rt-thread-official/libcpu/aarch64/common/cpuport.h

72 lines
1.7 KiB
C

/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2023-10-25 Shell Move ffs to cpuport, add general implementation
* by inline assembly
*/
#ifndef CPUPORT_H__
#define CPUPORT_H__
#include <armv8.h>
#include <rtdef.h>
#ifdef RT_USING_SMP
typedef struct {
volatile unsigned int lock;
} rt_hw_spinlock_t;
#endif
#define rt_hw_barrier(cmd, ...) \
__asm__ volatile (RT_STRINGIFY(cmd) " "RT_STRINGIFY(__VA_ARGS__):::"memory")
#define rt_hw_isb() rt_hw_barrier(isb)
#define rt_hw_dmb() rt_hw_barrier(dmb, ish)
#define rt_hw_wmb() rt_hw_barrier(dmb, ishst)
#define rt_hw_rmb() rt_hw_barrier(dmb, ishld)
#define rt_hw_dsb() rt_hw_barrier(dsb, ish)
#define rt_hw_wfi() rt_hw_barrier(wfi)
#define rt_hw_wfe() rt_hw_barrier(wfe)
#define rt_hw_sev() rt_hw_barrier(sev)
#define rt_hw_cpu_relax() rt_hw_barrier(yield)
void _thread_start(void);
#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.
*/
rt_inline int __rt_ffs(int value)
{
#ifdef __GNUC__
return __builtin_ffs(value);
#else
__asm__ volatile (
"rbit w1, %w0\n"
"cmp %w0, 0\n"
"clz w1, w1\n"
"csinc %w0, wzr, w1, eq\n"
: "=r"(value)
: "0"(value)
);
return value;
#endif
}
#endif /* RT_USING_CPU_FFS */
#endif /*CPUPORT_H__*/