[PATCH 4/5] iommu/amd: x2apic mode: mask/unmask interrupts on suspend/resume

From: Maxim Levitsky <mlevitsk@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: David Woodhouse <dwmw@amazon.co.uk>,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
	Joerg Roedel <joro@8bytes.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	iommu@lists.linux-foundation.org (open list:AMD IOMMU (AMD-VI)),
	Will Deacon <will@kernel.org>,
	Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH 4/5] iommu/amd: x2apic mode: mask/unmask interrupts on suspend/resume
Date: Tue, 23 Nov 2021 18:10:37 +0200	[thread overview]
Message-ID: <20211123161038.48009-5-mlevitsk@redhat.com> (raw)
In-Reply-To: <20211123161038.48009-1-mlevitsk@redhat.com>

Use IRQCHIP_MASK_ON_SUSPEND to make the core irq code to
mask the iommu interrupt on suspend and unmask it on the resume.

Since now the unmask function updates the INTX settings,
that will restore them on resume from s3/s4.

Since IRQCHIP_MASK_ON_SUSPEND is only effective for interrupts
which are not wakeup sources, remove IRQCHIP_SKIP_SET_WAKE flag
and instead implement a dummy .irq_set_wake which doesn't allow
the interrupt to become a wakeup source.

Fixes: 66929812955bb ("iommu/amd: Add support for X2APIC IOMMU interrupts")

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 drivers/iommu/amd/init.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 9e895bb8086a6..b94822fc2c9f7 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -2104,6 +2104,11 @@ static int intcapxt_set_affinity(struct irq_data *irqd,
 	return 0;
 }
 
+static int intcapxt_set_wake(struct irq_data *irqd, unsigned int on)
+{
+	return on ? -EOPNOTSUPP : 0;
+}
+
 static struct irq_chip intcapxt_controller = {
 	.name			= "IOMMU-MSI",
 	.irq_unmask		= intcapxt_unmask_irq,
@@ -2111,7 +2116,8 @@ static struct irq_chip intcapxt_controller = {
 	.irq_ack		= irq_chip_ack_parent,
 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
 	.irq_set_affinity       = intcapxt_set_affinity,
-	.flags			= IRQCHIP_SKIP_SET_WAKE,
+	.irq_set_wake		= intcapxt_set_wake,
+	.flags			= IRQCHIP_MASK_ON_SUSPEND,
 };
 
 static const struct irq_domain_ops intcapxt_domain_ops = {
-- 
2.26.3

