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[ Upstream commit 1a3f2fd7fc ]
Lock(&iommu->lock) without disabling irq causes lockdep warnings.
[ 12.703950] ========================================================
[ 12.703962] WARNING: possible irq lock inversion dependency detected
[ 12.703975] 5.9.0-rc6+ #659 Not tainted
[ 12.703983] --------------------------------------------------------
[ 12.703995] systemd-udevd/284 just changed the state of lock:
[ 12.704007] ffffffffbd6ff4d8 (device_domain_lock){..-.}-{2:2}, at:
iommu_flush_dev_iotlb.part.57+0x2e/0x90
[ 12.704031] but this lock took another, SOFTIRQ-unsafe lock in the past:
[ 12.704043] (&iommu->lock){+.+.}-{2:2}
[ 12.704045]
and interrupts could create inverse lock ordering between
them.
[ 12.704073]
other info that might help us debug this:
[ 12.704085] Possible interrupt unsafe locking scenario:
[ 12.704097] CPU0 CPU1
[ 12.704106] ---- ----
[ 12.704115] lock(&iommu->lock);
[ 12.704123] local_irq_disable();
[ 12.704134] lock(device_domain_lock);
[ 12.704146] lock(&iommu->lock);
[ 12.704158] <Interrupt>
[ 12.704164] lock(device_domain_lock);
[ 12.704174]
*** DEADLOCK ***
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200927062428.13713-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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