arch/arm/src/sam34/sam4cm_smpcall.c

/****************************************************************************
 * arch/arm/src/sam34/sam4cm_smpcall.c
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdint.h>
#include <assert.h>
#include <debug.h>
#include <string.h>
#include <stdio.h>

#include <nuttx/arch.h>
#include <nuttx/spinlock.h>
#include <nuttx/sched_note.h>

#include "sched/sched.h"
#include "arm_internal.h"
#include "hardware/sam4cm_ipc.h"

#ifdef CONFIG_SMP

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#if 0
#  define DPRINTF(fmt, args...) _err(fmt, ##args)
#else
#  define DPRINTF(fmt, args...) do {} while (0)
#endif

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: sam4cm_smp_call_handler
 *
 * Description:
 *   This is the handler for SMP_CALL.
 *
 ****************************************************************************/

int sam4cm_smp_call_handler(int irq, void *c, void *arg)
{
  int cpu = this_cpu();

  nxsched_smp_call_handler(irq, c, arg);

  /* Clear : Pause IRQ */

  /* IPC Interrupt Clear Command Register (write-only) */

  if (1 == cpu)
    {
      DPRINTF("CPU0 -> CPU1\n");
      putreg32(0x1, SAM_IPC1_ICCR);
    }
  else
    {
      DPRINTF("CPU1 -> CPU0\n");
      putreg32(0x1, SAM_IPC0_ICCR);
    }

  nxsched_process_delivered(cpu);

  return OK;
}

/****************************************************************************
 * Name: up_send_smp_sched
 *
 * Description:
 *   pause task execution on the CPU
 *   check whether there are tasks delivered to specified cpu
 *   and try to run them.
 *
 * Input Parameters:
 *   cpu - The index of the CPU to be paused.
 *
 * Returned Value:
 *   Zero on success; a negated errno value on failure.
 *
 * Assumptions:
 *   Called from within a critical section;
 *
 ****************************************************************************/

int up_send_smp_sched(int cpu)
{
  /* Execute Pause IRQ to CPU(cpu) */

  /* Set IPC Interrupt (IRQ0) (write-only) */

  if (cpu == 1)
    {
      putreg32(0x1, SAM_IPC1_ISCR);
    }
  else
    {
      putreg32(0x1, SAM_IPC0_ISCR);
    }

  return OK;
}

/****************************************************************************
 * Name: up_send_smp_call
 *
 * Description:
 *   Send smp call to target cpu.
 *
 * Input Parameters:
 *   cpuset - The set of CPUs to receive the SGI.
 *
 * Returned Value:
 *   None.
 *
 ****************************************************************************/

void up_send_smp_call(cpu_set_t cpuset)
{
  int cpu;

  for (; cpuset != 0; cpuset &= ~(1 << cpu))
    {
      cpu = ffs(cpuset) - 1;
      up_send_smp_sched(cpu);
    }
}

#endif /* CONFIG_SMP */