Le 23/11/2017 à 21:41, Benjamin Herrenschmidt a écrit :
On Thu, 2017-11-23 at 12:05 +0100, Christophe Lombard wrote:
The POWER9 core supports a new feature: ASB_Notify which requires the
support of the Special Purpose Register: TIDR.
The ASB_Notify command, generated by the AFU, will attempt to
wake-up the host thread identified by the particular LPID:PID:TID.
This patch assign a unique TIDR (thread id) for the current thread which
will be used in the process element entry.
Is that keyd off some device-tree property or similar ? There is no
guarantee that the TIDR and ASB_Notify still exist on future chips...
Ben.
To my knowledge, there is no property (or similar), somewhere, that
indicating that the TIDR is supported or not.
For the time being, if I am not wrong, the only check we have, is
this condition in the function set_thread_tidr(struct task_struct *t):
if (!cpu_has_feature(CPU_FTR_ARCH_300))
return -EINVAL;
Christophe
