#include <zinnia/alloc.h>
#include <zinnia/utils.h>
#include <zinnia/virt.h>
#include <stdatomic.h>
#include <stddef.h>

struct page* vm_pfndb = nullptr;

// TODO: Replace with actual allocator.

static _Atomic(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_explicit(&mapping_offset, ALIGN_UP(length, arch_mem_page_size()), memory_order_acquire);

    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();
}