n200_func.c

/*
 * Copyright (c) 2021-2022 Amlogic, Inc. All rights reserved.
 *
 * SPDX-License-Identifier: MIT
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "n200_func.h"
#include "register.h"
#include "common.h"
#include "n200_timer.h"
#include "gcc_compiler_attributes.h"
#include "riscv_encoding.h"
#include "lscript.h"

#define PMP_PRINT(...) printf(__VA_ARGS__)
#define PMP_PRINT_DEBUG(...) //printf(__VA_ARGS__)

/*
 * -- Configure PMP --
 * For User mode only.
 * To make all the address space accessible and executable
 */
void pmp_open_all_space(void)
{
	// Config entry0 addr to all 1s to make the range cover all space
	asm volatile ("li x6, 0xffffffff":::"x6");
	asm volatile ("csrw pmpaddr0, x6":::);
	// Config entry0 cfg to make it NAPOT address mode, and R/W/X okay
	asm volatile ("li x6, 0x7f":::"x6");
	asm volatile ("csrw pmpcfg0, x6":::);
}

#ifndef CONFIG_N200_REVA
static uint32_t pmpcfg_order_get(uint32_t pmp_size)
{
	int pmpcfg_order = 0;

	if ((pmp_size & (pmp_size - 1)) != 0) {
		printf("error: pmp_size is not 2^n\n");
		return 0;
	}

	while (pmp_size > 1) {
		pmp_size >>= 1;
		pmpcfg_order++;
	}

	return pmpcfg_order;
}

static uint32_t pmpaddr_encode(uint32_t pmp_base_addr, uint32_t pmp_cfg_order)
{
	uint32_t addrmask, pmpaddr;

	addrmask = (1UL << (pmp_cfg_order - PMP_SHIFT)) - 1;
	pmpaddr = ((pmp_base_addr >> PMP_SHIFT) & ~addrmask);
	pmpaddr |= (addrmask >> 1);

	return pmpaddr;
}


/*
 * -- Configure PMP --
 * For both Machine and User mode.
 * To make aocpu text/ro data space readable and executable.
 * Note:
 *     If config_pmp is called, pmp_open_all_space is invalid.
 */
uint32_t config_pmp(void)
{
	uint32_t start_text_addr = (uint32_t)&_text;
	uint32_t end_text_addr = (uint32_t)&_etext;
	uint32_t text_len_left = end_text_addr - start_text_addr;
	uint32_t next_seg_len = 0;
	uint32_t pmp_cfg[8] = {0}, pmp_addr[8] = {0};
	int pmp_entry_used = 0;
	uint32_t pmp_region_base = start_text_addr;

	PMP_PRINT("AOCPU: configure PMP for memory 0x%lx ~ 0x%lx\n",
			start_text_addr, end_text_addr);

	while (text_len_left > 0) {
		if ((text_len_left >= SIZE_64K) && ((pmp_region_base & (SIZE_64K - 1)) == 0))
			next_seg_len = SIZE_64K;
		else if ((text_len_left >= SIZE_32K) && ((pmp_region_base & (SIZE_32K - 1)) == 0))
			next_seg_len = SIZE_32K;
		else if ((text_len_left >= SIZE_16K) && ((pmp_region_base & (SIZE_16K - 1)) == 0))
			next_seg_len = SIZE_16K;
		else if ((text_len_left >= SIZE_8K) && ((pmp_region_base & (SIZE_8K - 1)) == 0))
			next_seg_len = SIZE_8K;
		else if ((text_len_left >= SIZE_4K) && ((pmp_region_base & (SIZE_4K - 1)) == 0))
			next_seg_len = SIZE_4K;
		else if ((text_len_left >= SIZE_2K) && ((pmp_region_base & (SIZE_2K - 1)) == 0))
			next_seg_len = SIZE_2K;
		else if ((text_len_left >= SIZE_1K) && ((pmp_region_base & (SIZE_1K - 1)) == 0))
			next_seg_len = SIZE_1K;

		if (next_seg_len == 0) {
			PMP_PRINT("pmp config error: not aligned.\n");
			PMP_PRINT("pmp base: 0x%x, segment left: 0x%x\n",
				pmp_region_base, text_len_left);
			break;
		}

		text_len_left -= next_seg_len;
		PMP_PRINT_DEBUG("pm pregion base: %lx\n", pmp_region_base);
		PMP_PRINT_DEBUG("segment length : %lx\n", next_seg_len);
		PMP_PRINT_DEBUG("length left    : %lx\n", text_len_left);

		pmp_addr[pmp_entry_used] = pmpaddr_encode(pmp_region_base,
						pmpcfg_order_get(next_seg_len));
		pmp_cfg[pmp_entry_used] = (PMP_CFG_R_EN | PMP_CFG_X_EN |
						PMP_CFG_A_NAPOT | PMP_CFG_L_EN);
		pmp_entry_used++;
		pmp_region_base += next_seg_len;
		PMP_PRINT_DEBUG("pmp_entry_used : %d\n", pmp_entry_used);
		next_seg_len = 0;

		if (pmp_entry_used >= 8) {
			PMP_PRINT_DEBUG("Note: pmp entry has been full used\n");
			break;
		}
	}

	write_csr(pmpaddr0, pmp_addr[0]);
	write_csr(pmpaddr1, pmp_addr[1]);
	write_csr(pmpaddr2, pmp_addr[2]);
	write_csr(pmpaddr3, pmp_addr[3]);
	write_csr(pmpaddr4, pmp_addr[4]);
	write_csr(pmpaddr5, pmp_addr[5]);
	write_csr(pmpaddr6, pmp_addr[6]);
	write_csr(pmpaddr7, pmp_addr[7]);
	PMP_PRINT_DEBUG("pmpaddr0 : %lx\n", read_csr(pmpaddr0));
	PMP_PRINT_DEBUG("pmpaddr1 : %lx\n", read_csr(pmpaddr1));
	PMP_PRINT_DEBUG("pmpaddr2 : %lx\n", read_csr(pmpaddr2));
	PMP_PRINT_DEBUG("pmpaddr3 : %lx\n", read_csr(pmpaddr3));
	PMP_PRINT_DEBUG("pmpaddr4 : %lx\n", read_csr(pmpaddr4));
	PMP_PRINT_DEBUG("pmpaddr5 : %lx\n", read_csr(pmpaddr5));
	PMP_PRINT_DEBUG("pmpaddr6 : %lx\n", read_csr(pmpaddr6));
	PMP_PRINT_DEBUG("pmpaddr7 : %lx\n", read_csr(pmpaddr7));

	write_csr(pmpcfg0, (pmp_cfg[3] << 24) | (pmp_cfg[2] << 16) |
				(pmp_cfg[1] << 8) | (pmp_cfg[0] << 0));
	PMP_PRINT_DEBUG("pmpcfg0  : %lx\n", read_csr(pmpcfg0));

	write_csr(pmpcfg1, (pmp_cfg[7] << 24) | (pmp_cfg[6] << 16) |
				(pmp_cfg[5] << 8) | (pmp_cfg[4] << 0));
	PMP_PRINT_DEBUG("pmpcfg1  : %lx\n", read_csr(pmpcfg1));

	PMP_PRINT("AOCPU: configure PMP end\n");

	return 0;
}
#endif

void switch_m2u_mode(void)
{
	clear_csr(mstatus, MSTATUS_MPP);
	//printf("\nIn the m2u function, the mstatus is 0x%x\n", read_csr(mstatus));
	//printf("\nIn the m2u function, the mepc is 0x%x\n", read_csr(mepc));
	asm volatile("la x6, 1f    " ::: "x6");
	asm volatile("csrw mepc, x6" :::);
	asm volatile("mret" :::);
	asm volatile("1:" :::);
}

uint32_t mtime_lo(void)
{
#ifdef configSOC_TIMER_AS_TICK
	return *(volatile uint32_t *)TIMERE_LOW_REG;
#else
	return *(volatile uint32_t *)(TIMER_CTRL_ADDR + TIMER_MTIME);
#endif
}

uint32_t mtime_hi(void)
{
#ifdef configSOC_TIMER_AS_TICK
	return *(volatile uint32_t *)TIMERE_HIG_REG;
#else
	return *(volatile uint32_t *)(TIMER_CTRL_ADDR + TIMER_MTIME + 4);
#endif
}

uint64_t get_timer_value(void)
{
	while (1) {
		uint32_t hi = mtime_hi();
		uint32_t lo = mtime_lo();

		if (hi == mtime_hi())
			return ((uint64_t)hi << 32) | lo;
	}
}

uint32_t get_timer_freq(void)
{
	return TIMER_FREQ;
}

uint64_t get_instret_value(void)
{
	while (1) {
		uint32_t hi = read_csr(minstreth);
		uint32_t lo = read_csr(minstret);

		if (hi == read_csr(minstreth))
			return ((uint64_t)hi << 32) | lo;
	}
}

uint64_t get_cycle_value(void)
{
	while (1) {
		uint32_t hi = read_csr(mcycleh);
		uint32_t lo = read_csr(mcycle);

		if (hi == read_csr(mcycleh))
			return ((uint64_t)hi << 32) | lo;
	}
}

unsigned long interrupt_status_get(void)
{
	return read_csr(mstatus) >> 0x3;
}

void interrupt_disable(void)
{
	clear_csr(mstatus, MSTATUS_MIE);
}

void interrupt_enable(void)
{
	set_csr(mstatus, MSTATUS_MIE);
}

#ifndef CONFIG_N200_REVA

uint32_t __noinline measure_cpu_freq(size_t n)
{
	uint32_t start_mtime, delta_mtime;
	uint32_t mtime_freq = get_timer_freq();
	// Don't start measuruing until we see an mtime tick
	uint32_t tmp = mtime_lo();

	do {
		start_mtime = mtime_lo();
	} while (start_mtime == tmp);

	uint32_t start_mcycle = read_csr(mcycle);

	do {
		delta_mtime = mtime_lo() - start_mtime;
	} while (delta_mtime < n);

	uint32_t delta_mcycle = read_csr(mcycle) - start_mcycle;

	return (delta_mcycle / delta_mtime) * mtime_freq +
	       ((delta_mcycle % delta_mtime) * mtime_freq) / delta_mtime;
}

uint32_t get_cpu_freq(void)
{
	uint32_t cpu_freq;

	// warm up
	measure_cpu_freq(1);
	// measure for real
	cpu_freq = measure_cpu_freq(100);

	return cpu_freq;
}

unsigned int xPortIsIsrContext(void)
{
	return (read_csr_msubmode & 0xff);
}

#else

unsigned int xPortIsIsrContext(void)
{
	return read_csr_msubmode;
}

#endif