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perf/x86/amd: Constrain Large Increment per Cycle events
AMD Family 17h processors and above gain support for Large Increment per Cycle events. Unfortunately there is no CPUID or equivalent bit that indicates whether the feature exists or not, so we continue to determine eligibility based on a CPU family number comparison. For Large Increment per Cycle events, we add a f17h-and-compatibles get_event_constraints_f17h() that returns an even counter bitmask: Large Increment per Cycle events can only be placed on PMCs 0, 2, and 4 out of the currently available 0-5. The only currently public event that requires this feature to report valid counts is PMCx003 "Retired SSE/AVX Operations". Note that the CPU family logic in amd_core_pmu_init() is changed so as to be able to selectively add initialization for features available in ranges of backward-compatible CPU families. This Large Increment per Cycle feature is expected to be retained in future families. A side-effect of assigning a new get_constraints function for f17h disables calling the old (prior to f15h) amd_get_event_constraints implementation left enabled by commit e40ed15 ("perf/x86: Add perf support for AMD family-17h processors"), which is no longer necessary since those North Bridge event codes are obsoleted. Also fix a spelling mistake whilst in the area (calulating -> calculating). Fixes: e40ed15 ("perf/x86: Add perf support for AMD family-17h processors") Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191114183720.19887-2-kim.phillips@amd.com
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Kim Phillips
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Peter Zijlstra
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Jan 17, 2020
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