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authorJoerg Roedel <jroedel@suse.de>2017-10-06 15:00:53 +0200
committerJoerg Roedel <jroedel@suse.de>2017-10-06 15:09:30 +0200
commitec154bf56b276a0bb36079a5d22a267b5f417801 (patch)
tree42d05fab0d9473435a887dba7589f1659863af9c
parent9e66317d3c92ddaab330c125dfe9d06eee268aff (diff)
iommu/vt-d: Don't register bus-notifier under dmar_global_lock
The notifier function will take the dmar_global_lock too, so lockdep complains about inverse locking order when the notifier is registered under the dmar_global_lock. Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Fixes: 59ce0515cdaf ('iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens') Signed-off-by: Joerg Roedel <jroedel@suse.de>
-rw-r--r--drivers/iommu/dmar.c7
-rw-r--r--drivers/iommu/intel-iommu.c10
-rw-r--r--include/linux/dmar.h1
3 files changed, 16 insertions, 2 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 57c920c1372d..1ea7cd537873 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -801,13 +801,16 @@ int __init dmar_dev_scope_init(void)
dmar_free_pci_notify_info(info);
}
}
-
- bus_register_notifier(&pci_bus_type, &dmar_pci_bus_nb);
}
return dmar_dev_scope_status;
}
+void dmar_register_bus_notifier(void)
+{
+ bus_register_notifier(&pci_bus_type, &dmar_pci_bus_nb);
+}
+
int __init dmar_table_init(void)
{
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 6784a05dd6b2..934cef924461 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4752,6 +4752,16 @@ int __init intel_iommu_init(void)
goto out_free_dmar;
}
+ up_write(&dmar_global_lock);
+
+ /*
+ * The bus notifier takes the dmar_global_lock, so lockdep will
+ * complain later when we register it under the lock.
+ */
+ dmar_register_bus_notifier();
+
+ down_write(&dmar_global_lock);
+
if (no_iommu || dmar_disabled) {
/*
* We exit the function here to ensure IOMMU's remapping and
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index e8ffba1052d3..e2433bc50210 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -112,6 +112,7 @@ static inline bool dmar_rcu_check(void)
extern int dmar_table_init(void);
extern int dmar_dev_scope_init(void);
+extern void dmar_register_bus_notifier(void);
extern int dmar_parse_dev_scope(void *start, void *end, int *cnt,
struct dmar_dev_scope **devices, u16 segment);
extern void *dmar_alloc_dev_scope(void *start, void *end, int *cnt);