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[ Upstream commit8f5d41f3a0] There are some updates for the Icelake model specific uncore performance monitors. (The update can be found at 10th generation intel core processors families specification update Revision 004, ICL068) 1) Counter 0 of ARB uncore unit is not available for software use 2) The global 'enable bit' (bit 29) and 'freeze bit' (bit 31) of MSR_UNC_PERF_GLOBAL_CTRL cannot be used to control counter behavior. Needs to use local enable in event select MSR. Accessing the modified bit/registers will be ignored by HW. Users may observe inaccurate results with the current code. The changes of the MSR_UNC_PERF_GLOBAL_CTRL imply that groups cannot be read atomically anymore. Although the error of the result for a group becomes a bit bigger, it still far lower than not using a group. The group support is still kept. Only Remove the *_box() related implementation. Since the counter 0 of ARB uncore unit is not available, update the MSR address for the ARB uncore unit. There is no change for IMC uncore unit, which only include free-running counters. Fixes:6e394376ee("perf/x86/intel/uncore: Add Intel Icelake uncore support") Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200925134905.8839-2-kan.liang@linux.intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.