/* SPDX-License-Identifier: copyleft-next-0.3.1 */
/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */

/**
 * @file mem.c
 * Generic memory handling, used both by physical and virtual memory.
 */

#include <kmi/types.h>
#include <kmi/mem.h>
#include <kmi/vmem.h>
#include <libfdt.h>

size_t __mm_shifts[10];
size_t __mm_widths[10];
size_t __mm_sizes[10];
size_t __mm_page_shift;
enum mm_order __mm_max_order;

/**
 * RAM base address. Not sure if it should be provided through a macro
 * like __mm_*.
 */
pm_t ram_base;
size_t ram_size;

enum mm_order nearest_order(size_t size)
{
	for (enum mm_order order = max_order(); order >= MM_MIN; --order)
		if (order_size(order) >= size)
			return order;

	return MM_O0;
}

void init_mem(void *fdt)
{
	size_t max_order = 0;
	size_t base_bits = 0;
	size_t bits[NUM_ORDERS] = { 0 };
	stat_pmem_conf(fdt, &max_order, &base_bits, bits);

	__mm_max_order = max_order;
	__mm_page_shift = base_bits;

	__mm_shifts[0] = __mm_page_shift;
	__mm_widths[0] = 1 << bits[0];
	__mm_sizes[0] = 1 << __mm_page_shift;

	for (enum mm_order i = MM_O1; i <= max_order(); ++i) {
		__mm_widths[i] = 1 << bits[i];
		__mm_shifts[i] = __mm_shifts[i - 1] + bits[i - 1];
		__mm_sizes[i] = 1UL << __mm_shifts[i];
	}
}

void set_ram_base(uintptr_t base)
{
	ram_base = base;
}

void set_ram_size(size_t size)
{
	ram_size = size;
}

uintptr_t get_ram_base()
{
	return ram_base;
}

size_t get_ram_size()
{
	return ram_size;
}