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

From: Anshuman Khandual
Date: Tue Aug 10 2021 - 01:06:06 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: Marc Zyngier <maz@xxxxxxxxxx>
Cc: linux-perf-users@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
This applies on v5.14-rc5

arch/arm64/include/asm/cpufeature.h | 2 +-
arch/arm64/kernel/perf_event.c | 2 +-
arch/arm64/kvm/perf.c | 2 +-
arch/arm64/kvm/pmu-emul.c | 6 +++---
4 files changed, 6 insertions(+), 6 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;
diff --git a/arch/arm64/kvm/perf.c b/arch/arm64/kvm/perf.c
index 151c31fb9860..f9bb3b14130e 100644
--- a/arch/arm64/kvm/perf.c
+++ b/arch/arm64/kvm/perf.c
@@ -50,7 +50,7 @@ static struct perf_guest_info_callbacks kvm_guest_cbs = {

int kvm_perf_init(void)
{
- if (kvm_pmu_probe_pmuver() != 0xf && !is_protected_kvm_enabled())
+ if (kvm_pmu_probe_pmuver() != ID_AA64DFR0_PMUVER_IMP_DEF && !is_protected_kvm_enabled())
static_branch_enable(&kvm_arm_pmu_available);

return perf_register_guest_info_callbacks(&kvm_guest_cbs);
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index f33825c995cb..60f89bdbeebb 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -745,7 +745,7 @@ int kvm_pmu_probe_pmuver(void)
struct perf_event_attr attr = { };
struct perf_event *event;
struct arm_pmu *pmu;
- int pmuver = 0xf;
+ int pmuver = ID_AA64DFR0_PMUVER_IMP_DEF;

/*
* Create a dummy event that only counts user cycles. As we'll never
@@ -770,7 +770,7 @@ int kvm_pmu_probe_pmuver(void)
if (IS_ERR(event)) {
pr_err_once("kvm: pmu event creation failed %ld\n",
PTR_ERR(event));
- return 0xf;
+ return ID_AA64DFR0_PMUVER_IMP_DEF;
}

if (event->pmu) {
@@ -923,7 +923,7 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
if (!vcpu->kvm->arch.pmuver)
vcpu->kvm->arch.pmuver = kvm_pmu_probe_pmuver();

- if (vcpu->kvm->arch.pmuver == 0xf)
+ if (vcpu->kvm->arch.pmuver == ID_AA64DFR0_PMUVER_IMP_DEF)
return -ENODEV;

switch (attr->attr) {
--
2.20.1