esp-idf/components/esp32s2beta/crosscore_int.c

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2019-05-09 23:34:06 -04:00
// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <stdint.h>
#include <string.h>
#include "esp_attr.h"
#include "esp_err.h"
#include "esp_intr_alloc.h"
#include "esp32s2beta/rom/ets_sys.h"
#include "esp32s2beta/rom/uart.h"
#include "soc/cpu.h"
#include "soc/dport_reg.h"
#include "soc/io_mux_reg.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/periph_defs.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "freertos/queue.h"
#include "freertos/portmacro.h"
#define REASON_YIELD BIT(0)
#define REASON_FREQ_SWITCH BIT(1)
static portMUX_TYPE reason_spinlock = portMUX_INITIALIZER_UNLOCKED;
static volatile uint32_t reason[ portNUM_PROCESSORS ];
#warning "crosscore_int: TODO: simplify for esp32s2beta"
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/*
ToDo: There is a small chance the CPU already has yielded when this ISR is serviced. In that case, it's running the intended task but
the ISR will cause it to switch _away_ from it. portYIELD_FROM_ISR will probably just schedule the task again, but have to check that.
*/
static inline void IRAM_ATTR esp_crosscore_isr_handle_yield()
{
portYIELD_FROM_ISR();
}
static void IRAM_ATTR esp_crosscore_isr(void *arg) {
uint32_t my_reason_val;
//A pointer to the correct reason array item is passed to this ISR.
volatile uint32_t *my_reason=arg;
//Clear the interrupt first.
if (xPortGetCoreID()==0) {
DPORT_WRITE_PERI_REG(DPORT_CPU_INTR_FROM_CPU_0_REG, 0);
} else {
DPORT_WRITE_PERI_REG(DPORT_CPU_INTR_FROM_CPU_1_REG, 0);
}
//Grab the reason and clear it.
portENTER_CRITICAL_ISR(&reason_spinlock);
my_reason_val=*my_reason;
*my_reason=0;
portEXIT_CRITICAL_ISR(&reason_spinlock);
//Check what we need to do.
if (my_reason_val & REASON_YIELD) {
esp_crosscore_isr_handle_yield();
}
if (my_reason_val & REASON_FREQ_SWITCH) {
/* Nothing to do here; the frequency switch event was already
* handled by a hook in xtensa_vectors.S. Could be used in the future
* to allow DFS features without the extra latency of the ISR hook.
*/
}
}
//Initialize the crosscore interrupt on this core. Call this once
//on each active core.
void esp_crosscore_int_init() {
portENTER_CRITICAL(&reason_spinlock);
reason[xPortGetCoreID()]=0;
portEXIT_CRITICAL(&reason_spinlock);
esp_err_t err;
if (xPortGetCoreID()==0) {
err = esp_intr_alloc(ETS_FROM_CPU_INTR0_SOURCE, ESP_INTR_FLAG_IRAM, esp_crosscore_isr, (void*)&reason[0], NULL);
} else {
err = esp_intr_alloc(ETS_FROM_CPU_INTR1_SOURCE, ESP_INTR_FLAG_IRAM, esp_crosscore_isr, (void*)&reason[1], NULL);
}
assert(err == ESP_OK);
}
static void IRAM_ATTR esp_crosscore_int_send(int core_id, uint32_t reason_mask) {
assert(core_id<portNUM_PROCESSORS);
//Mark the reason we interrupt the other CPU
portENTER_CRITICAL(&reason_spinlock);
reason[core_id] |= reason_mask;
portEXIT_CRITICAL(&reason_spinlock);
//Poke the other CPU.
if (core_id==0) {
DPORT_WRITE_PERI_REG(DPORT_CPU_INTR_FROM_CPU_0_REG, DPORT_CPU_INTR_FROM_CPU_0);
} else {
DPORT_WRITE_PERI_REG(DPORT_CPU_INTR_FROM_CPU_1_REG, DPORT_CPU_INTR_FROM_CPU_1);
}
}
void IRAM_ATTR esp_crosscore_int_send_yield(int core_id)
{
esp_crosscore_int_send(core_id, REASON_YIELD);
}
void IRAM_ATTR esp_crosscore_int_send_freq_switch(int core_id)
{
esp_crosscore_int_send(core_id, REASON_FREQ_SWITCH);
}