Commit cc91b948 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Will Deacon
Browse files

arm64/perf: Replace PMU version number '0' with ID_AA64DFR0_EL1_PMUVer_NI 



__armv8pmu_probe_pmu() returns if detected PMU is either not implemented or
implementation defined. Extracted ID_AA64DFR0_EL1_PMUVer value, when PMU is
not implemented is '0' which can be replaced with ID_AA64DFR0_EL1_PMUVer_NI
defined as '0b0000'.

Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-perf-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20221128025449.39085-1-anshuman.khandual@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent ce00d127

arch/arm64/kernel/perf_event.c

+2 −1
Original line number Diff line number Diff line
@@ -1146,7 +1146,8 @@ static void __armv8pmu_probe_pmu(void *info) 
	dfr0 = read_sysreg(id_aa64dfr0_el1);

	pmuver = cpuid_feature_extract_unsigned_field(dfr0,

			ID_AA64DFR0_EL1_PMUVer_SHIFT);

	if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF || pmuver == 0)

	if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF ||

	    pmuver == ID_AA64DFR0_EL1_PMUVer_NI)

		return;



	cpu_pmu->pmuver = pmuver;