/*
 * Copyright (C) 2018 Intel Corporation. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <hypervisor.h>
#include <multiboot.h>

#define MAX_PORT			0x10000  /* port 0 - 64K */
#define DEFAULT_UART_PORT	0x3F8

#define ACRN_DBG_PARSE		6

#define MAX_CMD_LEN		64

static const char * const cmd_list[] = {
	"uart=disabled",	/* to disable uart */
	"uart=port@",		/* like uart=port@0x3F8 */
	"uart=mmio@",	/*like: uart=mmio@0xFC000000 */
};

enum IDX_CMD {
	IDX_DISABLE_UART,
	IDX_PORT_UART,
	IDX_MMIO_UART,

	IDX_MAX_CMD,
};

static void handle_cmd(const char *cmd, int len)
{
	int i;

	for (i = 0; i < IDX_MAX_CMD; i++) {
		int tmp = strnlen_s(cmd_list[i], MAX_CMD_LEN);

		/*cmd prefix should be same with one in cmd_list */
		if (len < tmp)
			continue;

		if (strncmp(cmd_list[i], cmd, tmp) != 0)
			continue;

		if (i == IDX_DISABLE_UART) {
			/* set uart disabled*/
			uart16550_set_property(false, false, 0UL);
		} else if ((i == IDX_PORT_UART) || (i == IDX_MMIO_UART)) {
			uint64_t addr = strtoul_hex(cmd + tmp);

			dev_dbg(ACRN_DBG_PARSE, "uart addr=0x%llx", addr);

			if (i == IDX_PORT_UART) {
				if (addr > MAX_PORT)
					addr = DEFAULT_UART_PORT;

				uart16550_set_property(true, true, addr);
			} else {
				uart16550_set_property(true, false, addr);
			}
		}
	}
}

int parse_hv_cmdline(void)
{
	const char *start;
	const char *end;
	struct multiboot_info *mbi = NULL;

	if (boot_regs[0] != MULTIBOOT_INFO_MAGIC) {
		ASSERT(0, "no multiboot info found");
		return -EINVAL;
	}

	mbi = (struct multiboot_info *)(hpa2hva((uint64_t)boot_regs[1]));
	dev_dbg(ACRN_DBG_PARSE, "Multiboot detected, flag=0x%x", mbi->mi_flags);

	if (!(mbi->mi_flags & MULTIBOOT_INFO_HAS_CMDLINE)) {
		dev_dbg(ACRN_DBG_PARSE, "no hv cmdline!");
		return -EINVAL;
	}

	start = (char *)hpa2hva((uint64_t)mbi->mi_cmdline);
	dev_dbg(ACRN_DBG_PARSE, "hv cmdline: %s", start);

	do {
		while (*start == ' ')
			start++;

		end = start + 1;
		while (*end != ' ' && *end)
			end++;

		handle_cmd(start, end - start);
		start = end + 1;

	} while (*end && *start);

	return 0;
}
