[rtems commit] riscv: Implement CPU counter

[Sebastian Huber]

----- Am 6. Jul 2018 um 15:11 schrieb Hesham Almatary heshamelmatary at gmail.com:

> On Fri, 6 Jul 2018 at 1:28 pm, Sebastian Huber <sebh at rtems.org> wrote:
[...]
>> -CPU_Counter_ticks _CPU_Counter_read( void );
>> +static inline CPU_Counter_ticks _CPU_Counter_read( void )
>> +{
>> +  unsigned long ticks;
>> +
>> +  __asm__ volatile ( "rdtime %0" : "=&r" ( ticks ) );
>> +
> 
> Shouldn’t this be “rdcycle” instead of “rdtime”?

The rdcycle is affected by power saving states. If you want to use the CPU counter for fast timestamps, then this is bad.