rt-thread/libcpu/mips/loongson/mipscfg.c

/*
 * File      : mipscfg.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2010, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-05-27     swkyer       first version
 */
#include <rtthread.h>
#include "../common/mipsregs.h"
#include "../common/mipscfg.h"

mips32_core_cfg_t g_mips_core =
{
	16,		/* icache_line_size */
	256,	/* icache_lines_per_way */
	4,		/* icache_ways */
	16,		/* dcache_line_size */
	256,	/* dcache_lines_per_way */
	4,		/* dcache_ways */
	16,		/* max_tlb_entries */
};

static rt_uint16_t m_pow(rt_uint16_t b, rt_uint16_t n)
{
	rt_uint16_t rets = 1;

    while (n--)
        rets *= b;

    return rets;
}

static rt_uint16_t m_log2(rt_uint16_t b)
{
	rt_uint16_t rets = 0;

    while (b != 1)
    {
        b /= 2;
        rets++;
    }

    return rets;
}

/**
 * read core attribute
 */
void mips32_cfg_init(void)
{
	rt_uint16_t val;
	rt_uint32_t cp0_config1;

	cp0_config1 = read_c0_config();
	if (cp0_config1 & 0x80000000)
	{
		cp0_config1 = read_c0_config1();

		val = (cp0_config1 & (7<<22))>>22;
		g_mips_core.icache_lines_per_way = 64 * m_pow(2, val);
		val = (cp0_config1 & (7<<19))>>19;
		g_mips_core.icache_line_size = 2 * m_pow(2, val);
		val = (cp0_config1 & (7<<16))>>16;
		g_mips_core.icache_ways = val + 1;

		val = (cp0_config1 & (7<<13))>>13;
		g_mips_core.dcache_lines_per_way = 64 * m_pow(2, val);
		val = (cp0_config1 & (7<<10))>>10;
		g_mips_core.dcache_line_size = 2 * m_pow(2, val);
		val = (cp0_config1 & (7<<7))>>7;
		g_mips_core.dcache_ways = val + 1;

		val = (cp0_config1 & (0x3F<<25))>>25;
		g_mips_core.max_tlb_entries = val + 1;
	}
}