/**
 * \file executer/kernel/driver.c
 *  License details are found in the file LICENSE.
 * \brief
 *  kernel module entry
 * \author Taku Shimosawa  <shimosawa@is.s.u-tokyo.ac.jp> \par
 *      Copyright (C) 2011 - 2012  Taku Shimosawa
 * \author Balazs Gerofi  <bgerofi@riken.jp> \par
 *      Copyright (C) 2012  RIKEN AICS
 * \author Gou Nakamura  <go.nakamura.yw@hitachi-solutions.com> \par
 *      Copyright (C) 2012 - 2013 Hitachi, Ltd.
 * \author Tomoki Shirasawa  <tomoki.shirasawa.kk@hitachi-solutions.com> \par
 *      Copyright (C) 2012 - 2013 Hitachi, Ltd.
 * \author Balazs Gerofi  <bgerofi@is.s.u-tokyo.ac.jp> \par
 *      Copyright (C) 2013  The University of Tokyo
 */
/*
 * HISTORY:
 *  2013/09/02 shirasawa add terminate thread
 *  2013/08/19 shirasawa mcexec forward signal to MIC process
 */

#include <linux/sched.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/device.h>
#include "mcctrl.h"

#define OS_MAX_MINOR 64

extern long __mcctrl_control(ihk_os_t, unsigned int, unsigned long,
                             struct file *);
extern int prepare_ikc_channels(ihk_os_t os);
extern void destroy_ikc_channels(ihk_os_t os);
#ifndef DO_USER_MODE
extern void mcctrl_syscall_init(void);
#endif
extern void procfs_init(int);
extern void procfs_exit(int);

extern void rus_page_hash_init(void);
extern void rus_page_hash_put_pages(void);
extern void binfmt_mcexec_init(void);
extern void binfmt_mcexec_exit(void);

static long mcctrl_ioctl(ihk_os_t os, unsigned int request, void *priv,
                         unsigned long arg, struct file *file)
{
	return __mcctrl_control(os, request, arg, file);
}

static struct ihk_os_user_call_handler mcctrl_uchs[] = {
	{ .request = MCEXEC_UP_PREPARE_IMAGE, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_TRANSFER, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_START_IMAGE, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_WAIT_SYSCALL, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_RET_SYSCALL, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_LOAD_SYSCALL, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_SEND_SIGNAL, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_GET_CPU, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_GET_NODES, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_GET_CPUSET, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_STRNCPY_FROM_USER, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_NEW_PROCESS, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_PREPARE_DMA, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_FREE_DMA, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_OPEN_EXEC, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_CLOSE_EXEC, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_GET_CRED, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_GET_CREDV, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_SYS_MOUNT, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_SYS_UMOUNT, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_SYS_UNSHARE, .func = mcctrl_ioctl },
	{ .request = MCEXEC_UP_DEBUG_LOG, .func = mcctrl_ioctl },
};

static struct ihk_os_user_call mcctrl_uc_proto = {
	.num_handlers = sizeof(mcctrl_uchs) / sizeof(mcctrl_uchs[0]),
	.handlers = mcctrl_uchs,
};

static struct ihk_os_user_call mcctrl_uc[OS_MAX_MINOR];

static ihk_os_t os[OS_MAX_MINOR];

ihk_os_t osnum_to_os(int n)
{
	return os[n];
}

/* OS event notifier implementation */
int mcctrl_os_boot_notifier(int os_index)
{
	int	rc;

	os[os_index] = ihk_host_find_os(os_index, NULL);
	if (!os[os_index]) {
		printk("mcctrl: error: OS ID %d couldn't be found\n", os_index);
		return -EINVAL;
	}

	if (prepare_ikc_channels(os[os_index]) != 0) {
		printk("mcctrl: error: preparing IKC channels for OS %d\n", os_index);

		os[os_index] = NULL;
		return -EFAULT;
	}

	memcpy(mcctrl_uc + os_index, &mcctrl_uc_proto, sizeof mcctrl_uc_proto);

	rc = ihk_os_register_user_call_handlers(os[os_index], mcctrl_uc + os_index);
	if (rc < 0) {
		destroy_ikc_channels(os[os_index]);
		printk("mcctrl: error: registering callbacks for OS %d\n", os_index);

		goto error_cleanup_channels;
	}

	procfs_init(os_index);
	printk("mcctrl: OS ID %d boot event handled\n", os_index);

	return 0;

error_cleanup_channels:
	destroy_ikc_channels(os[os_index]);

	os[os_index] = NULL;
	return rc;
}

int mcctrl_os_shutdown_notifier(int os_index)
{
	if (os[os_index]) {
		sysfsm_cleanup(os[os_index]);
		free_topology_info(os[os_index]);
		ihk_os_unregister_user_call_handlers(os[os_index], mcctrl_uc + os_index);
		destroy_ikc_channels(os[os_index]);
		procfs_exit(os_index);
	}

	os[os_index] = NULL;

	printk("mcctrl: OS ID %d shutdown event handled\n", os_index);
	return 0;
}

static struct ihk_os_notifier_ops mcctrl_os_notifier_ops = {
	.boot = mcctrl_os_boot_notifier,
	.shutdown = mcctrl_os_shutdown_notifier,
};

static struct ihk_os_notifier mcctrl_os_notifier = {
	.ops = &mcctrl_os_notifier_ops,
};

static int __init mcctrl_init(void)
{
	int ret = 0;
	int i;

#ifndef DO_USER_MODE
	mcctrl_syscall_init();
#endif

	for (i = 0; i < OS_MAX_MINOR; ++i) {
		os[i] = NULL;
	}

	rus_page_hash_init();

	binfmt_mcexec_init();

	if ((ret = ihk_host_register_os_notifier(&mcctrl_os_notifier)) != 0) {
		printk("mcctrl: error: registering OS notifier\n");
		goto error;
	}

	printk("mcctrl: initialized successfully.\n");
	return ret;

error:
	binfmt_mcexec_exit();
	rus_page_hash_put_pages();

	return ret;
}

static void __exit mcctrl_exit(void)
{
	if (ihk_host_deregister_os_notifier(&mcctrl_os_notifier) != 0) {
		printk("mcctrl: warning: failed to deregister OS notifier??\n");
	}

	binfmt_mcexec_exit();
	rus_page_hash_put_pages();

	printk("mcctrl: unregistered.\n");
}

MODULE_LICENSE("GPL v2");
module_init(mcctrl_init);
module_exit(mcctrl_exit);