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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>,
	Christoph Hellwig <hch@lst.de>, Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Jens Axboe <axboe@kernel.dk>, Keith Busch <keith.busch@intel.com>
Subject: [patch 50/55] genirq: Handle managed irqs gracefully in irq_startup()
Date: Tue, 20 Jun 2017 01:37:50 +0200
Message-ID: <20170619235447.189851170@linutronix.de> (raw)
In-Reply-To: <20170619233700.547167146@linutronix.de>


[-- Attachment #0: genirq--Handle-managed-irqs-gracefully-in-irq_startup--.patch --]
[-- Type: text/plain, Size: 3553 bytes --]

Affinity managed interrupts should keep their assigned affinity accross CPU
hotplug. To avoid magic hackery in device drivers, the core code shall
manage them transparently and set these interrupts into a managed shutdown
state when the last CPU of the assigned affinity mask goes offline. The
interrupt will be restarted when one of the CPUs in the assigned affinity
mask comes back online.

Add the necessary logic to irq_startup(). If an interrupt is requested and
started up, the code checks whether it is affinity managed and if so, it
checks whether a CPU in the interrupts affinity mask is online. If not, it
puts the interrupt into managed shutdown state. 

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 include/linux/irq.h |    2 -
 kernel/irq/chip.c   |   64 +++++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 62 insertions(+), 4 deletions(-)

--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -345,7 +345,7 @@ static inline bool irqd_is_started(struc
 	return __irqd_to_state(d) & IRQD_IRQ_STARTED;
 }
 
-static inline bool irqd_is_managed_shutdown(struct irq_data *d)
+static inline bool irqd_is_managed_and_shutdown(struct irq_data *d)
 {
 	return __irqd_to_state(d) & IRQD_MANAGED_SHUTDOWN;
 }
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -195,6 +195,52 @@ static void irq_state_set_started(struct
 	irqd_set(&desc->irq_data, IRQD_IRQ_STARTED);
 }
 
+enum {
+	IRQ_STARTUP_NORMAL,
+	IRQ_STARTUP_MANAGED,
+	IRQ_STARTUP_ABORT,
+};
+
+#ifdef CONFIG_SMP
+static int
+__irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
+{
+	struct irq_data *d = irq_desc_get_irq_data(desc);
+
+	if (!irqd_affinity_is_managed(d))
+		return IRQ_STARTUP_NORMAL;
+
+	irqd_clr_managed_shutdown(d);
+
+	if (cpumask_any_and(aff, cpu_online_mask) > nr_cpu_ids) {
+		/*
+		 * Catch code which fiddles with enable_irq() on a managed
+		 * and potentially shutdown IRQ. Chained interrupt
+		 * installment or irq auto probing should not happen on
+		 * managed irqs either. Emit a warning, break the affinity
+		 * and start it up as a normal interrupt.
+		 */
+		if (WARN_ON_ONCE(force))
+			return IRQ_STARTUP_NORMAL;
+		/*
+		 * The interrupt was requested, but there is no online CPU
+		 * in it's affinity mask. Put it into managed shutdown
+		 * state and let the cpu hotplug mechanism start it up once
+		 * a CPU in the mask becomes available.
+		 */
+		irqd_set_managed_shutdown(d);
+		return IRQ_STARTUP_ABORT;
+	}
+	return IRQ_STARTUP_MANAGED;
+}
+#else
+static int
+__irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
+{
+	return IRQ_STARTUP_NORMAL;
+}
+#endif
+
 static int __irq_startup(struct irq_desc *desc)
 {
 	struct irq_data *d = irq_desc_get_irq_data(desc);
@@ -214,15 +260,27 @@ static int __irq_startup(struct irq_desc
 
 int irq_startup(struct irq_desc *desc, bool resend, bool force)
 {
+	struct irq_data *d = irq_desc_get_irq_data(desc);
+	struct cpumask *aff = irq_data_get_affinity_mask(d);
 	int ret = 0;
 
 	desc->depth = 0;
 
-	if (irqd_is_started(&desc->irq_data)) {
+	if (irqd_is_started(d)) {
 		irq_enable(desc);
 	} else {
-		ret = __irq_startup(desc);
-		irq_setup_affinity(desc);
+		switch (__irq_startup_managed(desc, aff, force)) {
+		case IRQ_STARTUP_NORMAL:
+			ret = __irq_startup(desc);
+			irq_setup_affinity(desc);
+			break;
+		case IRQ_STARTUP_MANAGED:
+			ret = __irq_startup(desc);
+			irq_set_affinity_locked(d, aff, false);
+			break;
+		case IRQ_STARTUP_ABORT:
+			return 0;
+		}
 	}
 	if (resend)
 		check_irq_resend(desc);

  parent reply index

Thread overview: 122+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-19 23:37 [patch 00/55] genirq: Debuggability, consolidation and managed affinities Thomas Gleixner
2017-06-19 23:37 ` [patch 01/55] x86/apic: Add name to irq chip Thomas Gleixner
2017-06-22 16:40   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 02/55] iommu/amd: " Thomas Gleixner
2017-06-21 15:51   ` Joerg Roedel
2017-06-22 16:40   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 03/55] iommu/vt-d: " Thomas Gleixner
2017-06-21 15:51   ` Joerg Roedel
2017-06-22 16:41   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 04/55] genirq/msi: Prevent overwriting domain name Thomas Gleixner
2017-06-22 16:41   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 05/55] genirq: Allow fwnode to carry name information only Thomas Gleixner
2017-06-22 16:42   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 06/55] x86/vector: Create named irq domain Thomas Gleixner
2017-06-22 16:42   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 07/55] x86/ioapic: " Thomas Gleixner
2017-06-22 16:43   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 08/55] x86/htirq: Create named domain Thomas Gleixner
2017-06-22 16:44   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 09/55] x86/uv: Create named irq domain Thomas Gleixner
2017-06-22 16:44   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 10/55] x86/msi: Provide new iommu irqdomain interface Thomas Gleixner
2017-06-22 16:45   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 11/55] iommu/vt-d: Use named irq domain interface Thomas Gleixner
2017-06-21 15:52   ` Joerg Roedel
2017-06-22 16:45   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 12/55] iommu/amd: " Thomas Gleixner
2017-06-21 15:52   ` Joerg Roedel
2017-06-22 16:46   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 13/55] x86/msi: Remove unused remap " Thomas Gleixner
2017-06-22 16:46   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 14/55] x86/msi: Create named irq domains Thomas Gleixner
2017-06-22 16:47   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 15/55] PCI: vmd: Create named irq domain Thomas Gleixner
2017-06-20 20:07   ` Keith Busch
2017-06-20 20:07     ` Thomas Gleixner
2017-06-20 20:39       ` Thomas Gleixner
2017-06-22 16:47   ` [tip:irq/core] PCI/vmd: " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 16/55] genirq/irqdomain: Add map counter Thomas Gleixner
2017-06-22 16:48   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 17/55] genirq/debugfs: Add proper debugfs interface Thomas Gleixner
2017-06-22 16:49   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 18/55] genirq: Add missing comment for IRQD_STARTED Thomas Gleixner
2017-06-22 16:49   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 19/55] genirq: Provide irq_fixup_move_pending() Thomas Gleixner
2017-06-20  4:21   ` Dou Liyang
2017-06-20  6:58     ` Thomas Gleixner
2017-06-22 16:50   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 20/55] x86/irq: Cleanup pending irq move in fixup_irqs() Thomas Gleixner
2017-06-22 16:50   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 21/55] genirq: Remove mask argument from setup_affinity() Thomas Gleixner
2017-06-22 16:51   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 22/55] genirq: Rename setup_affinity() to irq_setup_affinity() Thomas Gleixner
2017-06-22 16:52   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 23/55] genirq: Move initial affinity setup to irq_startup() Thomas Gleixner
2017-06-22 16:52   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 24/55] genirq: Move pending helpers to internal.h Thomas Gleixner
2017-06-22 16:53   ` [tip:irq/core] " tip-bot for Christoph Hellwig
2017-06-19 23:37 ` [patch 25/55] genirq/cpuhotplug: Remove irq disabling logic Thomas Gleixner
2017-06-22 16:53   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 26/55] genirq/cpuhotplug: Dont claim success on error Thomas Gleixner
2017-06-22 16:54   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 27/55] genirq/cpuhotplug: Reorder check logic Thomas Gleixner
2017-06-22 16:54   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 28/55] genirq/cpuhotplug: Do not migrated shutdown irqs Thomas Gleixner
2017-06-22 16:55   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 29/55] genirq/cpuhotplug: Add support for cleaning up move in progress Thomas Gleixner
2017-06-22 16:56   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 30/55] genirq/cpuhotplug: Add support for conditional masking Thomas Gleixner
2017-06-22 16:56   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 31/55] genirq/cpuhotplug: Set force affinity flag on hotplug migration Thomas Gleixner
2017-06-22 16:57   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 32/55] x86/irq: Restructure fixup_irqs() Thomas Gleixner
2017-06-20 21:34   ` Keith Busch
2017-06-20 21:28     ` Thomas Gleixner
2017-06-22 16:57   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 33/55] x86/irq: Use irq_migrate_all_off_this_cpu() Thomas Gleixner
2017-06-22 16:58   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 34/55] genirq: Move irq_fixup_move_pending() to core Thomas Gleixner
2017-06-22 16:58   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 35/55] genirq: Remove pointless arg from show_irq_affinity Thomas Gleixner
2017-06-22 16:59   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 36/55] genirq: Remove pointless gfp argument Thomas Gleixner
2017-06-22 17:00   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 37/55] genirq/proc: Replace ever repeating type cast Thomas Gleixner
2017-06-22 17:00   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 38/55] genirq: Introduce effective affinity mask Thomas Gleixner
2017-06-22 17:01   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 39/55] genirq/cpuhotplug: Use " Thomas Gleixner
2017-06-22 17:01   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 40/55] x86/apic: Move flat_cpu_mask_to_apicid_and() into C source Thomas Gleixner
2017-06-22 17:02   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 41/55] x86/uv: Use default_cpu_mask_to_apicid_and() Thomas Gleixner
2017-06-22 17:03   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 42/55] x86/apic: Move online masking to core code Thomas Gleixner
2017-06-22 17:03   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 43/55] x86/apic: Move cpumask and " Thomas Gleixner
2017-06-22 17:04   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 44/55] x86/apic: Add irq_data argument to apic->cpu_mask_to_apicid() Thomas Gleixner
2017-06-22 17:04   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 45/55] xen/events: Add support for effective affinity mask Thomas Gleixner
2017-06-22 17:05   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 46/55] x86/apic: Implement effective irq mask update Thomas Gleixner
2017-06-22 17:05   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 47/55] genirq: Introduce IRQD_MANAGED_SHUTDOWN Thomas Gleixner
2017-06-22 17:06   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 48/55] genirq: Split out irq_startup() code Thomas Gleixner
2017-06-22 17:06   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 49/55] genirq: Add force argument to irq_startup() Thomas Gleixner
2017-06-22 17:07   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` Thomas Gleixner [this message]
2017-06-22 17:08   ` [tip:irq/core] genirq: Handle managed irqs gracefully in irq_startup() tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 51/55] genirq/cpuhotplug: Handle managed IRQs on CPU hotplug Thomas Gleixner
2017-06-22 17:08   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 52/55] genirq: Introduce IRQD_SINGLE_TARGET flag Thomas Gleixner
2017-06-22 17:09   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 53/55] genirq/cpuhotplug: Avoid irq affinity setting for single targets Thomas Gleixner
2017-06-22 17:09   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 54/55] x86/apic: Mark single target interrupts Thomas Gleixner
2017-06-22 17:10   ` [tip:irq/core] " tip-bot for Thomas Gleixner
2017-06-19 23:37 ` [patch 55/55] genirq/affinity: Assign vectors to all present CPUs Thomas Gleixner
2017-06-20  9:23 ` [patch 00/55] genirq: Debuggability, consolidation and managed affinities Christoph Hellwig

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