/*
 * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/*
 The cache has an interrupt that can be raised as soon as an access to a cached
 region (flash, psram) is done without the cache being enabled. We use that here
 to panic the CPU, which from a debugging perspective is better than grabbing bad
 data from the bus.
*/

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#include "esp_err.h"
#include "esp_attr.h"
#include "esp_cpu.h"

#include "esp_intr_alloc.h"
#include "soc/dport_reg.h"

#include "esp_rom_sys.h"

#include "sdkconfig.h"

void esp_cache_err_int_init(void)
{
    uint32_t core_id = esp_cpu_get_core_id();
    ESP_INTR_DISABLE(ETS_MEMACCESS_ERR_INUM);

    // We do not register a handler for the interrupt because it is interrupt
    // level 4 which is not serviceable from C. Instead, xtensa_vectors.S has
    // a call to the panic handler for
    // this interrupt.
    esp_rom_route_intr_matrix(core_id, ETS_CACHE_IA_INTR_SOURCE, ETS_MEMACCESS_ERR_INUM);

    // Enable invalid cache access interrupt when the cache is disabled.
    // When the interrupt happens, we can not determine the CPU where the
    // invalid cache access has occurred. We enable the interrupt to catch
    // invalid access on both CPUs, but the interrupt is connected to the
    // CPU which happens to call this function.
    // For this reason, panic handler backtrace will not be correct if the
    // interrupt is connected to PRO CPU and invalid access happens on the APP
    // CPU.

    if (core_id == PRO_CPU_NUM) {
        DPORT_SET_PERI_REG_MASK(DPORT_CACHE_IA_INT_EN_REG,
            DPORT_CACHE_IA_INT_PRO_OPPOSITE |
            DPORT_CACHE_IA_INT_PRO_DRAM1 |
            DPORT_CACHE_IA_INT_PRO_DROM0 |
            DPORT_CACHE_IA_INT_PRO_IROM0 |
            DPORT_CACHE_IA_INT_PRO_IRAM0 |
            DPORT_CACHE_IA_INT_PRO_IRAM1);
    } else {
        DPORT_SET_PERI_REG_MASK(DPORT_CACHE_IA_INT_EN_REG,
            DPORT_CACHE_IA_INT_APP_OPPOSITE |
            DPORT_CACHE_IA_INT_APP_DRAM1 |
            DPORT_CACHE_IA_INT_APP_DROM0 |
            DPORT_CACHE_IA_INT_APP_IROM0 |
            DPORT_CACHE_IA_INT_APP_IRAM0 |
            DPORT_CACHE_IA_INT_APP_IRAM1);
    }
    ESP_INTR_ENABLE(ETS_MEMACCESS_ERR_INUM);
}

int IRAM_ATTR esp_cache_err_get_cpuid(void)
{
    const uint32_t pro_mask =
            DPORT_PRO_CPU_DISABLED_CACHE_IA_DRAM1 |
            DPORT_PRO_CPU_DISABLED_CACHE_IA_DROM0 |
            DPORT_PRO_CPU_DISABLED_CACHE_IA_IROM0 |
            DPORT_PRO_CPU_DISABLED_CACHE_IA_IRAM0 |
            DPORT_PRO_CPU_DISABLED_CACHE_IA_IRAM1 |
            DPORT_APP_CPU_DISABLED_CACHE_IA_OPPOSITE;

    if (DPORT_GET_PERI_REG_MASK(DPORT_PRO_DCACHE_DBUG3_REG, pro_mask)) {
        return PRO_CPU_NUM;
    }

    const uint32_t app_mask =
            DPORT_APP_CPU_DISABLED_CACHE_IA_DRAM1 |
            DPORT_APP_CPU_DISABLED_CACHE_IA_DROM0 |
            DPORT_APP_CPU_DISABLED_CACHE_IA_IROM0 |
            DPORT_APP_CPU_DISABLED_CACHE_IA_IRAM0 |
            DPORT_APP_CPU_DISABLED_CACHE_IA_IRAM1 |
            DPORT_PRO_CPU_DISABLED_CACHE_IA_OPPOSITE;

    if (DPORT_GET_PERI_REG_MASK(DPORT_APP_DCACHE_DBUG3_REG, app_mask)) {
        return APP_CPU_NUM;
    }
    return -1;
}
