From 91f528f6700090e3936061564fe03ee2eb0a8127 Mon Sep 17 00:00:00 2001
From: John Keeping <john@metanate.com>
Date: Wed, 6 Sep 2017 10:35:40 +0100
Subject: [PATCH 04/10] genirq/msi: Fix populating multiple interrupts

References: bsc#1070194
Patch-mainline: v4.14-rc1
Git-commit: 596a7a1d0989c621c3ae49be73a1d1f9de22eb5a

On allocating the interrupts routed via a wire-to-MSI bridge, the allocator
iterates over the MSI descriptors to build the hierarchy, but fails to use
the descriptor interrupt number, and instead uses the base number,
generating the wrong IRQ domain mappings.

The fix is to use the MSI descriptor interrupt number when setting up
the interrupt instead of the base interrupt for the allocation range.

The only saving grace is that although the MSI descriptors are allocated
in bulk, the wired interrupts are only allocated one by one (so
desc->irq == virq) and the bug went unnoticed so far.

Fixes: 2145ac9310b60 ("genirq/msi: Add msi_domain_populate_irqs")
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170906103540.373864a2.john@metanate.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 kernel/irq/msi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index ddc2f5427f75..506a23c58443 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -308,11 +308,12 @@ int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
 
 		ops->set_desc(arg, desc);
 		/* Assumes the domain mutex is held! */
-		ret = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg);
+		ret = irq_domain_alloc_irqs_hierarchy(domain, desc->irq, 1,
+						      arg);
 		if (ret)
 			break;
 
-		irq_set_msi_desc_off(virq, 0, desc);
+		irq_set_msi_desc_off(desc->irq, 0, desc);
 	}
 
 	if (ret) {
-- 
2.13.6