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    Subject[PATCH v5 09/13] mailbox: Add Gunyah message queue mailbox
    Date
    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.

    Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
    ---
    MAINTAINERS | 2 +
    drivers/mailbox/Kconfig | 10 ++
    drivers/mailbox/Makefile | 2 +
    drivers/mailbox/gunyah-msgq.c | 254 ++++++++++++++++++++++++++++++++++
    drivers/virt/gunyah/Kconfig | 2 +
    include/linux/gunyah.h | 67 +++++++++
    6 files changed, 337 insertions(+)
    create mode 100644 drivers/mailbox/gunyah-msgq.c
    create mode 100644 include/linux/gunyah.h

    diff --git a/MAINTAINERS b/MAINTAINERS
    index c5458aeec023..599804836d05 100644
    --- a/MAINTAINERS
    +++ b/MAINTAINERS
    @@ -8888,8 +8888,10 @@ F: Documentation/ABI/testing/sysfs-hypervisor-gunyah
    F: Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
    F: Documentation/virt/gunyah/
    F: arch/arm64/gunyah/
    +F: drivers/mailbox/gunyah-msgq.c
    F: drivers/virt/gunyah/
    F: include/asm-generic/gunyah.h
    +F: include/linux/gunyah.h

    HABANALABS PCI DRIVER
    M: Oded Gabbay <ogabbay@kernel.org>
    diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
    index 05d6fae800e3..baf9451c5f04 100644
    --- a/drivers/mailbox/Kconfig
    +++ b/drivers/mailbox/Kconfig
    @@ -41,6 +41,16 @@ config IMX_MBOX
    help
    Mailbox implementation for i.MX Messaging Unit (MU).

    +config GUNYAH_MESSAGE_QUEUES
    + tristate "Gunyah Message Queue Mailbox"
    + depends on GUNYAH
    + help
    + Mailbox implementation for Gunyah Message Queues. Gunyah message queues
    + are an IPC mechanism to pass short messages between virtual machines
    + running under the Gunyah hypervisor.
    +
    + Say Y here if you run Linux as a Gunyah virtual machine.
    +
    config PLATFORM_MHU
    tristate "Platform MHU Mailbox"
    depends on OF
    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..f0cd96920c64
    --- /dev/null
    +++ b/drivers/mailbox/gunyah-msgq.c
    @@ -0,0 +1,254 @@
    +// SPDX-License-Identifier: GPL-2.0-only
    +/*
    + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
    + */
    +
    +#include <linux/mailbox_controller.h>
    +#include <linux/module.h>
    +#include <linux/interrupt.h>
    +#include <linux/gunyah.h>
    +#include <linux/printk.h>
    +#include <linux/init.h>
    +#include <linux/slab.h>
    +#include <linux/wait.h>
    +
    +#define mbox_chan_to_msgq(chan) (container_of(chan->mbox, struct gunyah_msgq, mbox))
    +
    +static inline bool gh_msgq_has_tx(struct gunyah_msgq *msgq)
    +{
    + return msgq->tx_ghrsc.type == GUNYAH_RESOURCE_TYPE_MSGQ_TX;
    +}
    +
    +static inline bool gh_msgq_has_rx(struct gunyah_msgq *msgq)
    +{
    + return msgq->rx_ghrsc.type == GUNYAH_RESOURCE_TYPE_MSGQ_RX;
    +}
    +
    +static ssize_t __gh_msgq_recv(struct gunyah_msgq *msgq, void *buff, size_t size, bool *ready)
    +{
    + unsigned long gh_err;
    + size_t recv_size;
    + ssize_t ret;
    +
    + gh_err = gh_hypercall_msgq_recv(msgq->rx_ghrsc.capid, (uintptr_t)buff, size,
    + &recv_size, ready);
    + switch (gh_err) {
    + case GH_ERROR_OK:
    + ret = recv_size;
    + break;
    + case GH_ERROR_MSGQUEUE_EMPTY:
    + ret = -EAGAIN;
    + *ready = false;
    + break;
    + default:
    + ret = gh_remap_error(gh_err);
    + break;
    + }
    +
    + return ret;
    +}
    +
    +static irqreturn_t gh_msgq_rx_irq_handler(int irq, void *data)
    +{
    + struct gunyah_msgq *msgq = data;
    + struct gunyah_msgq_rx_data rx_data;
    + ssize_t ret;
    + bool more;
    +
    + do {
    + ret = __gh_msgq_recv(msgq, &rx_data.data, sizeof(rx_data.data), &more);
    +
    + if (ret >= 0) {
    + rx_data.length = ret;
    + mbox_chan_received_data(gunyah_msgq_chan(msgq), &rx_data);
    + } else if (ret != -EAGAIN)
    + pr_warn("Failed to receive data from msgq for %s: %ld\n",
    + msgq->mbox.dev ? dev_name(msgq->mbox.dev) : "", ret);
    + } while (ret >= 0);
    +
    + return IRQ_HANDLED;
    +}
    +
    +static irqreturn_t gh_msgq_tx_irq_handler(int irq, void *data)
    +{
    + struct gunyah_msgq *msgq = data;
    +
    + mbox_chan_txdone(gunyah_msgq_chan(msgq), 0);
    +
    + return IRQ_HANDLED;
    +}
    +
    +static void gh_msgq_txdone_tasklet(unsigned long data)
    +{
    + struct gunyah_msgq *msgq = (struct gunyah_msgq *)data;
    +
    + mbox_chan_txdone(gunyah_msgq_chan(msgq), msgq->last_status);
    +}
    +
    +static int __gh_msgq_send(struct gunyah_msgq *msgq, void *buff, size_t size, u64 tx_flags)
    +{
    + unsigned long gh_err;
    + ssize_t ret;
    + bool ready;
    +
    + gh_err = gh_hypercall_msgq_send(msgq->tx_ghrsc.capid, size, (uintptr_t)buff, tx_flags,
    + &ready);
    + switch (gh_err) {
    + case GH_ERROR_OK:
    + ret = !ready;
    + break;
    + case GH_ERROR_MSGQUEUE_FULL:
    + ret = -EAGAIN;
    + break;
    + default:
    + /* Not sure how to propagate these out to client. If we get here, nobody is going
    + * to trigger a retry
    + */
    + ret = gh_remap_error(gh_err);
    + break;
    + }
    +
    + return ret;
    +}
    +
    +static int gh_msgq_send_data(struct mbox_chan *chan, void *data)
    +{
    + struct gunyah_msgq *msgq = mbox_chan_to_msgq(chan);
    + struct gunyah_msgq_tx_data *msgq_data = data;
    + u64 tx_flags = 0;
    + int ret;
    +
    + if (msgq_data->push)
    + tx_flags |= GH_HYPERCALL_MSGQ_TX_FLAGS_PUSH;
    +
    + ret = __gh_msgq_send(msgq, msgq_data->data, msgq_data->length, tx_flags);
    +
    + /**
    + * EAGAIN: message didn't send.
    + * ret = 1: message sent, but now the message queue is full and we can't send any more msgs.
    + * Either way, don't report that this message is done.
    + */
    + if (ret == -EAGAIN || ret == 1)
    + return ret;
    +
    + /**
    + * Mailbox framework requires that tx done happens asynchronously to sending the message
    + * IOW, a notification that the message was sent happens after sending the message.
    + * To work around this, defer the txdone to a tasklet.
    + */
    + msgq->last_status = ret;
    + tasklet_schedule(&msgq->txdone_tasklet);
    +
    + return 0;
    +}
    +
    +struct mbox_chan_ops gunyah_msgq_ops = {
    + .send_data = gh_msgq_send_data,
    +};
    +
    +/**
    + * gunyah_msgq_init() - Initialize a Gunyah message queue with an mbox_client
    + * @parent: optional, device parent used for the mailbox controller
    + * @msgq: Pointer to the gunyah_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 should be not NULL. Most message queue use cases come with
    + * a pair of message queues to facilitiate bidirectional communication. When tx_ghrsc is set,
    + * the client can send messages with mbox_send_message(gunyah_msgq_chan(msgq), msg). When rx_ghrsc
    + * is set, the mbox_client should register an .rx_callback() and the message queue driver will
    + * push all available messages upon receiving the RX ready interrupt. The messages should be
    + * consumed or copied by the client right away as the gunyah_msgq_rx_data will be replaced/destroyed
    + * after the callback.
    + *
    + * Returns - 0 on success, negative otherwise
    + */
    +int gunyah_msgq_init(struct device *parent, struct gunyah_msgq *msgq, struct mbox_client *cl,
    + struct gunyah_resource *tx_ghrsc, struct gunyah_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 != GUNYAH_RESOURCE_TYPE_MSGQ_TX) ||
    + (rx_ghrsc && rx_ghrsc->type != GUNYAH_RESOURCE_TYPE_MSGQ_RX))
    + return -EINVAL;
    +
    + msgq->tx_ghrsc = *tx_ghrsc;
    + msgq->rx_ghrsc = *rx_ghrsc;
    +
    + msgq->mbox.dev = parent;
    + msgq->mbox.ops = &gunyah_msgq_ops;
    + msgq->mbox.chans = kcalloc(1, sizeof(*msgq->mbox.chans), GFP_KERNEL);
    + msgq->mbox.num_chans = 1;
    + msgq->mbox.txdone_irq = true;
    +
    + if (gh_msgq_has_tx(msgq)) {
    + ret = request_irq(msgq->tx_ghrsc.irq, gh_msgq_tx_irq_handler, 0, "gh_msgq_tx",
    + msgq);
    + if (ret)
    + goto err_chans;
    + }
    +
    + if (gh_msgq_has_rx(msgq)) {
    + 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_init(&msgq->txdone_tasklet, gh_msgq_txdone_tasklet, (unsigned long)msgq);
    +
    + ret = mbox_controller_register(&msgq->mbox);
    + if (ret)
    + goto err_rx_irq;
    +
    + ret = mbox_bind_client(gunyah_msgq_chan(msgq), cl);
    + if (ret)
    + goto err_mbox;
    +
    + return 0;
    +err_mbox:
    + mbox_controller_unregister(&msgq->mbox);
    +err_rx_irq:
    + if (gh_msgq_has_rx(msgq))
    + free_irq(msgq->rx_ghrsc.irq, msgq);
    +err_tx_irq:
    + if (gh_msgq_has_tx(msgq))
    + free_irq(msgq->tx_ghrsc.irq, msgq);
    +err_chans:
    + kfree(msgq->mbox.chans);
    + return ret;
    +}
    +EXPORT_SYMBOL_GPL(gunyah_msgq_init);
    +
    +void gunyah_msgq_remove(struct gunyah_msgq *msgq)
    +{
    + if (gh_msgq_has_tx(msgq))
    + free_irq(msgq->tx_ghrsc.irq, msgq);
    +
    + kfree(msgq->mbox.chans);
    +}
    +EXPORT_SYMBOL_GPL(gunyah_msgq_remove);
    +
    +
    +static int __init gh_msgq_init(void)
    +{
    + if (GH_API_INFO_API_VERSION(gunyah_api.api_info) != GUNYAH_API_V1) {
    + pr_warn("Unrecognized gunyah version: %llu. Currently supported: %d\n",
    + GH_API_INFO_API_VERSION(gunyah_api.api_info), GUNYAH_API_V1);
    + return -ENODEV;
    + }
    +
    + return 0;
    +}
    +module_init(gh_msgq_init);
    +
    +static void __exit gh_msgq_exit(void)
    +{
    +}
    +module_exit(gh_msgq_exit);
    +
    +MODULE_LICENSE("GPL");
    +MODULE_DESCRIPTION("Gunyah Message Queue Driver");
    diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
    index 7ac917e0aa3f..f4c822a82f1a 100644
    --- a/drivers/virt/gunyah/Kconfig
    +++ b/drivers/virt/gunyah/Kconfig
    @@ -4,6 +4,8 @@ config GUNYAH
    tristate "Gunyah Virtualization drivers"
    depends on ARM64
    select AUXILIARY_BUS
    + select MAILBOX
    + select GUNYAH_MESSAGE_QUEUES
    help
    The Gunyah drivers are the helper interfaces that runs in a guest VM
    such as basic inter-VM IPC and signaling mechanisms, and higher level
    diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
    new file mode 100644
    index 000000000000..0e9709555c79
    --- /dev/null
    +++ b/include/linux/gunyah.h
    @@ -0,0 +1,67 @@
    +/* SPDX-License-Identifier: GPL-2.0-only */
    +/*
    + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
    + */
    +
    +#ifndef _GUNYAH_H
    +#define _GUNYAH_H
    +
    +#include <linux/mailbox_controller.h>
    +#include <linux/mailbox_client.h>
    +#include <linux/interrupt.h>
    +
    +#include <asm-generic/gunyah.h>
    +
    +/* Follows resource manager's resource types for VM_GET_HYP_RESOURCES */
    +enum gunyah_resource_type {
    + GUNYAH_RESOURCE_TYPE_BELL_TX = 0,
    + GUNYAH_RESOURCE_TYPE_BELL_RX = 1,
    + GUNYAH_RESOURCE_TYPE_MSGQ_TX = 2,
    + GUNYAH_RESOURCE_TYPE_MSGQ_RX = 3,
    + GUNYAH_RESOURCE_TYPE_VCPU = 4,
    +};
    +
    +struct gunyah_resource {
    + enum gunyah_resource_type type;
    + u64 capid;
    + int irq;
    +};
    +
    +/**
    + * Gunyah Message Queues
    + */
    +
    +#define GH_MSGQ_MAX_MSG_SIZE 240
    +
    +struct gunyah_msgq_tx_data {
    + size_t length;
    + bool push;
    + char data[];
    +};
    +
    +struct gunyah_msgq_rx_data {
    + size_t length;
    + char data[GH_MSGQ_MAX_MSG_SIZE];
    +};
    +
    +struct gunyah_msgq {
    + struct gunyah_resource tx_ghrsc;
    + struct gunyah_resource rx_ghrsc;
    +
    + /* msgq private */
    + int last_status;
    + struct mbox_controller mbox;
    + struct tasklet_struct txdone_tasklet;
    +};
    +
    +
    +int gunyah_msgq_init(struct device *parent, struct gunyah_msgq *msgq, struct mbox_client *cl,
    + struct gunyah_resource *tx_ghrsc, struct gunyah_resource *rx_ghrsc);
    +void gunyah_msgq_remove(struct gunyah_msgq *msgq);
    +
    +static inline struct mbox_chan *gunyah_msgq_chan(struct gunyah_msgq *msgq)
    +{
    + return &msgq->mbox.chans[0];
    +}
    +
    +#endif
    --
    2.25.1
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      Last update: 2022-10-11 02:10    [W:5.959 / U:0.024 seconds]
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