rt-thread/libcpu/arm/cortex-a/cpu.c

96 lines
2.1 KiB
C

/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2011-09-15 Bernard first version
* 2018-11-22 Jesven add rt_hw_cpu_id()
*/
#include <rthw.h>
#include <rtthread.h>
#include <board.h>
#ifdef RT_USING_SMP
void rt_hw_spin_lock_init(rt_hw_spinlock_t *lock)
{
lock->slock = 0;
}
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*/
/**
* @addtogroup ARM CPU
*/
/*@{*/
/** shutdown CPU */
RT_WEAK void rt_hw_cpu_shutdown()
{
rt_uint32_t level;
rt_kprintf("shutdown...\n");
level = rt_hw_interrupt_disable();
while (level)
{
RT_ASSERT(0);
}
}
#ifdef RT_USING_CPU_FFS
/**
* This function finds the first bit set (beginning with the least significant bit)
* in value and return the index of that bit.
*
* Bits are numbered starting at 1 (the least significant bit). A return value of
* zero from any of these functions means that the argument was zero.
*
* @return return the index of the first bit set. If value is 0, then this function
* shall return 0.
*/
int __rt_ffs(int value)
{
return __builtin_ffs(value);
}
#endif
/*@}*/