// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2013-2020 TRUSTONIC LIMITED
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/vmalloc.h>

#include "public/mc_user.h"
#include "public/mc_admin.h"
#include "public/mobicore_driver_api.h"

#include "main.h"
#include "client.h"
#include "protocol.h"

static enum mc_result convert(int err)
{
	switch (-err) {
	case 0:
		return MC_DRV_OK;
	case ENOMSG:
		return MC_DRV_NO_NOTIFICATION;
	case EBADMSG:
		return MC_DRV_ERR_NOTIFICATION;
	case EAGAIN:
		return MC_DRV_ERR_OUT_OF_RESOURCES;
	case EHOSTDOWN:
		return MC_DRV_ERR_INIT;
	case ENODEV:
		return MC_DRV_ERR_UNKNOWN_DEVICE;
	case ENXIO:
		return MC_DRV_ERR_UNKNOWN_SESSION;
	case EPERM:
		return MC_DRV_ERR_INVALID_OPERATION;
	case EBADE:
		return MC_DRV_ERR_INVALID_RESPONSE;
	case ETIME:
		return MC_DRV_ERR_TIMEOUT;
	case ENOMEM:
		return MC_DRV_ERR_NO_FREE_MEMORY;
	case EUCLEAN:
		return MC_DRV_ERR_FREE_MEMORY_FAILED;
	case ENOTEMPTY:
		return MC_DRV_ERR_SESSION_PENDING;
	case EHOSTUNREACH:
		return MC_DRV_ERR_DAEMON_UNREACHABLE;
	case ENOENT:
		return MC_DRV_ERR_INVALID_DEVICE_FILE;
	case EINVAL:
		return MC_DRV_ERR_INVALID_PARAMETER;
	case EPROTO:
		return MC_DRV_ERR_KERNEL_MODULE;
	case ECOMM:
		return MC_DRV_INFO_NOTIFICATION;
	case EUNATCH:
		return MC_DRV_ERR_NQ_FAILED;
	case ERESTARTSYS:
		return MC_DRV_ERR_INTERRUPTED_BY_SIGNAL;
	default:
		mc_dev_devel("error is %d", err);
		return MC_DRV_ERR_UNKNOWN;
	}
}

static inline bool is_valid_device(u32 device_id)
{
	return device_id == MC_DEVICE_ID_DEFAULT;
}

static struct tee_client *client;
static int open_count;
static DEFINE_MUTEX(dev_mutex);	/* Lock for the device */

static bool clientlib_client_get(void)
{
	int ret = true;

	mutex_lock(&dev_mutex);
	if (!client)
		ret = false;
	else
		client_get(client);

	mutex_unlock(&dev_mutex);
	return ret;
}

static void clientlib_client_put(void)
{
	mutex_lock(&dev_mutex);
	if (client_put(client))
		client = NULL;

	mutex_unlock(&dev_mutex);
}

enum mc_result mc_open_device(u32 device_id)
{
	enum mc_result mc_result = MC_DRV_OK;
	int ret;

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!is_valid_device(device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	mutex_lock(&dev_mutex);
	/* Make sure TEE was started */
	ret = mc_wait_tee_start();
	if (ret) {
		mc_dev_err(ret, "TEE failed to start, now or in the past");
		mc_result = MC_DRV_ERR_INVALID_DEVICE_FILE;
		goto end;
	}

	if (!open_count)
		client = client_create(true, protocol_vm_id());

	if (client) {
		open_count++;
		mc_dev_devel("successfully opened the device");
	} else {
		mc_result = MC_DRV_ERR_INVALID_DEVICE_FILE;
		mc_dev_err(-ENOMEM, "could not open device");
	}

end:
	mutex_unlock(&dev_mutex);
	return mc_result;
}
EXPORT_SYMBOL(mc_open_device);

enum mc_result mc_close_device(u32 device_id)
{
	enum mc_result mc_result = MC_DRV_OK;

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!is_valid_device(device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	mutex_lock(&dev_mutex);
	if (open_count > 1) {
		open_count--;
		goto end;
	}

	/* Check sessions and freeze client */
	if (client_has_sessions(client)) {
		mc_result = MC_DRV_ERR_SESSION_PENDING;
		goto end;
	}

	/* Close the device */
	client_close(client);
	open_count = 0;

end:
	mutex_unlock(&dev_mutex);
	clientlib_client_put();
	return mc_result;
}
EXPORT_SYMBOL(mc_close_device);

enum mc_result mc_open_session(struct mc_session_handle *session,
			       const struct mc_uuid_t *uuid,
			       u8 *tci_va, u32 tci_len)
{
	enum mc_result ret;

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!session || !uuid)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!is_valid_device(session->device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	/* Call core api */
	ret = convert(
		client_mc_open_session(client, uuid, (uintptr_t)tci_va, tci_len,
				       &session->session_id));
	clientlib_client_put();
	return ret;
}
EXPORT_SYMBOL(mc_open_session);

enum mc_result mc_open_trustlet(struct mc_session_handle *session,
				u8 *ta_va, u32 ta_len, u8 *tci_va, u32 tci_len)
{
	enum mc_result ret;

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!session || !ta_va || !ta_len)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!is_valid_device(session->device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	/* Call core api */
	ret = convert(
		client_mc_open_trustlet(client, (uintptr_t)ta_va, ta_len,
					(uintptr_t)tci_va, tci_len,
					&session->session_id));
	clientlib_client_put();
	return ret;
}
EXPORT_SYMBOL(mc_open_trustlet);

enum mc_result mc_close_session(struct mc_session_handle *session)
{
	enum mc_result ret;

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!session)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!is_valid_device(session->device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	/* Call core api */
	ret = convert(client_remove_session(client, session->session_id));
	clientlib_client_put();
	return ret;
}
EXPORT_SYMBOL(mc_close_session);

enum mc_result mc_notify(struct mc_session_handle *session)
{
	enum mc_result ret;

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!session)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!is_valid_device(session->device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	/* Call core api */
	ret = convert(client_notify_session(client, session->session_id));
	clientlib_client_put();
	return ret;
}
EXPORT_SYMBOL(mc_notify);

enum mc_result mc_wait_notification(struct mc_session_handle *session,
				    s32 timeout)
{
	enum mc_result ret;

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!session)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!is_valid_device(session->device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	/* Call core api */
	do {
		ret = convert(client_waitnotif_session(client,
						       session->session_id,
						       timeout));
	} while ((timeout == MC_INFINITE_TIMEOUT) &&
		 (ret == MC_DRV_ERR_INTERRUPTED_BY_SIGNAL));

	clientlib_client_put();
	return ret;
}
EXPORT_SYMBOL(mc_wait_notification);

enum mc_result mc_malloc_wsm(u32 device_id, u32 align, u32 len, u8 **wsm,
			     u32 wsm_flags)
{
	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!is_valid_device(device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!len)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!wsm)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (len > BUFFER_LENGTH_MAX)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	*wsm = vmalloc(len);
	if (!*wsm)
		return MC_DRV_ERR_NO_FREE_MEMORY;

	clientlib_client_put();
	return MC_DRV_OK;
}
EXPORT_SYMBOL(mc_malloc_wsm);

enum mc_result mc_free_wsm(u32 device_id, u8 *wsm)
{
	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!is_valid_device(device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	if (!wsm)
		return MC_DRV_ERR_INVALID_PARAMETER;

	vfree(wsm);
	clientlib_client_put();
	return MC_DRV_OK;
}
EXPORT_SYMBOL(mc_free_wsm);

enum mc_result mc_map(struct mc_session_handle *session, void *address,
		      u32 length, struct mc_bulk_map *map_info)
{
	enum mc_result ret;
	struct mc_ioctl_buffer buf = {
		.va = (uintptr_t)address,
		.len = length,
		.flags = MC_IO_MAP_INPUT_OUTPUT,
	};

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!session)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!is_valid_device(session->device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!map_info)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	/* Call core api */
	ret = convert(client_mc_map(client, session->session_id, NULL, &buf));
	if (ret == MC_DRV_OK) {
		map_info->secure_virt_addr = buf.sva;
		map_info->secure_virt_len = buf.len;
	}

	clientlib_client_put();
	return ret;
}
EXPORT_SYMBOL(mc_map);

enum mc_result mc_unmap(struct mc_session_handle *session, void *address,
			struct mc_bulk_map *map_info)
{
	enum mc_result ret;
	struct mc_ioctl_buffer buf = {
		.va = (uintptr_t)address,
		.flags = MC_IO_MAP_INPUT_OUTPUT,
	};

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!session)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!is_valid_device(session->device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!map_info)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	/* Call core api */
	buf.len = map_info->secure_virt_len;
	buf.sva = map_info->secure_virt_addr;

	ret = convert(client_mc_unmap(client, session->session_id, &buf));
	clientlib_client_put();
	return ret;
}
EXPORT_SYMBOL(mc_unmap);

enum mc_result mc_get_session_error_code(struct mc_session_handle *session,
					 s32 *exit_code)
{
	enum mc_result ret;

	if (!g_ctx.real_drv)
		return MC_DRV_ERR_NOT_IMPLEMENTED;

	/* Check parameters */
	if (!session)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!is_valid_device(session->device_id))
		return MC_DRV_ERR_UNKNOWN_DEVICE;

	if (!exit_code)
		return MC_DRV_ERR_INVALID_PARAMETER;

	if (!clientlib_client_get())
		return MC_DRV_ERR_DAEMON_DEVICE_NOT_OPEN;

	/* Call core api */
	ret = convert(client_get_session_exitcode(client, session->session_id,
						  exit_code));
	clientlib_client_put();
	return ret;
}
EXPORT_SYMBOL(mc_get_session_error_code);