From: Alexandru Elisei <alexandru.elisei@arm.com>
To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: mark.rutland@arm.com, maz@kernel.org, will@kernel.org,
catalin.marinas@arm.com, swboyd@chromium.org,
sumit.garg@linaro.org, Julien Thierry <julien.thierry@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Will Deacon <will.deacon@arm.com>
Subject: [PATCH v6 7/7] arm_pmu: arm64: Use NMIs for PMU
Date: Wed, 19 Aug 2020 14:34:19 +0100 [thread overview]
Message-ID: <20200819133419.526889-8-alexandru.elisei@arm.com> (raw)
In-Reply-To: <20200819133419.526889-1-alexandru.elisei@arm.com>
From: Julien Thierry <julien.thierry@arm.com>
Add required PMU interrupt operations for NMIs. Request interrupt lines as
NMIs when possible, otherwise fall back to normal interrupts.
NMIs are only supported on the arm64 architecture with a GICv3 irqchip.
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
[Added that NMIs only work on arm64 + GICv3]
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
drivers/perf/arm_pmu.c | 62 ++++++++++++++++++++++++++++++++++++++----
1 file changed, 56 insertions(+), 6 deletions(-)
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 17e5952d21e4..dd9d7f61ee29 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -45,6 +45,17 @@ static const struct pmu_irq_ops pmuirq_ops = {
.free_pmuirq = armpmu_free_pmuirq
};
+static void armpmu_free_pmunmi(unsigned int irq, int cpu, void __percpu *devid)
+{
+ free_nmi(irq, per_cpu_ptr(devid, cpu));
+}
+
+static const struct pmu_irq_ops pmunmi_ops = {
+ .enable_pmuirq = enable_nmi,
+ .disable_pmuirq = disable_nmi_nosync,
+ .free_pmuirq = armpmu_free_pmunmi
+};
+
static void armpmu_enable_percpu_pmuirq(unsigned int irq)
{
enable_percpu_irq(irq, IRQ_TYPE_NONE);
@@ -63,6 +74,31 @@ static const struct pmu_irq_ops percpu_pmuirq_ops = {
.free_pmuirq = armpmu_free_percpu_pmuirq
};
+static void armpmu_enable_percpu_pmunmi(unsigned int irq)
+{
+ if (!prepare_percpu_nmi(irq))
+ enable_percpu_nmi(irq, IRQ_TYPE_NONE);
+}
+
+static void armpmu_disable_percpu_pmunmi(unsigned int irq)
+{
+ disable_percpu_nmi(irq);
+ teardown_percpu_nmi(irq);
+}
+
+static void armpmu_free_percpu_pmunmi(unsigned int irq, int cpu,
+ void __percpu *devid)
+{
+ if (armpmu_count_irq_users(irq) == 1)
+ free_percpu_nmi(irq, devid);
+}
+
+static const struct pmu_irq_ops percpu_pmunmi_ops = {
+ .enable_pmuirq = armpmu_enable_percpu_pmunmi,
+ .disable_pmuirq = armpmu_disable_percpu_pmunmi,
+ .free_pmuirq = armpmu_free_percpu_pmunmi
+};
+
static DEFINE_PER_CPU(struct arm_pmu *, cpu_armpmu);
static DEFINE_PER_CPU(int, cpu_irq);
static DEFINE_PER_CPU(const struct pmu_irq_ops *, cpu_irq_ops);
@@ -633,15 +669,29 @@ int armpmu_request_irq(int irq, int cpu)
IRQF_NO_THREAD;
irq_set_status_flags(irq, IRQ_NOAUTOEN);
- err = request_irq(irq, handler, irq_flags, "arm-pmu",
+
+ err = request_nmi(irq, handler, irq_flags, "arm-pmu",
per_cpu_ptr(&cpu_armpmu, cpu));
- irq_ops = &pmuirq_ops;
+ /* If cannot get an NMI, get a normal interrupt */
+ if (err) {
+ err = request_irq(irq, handler, irq_flags, "arm-pmu",
+ per_cpu_ptr(&cpu_armpmu, cpu));
+ irq_ops = &pmuirq_ops;
+ } else {
+ irq_ops = &pmunmi_ops;
+ }
} else if (armpmu_count_irq_users(irq) == 0) {
- err = request_percpu_irq(irq, handler, "arm-pmu",
- &cpu_armpmu);
-
- irq_ops = &percpu_pmuirq_ops;
+ err = request_percpu_nmi(irq, handler, "arm-pmu", &cpu_armpmu);
+
+ /* If cannot get an NMI, get a normal interrupt */
+ if (err) {
+ err = request_percpu_irq(irq, handler, "arm-pmu",
+ &cpu_armpmu);
+ irq_ops = &percpu_pmuirq_ops;
+ } else {
+ irq_ops = &percpu_pmunmi_ops;
+ }
} else {
/* Per cpudevid irq was already requested by another CPU */
irq_ops = armpmu_find_irq_ops(irq);
--
2.28.0
next prev parent reply other threads:[~2020-08-19 13:35 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-19 13:34 [PATCH v6 0/7] arm_pmu: Use NMI for perf interrupt Alexandru Elisei
2020-08-19 13:34 ` [PATCH v6 1/7] arm64: perf: Add missing ISB in armv8pmu_enable_event() Alexandru Elisei
2020-08-19 13:34 ` [PATCH v6 2/7] arm64: perf: Avoid PMXEV* indirection Alexandru Elisei
2020-09-21 13:43 ` Will Deacon
2020-08-19 13:34 ` [PATCH v6 3/7] arm64: perf: Remove PMU locking Alexandru Elisei
2020-08-19 13:34 ` [PATCH v6 4/7] arm64: perf: Defer irq_work to IPI_IRQ_WORK Alexandru Elisei
2020-08-19 14:23 ` peterz
2020-08-19 13:34 ` [PATCH v6 5/7] KVM: arm64: pmu: Make overflow handler NMI safe Alexandru Elisei
2020-09-21 13:43 ` Will Deacon
2020-09-21 15:45 ` Alexandru Elisei
2020-08-19 13:34 ` [PATCH v6 6/7] arm_pmu: Introduce pmu_irq_ops Alexandru Elisei
2020-09-21 13:55 ` Will Deacon
2020-09-23 15:46 ` Alexandru Elisei
2020-08-19 13:34 ` Alexandru Elisei [this message]
2020-09-04 8:58 ` [PATCH v6 0/7] arm_pmu: Use NMI for perf interrupt Sumit Garg
2020-09-21 13:59 ` Will Deacon
2020-09-21 15:41 ` Alexandru Elisei
2020-09-21 17:53 ` Will Deacon
2020-09-22 16:30 ` Alexandru Elisei
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