Messages in this thread Patch in this message | | | Date | Thu, 2 Feb 2023 09:59:11 +0000 | Subject | Re: [PATCH v9 08/27] mailbox: Add Gunyah message queue mailbox | From | Srinivas Kandagatla <> |
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On 20/01/2023 22:46, 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. > > Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> > --- > Documentation/virt/gunyah/message-queue.rst | 8 + > MAINTAINERS | 1 + > drivers/mailbox/Makefile | 2 + > drivers/mailbox/gunyah-msgq.c | 214 ++++++++++++++++++++ > include/linux/gunyah.h | 59 +++++- > 5 files changed, 283 insertions(+), 1 deletion(-) > 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 0667b3eb1ff9..082085e981e0 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/MAINTAINERS b/MAINTAINERS > index fe19e71efc6d..d02e8abe6457 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -9049,6 +9049,7 @@ S: Supported > 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/linux/gunyah.h > > 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..caa283f7248b > --- /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 <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 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; > + unsigned long gh_err; > + bool ready = true; > + > + while (ready) { > + gh_err = gh_hypercall_msgq_recv(msgq->rx_ghrsc->capid, > + (uintptr_t)&rx_data.data, sizeof(rx_data.data), you should proabably use GH_MSGQ_MAX_MSG_SIZE instead of calling sizeof for every loop.
> + &rx_data.length, &ready); > + if (gh_err == GH_ERROR_OK) { > + mbox_chan_received_data(gh_msgq_chan(msgq), &rx_data); > + } else if (gh_err == GH_ERROR_MSGQUEUE_EMPTY) { > + break; > + } else { > + pr_warn("Failed to receive data from msgq for %s: %zd\n", > + msgq->mbox.dev ? dev_name(msgq->mbox.dev) : "", gh_err); > + break; > + } > + } > + > + return IRQ_HANDLED; > +} How about making this more readable. also use of gh_ in local variables is not really adding any value.
while (ready) { err = gh_hypercall_msgq_recv(...); if (err) { if (err != GH_ERROR_MSGQUEUE_EMPTY) dev_warn(msgq->mbox.dev, "Failed to receive data %zd\n", err); break;
} mbox_chan_received_data(gh_msgq_chan(msgq), &rx_data); }
> + > +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); What is this irq for? Is it for tx done ack?
> + > + return IRQ_HANDLED; > +} > + > +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; > + unsigned long ret; > + bool ready; > + > + if (msgq_data->push) > + tx_flags |= GH_HYPERCALL_MSGQ_TX_FLAGS_PUSH; > + > + ret = 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(ret == 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(ret); > + > + /** > + * 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 (ret == 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_warn("Unrecognized gunyah version: %u. Currently supported: %d\n", > + gh_api_version(), GUNYAH_API_V1); how about using dev_err here?
> + return -ENODEV;
-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.chans = kcalloc(msgq->mbox.num_chans, sizeof(*msgq->mbox.chans), GFP_KERNEL); > + if (!msgq->mbox.chans) > + return -ENOMEM;
new line here would be nice. > + msgq->mbox.txdone_irq = true; > + > + 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);
AFAIU, this looks like duplicating what core already has with TXDONE_BY_POLL.
can we not use txdone_poll = true and implement last_tx_done callback to use hrtimer from the core to tick tx.
--srini > + > + 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 b5f61c14ec1e..5d6fc9f88718 100644 > --- a/include/linux/gunyah.h > +++ b/include/linux/gunyah.h > @@ -8,10 +8,67 @@ > > #include <linux/bitfield.h> > #include <linux/errno.h> > +#include <linux/interrupt.h> > #include <linux/limits.h> > +#include <linux/mailbox_controller.h> > +#include <linux/mailbox_client.h> > #include <linux/types.h> > > -/* Common Gunyah macros */ > +/* 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 macros and definitions for Gunyah hypercalls */ > + > #define GH_CAPID_INVAL U64_MAX > #define GH_VMID_ROOT_VM 0xff >
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