From 371256882c2289c187fee3e7772758e8a54b9a21 Mon Sep 17 00:00:00 2001 From: Julien Thierry Date: Wed, 20 Mar 2019 14:35:22 +0800 Subject: [PATCH] arm_pmu: Use NMIs for PMU hulk inclusion category: feature bugzilla: 12804 CVE: NA ------------------------------------------------- Add required PMU interrupt operations for NMIs. Request interrupt lines as NMIs when possible, otherwise fall back to normal interrupts. Signed-off-by: Julien Thierry Signed-off-by: Wei Li Signed-off-by: Yang Yingliang --- 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 14293cdcda7e..0b2292aba18b 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -44,6 +44,17 @@ 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); @@ -62,6 +73,31 @@ 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); @@ -640,15 +676,29 @@ 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); -- GitLab