#include <lunaix/mm/region.h>
#include <lunaix/mm/valloc.h>

#include <klibc/string.h>

struct mm_region*
region_create(ptr_t start, ptr_t end, u32_t attr)
{
    return valloc(sizeof(struct mm_region));
}

void
region_add(vm_regions_t* lead, struct mm_region* vmregion)
{
    if (llist_empty(lead)) {
        llist_append(lead, &vmregion->head);
        return vmregion;
    }

    ptr_t cur_end = 0;
    struct mm_region *pos = (struct mm_region*)lead,
                     *n = list_entry(lead->next, struct mm_region, head);
    do {
        if (vmregion->start >= cur_end && vmregion->end <= n->start) {
            break;
        }
        cur_end = n->end;
        pos = n;
        n = list_entry(n->head.next, struct mm_region, head);
    } while ((ptr_t)&pos->head != (ptr_t)lead);

    // XXX caution. require mm_region::head to be the lead of struct
    llist_insert_after(&pos->head, &vmregion->head);
}

void
region_release_all(vm_regions_t* lead)
{
    struct mm_region *pos, *n;

    llist_for_each(pos, n, lead, head)
    {
        vfree(pos);
    }
}

void
region_copy(vm_regions_t* src, vm_regions_t* dest)
{
    if (!src) {
        return;
    }

    struct mm_region *pos, *n, *dup;

    llist_for_each(pos, n, src, head)
    {
        dup = valloc(sizeof(struct mm_region));
        memcpy(dup, pos, sizeof(*pos));
        region_add(dest, dup);
    }
}

struct mm_region*
region_get(vm_regions_t* lead, unsigned long vaddr)
{
    if (llist_empty(lead)) {
        return NULL;
    }

    struct mm_region *pos, *n;

    llist_for_each(pos, n, lead, head)
    {
        if (pos->start <= vaddr && vaddr < pos->end) {
            return pos;
        }
    }
    return NULL;
}