From edf95a158cea2c5a8db8f4baf84d1f883412f74f Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 22 Mar 2018 16:22:36 +0100
Subject: [PATCH 010/518] iommu/amd: Split irq_lookup_table out of the
 amd_iommu_devtable_lock

Upstream commit ea6166f4b83e9cfba1c18f46a764d50045682fe5

The function get_irq_table() reads/writes irq_lookup_table while holding
the amd_iommu_devtable_lock. It also modifies
amd_iommu_dev_table[].data[2].
set_dte_entry() is using amd_iommu_dev_table[].data[0|1] (under the
domain->lock) so it should be okay. The access to the iommu is
serialized with its own (iommu's) lock.

So split out get_irq_table() out of amd_iommu_devtable_lock's lock.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/amd_iommu.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index c74172ee3772b..e197815b8cc59 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -83,6 +83,7 @@
 
 static DEFINE_RWLOCK(amd_iommu_devtable_lock);
 static DEFINE_SPINLOCK(pd_bitmap_lock);
+static DEFINE_SPINLOCK(iommu_table_lock);
 
 /* List of all available dev_data structures */
 static LLIST_HEAD(dev_data_list);
@@ -3668,7 +3669,7 @@ static struct irq_remap_table *alloc_irq_table(u16 devid, bool ioapic)
 	unsigned long flags;
 	u16 alias;
 
-	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+	spin_lock_irqsave(&iommu_table_lock, flags);
 
 	iommu = amd_iommu_rlookup_table[devid];
 	if (!iommu)
@@ -3733,7 +3734,7 @@ static struct irq_remap_table *alloc_irq_table(u16 devid, bool ioapic)
 	iommu_completion_wait(iommu);
 
 out_unlock:
-	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+	spin_unlock_irqrestore(&iommu_table_lock, flags);
 
 	return table;
 }
-- 
2.41.0

