#include <sys/param.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>

#include <sys/param.h>
#include <sys/bio.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <sys/eventhandler.h>

#include <machine/bus.h>

#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vm_phys.h>

#define HUGE_PAGE_SIZE (2 * 1024 * 1024)  // 2MB Large Page

static void *hugepage_ptr = NULL;

static int load_handler(module_t mod, int event, void *arg) {
    switch (event) {
        case MOD_LOAD:
            printf("Loading Huge Page Kernel Module...\n");

            hugepage_ptr = kmem_alloc_contig(HUGE_PAGE_SIZE, M_WAITOK,
                                             0, BUS_SPACE_MAXADDR,
                                             HUGE_PAGE_SIZE, 0,
                                             VM_MEMATTR_DEFAULT);

            if (!hugepage_ptr) {
                printf("Failed to allocate a huge page!\n");
                return ENOMEM;
            }
            printf("Huge page allocated at %p\n", hugepage_ptr);
            break;

        case MOD_UNLOAD:
            if (hugepage_ptr) {
                kmem_free(hugepage_ptr, HUGE_PAGE_SIZE);
                printf("Huge page freed.\n");
            }
            printf("Unloading module...\n");
            break;

        default:
            return EOPNOTSUPP;
    }
    return 0;
}

static moduledata_t superpage_mod = {
    "superpage",
    load_handler,
    NULL
};

DECLARE_MODULE(superpage, superpage_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);