esp-idf/components/esp_mm/esp_cache.c

/*
 * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <sys/param.h>
#include <inttypes.h>
#include "sdkconfig.h"
#include "esp_check.h"
#include "esp_log.h"
#include "soc/soc_caps.h"
#include "hal/mmu_hal.h"
#include "hal/cache_hal.h"
#include "esp_cache.h"
#include "esp_private/critical_section.h"


static const char *TAG = "cache";
DEFINE_CRIT_SECTION_LOCK_STATIC(s_spinlock);

void s_cache_freeze(void)
{
#if SOC_CACHE_FREEZE_SUPPORTED
    cache_hal_freeze(CACHE_TYPE_DATA | CACHE_TYPE_INSTRUCTION);
#endif

    /**
     * For writeback supported, but the freeze not supported chip (Now only S2),
     * as it's single core, the critical section is enough to prevent preemption from an non-IRAM ISR
     */
}

void s_cache_unfreeze(void)
{
#if SOC_CACHE_FREEZE_SUPPORTED
    cache_hal_unfreeze(CACHE_TYPE_DATA | CACHE_TYPE_INSTRUCTION);
#endif

    /**
     * Similarly, for writeback supported, but the freeze not supported chip (Now only S2),
     * we don't need to do more
     */
}


esp_err_t esp_cache_msync(void *addr, size_t size, int flags)
{
    ESP_RETURN_ON_FALSE_ISR(addr, ESP_ERR_INVALID_ARG, TAG, "null pointer");
    ESP_RETURN_ON_FALSE_ISR(mmu_hal_check_valid_ext_vaddr_region(0, (uint32_t)addr, size, MMU_VADDR_DATA), ESP_ERR_INVALID_ARG, TAG, "invalid address");
    bool both_dir = (flags & ESP_CACHE_MSYNC_FLAG_DIR_C2M) && (flags & ESP_CACHE_MSYNC_FLAG_DIR_M2C);
    ESP_RETURN_ON_FALSE_ISR(!both_dir, ESP_ERR_INVALID_ARG, TAG, "both C2M and M2C directions are selected, you should only select one");

    uint32_t vaddr = (uint32_t)addr;

    if (flags & ESP_CACHE_MSYNC_FLAG_DIR_M2C) {
        ESP_EARLY_LOGD(TAG, "M2C DIR");

        esp_os_enter_critical_safe(&s_spinlock);
        s_cache_freeze();

        //Add preload feature / flag here, IDF-7800
        cache_hal_invalidate_addr(vaddr, size);

        s_cache_unfreeze();
        esp_os_exit_critical_safe(&s_spinlock);

    } else {
        ESP_EARLY_LOGD(TAG, "C2M DIR");

#if SOC_CACHE_WRITEBACK_SUPPORTED
        esp_os_enter_critical_safe(&s_spinlock);
        uint32_t data_cache_line_size = cache_hal_get_cache_line_size(CACHE_TYPE_DATA);
        esp_os_exit_critical_safe(&s_spinlock);

        if ((flags & ESP_CACHE_MSYNC_FLAG_UNALIGNED) == 0) {
            bool aligned_addr = (((uint32_t)addr % data_cache_line_size) == 0) && ((size % data_cache_line_size) == 0);
            ESP_RETURN_ON_FALSE_ISR(aligned_addr, ESP_ERR_INVALID_ARG, TAG, "start address, end address or the size is(are) not aligned with the data cache line size (%d)B", data_cache_line_size);
        }

        esp_os_enter_critical_safe(&s_spinlock);
        s_cache_freeze();

        cache_hal_writeback_addr(vaddr, size);
        if (flags & ESP_CACHE_MSYNC_FLAG_INVALIDATE) {
            cache_hal_invalidate_addr(vaddr, size);
        }

        s_cache_unfreeze();
        esp_os_exit_critical_safe(&s_spinlock);
#endif
    }

    return ESP_OK;
}