/*
 * Copyright (C) 2010-2015 ARM Limited. All rights reserved.
 * 
 * This program is free software and is provided to you under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation, and any use by you of this program is subject to the terms of such GNU licence.
 * 
 * A copy of the licence is included with the program, and can also be obtained from Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/module.h>            /* kernel module definitions */
#include <linux/fs.h>                /* file system operations */
#include <linux/cdev.h>              /* character device definitions */
#include <linux/ioport.h>            /* request_mem_region */
#include <linux/mm.h>                /* memory management functions and types */
#include <asm/uaccess.h>             /* user space access */
#include <asm/atomic.h>
#include <linux/device.h>
#include <linux/debugfs.h>

#include "arch/config.h"             /* Configuration for current platform. The symlinc for arch is set by Makefile */
#include "ump_ioctl.h"
#include "ump_kernel_common.h"
#include "ump_kernel_interface.h"
#include "ump_kernel_interface_ref_drv.h"
#include "ump_kernel_descriptor_mapping.h"
#include "ump_kernel_memory_backend.h"
#include "ump_kernel_memory_backend_os.h"
#include "ump_kernel_memory_backend_dedicated.h"
#include "ump_kernel_license.h"

#include "ump_osk.h"
#include "ump_ukk.h"
#include "ump_uk_types.h"
#include "ump_ukk_wrappers.h"
#include "ump_ukk_ref_wrappers.h"


/* Module parameter to control log level */
int ump_debug_level = 2;
module_param(ump_debug_level, int, S_IRUSR | S_IWUSR | S_IWGRP | S_IRGRP | S_IROTH); /* rw-rw-r-- */
MODULE_PARM_DESC(ump_debug_level, "Higher number, more dmesg output");

/* By default the module uses any available major, but it's possible to set it at load time to a specific number */
int ump_major = 0;
module_param(ump_major, int, S_IRUGO); /* r--r--r-- */
MODULE_PARM_DESC(ump_major, "Device major number");

/* Name of the UMP device driver */
static char ump_dev_name[] = "ump"; /* should be const, but the functions we call requires non-cost */


#if UMP_LICENSE_IS_GPL
static struct dentry *ump_debugfs_dir = NULL;
#endif

/*
 * The data which we attached to each virtual memory mapping request we get.
 * Each memory mapping has a reference to the UMP memory it maps.
 * We release this reference when the last memory mapping is unmapped.
 */
typedef struct ump_vma_usage_tracker {
        int references;
        ump_dd_handle handle;
} ump_vma_usage_tracker;

struct ump_device {
        struct cdev cdev;
#if UMP_LICENSE_IS_GPL
        struct class *ump_class;
#endif
};

/* The global variable containing the global device data */
static struct ump_device ump_device;


/* Forward declare static functions */
static int ump_file_open(struct inode *inode, struct file *filp);
static int ump_file_release(struct inode *inode, struct file *filp);
#ifdef HAVE_UNLOCKED_IOCTL
static long ump_file_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
#else
static int ump_file_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
#endif
static int ump_file_mmap(struct file *filp, struct vm_area_struct *vma);


/* This variable defines the file operations this UMP device driver offer */
static struct file_operations ump_fops = {
        .owner   = THIS_MODULE,
        .open    = ump_file_open,
        .release = ump_file_release,
#ifdef HAVE_UNLOCKED_IOCTL
        .unlocked_ioctl   = ump_file_ioctl,
#else
        .ioctl   = ump_file_ioctl,
#endif
        .mmap    = ump_file_mmap
};


/* This function is called by Linux to initialize this module.
 * All we do is initialize the UMP device driver.
 */
static int ump_initialize_module(void)
{
        _mali_osk_errcode_t err;

        DBG_MSG(2, ("Inserting UMP device driver. Compiled: %s, time: %s\n", __DATE__, __TIME__));

        err = ump_kernel_constructor();
        if (_MALI_OSK_ERR_OK != err) {
                MSG_ERR(("UMP device driver init failed\n"));
                return map_errcode(err);
        }

        MSG(("UMP device driver %s loaded\n", SVN_REV_STRING));
        return 0;
}



/*
 * This function is called by Linux to unload/terminate/exit/cleanup this module.
 * All we do is terminate the UMP device driver.
 */
static void ump_cleanup_module(void)
{
        DBG_MSG(2, ("Unloading UMP device driver\n"));
        ump_kernel_destructor();
        DBG_MSG(2, ("Module unloaded\n"));
}



static ssize_t ump_memory_used_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
{
        char buf[64];
        size_t r;
        u32 mem = _ump_ukk_report_memory_usage();

        r = snprintf(buf, 64, "%u\n", mem);
        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

static const struct file_operations ump_memory_usage_fops = {
        .owner = THIS_MODULE,
        .read = ump_memory_used_read,
};

/*
 * Initialize the UMP device driver.
 */
int ump_kernel_device_initialize(void)
{
        int err;
        dev_t dev = 0;
#if UMP_LICENSE_IS_GPL
        ump_debugfs_dir = debugfs_create_dir(ump_dev_name, NULL);
        if (ERR_PTR(-ENODEV) == ump_debugfs_dir) {
                ump_debugfs_dir = NULL;
        } else {
                debugfs_create_file("memory_usage", 0400, ump_debugfs_dir, NULL, &ump_memory_usage_fops);
        }
#endif

        if (0 == ump_major) {
                /* auto select a major */
                err = alloc_chrdev_region(&dev, 0, 1, ump_dev_name);
                ump_major = MAJOR(dev);
        } else {
                /* use load time defined major number */
                dev = MKDEV(ump_major, 0);
                err = register_chrdev_region(dev, 1, ump_dev_name);
        }

        if (0 == err) {
                memset(&ump_device, 0, sizeof(ump_device));

                /* initialize our char dev data */
                cdev_init(&ump_device.cdev, &ump_fops);
                ump_device.cdev.owner = THIS_MODULE;
                ump_device.cdev.ops = &ump_fops;

                /* register char dev with the kernel */
                err = cdev_add(&ump_device.cdev, dev, 1/*count*/);
                if (0 == err) {

#if UMP_LICENSE_IS_GPL
                        ump_device.ump_class = class_create(THIS_MODULE, ump_dev_name);
                        if (IS_ERR(ump_device.ump_class)) {
                                err = PTR_ERR(ump_device.ump_class);
                        } else {
                                struct device *mdev;
                                mdev = device_create(ump_device.ump_class, NULL, dev, NULL, ump_dev_name);
                                if (!IS_ERR(mdev)) {
                                        return 0;
                                }

                                err = PTR_ERR(mdev);
                        }
                        cdev_del(&ump_device.cdev);
#else
                        return 0;
#endif
                }

                unregister_chrdev_region(dev, 1);
        }

        return err;
}



/*
 * Terminate the UMP device driver
 */
void ump_kernel_device_terminate(void)
{
        dev_t dev = MKDEV(ump_major, 0);

#if UMP_LICENSE_IS_GPL
        device_destroy(ump_device.ump_class, dev);
        class_destroy(ump_device.ump_class);
#endif

        /* unregister char device */
        cdev_del(&ump_device.cdev);

        /* free major */
        unregister_chrdev_region(dev, 1);

#if UMP_LICENSE_IS_GPL
        if (ump_debugfs_dir)
                debugfs_remove_recursive(ump_debugfs_dir);
#endif
}

/*
 * Open a new session. User space has called open() on us.
 */
static int ump_file_open(struct inode *inode, struct file *filp)
{
        struct ump_session_data *session_data;
        _mali_osk_errcode_t err;

        /* input validation */
        if (0 != MINOR(inode->i_rdev)) {
                MSG_ERR(("Minor not zero in ump_file_open()\n"));
                return -ENODEV;
        }

        /* Call the OS-Independent UMP Open function */
        err = _ump_ukk_open((void **) &session_data);
        if (_MALI_OSK_ERR_OK != err) {
                MSG_ERR(("Ump failed to open a new session\n"));
                return map_errcode(err);
        }

        filp->private_data = (void *)session_data;
        filp->f_pos = 0;

        return 0; /* success */
}



/*
 * Close a session. User space has called close() or crashed/terminated.
 */
static int ump_file_release(struct inode *inode, struct file *filp)
{
        _mali_osk_errcode_t err;

        err = _ump_ukk_close((void **) &filp->private_data);
        if (_MALI_OSK_ERR_OK != err) {
                return map_errcode(err);
        }

        return 0;  /* success */
}



/*
 * Handle IOCTL requests.
 */
#ifdef HAVE_UNLOCKED_IOCTL
static long ump_file_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
#else
static int ump_file_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
#endif
{
        int err = -ENOTTY;
        void __user *argument;
        struct ump_session_data *session_data;

#ifndef HAVE_UNLOCKED_IOCTL
        (void)inode; /* inode not used */
#endif

        session_data = (struct ump_session_data *)filp->private_data;
        if (NULL == session_data) {
                MSG_ERR(("No session data attached to file object\n"));
                return -ENOTTY;
        }

        /* interpret the argument as a user pointer to something */
        argument = (void __user *)arg;

        switch (cmd) {
        case UMP_IOC_QUERY_API_VERSION:
                err = ump_get_api_version_wrapper((u32 __user *)argument, session_data);
                break;

        case UMP_IOC_ALLOCATE :
                err = ump_allocate_wrapper((u32 __user *)argument, session_data);
                break;

        case UMP_IOC_RELEASE:
                err = ump_release_wrapper((u32 __user *)argument, session_data);
                break;

        case UMP_IOC_SIZE_GET:
                err = ump_size_get_wrapper((u32 __user *)argument, session_data);
                break;

        case UMP_IOC_MSYNC:
                err = ump_msync_wrapper((u32 __user *)argument, session_data);
                break;

        case UMP_IOC_CACHE_OPERATIONS_CONTROL:
                err = ump_cache_operations_control_wrapper((u32 __user *)argument, session_data);
                break;

        case UMP_IOC_SWITCH_HW_USAGE:
                err = ump_switch_hw_usage_wrapper((u32 __user *)argument, session_data);
                break;

        case UMP_IOC_LOCK:
                err = ump_lock_wrapper((u32 __user *)argument, session_data);
                break;

        case UMP_IOC_UNLOCK:
                err = ump_unlock_wrapper((u32 __user *)argument, session_data);
                break;

        default:
                DBG_MSG(1, ("No handler for IOCTL. cmd: 0x%08x, arg: 0x%08lx\n", cmd, arg));
                err = -EFAULT;
                break;
        }

        return err;
}

int map_errcode(_mali_osk_errcode_t err)
{
        switch (err) {
        case _MALI_OSK_ERR_OK :
                return 0;
        case _MALI_OSK_ERR_FAULT:
                return -EFAULT;
        case _MALI_OSK_ERR_INVALID_FUNC:
                return -ENOTTY;
        case _MALI_OSK_ERR_INVALID_ARGS:
                return -EINVAL;
        case _MALI_OSK_ERR_NOMEM:
                return -ENOMEM;
        case _MALI_OSK_ERR_TIMEOUT:
                return -ETIMEDOUT;
        case _MALI_OSK_ERR_RESTARTSYSCALL:
                return -ERESTARTSYS;
        case _MALI_OSK_ERR_ITEM_NOT_FOUND:
                return -ENOENT;
        default:
                return -EFAULT;
        }
}

/*
 * Handle from OS to map specified virtual memory to specified UMP memory.
 */
static int ump_file_mmap(struct file *filp, struct vm_area_struct *vma)
{
        _ump_uk_map_mem_s args;
        _mali_osk_errcode_t err;
        struct ump_session_data *session_data;

        /* Validate the session data */
        session_data = (struct ump_session_data *)filp->private_data;
        if (NULL == session_data) {
                MSG_ERR(("mmap() called without any session data available\n"));
                return -EFAULT;
        }

        /* Re-pack the arguments that mmap() packed for us */
        args.ctx = session_data;
        args.phys_addr = 0;
        args.size = vma->vm_end - vma->vm_start;
        args._ukk_private = vma;
        args.secure_id = vma->vm_pgoff;
        args.is_cached = 0;

        if (!(vma->vm_flags & VM_SHARED)) {
                args.is_cached = 1;
                vma->vm_flags = vma->vm_flags | VM_SHARED | VM_MAYSHARE  ;
                DBG_MSG(3, ("UMP Map function: Forcing the CPU to use cache\n"));
        }
        /* By setting this flag, during a process fork; the child process will not have the parent UMP mappings */
        vma->vm_flags |= VM_DONTCOPY;

        DBG_MSG(4, ("UMP vma->flags: %x\n", vma->vm_flags));

        /* Call the common mmap handler */
        err = _ump_ukk_map_mem(&args);
        if (_MALI_OSK_ERR_OK != err) {
                MSG_ERR(("_ump_ukk_map_mem() failed in function ump_file_mmap()"));
                return map_errcode(err);
        }

        return 0; /* success */
}

/* Export UMP kernel space API functions */
EXPORT_SYMBOL(ump_dd_secure_id_get);
EXPORT_SYMBOL(ump_dd_handle_create_from_secure_id);
EXPORT_SYMBOL(ump_dd_phys_block_count_get);
EXPORT_SYMBOL(ump_dd_phys_block_get);
EXPORT_SYMBOL(ump_dd_phys_blocks_get);
EXPORT_SYMBOL(ump_dd_size_get);
EXPORT_SYMBOL(ump_dd_reference_add);
EXPORT_SYMBOL(ump_dd_reference_release);

/* Export our own extended kernel space allocator */
EXPORT_SYMBOL(ump_dd_handle_create_from_phys_blocks);

/* Setup init and exit functions for this module */
module_init(ump_initialize_module);
module_exit(ump_cleanup_module);

/* And some module informatio */
MODULE_LICENSE(UMP_KERNEL_LINUX_LICENSE);
MODULE_AUTHOR("ARM Ltd.");
MODULE_VERSION(SVN_REV_STRING);