haven: Add Haven Message Queue driver (0ae181fd) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/virt/Kconfig

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		@@ -32,4 +32,5 @@ config FSL_HV_MANAGER
		partition shuts down.

		source "drivers/virt/vboxguest/Kconfig"
		source "drivers/virt/haven/Kconfig"
		endif

drivers/virt/Makefile

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		@@ -5,3 +5,4 @@

		obj-$(CONFIG_FSL_HV_MANAGER) += fsl_hypervisor.o
		obj-y += vboxguest/
		obj-y += haven/

drivers/virt/haven/Kconfig

0 → 100644

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		# SPDX-License-Identifier: GPL-2.0-only

		menuconfig HAVEN_DRIVERS
		bool "Haven Virtualization drivers"
		help
		The Haven drivers are the helper interfaces that runs on the
		virtual machines that provides support such as memory/device
		sharing, IRQ sharing, IPC/signalling mechanisms, and so on.

		Say Y here to enable the drivers needed to work on Haven
		virtualization environment.

		If you say N, all options in this submenu will be skipped and disabled.

		if HAVEN_DRIVERS

		config HH_MSGQ
		tristate "Haven Message Queue driver"
		help
		Haven offers message-queues as one of the IPC mechanisms to
		communicate among the Virtual Machines. The message queue drivers
		runs on the Virtual machines to provide an interface to the clients
		who wish to communicate to other clients on a different VM. Currently,
		the services offered by the drivers is simply to send and receive
		messages in a blocking manner.

		endif

drivers/virt/haven/Makefile

0 → 100644

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		# SPDX-License-Identifier: GPL-2.0-only
		obj-$(CONFIG_HH_MSGQ) += hh_msgq.o

drivers/virt/haven/hh_msgq.c

0 → 100644

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Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* Copyright (c) 2020, The Linux Foundation. All rights reserved.
		*
		*/

		#include <linux/slab.h>
		#include <linux/wait.h>
		#include <linux/mutex.h>
		#include <linux/module.h>
		#include <linux/spinlock.h>
		#include <linux/interrupt.h>

		#include <linux/haven/hcall.h>
		#include <linux/haven/hh_msgq.h>
		#include <linux/haven/hh_errno.h>

		/* HVC call specific mask: 0 to 31 */
		#define HH_MSGQ_HVC_FLAGS_MASK GENMASK_ULL(31, 0)

		struct hh_msgq_desc {
		enum hh_msgq_label label;
		};

		struct hh_msgq_cap_table {
		struct hh_msgq_desc *client_desc;
		struct mutex cap_entry_lock;

		hh_capid_t tx_cap_id;
		hh_capid_t rx_cap_id;
		int tx_irq;
		int rx_irq;
		const char *tx_irq_name;
		const char *rx_irq_name;
		spinlock_t tx_lock;
		spinlock_t rx_lock;

		bool tx_full;
		bool rx_empty;
		wait_queue_head_t tx_wq;
		wait_queue_head_t rx_wq;
		};

		static struct hh_msgq_cap_table hh_msgq_cap_table[HH_MSGQ_LABEL_MAX];

		static irqreturn_t hh_msgq_rx_isr(int irq, void *dev)
		{
		struct hh_msgq_cap_table *cap_table_entry = dev;

		spin_lock(&cap_table_entry->rx_lock);
		cap_table_entry->rx_empty = false;
		spin_unlock(&cap_table_entry->rx_lock);

		wake_up_interruptible(&cap_table_entry->rx_wq);

		return IRQ_HANDLED;
		}

		static irqreturn_t hh_msgq_tx_isr(int irq, void *dev)
		{
		struct hh_msgq_cap_table *cap_table_entry = dev;

		spin_lock(&cap_table_entry->tx_lock);
		cap_table_entry->tx_full = false;
		spin_unlock(&cap_table_entry->tx_lock);

		wake_up_interruptible(&cap_table_entry->tx_wq);

		return IRQ_HANDLED;
		}

		static int __hh_msgq_recv(struct hh_msgq_cap_table *cap_table_entry,
		void buff, size_t size, u64 rx_flags)
		{
		struct hh_hcall_msgq_recv_resp resp = {};
		unsigned long flags;
		int hh_ret;
		int ret = 0;

		/* Discard the driver specific flags, and keep only HVC specifics */
		rx_flags &= HH_MSGQ_HVC_FLAGS_MASK;

		spin_lock_irqsave(&cap_table_entry->rx_lock, flags);
		hh_ret = hh_hcall_msgq_recv(cap_table_entry->rx_cap_id, buff,
		HH_MSGQ_MAX_MSG_SIZE_BYTES, &resp);

		switch (hh_ret) {
		case HH_ERROR_OK:
		*size = resp.recv_size;
		ret = 0;
		break;
		case HH_ERROR_MSGQUEUE_EMPTY:
		cap_table_entry->rx_empty = true;
		ret = -EAGAIN;
		break;
		default:
		ret = hh_remap_error(hh_ret);
		}

		spin_unlock_irqrestore(&cap_table_entry->rx_lock, flags);

		if (ret != 0 && ret != -EAGAIN)
		pr_err("%s: Failed to recv the message. Error: %d\n",
		__func__, hh_ret);

		return ret;
		}

		/**
		* hh_msgq_recv: Receive a message from the client running on a different VM
		* @client_desc: The client descriptor that was obtained via hh_msgq_register()
		* @buff: Pointer to the buffer where the received data must be placed. Note
		* that the caller is responsible to free the data contained in buff
		* @size: The size of the buffer received
		* @flags: Optional flags to pass to receive the data. For the list of flags,
		* see linux/haven/hh_msgq.h
		*
		* The function returns -EINVAL if the caller passes invalid arguments, -EAGAIN
		* if the message queue is not yet ready to communicate, and -EPERM if the
		* caller doesn't have permissions to receive the data. 0 is the data is
		* successfully received.
		*/
		int hh_msgq_recv(void *msgq_client_desc,
		void *buff, size_t size, unsigned long flags)
		{
		struct hh_msgq_desc *client_desc = msgq_client_desc;
		struct hh_msgq_cap_table *cap_table_entry;
		int ret;

		if (!client_desc \|\| !(*buff) \|\| !size)
		return -EINVAL;

		cap_table_entry = &hh_msgq_cap_table[client_desc->label];

		if (mutex_lock_interruptible(&cap_table_entry->cap_entry_lock))
		return -ERESTARTSYS;

		if (cap_table_entry->client_desc != client_desc) {
		pr_err("%s: Invalid client descriptor\n", __func__);
		ret = -EINVAL;
		goto err;
		}

		if (!cap_table_entry->rx_cap_id) {
		pr_err("%s: Recv info for label %d not yet initialized\n",
		__func__, client_desc->label);
		ret = -EAGAIN;
		goto err;
		}

		if (!cap_table_entry->rx_irq) {
		pr_err("%s: Rx IRQ for label %d not yet setup\n",
		__func__, client_desc->label);
		ret = -EAGAIN;
		goto err;
		}

		mutex_unlock(&cap_table_entry->cap_entry_lock);

		*buff = kzalloc(HH_MSGQ_MAX_MSG_SIZE_BYTES, GFP_KERNEL);
		if (!(*buff))
		return -ENOMEM;

		do {
		if (cap_table_entry->rx_empty && (flags & HH_MSGQ_NONBLOCK)) {
		ret = -EAGAIN;
		goto buff_free;
		}

		if (wait_event_interruptible(cap_table_entry->rx_wq,
		!cap_table_entry->rx_empty)) {
		ret = -ERESTARTSYS;
		goto buff_free;
		}

		ret = __hh_msgq_recv(cap_table_entry, *buff, size, flags);
		} while (ret == -EAGAIN);

		buff_free:
		if (ret < 0) {
		kfree(*buff);
		*buff = NULL;
		}

		return ret;

		err:
		mutex_unlock(&cap_table_entry->cap_entry_lock);
		return ret;
		}
		EXPORT_SYMBOL(hh_msgq_recv);

		static int __hh_msgq_send(struct hh_msgq_cap_table *cap_table_entry,
		void *buff, size_t size, u64 tx_flags)
		{
		struct hh_hcall_msgq_send_resp resp = {};
		unsigned long flags;
		int hh_ret;
		int ret = 0;

		/* Discard the driver specific flags, and keep only HVC specifics */
		tx_flags &= HH_MSGQ_HVC_FLAGS_MASK;

		spin_lock_irqsave(&cap_table_entry->tx_lock, flags);
		hh_ret = hh_hcall_msgq_send(cap_table_entry->tx_cap_id,
		size, buff, tx_flags, &resp);

		switch (hh_ret) {
		case HH_ERROR_MSGQUEUE_FULL:
		cap_table_entry->tx_full = true;
		ret = -EAGAIN;
		break;
		default:
		ret = hh_remap_error(hh_ret);
		}

		spin_unlock_irqrestore(&cap_table_entry->tx_lock, flags);

		if (ret != 0 && ret != -EAGAIN)
		pr_err("%s: Failed to send the message. Error: %d\n",
		__func__, hh_ret);

		return ret;
		}

		/**
		* hh_msgq_send: Send a message to the client on a different VM
		* @client_desc: The client descriptor that was obtained via hh_msgq_register()
		* @buff: Pointer to the buffer that needs to be sent. The buffer should be
		* dynamically allocated via kmalloc/kzalloc.
		* @size: The size of the buffer
		* @flags: Optional flags to pass to send the data. For the list of flags,
		* see linux/haven/hh_msgq.h
		*
		* The function would free the buffer upon success, and returns 0. The caller
		* should not be referencing the buffer anymore.
		* On the other hand, it returns -EINVAL if the caller passes invalid arguments,
		* -EAGAIN if the message queue is not yet ready to communicate, and -EPERM if
		* the caller doesn't have permissions to send the data.
		*
		*/
		int hh_msgq_send(void *msgq_client_desc,
		void *buff, size_t size, unsigned long flags)
		{
		struct hh_msgq_desc *client_desc = msgq_client_desc;
		struct hh_msgq_cap_table *cap_table_entry;
		int ret;

		if (!client_desc \|\| !buff \|\| !size)
		return -EINVAL;

		if (size > HH_MSGQ_MAX_MSG_SIZE_BYTES)
		return -E2BIG;

		cap_table_entry = &hh_msgq_cap_table[client_desc->label];

		if (mutex_lock_interruptible(&cap_table_entry->cap_entry_lock))
		return -ERESTARTSYS;

		if (cap_table_entry->client_desc != client_desc) {
		pr_err("%s: Invalid client descriptor\n", __func__);
		ret = -EINVAL;
		goto err;
		}

		if (!cap_table_entry->tx_cap_id) {
		pr_err("%s: Send info for label %d not yet initialized\n",
		__func__, client_desc->label);
		ret = -EAGAIN;
		goto err;
		}

		if (!cap_table_entry->tx_irq) {
		pr_err("%s: Tx IRQ for label %d not yet setup\n",
		__func__, client_desc->label);
		ret = -EAGAIN;
		goto err;
		}

		mutex_unlock(&cap_table_entry->cap_entry_lock);

		do {
		if (cap_table_entry->tx_full && (flags & HH_MSGQ_NONBLOCK)) {
		ret = -EAGAIN;
		goto err;
		}

		if (wait_event_interruptible(cap_table_entry->tx_wq,
		!cap_table_entry->tx_full))
		return -ERESTARTSYS;

		ret = __hh_msgq_send(cap_table_entry, buff, size, flags);
		} while (ret == -EAGAIN);

		/* If the send is success, hypervisor should not be holding any
		* references to 'buff', and hence, can be released.
		*/
		if (!ret)
		kfree(buff);

		return ret;
		err:
		mutex_unlock(&cap_table_entry->cap_entry_lock);
		return ret;
		}
		EXPORT_SYMBOL(hh_msgq_send);

		/**
		* hh_msgq_register: Register as a client to the use the message queue
		* @label: The label associated to the message queue that the client wants
		* to communicate
		*
		* The function returns a descriptor for the clients to send and receive the
		* messages. Else, returns -EBUSY if some other client is already regitsered
		* to this label, and -EINVAL for invalid arguments. The caller should check
		* the return value using IS_ERR_OR_NULL() and PTR_ERR() to extract the error
		* code.
		*/
		void *hh_msgq_register(enum hh_msgq_label label)
		{
		struct hh_msgq_cap_table *cap_table_entry;
		struct hh_msgq_desc *client_desc;
		int ret;

		if (label < 0 \|\| label >= HH_MSGQ_LABEL_MAX)
		return ERR_PTR(-EINVAL);

		cap_table_entry = &hh_msgq_cap_table[label];

		if (mutex_lock_interruptible(&cap_table_entry->cap_entry_lock))
		return ERR_PTR(-ERESTARTSYS);

		/* Multiple clients cannot register to the same label (msgq) */
		if (cap_table_entry->client_desc) {
		ret = -EBUSY;
		goto err;
		}

		client_desc = kzalloc(sizeof(*client_desc), GFP_KERNEL);
		if (!client_desc) {
		ret = ENOMEM;
		goto err;
		}

		client_desc->label = label;

		cap_table_entry->client_desc = client_desc;

		pr_info("hh_msgq: Registered client for label: %d\n", label);

		mutex_unlock(&cap_table_entry->cap_entry_lock);
		return client_desc;

		err:
		mutex_unlock(&cap_table_entry->cap_entry_lock);
		return ERR_PTR(ret);
		}
		EXPORT_SYMBOL(hh_msgq_register);

		/**
		* hh_msgq_unregister: Unregister as a client to the use the message queue
		* @client_desc: The descriptor that was passed via hh_msgq_register()
		*
		* The function returns 0 is the client was unregistered successfully. Else,
		* -EINVAL for invalid arguments.
		*/
		int hh_msgq_unregister(void *msgq_client_desc)
		{
		struct hh_msgq_desc *client_desc = msgq_client_desc;
		struct hh_msgq_cap_table *cap_table_entry;

		if (!client_desc)
		return -EINVAL;

		cap_table_entry = &hh_msgq_cap_table[client_desc->label];

		if (mutex_lock_interruptible(&cap_table_entry->cap_entry_lock))
		return -ERESTARTSYS;

		/* Is the client trying to free someone else's msgq? */
		if (cap_table_entry->client_desc != client_desc) {
		pr_err("%s: Trying to free invalid client descriptor!\n",
		__func__);
		mutex_unlock(&cap_table_entry->cap_entry_lock);
		return -EINVAL;
		}

		cap_table_entry->client_desc = NULL;

		mutex_unlock(&cap_table_entry->cap_entry_lock);

		pr_info("%s: Unregistered client for label: %d\n",
		__func__, client_desc->label);

		kfree(client_desc);

		return 0;
		}
		EXPORT_SYMBOL(hh_msgq_unregister);

		int hh_msgq_populate_cap_info(enum hh_msgq_label label, u64 cap_id,
		int direction, int irq)
		{
		struct hh_msgq_cap_table *cap_table_entry;
		int ret;

		if (label < 0 \|\| label >= HH_MSGQ_LABEL_MAX) {
		pr_err("%s: Invalid label passed\n", __func__);
		return -EINVAL;
		}

		if (irq < 0) {
		pr_err("%s: Invalid IRQ number passed\n", __func__);
		return -ENXIO;
		}

		cap_table_entry = &hh_msgq_cap_table[label];

		if (mutex_lock_interruptible(&cap_table_entry->cap_entry_lock))
		return -ERESTARTSYS;

		if (direction == HH_MSGQ_DIRECTION_TX) {
		ret = request_irq(irq, hh_msgq_tx_isr, 0,
		cap_table_entry->tx_irq_name, cap_table_entry);
		if (ret < 0)
		goto err;

		cap_table_entry->tx_irq = irq;
		cap_table_entry->tx_cap_id = cap_id;
		} else if (direction == HH_MSGQ_DIRECTION_RX) {
		ret = request_irq(irq, hh_msgq_rx_isr, 0,
		cap_table_entry->rx_irq_name, cap_table_entry);
		if (ret < 0)
		goto err;

		cap_table_entry->rx_cap_id = cap_id;
		cap_table_entry->rx_irq = irq;
		} else {
		pr_err("%s: Invalid direction passed\n", __func__);
		ret = -EINVAL;
		goto err;
		}

		mutex_unlock(&cap_table_entry->cap_entry_lock);

		pr_debug(
		"%s: label: %d; cap_id: %llu; dir: %d; irq: %d\n",
		__func__, label, cap_id, direction, irq);

		return 0;

		err:
		mutex_unlock(&cap_table_entry->cap_entry_lock);
		return ret;
		}
		EXPORT_SYMBOL(hh_msgq_populate_cap_info);

		static void hh_msgq_cleanup(int begin_idx)
		{
		struct hh_msgq_cap_table *cap_table_entry;
		int i;

		if (begin_idx >= HH_MSGQ_LABEL_MAX)
		begin_idx = HH_MSGQ_LABEL_MAX - 1;

		for (i = begin_idx; i >= 0; i--) {
		cap_table_entry = &hh_msgq_cap_table[i];

		kfree(cap_table_entry->tx_irq_name);
		kfree(cap_table_entry->rx_irq_name);

		mutex_destroy(&cap_table_entry->cap_entry_lock);
		}
		}

		static int __init hh_msgq_init(void)
		{
		struct hh_msgq_cap_table *cap_table_entry;
		int ret;
		int i;

		for (i = 0; i < HH_MSGQ_LABEL_MAX; i++) {
		cap_table_entry = &hh_msgq_cap_table[i];

		cap_table_entry->tx_full = false;
		cap_table_entry->rx_empty = true;
		init_waitqueue_head(&cap_table_entry->tx_wq);
		init_waitqueue_head(&cap_table_entry->rx_wq);
		spin_lock_init(&cap_table_entry->tx_lock);
		spin_lock_init(&cap_table_entry->rx_lock);
		mutex_init(&cap_table_entry->cap_entry_lock);

		cap_table_entry->tx_irq_name = kasprintf(GFP_KERNEL,
		"hh_msgq_tx_%d", i);
		if (!cap_table_entry->tx_irq_name) {
		ret = -ENOMEM;
		goto err;
		}

		cap_table_entry->rx_irq_name = kasprintf(GFP_KERNEL,
		"hh_msgq_rx_%d", i);
		if (!cap_table_entry->rx_irq_name) {
		ret = -ENOMEM;
		goto err;
		}
		}

		return 0;

		err:
		hh_msgq_cleanup(i);
		return ret;
		}
		module_init(hh_msgq_init);

		static void __exit hh_msgq_exit(void)
		{
		hh_msgq_cleanup(HH_MSGQ_LABEL_MAX - 1);
		}
		module_exit(hh_msgq_exit);

		MODULE_LICENSE("GPL v2");
		MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Haven Message Queue Driver");