coresight: etm-pmu: Ensure the AUX handle is valid

mainline inclusion
from mainline-v5.15-rc3
commit 2ef43054
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5YCYK
CVE: NA

Reference: https://lore.kernel.org/r/20210914102641.1852544-4-suzuki.poulose@arm.com



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The ETM perf infrastructure closes out a handle during event_stop
or on an error in starting the event. In either case, it is possible
for a "sink" to update/close the handle, under certain circumstances.
(e.g no space in ring buffer.). So, ensure that we handle this
gracefully in the PMU driver by verifying the handle is still valid.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210914102641.1852544-4-suzuki.poulose@arm.com


Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>