// SPDX-License-Identifier: MIT

#include <common/utils.h>
#include <kernel/alloc.h>
#include <kernel/arch.h>
#include <kernel/virt.h>
#include <stdatomic.h>
#include <stddef.h>

struct page* vm_pfndb = nullptr;

// TODO: Replace with actual allocator.

static size_t mapping_offset = 0;

uintptr_t vm_alloc(size_t length) {
    uintptr_t base = arch_mem_mapping_addr();
    size_t offset = atomic_fetch_add(&mapping_offset, ALIGN_UP(length, arch_mem_page_size()));

    return (base + offset);
}

void vm_free(uintptr_t ptr, size_t length) {
    // TODO
}

uintptr_t vm_page_addr(struct page* page) {
    return (((uintptr_t)page - (uintptr_t)vm_pfndb) / sizeof(struct page)) * arch_mem_page_size();
}

size_t mem_high_shift() {
    return arch_mem_level_bits() * arch_mem_num_levels() + arch_mem_page_bits();
}