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From: Paul Burton <paul.burton@imgtec.com>
To: Thomas Gleixner <tglx@linutronix.de>, Ralf Baechle <ralf@linux-mips.org>
Cc: <dianders@chromium.org>, James Hogan <james.hogan@imgtec.com>,
	Brian Norris <briannorris@chromium.org>,
	Jason Cooper <jason@lakedaemon.net>, <jeffy.chen@rock-chips.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	<linux-kernel@vger.kernel.org>, <linux-mips@linux-mips.org>,
	<tfiga@chromium.org>, Paul Burton <paul.burton@imgtec.com>
Subject: [RFC PATCH v1 6/9] MIPS: perf: percpu_devid interrupt support
Date: Thu, 7 Sep 2017 16:25:39 -0700
Message-ID: <20170907232542.20589-7-paul.burton@imgtec.com> (raw)
In-Reply-To: <20170907232542.20589-1-paul.burton@imgtec.com>

The MIPS CPU performance counter overflow interrupt is really a percpu
interrupt, but up until now we have not used the percpu interrupt APIs
to configure & control it. In preparation for doing so, introduce
support for percpu_devid interrupts in the MIPS perf implementation.

We switch from using request_irq() to using either setup_irq() or
setup_percpu_irq() with an explicit struct irqaction such that we can
set the flags, handler & name for that struct irqaction once rather than
needing to duplicate them in calls to request_irq() and
request_percpu_irq().

The IRQF_NOAUTOEN flag is passed because percpu interrupts
automatically get IRQ_NOAUTOEN set by irq_set_percpu_devid_flags(). We
opt into accepting this behaviour & explicitly enable the interrupt in
mipspmu_enable() right after configuring the local performance counters.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
---

 arch/mips/kernel/perf_event_mipsxx.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/arch/mips/kernel/perf_event_mipsxx.c b/arch/mips/kernel/perf_event_mipsxx.c
index cae36ca400e9..af7bae79dc51 100644
--- a/arch/mips/kernel/perf_event_mipsxx.c
+++ b/arch/mips/kernel/perf_event_mipsxx.c
@@ -514,6 +514,11 @@ static void mipspmu_enable(struct pmu *pmu)
 	write_unlock(&pmuint_rwlock);
 #endif
 	resume_local_counters();
+
+	if (irq_is_percpu_devid(mipspmu.irq))
+		enable_percpu_irq(mipspmu.irq, IRQ_TYPE_NONE);
+	else
+		enable_irq(mipspmu.irq);
 }
 
 /*
@@ -538,24 +543,27 @@ static void mipspmu_disable(struct pmu *pmu)
 static atomic_t active_events = ATOMIC_INIT(0);
 static DEFINE_MUTEX(pmu_reserve_mutex);
 
+static struct irqaction c0_perf_irqaction = {
+	.handler = mipsxx_pmu_handle_irq,
+	.flags = IRQF_PERCPU | IRQF_TIMER | IRQF_SHARED | IRQF_NOAUTOEN,
+	.name = "mips_perf_pmu",
+	.percpu_dev_id = &mipspmu,
+};
+
 static int mipspmu_get_irq(void)
 {
-	int err;
+	if (irq_is_percpu_devid(mipspmu.irq))
+		return setup_percpu_irq(mipspmu.irq, &c0_perf_irqaction);
 
-	err = request_irq(mipspmu.irq, mipsxx_pmu_handle_irq,
-			  IRQF_PERCPU | IRQF_NOBALANCING |
-			  IRQF_NO_THREAD | IRQF_NO_SUSPEND |
-			  IRQF_SHARED,
-			  "mips_perf_pmu", &mipspmu);
-	if (err)
-		pr_warn("Unable to request IRQ%d for MIPS performance counters!\n",
-			mipspmu.irq);
-	return err;
+	return setup_irq(mipspmu.irq, &c0_perf_irqaction);
 }
 
 static void mipspmu_free_irq(void)
 {
-	free_irq(mipspmu.irq, &mipspmu);
+	if (irq_is_percpu_devid(mipspmu.irq))
+		remove_percpu_irq(mipspmu.irq, &c0_perf_irqaction);
+	else
+		remove_irq(mipspmu.irq, &c0_perf_irqaction);
 }
 
 /*
-- 
2.14.1

  parent reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1682867.tATABVWsV9@np-p-burton>
2017-09-07 23:25 ` [RFC PATCH v1 0/9] Support shared percpu interrupts; clean up MIPS hacks Paul Burton
2017-09-07 23:25   ` [RFC PATCH v1 1/9] genirq: Allow shared interrupt users to opt into IRQ_NOAUTOEN Paul Burton
2017-09-07 23:25   ` [RFC PATCH v1 2/9] genirq: Support shared per_cpu_devid interrupts Paul Burton
2017-09-25 21:06     ` Thomas Gleixner
2017-09-26 12:00       ` Thomas Gleixner
2017-10-19 14:08         ` Thomas Gleixner
2017-09-07 23:25   ` [RFC PATCH v1 3/9] genirq: Introduce irq_is_percpu_devid() Paul Burton
2017-09-07 23:25   ` [RFC PATCH v1 4/9] MIPS: Remove perf_irq interrupt sharing fallback Paul Burton
2017-09-07 23:25   ` [RFC PATCH v1 5/9] MIPS: Remove perf_irq Paul Burton
2017-09-07 23:25   ` Paul Burton [this message]
2017-10-19 14:12     ` [RFC PATCH v1 6/9] MIPS: perf: percpu_devid interrupt support Thomas Gleixner
2017-09-07 23:25   ` [RFC PATCH v1 7/9] MIPS: cevt-r4k: " Paul Burton
2017-09-07 23:25   ` [RFC PATCH v1 8/9] irqchip: mips-cpu: Set timer, FDC & perf interrupts percpu_devid Paul Burton
2017-09-07 23:25   ` [RFC PATCH v1 9/9] irqchip: mips-gic: Remove gic_all_vpes_local_irq_controller Paul Burton

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