know >> +     * to retry this message. > > If you weren't using the mailbox framework, would you be > sending the error to the client in this case?  (I'm just > curious; it's good to document the behavior if you were > to return it to the mailbox framework.) > >> +     */ >> +    msgq->last_ret = gh_remap_error(gh_error); >> + >> +    /** >> +     * This message was successfully sent, but message queue isn't >> ready to >> +     * accept more messages because it's now full. Mailbox framework >> +     * requires that we only report that message was transmitted when >> +     * we're ready to transmit another message. We'll get that in the >> form >> +     * of tx IRQ once the other side starts to drain the msgq. > > So you are forced to delay reporting the completion > here because you're using the mailbox framework. > >> +     */ >> +    if (gh_error == GH_ERROR_OK) { >> +        if (!ready) >> +            return 0; >> +    } else >> +        dev_err(msgq->mbox.dev, "Failed to send data: %d (%d)\n", >> gh_error, msgq->last_ret); >> + >> +    /** >> +     * We can send more messages. Mailbox framework requires that tx >> done >> +     * happens asynchronously to sending the message. Gunyah message >> queues >> +     * tell us right away on the hypercall return whether we can send >> more >> +     * messages. To work around this, defer the txdone to a tasklet. >> +     */ > > If you weren't using the mailbox framework, you'd send the next > message directly rather than scheduling this tasklet to do it. > That's correct for this and the other 2 comments above. >> +    tasklet_schedule(&msgq->txdone_tasklet); >> + >> +    return 0; >> +} >> + >> +static struct mbox_chan_ops gh_msgq_ops = { >> +    .send_data = gh_msgq_send_data, >> +}; >> + >> +/** >> + * gh_msgq_init() - Initialize a Gunyah message queue with an >> mbox_client >> + * @parent: optional, device parent used for the mailbox controller >> + * @msgq: Pointer to the gh_msgq to initialize >> + * @cl: A mailbox client to bind to the mailbox channel that the >> message queue creates >> + * @tx_ghrsc: optional, the transmission side of the message queue >> + * @rx_ghrsc: optional, the receiving side of the message queue >> + * >> + * At least one of tx_ghrsc and rx_ghrsc must be not NULL. Most >> message queue use cases come with >> + * a pair of message queues to facilitate bidirectional >> communication. When tx_ghrsc is set, >> + * the client can send messages with >> mbox_send_message(gh_msgq_chan(msgq), msg). When rx_ghrsc >> + * is set, the mbox_client must register an .rx_callback() and the >> message queue driver will >> + * deliver all available messages upon receiving the RX ready >> interrupt. The messages should be >> + * consumed or copied by the client right away as the gh_msgq_rx_data >> will be replaced/destroyed >> + * after the callback. >> + * >> + * Returns - 0 on success, negative otherwise >> + */ >> +int gh_msgq_init(struct device *parent, struct gh_msgq *msgq, struct >> mbox_client *cl, >> +         struct gh_resource *tx_ghrsc, struct gh_resource *rx_ghrsc) >> +{ >> +    int ret; >> + >> +    /* Must have at least a tx_ghrsc or rx_ghrsc and that they are >> the right device types */ >> +    if ((!tx_ghrsc && !rx_ghrsc) || >> +        (tx_ghrsc && tx_ghrsc->type != GH_RESOURCE_TYPE_MSGQ_TX) || >> +        (rx_ghrsc && rx_ghrsc->type != GH_RESOURCE_TYPE_MSGQ_RX)) >> +        return -EINVAL; >> + >> +    if (!gh_api_has_feature(GH_FEATURE_MSGQUEUE)) >> +        return -EOPNOTSUPP; >> + >> +    msgq->tx_ghrsc = tx_ghrsc; >> +    msgq->rx_ghrsc = rx_ghrsc; >> + >> +    msgq->mbox.dev = parent; >> +    msgq->mbox.ops = &gh_msgq_ops; >> +    msgq->mbox.num_chans = 1; >> +    msgq->mbox.txdone_irq = true; >> +    msgq->mbox.chans = &msgq->mbox_chan; >> + >> +    if (msgq->tx_ghrsc) { >> +        ret = request_irq(msgq->tx_ghrsc->irq, >> gh_msgq_tx_irq_handler, 0, "gh_msgq_tx", >> +                msgq); >> +        if (ret) >> +            goto err_chans; >> +    } >> + >> +    if (msgq->rx_ghrsc) { >> +        ret = request_threaded_irq(msgq->rx_ghrsc->irq, NULL, >> gh_msgq_rx_irq_handler, >> +                        IRQF_ONESHOT, "gh_msgq_rx", msgq); >> +        if (ret) >> +            goto err_tx_irq; >> +    } >> + >> +    tasklet_setup(&msgq->txdone_tasklet, gh_msgq_txdone_tasklet); >> + >> +    ret = mbox_controller_register(&msgq->mbox); >> +    if (ret) >> +        goto err_rx_irq; >> + >> +    ret = mbox_bind_client(gh_msgq_chan(msgq), cl); >> +    if (ret) >> +        goto err_mbox; >> + >> +    return 0; >> +err_mbox: >> +    mbox_controller_unregister(&msgq->mbox); >> +err_rx_irq: >> +    if (msgq->rx_ghrsc) >> +        free_irq(msgq->rx_ghrsc->irq, msgq); >> +err_tx_irq: >> +    if (msgq->tx_ghrsc) >> +        free_irq(msgq->tx_ghrsc->irq, msgq); >> +err_chans: >> +    kfree(msgq->mbox.chans); >> +    return ret; >> +} >> +EXPORT_SYMBOL_GPL(gh_msgq_init); >> + >> +void gh_msgq_remove(struct gh_msgq *msgq) >> +{ >> +    tasklet_kill(&msgq->txdone_tasklet); >> +    mbox_controller_unregister(&msgq->mbox); >> + >> +    if (msgq->rx_ghrsc) >> +        free_irq(msgq->rx_ghrsc->irq, msgq); >> + >> +    if (msgq->tx_ghrsc) >> +        free_irq(msgq->tx_ghrsc->irq, msgq); >> + >> +    kfree(msgq->mbox.chans); >> +} >> +EXPORT_SYMBOL_GPL(gh_msgq_remove); >> + >> +MODULE_LICENSE("GPL"); >> +MODULE_DESCRIPTION("Gunyah Message Queue Driver"); >> diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h >> index 18cfbf5ee48b..378bec0f2ce1 100644 >> --- a/include/linux/gunyah.h >> +++ b/include/linux/gunyah.h >> @@ -8,11 +8,68 @@ >>   #include >>   #include >> +#include >>   #include >> +#include >> +#include >>   #include >> +/* Follows resource manager's resource types for VM_GET_HYP_RESOURCES */ > > I'm not sure what you mean by "Follows" here.  You mean that these are > the gh_rm_hyp_resource type values that GET_HYP_RESOURCES can return? > Correct. I will say "Matches ... for VM_GET_HYP_RESOURCES RPC" if it helps make it clearer. > Note that gh_resource_type values must fit in an 8 bit field. > >> +enum gh_resource_type { >> +    GH_RESOURCE_TYPE_BELL_TX    = 0, >> +    GH_RESOURCE_TYPE_BELL_RX    = 1, >> +    GH_RESOURCE_TYPE_MSGQ_TX    = 2, >> +    GH_RESOURCE_TYPE_MSGQ_RX    = 3, > > Fix alignment below. > >> +    GH_RESOURCE_TYPE_VCPU    = 4, >> +}; >> + >> +struct gh_resource { >> +    enum gh_resource_type type; >> +    u64 capid; >> +    unsigned int irq; >> +}; >> + >> +/** >> + * Gunyah Message Queues >> + */ >> + >> +#define GH_MSGQ_MAX_MSG_SIZE    240 > > Maybe insert another tab the before 240.  You later define > GH_BELL_NONBLOCK that far out, and aligning them will look > better. > >> + >> +struct gh_msgq_tx_data { >> +    size_t length; >> +    bool push; >> +    char data[]; >> +}; >> + >> +struct gh_msgq_rx_data { >> +    size_t length; >> +    char data[GH_MSGQ_MAX_MSG_SIZE]; >> +}; >> + >> +struct gh_msgq { >> +    struct gh_resource *tx_ghrsc; >> +    struct gh_resource *rx_ghrsc; >> + >> +    /* msgq private */ >> +    int last_ret; /* Linux error, not GH_STATUS_* */ >> +    struct mbox_chan mbox_chan; >> +    struct mbox_controller mbox; >> +    struct tasklet_struct txdone_tasklet; >> +}; >> + >> + >> +int gh_msgq_init(struct device *parent, struct gh_msgq *msgq, struct >> mbox_client *cl, >> +             struct gh_resource *tx_ghrsc, struct gh_resource >> *rx_ghrsc); >> +void gh_msgq_remove(struct gh_msgq *msgq); >> + >> +static inline struct mbox_chan *gh_msgq_chan(struct gh_msgq *msgq) >> +{ >> +    return &msgq->mbox.chans[0]; >> +} >> + >> >> /******************************************************************************/ >>   /* Common arch-independent definitions for Gunyah >> hypercalls                  */ >> + >>   #define GH_CAPID_INVAL    U64_MAX >>   #define GH_VMID_ROOT_VM    0xff >