Commands which causes PUNIT writes, store them and restore them on system
resume. The driver stores all such requests in a hash table and stores the
the latest mailbox request parameters. On resume these commands mail box
commands are executed again. There are only 5 such mail box commands which
will trigger such processing so a very low overhead in store and execute
on resume. Also there is no order requirement for mail box commands for
these write/set commands. There is one MSR request for changing turbo
ratio limits, this also stored and get restored on resume and cpu online.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Add an IOCTL to send mailbox commands to PUNIT using PUNIT MSRs for
mailbox. Some CPU models don't have PCI device, so need to use MSRs.
A limited set of mailbox commands can be sent to PUNIT.
This MMIO interface is used by the intel-speed-select tool under
tools/x86/power to enumerate and control Intel Speed Select features.
The MBOX commands ids and semantics of the message can be checked from
the source code of the tool.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Srinivas Pandruvada