On Mon, Jan 30, 2017 at 05:49:59PM +0000, Mark Rutland wrote:
On Thu, Jan 26, 2017 at 01:49:03PM +0800, Fu Wei wrote:
And because Linux kernel is running on Non-secure EL1, so should we skip "SECURE" timer in Linux?
I guess you mean by checking the GTx Common flags, to see if the timer is secure? Yes, we must skip those.
Looking further at this, the ACPI spec is sorely lacking any statement as to the configuration of CNTCTLBase.{CNTSAR,CNTTIDR,CNTACR}, so it's not clear if we can access anything in a frame, even if it is listed as being a non-secure timer.
Given CNTNSAR.NS<n> enables non-secure access to CNTACR<n>, I guess the obvious interpretation is that for frames listed as non-secure, this has been configured to permit non-secure access to the frame and associated CNTACR<n>.
I will work to that assumption while reviewing, though I still believe this needs to be clarified in the spec.
Thanks, Mark.