From b427188cd418632da7b26f283f5d2c668038186f Mon Sep 17 00:00:00 2001 From: Elliot Berman Date: Tue, 14 Feb 2023 13:23:15 -0800 Subject: [PATCH] mailbox: Add Gunyah message queue mailbox 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 --- Documentation/virt/gunyah/message-queue.rst | 8 + drivers/mailbox/Makefile | 2 + drivers/mailbox/gunyah-msgq.c | 214 ++++++++++++++++++++ include/linux/gunyah.h | 56 +++++ 4 files changed, 280 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 0667b3eb1ff92f..082085e981e030 100644 --- a/Documentation/virt/gunyah/message-queue.rst +++ b/Documentation/virt/gunyah/message-queue.rst @@ -59,3 +59,11 @@ 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 fc93761171113e..5f929bb55e9a52 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 00000000000000..03ffaa30ce9bff --- /dev/null +++ b/drivers/mailbox/gunyah-msgq.c @@ -0,0 +1,214 @@ +// 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 err; + bool ready = true; + + while (ready) { + err = gh_hypercall_msgq_recv(msgq->rx_ghrsc->capid, + (uintptr_t)&rx_data.data, sizeof(rx_data.data), + &rx_data.length, &ready); + if (err != GH_ERROR_OK) { + if (err != GH_ERROR_MSGQUEUE_EMPTY) + pr_warn("Failed to receive data from msgq for %s: %d\n", + msgq->mbox.dev ? dev_name(msgq->mbox.dev) : "", err); + 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, + (uintptr_t)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. + */ + msgq->last_ret = gh_remap_error(gh_error); + + /** + * This message was successfully sent, but message queue isn't ready to + * receive 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. + */ + if (gh_error == GH_ERROR_OK && !ready) + return 0; + + /** + * 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. + */ + 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 should 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 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 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 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; + + if (gh_api_version() != GUNYAH_API_V1) { + pr_err("Unrecognized gunyah version: %u. Currently supported: %d\n", + gh_api_version(), GUNYAH_API_V1); + return -EOPNOTSUPP; + } + + if (!gh_api_has_feature(GH_API_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 = kcalloc(msgq->mbox.num_chans, sizeof(*msgq->mbox.chans), GFP_KERNEL); + if (!msgq->mbox.chans) + return -ENOMEM; + + 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) +{ + 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 cb6df4eec5c2f0..2e13669c6363bb 100644 --- a/include/linux/gunyah.h +++ b/include/linux/gunyah.h @@ -8,11 +8,67 @@ #include #include +#include #include +#include +#include #include +/* 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 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 gunyah_resource *tx_ghrsc; + struct gunyah_resource *rx_ghrsc; + + /* msgq private */ + int last_ret; /* Linux error, not GH_STATUS_* */ + 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 gunyah_resource *tx_ghrsc, struct gunyah_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