[PATCH V2] arm64/perf: Replace '0xf' instances with ID_AA64DFR0_PMUVER_IMP_DEF

From: Anshuman Khandual
Date: Tue Aug 10 2021 - 23:26:38 EST


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@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: linux-perf-users@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
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@xxxxxxx/

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