rt-thread-official/bsp/qemu-vexpress-a9/drivers/board.c

/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2012-11-20     Bernard    the first version
 * 2018-11-22     Jesven     add rt_hw_spin_lock
 *                           add rt_hw_spin_unlock
 *                           add smp ipi init
 */

#include <rthw.h>
#include <rtthread.h>

#include "board.h"
#include "drv_timer.h"

#define SYS_CTRL                        __REG32(REALVIEW_SCTL_BASE)

void idle_wfi(void)
{
    asm volatile ("wfi");
}

/**
 * This function will initialize beaglebone board
 */
void rt_hw_board_init(void)
{
    /* initialize hardware interrupt */
    rt_hw_interrupt_init();
    /* initialize system heap */
    rt_system_heap_init(HEAP_BEGIN, HEAP_END);

    rt_components_board_init();
    rt_console_set_device(RT_CONSOLE_DEVICE_NAME);

    rt_thread_idle_sethook(idle_wfi);

#ifdef RT_USING_SMP
    /* install IPI interrupt */
    rt_hw_interrupt_install(RT_SCHEDULE_IPI_IRQ, rt_scheduler_ipi_handler, RT_NULL, "ipi");
    rt_hw_interrupt_umask(RT_SCHEDULE_IPI_IRQ);
#endif
}

#ifdef RT_USING_SMP
void rt_hw_spin_lock(rt_hw_spinlock_t *lock)
{
    unsigned long tmp;
    unsigned long newval;
    rt_hw_spinlock_t lockval;

    __asm__ __volatile__(
            "pld [%0]"
            ::"r"(&lock->slock)
            );

    __asm__ __volatile__(
            "1: ldrex   %0, [%3]\n"
            "   add %1, %0, %4\n"
            "   strex   %2, %1, [%3]\n"
            "   teq %2, #0\n"
            "   bne 1b"
            : "=&r" (lockval), "=&r" (newval), "=&r" (tmp)
            : "r" (&lock->slock), "I" (1 << 16)
            : "cc");

    while (lockval.tickets.next != lockval.tickets.owner) {
        __asm__ __volatile__("wfe":::"memory");
        lockval.tickets.owner = *(volatile unsigned short *)(&lock->tickets.owner);
    }

    __asm__ volatile ("dmb":::"memory");
}

void rt_hw_spin_unlock(rt_hw_spinlock_t *lock)
{
    __asm__ volatile ("dmb":::"memory");
    lock->tickets.owner++;
    __asm__ volatile ("dsb ishst\nsev":::"memory");
}
#endif /*RT_USING_SMP*/