Re: [PATCH v9 09/27] gunyah: rsc_mgr: Add resource manager RPC core

Srinivas Kandagatla
2023-02-02T11:53:21Z

On 20/01/2023 22:46, Elliot Berman wrote:
> The resource manager is a special virtual machine which is always
> running on a Gunyah system. It provides APIs for creating and destroying
> VMs, secure memory management, sharing/lending of memory between VMs,
> and setup of inter-VM communication. Calls to the resource manager are
> made via message queues.
>
> This patch implements the basic probing and RPC mechanism to make those
> API calls. Request/response calls can be made with gh_rm_call.
> Drivers can also register to notifications pushed by RM via
> gh_rm_register_notifier
I dont see this notifier related change in this patch or in this series.

>
> Specific API calls that resource manager supports will be implemented in
> subsequent patches.
>
> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
> ---
> MAINTAINERS | 2 +-
> drivers/virt/gunyah/Kconfig | 1 -
> drivers/virt/gunyah/Makefile | 3 +
> drivers/virt/gunyah/rsc_mgr.c | 616 +++++++++++++++++++++++++++++++++
> drivers/virt/gunyah/rsc_mgr.h | 71 ++++
> include/linux/gunyah.h | 3 +-
> include/linux/gunyah_rsc_mgr.h | 18 +
> 7 files changed, 710 insertions(+), 4 deletions(-)
> create mode 100644 drivers/virt/gunyah/rsc_mgr.c
> create mode 100644 drivers/virt/gunyah/rsc_mgr.h
> create mode 100644 include/linux/gunyah_rsc_mgr.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d02e8abe6457..7ab1462577cc 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9051,7 +9051,7 @@ F: Documentation/virt/gunyah/
> F: arch/arm64/gunyah/
> F: drivers/mailbox/gunyah-msgq.c
> F: drivers/virt/gunyah/
> -F: include/linux/gunyah.h
> +F: include/linux/gunyah*.h
>

It might be good idea to add a dedicated patch for updating MAINTAINERS
file at the end of series.

> HABANALABS PCI DRIVER
> M: Oded Gabbay <ogabbay@kernel.org>
> diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
> index 71c38845bcea..1a737694c333 100644
> --- a/drivers/virt/gunyah/Kconfig
> +++ b/drivers/virt/gunyah/Kconfig
> @@ -4,7 +4,6 @@ config GUNYAH
> tristate "Gunyah Virtualization drivers"
> depends on ARM64
> depends on MAILBOX
> - select GUNYAH_PLATFORM_HOOKS
> help
> The Gunyah drivers are the helper interfaces that run in a guest VM
> such as basic inter-VM IPC and signaling mechanisms, and higher level
> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
> index 34f32110faf9..cc864ff5abbb 100644
> --- a/drivers/virt/gunyah/Makefile
> +++ b/drivers/virt/gunyah/Makefile
> @@ -1,3 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
>
> obj-$(CONFIG_GUNYAH) += gunyah.o
> +
> +gunyah_rsc_mgr-y += rsc_mgr.o
> +obj-$(CONFIG_GUNYAH) += gunyah_rsc_mgr.o
> diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c
> new file mode 100644
> index 000000000000..382f9943fd31
> --- /dev/null
> +++ b/drivers/virt/gunyah/rsc_mgr.c
> @@ -0,0 +1,616 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#include <linux/mutex.h>
> +#include <linux/sched.h>
> +#include <linux/gunyah.h>
> +#include <linux/module.h>
> +#include <linux/of_irq.h>
> +#include <linux/kthread.h>
> +#include <linux/notifier.h>
> +#include <linux/workqueue.h>
> +#include <linux/completion.h>
> +#include <linux/gunyah_rsc_mgr.h>
> +#include <linux/platform_device.h>
> +
> +#include "rsc_mgr.h"
> +
> +#define RM_RPC_API_VERSION_MASK GENMASK(3, 0)
> +#define RM_RPC_HEADER_WORDS_MASK GENMASK(7, 4)
> +#define RM_RPC_API_VERSION FIELD_PREP(RM_RPC_API_VERSION_MASK, 1)
> +#define RM_RPC_HEADER_WORDS FIELD_PREP(RM_RPC_HEADER_WORDS_MASK, \
> + (sizeof(struct gh_rm_rpc_hdr) / sizeof(u32)))
> +#define RM_RPC_API (RM_RPC_API_VERSION | RM_RPC_HEADER_WORDS)
> +
> +#define RM_RPC_TYPE_CONTINUATION 0x0
> +#define RM_RPC_TYPE_REQUEST 0x1
> +#define RM_RPC_TYPE_REPLY 0x2
> +#define RM_RPC_TYPE_NOTIF 0x3
> +#define RM_RPC_TYPE_MASK GENMASK(1, 0)
> +
> +#define GH_RM_MAX_NUM_FRAGMENTS 62
> +#define RM_RPC_FRAGMENTS_MASK GENMASK(7, 2)
> +
> +struct gh_rm_rpc_hdr {
> + u8 api;
> + u8 type;
> + __le16 seq;
> + __le32 msg_id;
> +} __packed;
> +
#define GH_RM_RPC_HDR_SZ sizeof(struct gh_rm_rpc_hdr)

You could use this in most of the places where sizeof is being called.

> +struct gh_rm_rpc_reply_hdr {
> + struct gh_rm_rpc_hdr rpc_hdr;
> + __le32 err_code; /* GH_RM_ERROR_* */
> +} __packed;
> +
> +#define GH_RM_MAX_MSG_SIZE (GH_MSGQ_MAX_MSG_SIZE - sizeof(struct gh_rm_rpc_hdr))
> +
> +/**
> + * struct gh_rm_connection - Represents a complete message from resource manager
> + * @payload: Combined payload of all the fragments (msg headers stripped off).
> + * @size: Size of the payload received so far.
> + * @ret: Linux return code, set in case there was an error processing connection
> + * @msg_id: Message ID from the header.
> + * @type: RM_RPC_TYPE_REPLY or RM_RPC_TYPE_NOTIF.
> + * @num_fragments: total number of fragments expected to be received.
> + * @fragments_received: fragments received so far.
> + * @rm_error: For request/reply sequences with standard replies.
> + * @seq: Sequence ID for the main message.
> + * @seq_done: Signals caller that the RM reply has been received
> + */
> +struct gh_rm_connection {
> + void *payload;
> + size_t size;
> + __le32 msg_id;
> + u8 type;
> +
> + u8 num_fragments;
> + u8 fragments_received;
> +
> + union {
> + struct {
> + /* only for req/reply sequence */
> + int ret;
> + u16 seq;
> + u32 rm_error; /* GH_RM_ERROR_* */
> + struct completion seq_done;
> + } reply;
> +
> + struct {
> + struct work_struct work;
> + } notification;
> + };
> +};
> +
> +struct gh_rm_notif_complete {
> + struct gh_rm_connection *conn;
> + struct work_struct work;
> +};
No users for this.

> +
> +struct gh_rm {
> + struct device *dev;
> + struct gunyah_resource tx_ghrsc, rx_ghrsc;
> + struct gh_msgq msgq;
> + struct mbox_client msgq_client;
> + struct gh_rm_connection *active_rx_connection;
> + int last_tx_ret;
> +
> + struct idr call_idr;
> + struct mutex call_idr_lock;
> +
> + struct kmem_cache *cache;
> + struct mutex send_lock;
> +
> + struct work_struct recv_work;
?? No users

> +};
> +
> +static struct gh_rm_connection *gh_rm_alloc_connection(__le32 msg_id, u8 type)
> +{
> + struct gh_rm_connection *connection;
> +
> + connection = kzalloc(sizeof(*connection), GFP_KERNEL);
> + if (!connection)
> + return NULL;
Error code is now lost here, we should probgate the error to the caller.

return ERR_PTR(-ENOMEM);
and let the caller check return value by IS_ERR()

> +
> + connection->type = type;
> + connection->msg_id = msg_id;
> +
> + return connection;
> +}
> +
> +static int gh_rm_init_connection_payload(struct gh_rm_connection *connection, void *msg,
> + size_t hdr_size, size_t msg_size)
> +{
> + struct gh_rm_rpc_hdr *hdr = msg;
> + size_t max_buf_size, payload_size;
> +
> + if (hdr_size > msg_size)
> + return -EINVAL;
> +
> + payload_size = msg_size - hdr_size;
> +
> + connection->num_fragments = FIELD_GET(RM_RPC_FRAGMENTS_MASK, hdr->type);
> + connection->fragments_received = 0;
> +
> + /* There's not going to be any payload, no need to allocate buffer. */
> + if (!payload_size && !connection->num_fragments)
> + return 0;
> +
> + if (connection->num_fragments > GH_RM_MAX_NUM_FRAGMENTS)
> + return -EINVAL;
> +
> + max_buf_size = payload_size + (connection->num_fragments * GH_RM_MAX_MSG_SIZE);
> +
> + connection->payload = kzalloc(max_buf_size, GFP_KERNEL);
> + if (!connection->payload)
> + return -ENOMEM;
> +
> + memcpy(connection->payload, msg + hdr_size, payload_size);
> + connection->size = payload_size;
> + return 0;
> +}
> +
> +static void gh_rm_notif_work(struct work_struct *work)
> +{
> + struct gh_rm_connection *connection = container_of(work, struct gh_rm_connection,
> + notification.work);
> +
> + /* No users of notifications, yet. */
> +
> + kfree(connection->payload);
> + kfree(connection);
> +}
> +
> +static struct gh_rm_connection *gh_rm_process_notif(struct gh_rm *rm, void *msg, size_t msg_size)
> +{
> + struct gh_rm_rpc_hdr *hdr = msg;
> + struct gh_rm_connection *connection;
> + int ret;
> +
> + connection = gh_rm_alloc_connection(hdr->msg_id, RM_RPC_TYPE_NOTIF);
> + if (!connection) {
> + dev_err(rm->dev, "Failed to alloc connection for notification, dropping.\n");
> + return NULL;
> + }
> +
> + INIT_WORK(&connection->notification.work, gh_rm_notif_work);
> +
> + ret = gh_rm_init_connection_payload(connection, msg, sizeof(*hdr), msg_size);
> + if (ret) {
> + dev_err(rm->dev, "Failed to initialize connection buffer for notification: %d\n",
> + ret);
> + kfree(connection);

> + return NULL;
> + }
> +
> + return connection;
> +}
> +
> +static struct gh_rm_connection *gh_rm_process_rply(struct gh_rm *rm, void *msg, size_t msg_size)
> +{
> + struct gh_rm_rpc_reply_hdr *reply_hdr = msg;
> + struct gh_rm_rpc_hdr *hdr = &reply_hdr->rpc_hdr;
> + struct gh_rm_connection *connection;
> + u16 seq_id = le16_to_cpu(hdr->seq);
> +
> + mutex_lock(&rm->call_idr_lock);
> + connection = idr_find(&rm->call_idr, seq_id);
> + mutex_unlock(&rm->call_idr_lock);
> +
> + if (!connection) {
> + dev_err(rm->dev, "Failed to find connection for sequence %u\n", seq_id);
> + return NULL;
> + }
> + if (connection->msg_id != hdr->msg_id) {
Are we saying that there will be multiple msg_ids for a single
connection seq_id?

> + dev_err(rm->dev, "Reply for sequence %u expected msg_id: %x but got %x\n",
> + seq_id, le32_to_cpu(connection->msg_id), le32_to_cpu(hdr->msg_id));
> + /*
> + * Don't complete connection and error the client, maybe
> + * resource manager will send us the expected reply sequence soon.
> + */
> + return NULL;
> + }
> +
> + if (gh_rm_init_connection_payload(connection, msg, sizeof(*reply_hdr), msg_size)) {
> + dev_err(rm->dev, "Failed to alloc connection buffer for sequence %d\n", seq_id);
> + /* Send connection complete and error the client. */
> + connection->reply.ret = -ENOMEM;
> + complete(&connection->reply.seq_done);
> + return NULL;
> + }
> +
> + connection->reply.rm_error = le32_to_cpu(reply_hdr->err_code);
> + return connection;
> +}
> +
> +static int gh_rm_process_cont(struct gh_rm *rm, struct gh_rm_connection *connection,
> + void *msg, size_t msg_size)
> +{
> + struct gh_rm_rpc_hdr *hdr = msg;
> + size_t payload_size = msg_size - sizeof(*hdr);

I think its worth defining GH_RM_RPC_HDR_SZ, looks like its used in many
places.

> +
> + /*
> + * hdr->fragments and hdr->msg_id preserves the value from first reply
> + * or notif message. To detect mishandling, check it's still intact.
> + */
> + if (connection->msg_id != hdr->msg_id) {
> + dev_err(rm->dev, "Appending mismatched continuation with id %d to connection with id %d\n",
> + le32_to_cpu(hdr->msg_id), le32_to_cpu(connection->msg_id));
> + return -EINVAL;
> + }
> + if (connection->num_fragments != FIELD_GET(RM_RPC_FRAGMENTS_MASK, hdr->type)) {
> + dev_err(rm->dev, "Number of fragments mismatch for message %x\n",
> + le32_to_cpu(hdr->msg_id));
> + return -EINVAL;
> + }
> +
> + memcpy(connection->payload + connection->size, msg + sizeof(*hdr), payload_size);
> + connection->size += payload_size;
> + connection->fragments_received++;
> + return 0;
> +}
> +
> +static bool gh_rm_complete_connection(struct gh_rm *rm, struct gh_rm_connection *connection)
> +{
> + if (!connection)
> + return false;
> +
> + if (connection->fragments_received != connection->num_fragments)
> + return false;
> +
> + switch (connection->type) {
> + case RM_RPC_TYPE_REPLY:
> + complete(&connection->reply.seq_done);
> + break;
> + case RM_RPC_TYPE_NOTIF:
> + schedule_work(&connection->notification.work);
If there are no real users for this why not just

kfree(connection->payload);
kfree(connection);

> + break;
> + default:
> + dev_err(rm->dev, "Invalid message type (%d) received\n", connection->type);

will we have this case at all? if yes then are we leaking connection object?

> + break;
> + }
> +
> + return true;
> +}
> +
> +static void gh_rm_abort_connection(struct gh_rm_connection *connection)
> +{
> + switch (connection->type) {
> + case RM_RPC_TYPE_REPLY:
> + connection->reply.ret = -EIO;
> + complete(&connection->reply.seq_done);
> + break;
> + case RM_RPC_TYPE_NOTIF:
> + fallthrough;
> + default:
> + kfree(connection->payload);
> + kfree(connection);
> + }
> +}
> +
> +static void gh_rm_msgq_rx_data(struct mbox_client *cl, void *mssg)
> +{
> + struct gh_rm *rm = container_of(cl, struct gh_rm, msgq_client);
> + struct gh_msgq_rx_data *rx_data = mssg;
> + void *msg = rx_data->data;
> + size_t msg_size = rx_data->length;
> + struct gh_rm_rpc_hdr *hdr;
> +
> + if (msg_size <= sizeof(struct gh_rm_rpc_hdr)) {
> + dev_err(rm->dev, "Incomplete message size: %ld is too small\n", msg_size);
> + return;
> + }
> +
> + hdr = msg;
> + if (hdr->api != RM_RPC_API) {
> + dev_err(rm->dev, "Unknown RM RPC API version: %x\n", hdr->api);
> + return;
> + }
> +
> + if (msg_size > GH_MSGQ_MAX_MSG_SIZE) {
> + dev_err(rm->dev, "Unexpected large message received: %ld\n", msg_size);
> + return;
> + }
> +
> + switch (FIELD_GET(RM_RPC_TYPE_MASK, hdr->type)) {
> + case RM_RPC_TYPE_NOTIF:
> + if (rm->active_rx_connection) {
> + /* Not possible per protocol. Do something better than BUG_ON */
> + dev_err(rm->dev, "Received start of new notification without finishing existing message series.\n");
> + gh_rm_abort_connection(rm->active_rx_connection);
> + }
> + rm->active_rx_connection = gh_rm_process_notif(rm, msg, msg_size);
> + break;
> + case RM_RPC_TYPE_REPLY:
> + if (rm->active_rx_connection) {
> + /* Not possible per protocol. Do something better than BUG_ON */
> + dev_err(rm->dev, "Received start of new reply without finishing existing message series.\n");
> + gh_rm_abort_connection(rm->active_rx_connection);
> + }
> + rm->active_rx_connection = gh_rm_process_rply(rm, msg, msg_size);
> + break;
> + case RM_RPC_TYPE_CONTINUATION:
> + if (!rm->active_rx_connection) {
> + dev_err(rm->dev, "Received a continuation message without receiving initial message\n");
> + break;
> + }
> + if (gh_rm_process_cont(rm, rm->active_rx_connection, msg, msg_size)) {
> + gh_rm_abort_connection(rm->active_rx_connection);
> + rm->active_rx_connection = NULL;
> + }
> + break;
> + default:
> + dev_err(rm->dev, "Invalid message type (%lu) received\n",
> + FIELD_GET(RM_RPC_TYPE_MASK, hdr->type));
> + return;
> + }
> +
> + if (gh_rm_complete_connection(rm, rm->active_rx_connection))
> + rm->active_rx_connection = NULL;
> +}
> +
> +static void gh_rm_msgq_tx_done(struct mbox_client *cl, void *mssg, int r)
> +{
> + struct gh_rm *rm = container_of(cl, struct gh_rm, msgq_client);
> +
> + kmem_cache_free(rm->cache, mssg);
> + rm->last_tx_ret = r;
> +}
> +
> +static int gh_rm_send_request(struct gh_rm *rm, u32 message_id,
> + const void *req_buff, size_t req_buff_size,
> + struct gh_rm_connection *connection)
> +{
> + size_t buff_size_remaining = req_buff_size;
> + u32 cont_fragments = 0;
> + struct gh_rm_rpc_hdr *hdr;
> + struct gh_msgq_tx_data *msg;
> + u8 msg_type = FIELD_PREP(RM_RPC_TYPE_MASK, RM_RPC_TYPE_REQUEST);
> + void *payload;
> + size_t payload_size;
> + const void *req_buff_curr = req_buff;
> + int ret;
> +
> + if (req_buff_size)
> + cont_fragments = (req_buff_size - 1) / GH_RM_MAX_MSG_SIZE;
> +
> + if (req_buff_size > GH_RM_MAX_NUM_FRAGMENTS * GH_RM_MAX_MSG_SIZE) {
> + pr_warn("Limit exceeded for the number of fragments: %u\n", cont_fragments);
> + dump_stack();
> + return -E2BIG;
> + }
> +
> + ret = mutex_lock_interruptible(&rm->send_lock);
> + if (ret)
> + return ret;
> +
> + /* Consider also the 'request' packet for the loop count */
> + do {
> + msg = kmem_cache_zalloc(rm->cache, GFP_KERNEL);
> + if (!msg) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + /* Fill header */
> + hdr = (struct gh_rm_rpc_hdr *)msg->data;
> + hdr->api = RM_RPC_API;
> + hdr->type = msg_type | FIELD_PREP(RM_RPC_FRAGMENTS_MASK, cont_fragments);
> + hdr->seq = cpu_to_le16(connection->reply.seq);
> + hdr->msg_id = cpu_to_le32(message_id);
> +
> + /* Copy payload */
> + payload = hdr + 1;
> + payload_size = min(buff_size_remaining, GH_RM_MAX_MSG_SIZE);
> + memcpy(payload, req_buff_curr, payload_size);
> + req_buff_curr += payload_size;
> + buff_size_remaining -= payload_size;
> +
> + /* Force the last fragment to immediately alert the receiver */
> + msg->push = !buff_size_remaining;
> + msg->length = sizeof(*hdr) + payload_size;
> +
> + ret = mbox_send_message(gh_msgq_chan(&rm->msgq), msg);
> + if (ret < 0) {
> + kmem_cache_free(rm->cache, msg);
> + break;
> + }
> +
> + if (rm->last_tx_ret) {
> + ret = rm->last_tx_ret;
> + break;
> + }
> +
> + msg_type = FIELD_PREP(RM_RPC_TYPE_MASK, RM_RPC_TYPE_CONTINUATION);
> + } while (buff_size_remaining);
> +
> +out:
> + mutex_unlock(&rm->send_lock);
> + return ret < 0 ? ret : 0;
> +}
> +
> +/**
> + * gh_rm_call: Achieve request-response type communication with RPC
> + * @rm: Pointer to Gunyah resource manager internal data
> + * @message_id: The RM RPC message-id
> + * @req_buff: Request buffer that contains the payload
> + * @req_buff_size: Total size of the payload
> + * @resp_buf: Pointer to a response buffer
> + * @resp_buff_size: Size of the response buffer
> + *
> + * Make a request to the RM-VM and wait for reply back. For a successful
> + * response, the function returns the payload. The size of the payload is set in
> + * resp_buff_size. The resp_buf should be freed by the caller.
> + *
> + * req_buff should be not NULL for req_buff_size >0. If req_buff_size == 0,
> + * req_buff *can* be NULL and no additional payload is sent.
> + *
> + * Context: Process context. Will sleep waiting for reply.
> + * Return: 0 on success. <0 if error.
> + */
> +int gh_rm_call(struct gh_rm *rm, u32 message_id, void *req_buff, size_t req_buff_size,
> + void **resp_buf, size_t *resp_buff_size)

Should we export this function or is this a static function?

> +{
> + struct gh_rm_connection *connection;
> + int ret;
> +
> + /* message_id 0 is reserved. req_buff_size implies req_buf is not NULL */
> + if (!message_id || (!req_buff && req_buff_size))
> + return -EINVAL;
> +
> + if (!rm)
> + return -EPROBE_DEFER;
Not sure what is the intent here, the caller should already know if he
is sending NULL ptr.

> +
> + connection = gh_rm_alloc_connection(cpu_to_le32(message_id), RM_RPC_TYPE_REPLY);
> + if (!connection)
> + return -ENOMEM;
> +
> + init_completion(&connection->reply.seq_done);
> +
> + /* Allocate a new seq number for this connection */
> + mutex_lock(&rm->call_idr_lock);
> + ret = idr_alloc_cyclic(&rm->call_idr, connection, 0, U16_MAX,
> + GFP_KERNEL);
> + mutex_unlock(&rm->call_idr_lock);
> + if (ret < 0)
> + goto out;
> + connection->reply.seq = ret;
> +
> + /* Send the request to the Resource Manager */
> + ret = gh_rm_send_request(rm, message_id, req_buff, req_buff_size, connection);
> + if (ret < 0)
> + goto out;
> +
> + /* Wait for response */
> + ret = wait_for_completion_interruptible(&connection->reply.seq_done);
> + if (ret)
> + goto out;
> +
> + /* Check for internal (kernel) error waiting for the response */
> + if (connection->reply.ret) {
You should probably check the ret to see if allocation of payload has
failed before calling kfree.

> + ret = connection->reply.ret;
> + kfree(connection->payload);
Atleast by the looks of gh_rm_init_connection_payload you should not
even call kfree in error cases.

> + goto out;
> + }
> +
> + /* Got a response, did resource manager give us an error? */
> + if (connection->reply.rm_error) {
> + pr_warn("RM rejected message %08x. Error: %d\n", message_id,
> + connection->reply.rm_error);
> + dump_stack();
> + ret = gh_rm_remap_error(connection->reply.rm_error);
> + kfree(connection->payload);
> + goto out;
> + }
> +
> + /* Everything looks good, return the payload */
> + *resp_buff_size = connection->size;
> + if (connection->size)
> + *resp_buf = connection->payload;
> + else {
> + /* kfree in case RM sent us multiple fragments but never any data in
> + * those fragments. We would've allocated memory for it, but connection->size == 0
> + */
> + kfree(connection->payload);
> + }
> +
> +out:
> + mutex_lock(&rm->call_idr_lock);
> + idr_remove(&rm->call_idr, connection->reply.seq);
> + mutex_unlock(&rm->call_idr_lock);
> + kfree(connection);
> + return ret;
> +}
> +
> +static int gh_msgq_platform_probe_direction(struct platform_device *pdev,
> + bool tx, int idx, struct gunyah_resource *ghrsc)
> +{
> + int ret;
> + struct device_node *node = pdev->dev.of_node;
> +
> + ghrsc->type = tx ? GUNYAH_RESOURCE_TYPE_MSGQ_TX : GUNYAH_RESOURCE_TYPE_MSGQ_RX;
> +
> + ghrsc->irq = platform_get_irq(pdev, idx);
> + if (ghrsc->irq < 0) {
> + dev_err(&pdev->dev, "Failed to get irq%d: %d\n", idx, ghrsc->irq);
> + return ghrsc->irq;
> + }
> +
> + ret = of_property_read_u64_index(node, "reg", idx, &ghrsc->capid);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to get capid%d: %d\n", idx, ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int gh_rm_drv_probe(struct platform_device *pdev)
> +{
> + struct gh_rm *rm;
> + int ret;
> +
> + rm = devm_kzalloc(&pdev->dev, sizeof(*rm), GFP_KERNEL);
> + if (!rm)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, rm);
> + rm->dev = &pdev->dev;
> +
> + mutex_init(&rm->call_idr_lock);
> + idr_init(&rm->call_idr);
> + rm->cache = kmem_cache_create("gh_rm", struct_size(msg, data, GH_MSGQ_MAX_MSG_SIZE), 0,
> + SLAB_HWCACHE_ALIGN, NULL);
> + if (!rm->cache)
> + return -ENOMEM;
> + mutex_init(&rm->send_lock);
> +
> + ret = gh_msgq_platform_probe_direction(pdev, true, 0, &rm->tx_ghrsc);
> + if (ret)
> + goto err_cache;
this lable does not exist in the patch.

> +
> + ret = gh_msgq_platform_probe_direction(pdev, false, 1, &rm->rx_ghrsc);
> + if (ret)
> + goto err_cache;
> +
> + rm->msgq_client.dev = &pdev->dev;
> + rm->msgq_client.tx_block = true;
> + rm->msgq_client.rx_callback = gh_rm_msgq_rx_data;
> + rm->msgq_client.tx_done = gh_rm_msgq_tx_done;
> +
> + return gh_msgq_init(&pdev->dev, &rm->msgq, &rm->msgq_client, &rm->tx_ghrsc, &rm->rx_ghrsc);
> +}
> +
> +static int gh_rm_drv_remove(struct platform_device *pdev)
> +{
> + struct gh_rm *rm = platform_get_drvdata(pdev);
> +
> + mbox_free_channel(gh_msgq_chan(&rm->msgq));
> + gh_msgq_remove(&rm->msgq);
> + kmem_cache_destroy(rm->cache);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id gh_rm_of_match[] = {
> + { .compatible = "gunyah-resource-manager" },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, gh_rm_of_match);
> +
> +static struct platform_driver gh_rm_driver = {
> + .probe = gh_rm_drv_probe,
> + .remove = gh_rm_drv_remove,
> + .driver = {
> + .name = "gh_rsc_mgr",
> + .of_match_table = gh_rm_of_match,
> + },
> +};
> +module_platform_driver(gh_rm_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Gunyah Resource Manager Driver");

--srini