On Fri, Mar 12, 2021 at 08:34:34AM -0800, kan.li...@linux.intel.com wrote: > From: Kan Liang <kan.li...@linux.intel.com> > > A self-describing mechanism for the uncore PerfMon hardware has been > introduced with the latest Intel platforms. By reading through an MMIO > page worth of information, perf can 'discover' all the standard uncore > PerfMon registers in a machine. > > The discovery mechanism relies on BIOS's support. With a proper BIOS, > a PCI device with the unique capability ID 0x23 can be found on each > die. Perf can retrieve the information of all available uncore PerfMons > from the device via MMIO. The information is composed of one global > discovery table and several unit discovery tables.
> If a BIOS doesn't support the 'discovery' mechanism, there is nothing > changed. What if the BIOS got it wrong? Will the driver still get it correct if it is a known platform? Do we need a chicken flag to kill the discovery? uncore_no_discover?
