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From:   Florian Fainelli <f.fainelli@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     Florian Fainelli <f.fainelli@gmail.com>,
        Ray Jui <rjui@broadcom.com>,
        Scott Branden <sbranden@broadcom.com>,
        bcm-kernel-feedback-list@broadcom.com (maintainer:BROADCOM
        BCM281XX/BCM11XXX/BCM216XX ARM ARCHITE...),
        Russell King <linux@armlinux.org.uk>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        linux-arm-kernel@lists.infradead.org (moderated list:ARM
        SUB-ARCHITECTURES), linux-mips@vger.kernel.org (open list:MIPS),
        devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED
        DEVICE TREE)
Subject: [PATCH v3 05/14] irqchip/irq-bcm7038-l1: Restrict affinity setting to MIPS
Date:   Tue, 28 Sep 2021 11:21:30 -0700
Message-Id: <20210928182139.652896-6-f.fainelli@gmail.com>
In-Reply-To: <20210928182139.652896-1-f.fainelli@gmail.com>
References: <20210928182139.652896-1-f.fainelli@gmail.com>
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Only MIPS based platforms using this interrupt controller as first level
interrupt controller can actually change the affinity of interrupts by
re-programming the affinity mask of the interrupt controller and use
another word group to have another CPU process the interrupt.

When this interrupt is used as a second level interrupt controller on
ARM/ARM64 there is no way to change the interrupt affinity. This fixes a
NULL pointer de-reference while trying to change the affinity since
there is only a single word group in that case, and we would have been
overruning the intc->cpus[] array.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/irqchip/irq-bcm7038-l1.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/irqchip/irq-bcm7038-l1.c b/drivers/irqchip/irq-bcm7038-l1.c
index 3c4e348c661e..357570dd8780 100644
--- a/drivers/irqchip/irq-bcm7038-l1.c
+++ b/drivers/irqchip/irq-bcm7038-l1.c
@@ -191,6 +191,7 @@ static void bcm7038_l1_mask(struct irq_data *d)
 	raw_spin_unlock_irqrestore(&intc->lock, flags);
 }
 
+#if defined(CONFIG_MIPS) && defined(CONFIG_SMP)
 static int bcm7038_l1_set_affinity(struct irq_data *d,
 				   const struct cpumask *dest,
 				   bool force)
@@ -217,6 +218,7 @@ static int bcm7038_l1_set_affinity(struct irq_data *d,
 
 	return 0;
 }
+#endif
 
 static int __init bcm7038_l1_init_one(struct device_node *dn,
 				      unsigned int idx,
@@ -365,7 +367,9 @@ static struct irq_chip bcm7038_l1_irq_chip = {
 	.name			= "bcm7038-l1",
 	.irq_mask		= bcm7038_l1_mask,
 	.irq_unmask		= bcm7038_l1_unmask,
+#if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
 	.irq_set_affinity	= bcm7038_l1_set_affinity,
+#endif
 #ifdef CONFIG_PM_SLEEP
 	.irq_set_wake		= bcm7038_l1_set_wake,
 #endif
-- 
2.25.1