tree 4ac6b0dc7c6a6f27b42498febee166bbcb280a9d
parent 9f2f681982b15b053dd214a10127b542728e8135
author Eric Auger <eric.auger@redhat.com> 1687205039 +0200
committer Andrew Jones <andrew.jones@linux.dev> 1688211624 +0200

arm: pmu: Fix chain counter enable/disable sequences

In some ARM ARM ddi0487 revisions it is said that
disabling/enabling a pair of counters that are paired
by a CHAIN event should follow a given sequence:

Enable the high counter first, isb, enable low counter
Disable the low counter first, isb, disable the high counter

This was the case in Fc. However this is not written anymore
in subsequent revions such as Ia.

Anyway, just in case, and because it also makes the code a
little bit simpler, introduce 2 helpers to enable/disable chain
counters that execute those sequences and replace the existing
PMCNTENCLR/ENSET calls (at least this cannot do any harm).

Also fix 2 write_sysreg_s(0x0, PMCNTENSET_EL0) in subtest 5 & 6
and replace them by PMCNTENCLR writes since writing 0 in
PMCNTENSET_EL0 has no effect. While at it, aslo removes a useless
pmevtyper setting in test_chained_sw_incr() since the type of the
counter is not reset by pmu_reset()

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Andrew Jones <andrew.jones@linux.dev>