perf/x86/amd: Constrain Large Increment per Cycle events

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[ Upstream commit 471af006a7 ]

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 e40ed1542d ("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: e40ed1542d ("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
Signed-off-by: Sasha Levin <sashal@kernel.org>

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This commit is contained in:

Kim Phillips 2019-11-14 12:37:19 -06:00 • committed by Greg Kroah-Hartman

parent 330a4a7e2b

commit 3512462036

2 changed files with 63 additions and 30 deletions

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arch/x86/events/amd/core.c

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2

arch/x86/events/perf_event.h

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