[PATCH v5 10/13] gunyah: rsc_mgr: Add resource manager RPC core

From: Elliot Berman
Date: Mon Oct 10 2022 - 20:11:02 EST

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

Specific API calls that resource manager supports will be implemented in
subsequent patches.

Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
MAINTAINERS | 2 +-
drivers/virt/gunyah/Kconfig | 20 +-
drivers/virt/gunyah/Makefile | 3 +
drivers/virt/gunyah/rsc_mgr.c | 601 +++++++++++++++++++++++++++++++++
drivers/virt/gunyah/rsc_mgr.h | 34 ++
include/linux/gunyah_rsc_mgr.h | 26 ++
6 files changed, 682 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 599804836d05..8a3d79b56698 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8891,7 +8891,7 @@ 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
+F: include/linux/gunyah*.h

HABANALABS PCI DRIVER
M: Oded Gabbay <ogabbay@xxxxxxxxxx>
diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
index f4c822a82f1a..78deed3c4562 100644
--- a/drivers/virt/gunyah/Kconfig
+++ b/drivers/virt/gunyah/Kconfig
@@ -3,9 +3,6 @@
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
@@ -13,3 +10,20 @@ config GUNYAH

Say Y/M here to enable the drivers needed to interact in a Gunyah
virtual environment.
+
+if GUNYAH
+
+config GUNYAH_RESORUCE_MANAGER
+ tristate "Gunyah Resource Manager"
+ select MAILBOX
+ select GUNYAH_MESSAGE_QUEUES
+ default y
+ help
+ The resource manager (RM) is a privileged application VM supporting
+ the Gunyah Hypervisor. Enable this driver to support communicating
+ with Gunyah RM. This is typically required for a VM running under
+ Gunyah wanting to have Gunyah-awareness.
+
+ Say Y/M here if unsure.
+
+endif
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
index dc081e2dc02b..2cae8ea5bc7d 100644
--- a/drivers/virt/gunyah/Makefile
+++ b/drivers/virt/gunyah/Makefile
@@ -1,2 +1,5 @@
gunyah-y += gunyah.o
obj-$(CONFIG_GUNYAH) += gunyah.o
+
+gunyah_rsc_mgr-y += rsc_mgr.o
+obj-$(CONFIG_GUNYAH_RESORUCE_MANAGER) += 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..0e2f04984ada
--- /dev/null
+++ b/drivers/virt/gunyah/rsc_mgr.c
@@ -0,0 +1,601 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "gh_rsc_mgr: " fmt
+
+#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"
+
+/* Resource Manager Header */
+struct gh_rm_rpc_hdr {
+ u8 version:4,
+ hdr_words:4;
+ u8 type:2,
+ fragments:6;
+ u16 seq;
+ u32 msg_id;
+} __packed;
+
+/* Standard reply header */
+struct gh_rm_rpc_reply_hdr {
+ struct gh_rm_rpc_hdr rpc_hdr;
+ u32 err_code;
+} __packed;
+
+/* RPC Header versions */
+#define GH_RM_RPC_HDR_VERSION_ONE 0x1
+
+/* RPC Header words */
+#define GH_RM_RPC_HDR_WORDS 0x2
+
+/* RPC Message types */
+#define GH_RM_RPC_TYPE_CONT 0x0
+#define GH_RM_RPC_TYPE_REQ 0x1
+#define GH_RM_RPC_TYPE_RPLY 0x2
+#define GH_RM_RPC_TYPE_NOTIF 0x3
+
+#define GH_RM_MAX_NUM_FRAGMENTS 62
+
+#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 (i.e. msg headers stripped off).
+ * @size: Size of the payload.
+ * @ret: Linux return code, set in case there was an error processing the connection.
+ * @msg_id: Message ID from the header.
+ * @type: GH_RM_RPC_TYPE_RPLY or GH_RM_RPC_TYPE_NOTIF.
+ * @num_fragments: total number of fragments expected to be received for this connection.
+ * @fragments_recieved: fragments received so far.
+ * @rm_error: For request/reply sequences with standard replies.
+ * @seq: Sequence ID for the main message.
+ */
+struct gh_rm_connection {
+ void *payload;
+ size_t size;
+ int ret;
+ u32 msg_id;
+ u8 type;
+
+ u8 num_fragments;
+ u8 fragments_received;
+
+ /* only for req/reply sequence */
+ u32 rm_error;
+ u16 seq;
+ struct completion seq_done;
+};
+
+struct gh_rm_notif_complete {
+ struct gh_rm_connection *conn;
+ struct work_struct work;
+};
+
+struct gh_rsc_mgr {
+ struct gunyah_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 mutex send_lock;
+
+ struct work_struct recv_work;
+};
+
+static struct gh_rsc_mgr *__rsc_mgr;
+SRCU_NOTIFIER_HEAD_STATIC(gh_rm_notifier);
+
+static struct gh_rm_connection *gh_rm_alloc_connection(u32 msg_id, u8 type)
+{
+ struct gh_rm_connection *connection;
+
+ connection = kzalloc(sizeof(*connection), GFP_KERNEL);
+ if (!connection)
+ return NULL;
+
+ connection->type = type;
+ connection->msg_id = msg_id;
+
+ return connection;
+}
+
+/**
+ * gh_rm_init_connection_payload() - Fills the first message for a connection.
+ */
+static int gh_rm_init_connection_payload(struct gh_rm_connection *connection, void *msg,
+ size_t hdr_size, size_t payload_size)
+{
+ struct gh_rm_rpc_hdr *hdr = msg;
+ size_t max_buf_size;
+
+ connection->num_fragments = hdr->fragments;
+ connection->fragments_received = 0;
+ connection->type = hdr->type;
+
+ /* There's not going to be any payload, no need to allocate buffer. */
+ if (!payload_size && !connection->num_fragments)
+ return 0;
+
+ /*
+ * maximum payload size is GH_MSGQ_MAX_MSG_SIZE - hdr_size
+ * and can received (hdr->fragments + 1) of those
+ */
+ max_buf_size = (GH_MSGQ_MAX_MSG_SIZE - hdr_size) * (hdr->fragments + 1);
+
+ 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_notif_complete *notif = container_of(work, struct gh_rm_notif_complete, work);
+ struct gh_rm_connection *connection = notif->conn;
+ u32 notif_id = connection->msg_id;
+ struct gh_rm_notification notification = {
+ .buff = connection->payload,
+ .size = connection->size,
+ };
+
+ srcu_notifier_call_chain(&gh_rm_notifier, notif_id, &notification);
+
+ kfree(connection->payload);
+ kfree(connection);
+ kfree(notif);
+}
+
+static struct gh_rm_connection *gh_rm_process_notif(struct gh_rsc_mgr *rsc_mgr,
+ void *msg, size_t msg_size)
+{
+ struct gh_rm_rpc_hdr *hdr = msg;
+ struct gh_rm_connection *connection;
+
+ connection = gh_rm_alloc_connection(hdr->msg_id, hdr->type);
+ if (!connection) {
+ pr_err("Failed to alloc connection for notification, dropping.\n");
+ return NULL;
+ }
+
+ if (gh_rm_init_connection_payload(connection, msg, sizeof(*hdr), msg_size - sizeof(*hdr))) {
+ pr_err("Failed to alloc connection buffer for notification, dropping.\n");
+ kfree(connection);
+ return NULL;
+ }
+
+ return connection;
+}
+
+static struct gh_rm_connection *gh_rm_process_rply(struct gh_rsc_mgr *rsc_mgr,
+ void *msg, size_t msg_size)
+{
+ struct gh_rm_rpc_reply_hdr *reply_hdr = msg;
+ struct gh_rm_rpc_hdr *hdr = msg;
+ struct gh_rm_connection *connection;
+
+ if (mutex_lock_interruptible(&rsc_mgr->call_idr_lock))
+ return ERR_PTR(-ERESTARTSYS);
+
+ connection = idr_find(&rsc_mgr->call_idr, hdr->seq);
+ mutex_unlock(&rsc_mgr->call_idr_lock);
+
+ if (!connection) {
+ pr_err("Failed to find connection for sequence %u\n", hdr->seq);
+ return NULL;
+ }
+ if (connection->msg_id != hdr->msg_id) {
+ pr_err("Reply for sequence %u expected msg_id: %x but got %x\n", hdr->seq,
+ connection->msg_id, 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 - sizeof(*reply_hdr))) {
+ pr_err("Failed to alloc connection buffer for sequence %d\n", hdr->seq);
+ /* Send connection complete and error the client. */
+ connection->ret = -ENOMEM;
+ complete(&connection->seq_done);
+ return NULL;
+ }
+
+ connection->rm_error = reply_hdr->err_code;
+ return connection;
+}
+
+static void gh_rm_process_cont(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);
+
+ /*
+ * hdr->fragments and hdr->msg_id preserves the value from first reply or notif message.
+ * For sake of sanity, check if it's still intact.
+ */
+ if (connection->msg_id != hdr->msg_id)
+ pr_warn("Appending mismatched continuation with id %d to connection with id %d\n",
+ hdr->msg_id, connection->msg_id);
+ if (connection->num_fragments != hdr->fragments)
+ pr_warn("Number of fragments mismatch for seq: %d\n", hdr->seq);
+
+ memcpy(connection->payload + connection->size, msg + sizeof(*hdr), payload_size);
+ connection->size += payload_size;
+ connection->fragments_received++;
+}
+
+static bool gh_rm_complete_connection(struct gh_rm_connection *connection)
+{
+ struct gh_rm_notif_complete *notif_work;
+
+ if (!connection)
+ return false;
+
+ if (connection->fragments_received != connection->num_fragments)
+ return false;
+
+ switch (connection->type) {
+ case GH_RM_RPC_TYPE_RPLY:
+ complete(&connection->seq_done);
+ break;
+ case GH_RM_RPC_TYPE_NOTIF:
+ notif_work = kzalloc(sizeof(*notif_work), GFP_KERNEL);
+ if (notif_work == NULL)
+ break;
+
+ notif_work->conn = connection;
+ INIT_WORK(&notif_work->work, gh_rm_notif_work);
+
+ schedule_work(&notif_work->work);
+ break;
+ default:
+ pr_err("Invalid message type (%d) received\n", connection->type);
+ break;
+ }
+
+ return true;
+}
+
+static void gh_rm_abort_connection(struct gh_rm_connection *connection)
+{
+ switch (connection->type) {
+ case GH_RM_RPC_TYPE_RPLY:
+ connection->ret = -EIO;
+ complete(&connection->seq_done);
+ break;
+ case GH_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_rsc_mgr *rsc_mgr = container_of(cl, struct gh_rsc_mgr, msgq_client);
+ struct gunyah_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)) {
+ pr_err("Invalid message size received: %ld is too small\n", msg_size);
+ return;
+ }
+
+ hdr = msg;
+ switch (hdr->type) {
+ case GH_RM_RPC_TYPE_NOTIF:
+ if (rsc_mgr->active_rx_connection) {
+ /* Not possible per protocol. Do something better than BUG_ON */
+ pr_warn("Received start of new notification without finishing existing message series.\n");
+ gh_rm_abort_connection(rsc_mgr->active_rx_connection);
+ }
+ rsc_mgr->active_rx_connection = gh_rm_process_notif(rsc_mgr, msg, msg_size);
+ break;
+ case GH_RM_RPC_TYPE_RPLY:
+ if (rsc_mgr->active_rx_connection) {
+ /* Not possible per protocol. Do something better than BUG_ON */
+ pr_warn("Received start of new reply without finishing existing message series.\n");
+ gh_rm_abort_connection(rsc_mgr->active_rx_connection);
+ }
+ rsc_mgr->active_rx_connection = gh_rm_process_rply(rsc_mgr, msg, msg_size);
+ break;
+ case GH_RM_RPC_TYPE_CONT:
+ if (!rsc_mgr->active_rx_connection) {
+ pr_warn("Received a continuation message without receiving initial message\n");
+ break;
+ }
+ gh_rm_process_cont(rsc_mgr->active_rx_connection, msg, msg_size);
+ break;
+ default:
+ pr_err("Invalid message type (%d) received\n", hdr->type);
+ return;
+ }
+
+ if (gh_rm_complete_connection(rsc_mgr->active_rx_connection))
+ rsc_mgr->active_rx_connection = NULL;
+}
+
+static void gh_rm_msgq_tx_done(struct mbox_client *cl, void *mssg, int r)
+{
+ struct gh_rsc_mgr *rsc_mgr = container_of(cl, struct gh_rsc_mgr, msgq_client);
+
+ kfree(mssg);
+ rsc_mgr->last_tx_ret = r;
+}
+
+static int gh_rm_send_request(struct gh_rsc_mgr *rsc_mgr, 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;
+ const void *req_buff_curr = req_buff;
+ struct gh_rm_rpc_hdr *hdr;
+ u32 cont_fragments = req_buff_size / GH_RM_MAX_MSG_SIZE;
+ size_t payload_size;
+ struct gunyah_msgq_tx_data *msg;
+ int i, ret;
+
+ if (WARN(cont_fragments > GH_RM_MAX_NUM_FRAGMENTS,
+ "Limit exceeded for the number of fragments: %u\n", cont_fragments))
+ return -E2BIG;
+
+ ret = mutex_lock_interruptible(&rsc_mgr->send_lock);
+ if (ret)
+ return ret;
+
+ /* Consider also the 'request' packet for the loop count */
+ for (i = 0; i <= cont_fragments; i++) {
+ if (buff_size_remaining > GH_RM_MAX_MSG_SIZE) {
+ payload_size = GH_RM_MAX_MSG_SIZE;
+ buff_size_remaining -= payload_size;
+ } else {
+ payload_size = buff_size_remaining;
+ }
+
+ msg = kzalloc(sizeof(*msg) + GH_MSGQ_MAX_MSG_SIZE, GFP_KERNEL);
+ if (!msg) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* Fill header */
+ hdr = (struct gh_rm_rpc_hdr *)msg->data;
+ hdr->version = GH_RM_RPC_HDR_VERSION_ONE;
+ hdr->hdr_words = GH_RM_RPC_HDR_WORDS;
+ hdr->type = i == 0 ? GH_RM_RPC_TYPE_REQ : GH_RM_RPC_TYPE_CONT;
+ hdr->fragments = cont_fragments;
+ hdr->seq = connection->seq;
+ hdr->msg_id = message_id;
+
+ /* Copy payload */
+ memcpy(msg->data + sizeof(*hdr), req_buff_curr, payload_size);
+ req_buff_curr += payload_size;
+
+ /* Force the last fragment to immediately alert the receiver */
+ msg->push = i == cont_fragments;
+ msg->length = sizeof(*hdr) + payload_size;
+
+ ret = mbox_send_message(gunyah_msgq_chan(&rsc_mgr->msgq), msg);
+ if (ret < 0) {
+ kfree(msg);
+ break;
+ }
+
+ if (rsc_mgr->last_tx_ret) {
+ ret = rsc_mgr->last_tx_ret;
+ break;
+ }
+ }
+
+out:
+ mutex_unlock(&rsc_mgr->send_lock);
+ return ret < 0 ? ret : 0;
+}
+
+/**
+ * gh_rm_call: Achieve request-response type communication with RPC
+ * @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
+ * @reply_err_code: Returns Gunyah standard error code for the response
+ *
+ * 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.
+ *
+ * Context: Process context. Will sleep waiting for reply.
+ * Return: >0 is standard reply error from RM. <0 on internal error.
+ */
+int gh_rm_call(u32 message_id, void *req_buff, size_t req_buff_size,
+ void **resp_buf, size_t *resp_buff_size)
+{
+ struct gh_rm_connection *connection;
+ int ret;
+ struct gh_rsc_mgr *rsc_mgr = __rsc_mgr;
+
+ /* messaged_id 0 is reserved */
+ if (!message_id)
+ return -EINVAL;
+
+ if (!rsc_mgr)
+ return -EPROBE_DEFER;
+
+ connection = gh_rm_alloc_connection(message_id, GH_RM_RPC_TYPE_RPLY);
+ if (!connection)
+ return -ENOMEM;
+
+ init_completion(&connection->seq_done);
+
+ /* Allocate a new seq number for this connection */
+ if (mutex_lock_interruptible(&rsc_mgr->call_idr_lock)) {
+ kfree(connection);
+ return -ERESTARTSYS;
+ }
+ connection->seq = idr_alloc_cyclic(&rsc_mgr->call_idr, connection, 0, U16_MAX, GFP_KERNEL);
+ mutex_unlock(&rsc_mgr->call_idr_lock);
+
+ /* Send the request to the Resource Manager */
+ ret = gh_rm_send_request(rsc_mgr, message_id, req_buff, req_buff_size, connection);
+ if (ret < 0)
+ goto out;
+
+ /* Wait for response */
+ ret = wait_for_completion_interruptible(&connection->seq_done);
+ if (ret)
+ goto out;
+
+ if (connection->ret) {
+ ret = connection->ret;
+ kfree(connection->payload);
+ goto out;
+ }
+
+ if (connection->rm_error) {
+ ret = connection->rm_error;
+ kfree(connection->payload);
+ goto out;
+ }
+
+ *resp_buf = connection->payload;
+ *resp_buff_size = connection->size;
+
+out:
+ mutex_lock(&rsc_mgr->call_idr_lock);
+ idr_remove(&rsc_mgr->call_idr, connection->seq);
+ mutex_unlock(&rsc_mgr->call_idr_lock);
+
+ kfree(connection);
+ return ret;
+}
+
+int gh_rm_register_notifier(struct notifier_block *nb)
+{
+ return srcu_notifier_chain_register(&gh_rm_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(gh_rm_register_notifier);
+
+int gh_rm_unregister_notifier(struct notifier_block *nb)
+{
+ return srcu_notifier_chain_unregister(&gh_rm_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(gh_rm_unregister_notifier);
+
+static int gh_msgq_platform_probe_direction(struct platform_device *pdev,
+ u8 gh_type, int idx, struct gunyah_resource *ghrsc)
+{
+ int ret;
+ struct device_node *node = pdev->dev.of_node;
+
+ ghrsc->type = gh_type;
+
+ 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_rsc_mgr *rsc_mgr;
+ struct gunyah_resource tx_ghrsc, rx_ghrsc;
+ int ret;
+
+ rsc_mgr = devm_kzalloc(&pdev->dev, sizeof(*rsc_mgr), GFP_KERNEL);
+ if (!rsc_mgr)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, rsc_mgr);
+
+ mutex_init(&rsc_mgr->call_idr_lock);
+ idr_init(&rsc_mgr->call_idr);
+ mutex_init(&rsc_mgr->send_lock);
+
+ ret = gh_msgq_platform_probe_direction(pdev, GUNYAH_RESOURCE_TYPE_MSGQ_TX, 0, &tx_ghrsc);
+ if (ret)
+ return ret;
+
+ ret = gh_msgq_platform_probe_direction(pdev, GUNYAH_RESOURCE_TYPE_MSGQ_RX, 1, &rx_ghrsc);
+ if (ret)
+ return ret;
+
+ rsc_mgr->msgq_client.dev = &pdev->dev;
+ rsc_mgr->msgq_client.tx_block = true;
+ rsc_mgr->msgq_client.rx_callback = gh_rm_msgq_rx_data;
+ rsc_mgr->msgq_client.tx_done = gh_rm_msgq_tx_done;
+
+ ret = gunyah_msgq_init(&pdev->dev, &rsc_mgr->msgq, &rsc_mgr->msgq_client,
+ &tx_ghrsc, &rx_ghrsc);
+ if (ret)
+ return ret;
+
+ __rsc_mgr = rsc_mgr;
+
+ return 0;
+}
+
+static int gh_rm_drv_remove(struct platform_device *pdev)
+{
+ struct gh_rsc_mgr *rsc_mgr = platform_get_drvdata(pdev);
+
+ __rsc_mgr = NULL;
+
+ mbox_free_channel(gunyah_msgq_chan(&rsc_mgr->msgq));
+ gunyah_msgq_remove(&rsc_mgr->msgq);
+
+ 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_rsc_mgr_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Gunyah Resource Manager Driver");
diff --git a/drivers/virt/gunyah/rsc_mgr.h b/drivers/virt/gunyah/rsc_mgr.h
new file mode 100644
index 000000000000..e4f2499267bf
--- /dev/null
+++ b/drivers/virt/gunyah/rsc_mgr.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#ifndef __GH_RSC_MGR_PRIV_H
+#define __GH_RSC_MGR_PRIV_H
+
+#include <linux/gunyah.h>
+
+/* RM Error codes */
+#define GH_RM_ERROR_OK 0x0
+#define GH_RM_ERROR_UNIMPLEMENTED 0xFFFFFFFF
+#define GH_RM_ERROR_NOMEM 0x1
+#define GH_RM_ERROR_NORESOURCE 0x2
+#define GH_RM_ERROR_DENIED 0x3
+#define GH_RM_ERROR_INVALID 0x4
+#define GH_RM_ERROR_BUSY 0x5
+#define GH_RM_ERROR_ARGUMENT_INVALID 0x6
+#define GH_RM_ERROR_HANDLE_INVALID 0x7
+#define GH_RM_ERROR_VALIDATE_FAILED 0x8
+#define GH_RM_ERROR_MAP_FAILED 0x9
+#define GH_RM_ERROR_MEM_INVALID 0xA
+#define GH_RM_ERROR_MEM_INUSE 0xB
+#define GH_RM_ERROR_MEM_RELEASED 0xC
+#define GH_RM_ERROR_VMID_INVALID 0xD
+#define GH_RM_ERROR_LOOKUP_FAILED 0xE
+#define GH_RM_ERROR_IRQ_INVALID 0xF
+#define GH_RM_ERROR_IRQ_INUSE 0x10
+#define GH_RM_ERROR_IRQ_RELEASED 0x11
+
+int gh_rm_call(u32 message_id, void *req_buff, size_t req_buff_size,
+ void **resp_buf, size_t *resp_buff_size);
+
+#endif
diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h
new file mode 100644
index 000000000000..b3b37225b7fb
--- /dev/null
+++ b/include/linux/gunyah_rsc_mgr.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _GUNYAH_RSC_MGR_H
+#define _GUNYAH_RSC_MGR_H
+
+#include <linux/list.h>
+#include <linux/notifier.h>
+#include <linux/gunyah.h>
+
+#define GH_VMID_INVAL U16_MAX
+
+/* Gunyah recognizes VMID0 as an alias to the current VM's ID */
+#define GH_VMID_SELF 0
+
+struct gh_rm_notification {
+ const void *buff;
+ const size_t size;
+};
+
+int gh_rm_register_notifier(struct notifier_block *nb);
+int gh_rm_unregister_notifier(struct notifier_block *nb);
+
+#endif
--
2.25.1