linux-kernel - [PATCH V2] arm64/perf: Replace '0xf' instances with ID_AA64DFR0_PMUVER_IMP

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Date:   Wed, 11 Aug 2021 08:57:07 +0530
From:   Anshuman Khandual <anshuman.khandual@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     Anshuman Khandual <anshuman.khandual@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Peter Zijlstra <peterz@...radead.org>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH V2] arm64/perf: Replace '0xf' instances with ID_AA64DFR0_PMUVER_IMP_DEF

ID_AA64DFR0_PMUVER_IMP_DEF which indicate implementation defined PMU, never
actually gets used although there are '0xf' instances scattered all around.
Just do the macro replacement to improve readability.

Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will@...nel.org>
Cc: Mark Rutland <mark.rutland@....com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: linux-perf-users@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
---
This applies on v5.14-rc5

Changes in V2:

- Split out the arm64 part

Changes in V1:

https://lore.kernel.org/linux-perf-users/1628571998-13634-1-git-send-email-anshuman.khandual@arm.com/

 arch/arm64/include/asm/cpufeature.h | 2 +-
 arch/arm64/kernel/perf_event.c      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 9bb9d11750d7..54474e76ad86 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -552,7 +552,7 @@ cpuid_feature_cap_perfmon_field(u64 features, int field, u64 cap)
 	u64 mask = GENMASK_ULL(field + 3, field);
 
 	/* Treat IMPLEMENTATION DEFINED functionality as unimplemented */
-	if (val == 0xf)
+	if (val == ID_AA64DFR0_PMUVER_IMP_DEF)
 		val = 0;
 
 	if (val > cap) {
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index d07788dad388..b4044469527e 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -1055,7 +1055,7 @@ static void __armv8pmu_probe_pmu(void *info)
 	dfr0 = read_sysreg(id_aa64dfr0_el1);
 	pmuver = cpuid_feature_extract_unsigned_field(dfr0,
 			ID_AA64DFR0_PMUVER_SHIFT);
-	if (pmuver == 0xf || pmuver == 0)
+	if (pmuver == ID_AA64DFR0_PMUVER_IMP_DEF || pmuver == 0)
 		return;
 
 	cpu_pmu->pmuver = pmuver;
-- 
2.20.1