[RFT 1/2] Revert "iommu/vt-d: Fix suspicious RCU usage"

[Luca Coelho]

This reverts commit b150654f74bf0df8e6a7936d5ec51400d9ec06d8.

Signed-off-by: Luca Coelho <luciano.coelho at intel.com>
---
 drivers/iommu/intel/dmar.c  | 1 -
 drivers/iommu/intel/iommu.c | 7 -------
 2 files changed, 8 deletions(-)

diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index e540092d664d..9f424acf474e 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -2043,7 +2043,6 @@ int enable_drhd_fault_handling(unsigned int cpu)
 	/*
 	 * Enable fault control interrupt.
 	 */
-	guard(rwsem_read)(&dmar_global_lock);
 	for_each_iommu(iommu, drhd) {
 		u32 fault_status;
 		int ret;
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index bf1f0c814348..4d8d4593c9c8 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3146,14 +3146,7 @@ int __init intel_iommu_init(void)
 		iommu_device_sysfs_add(&iommu->iommu, NULL,
 				       intel_iommu_groups,
 				       "%s", iommu->name);
-		/*
-		 * The iommu device probe is protected by the iommu_probe_device_lock.
-		 * Release the dmar_global_lock before entering the device probe path
-		 * to avoid unnecessary lock order splat.
-		 */
-		up_read(&dmar_global_lock);
 		iommu_device_register(&iommu->iommu, &intel_iommu_ops, NULL);
-		down_read(&dmar_global_lock);
 
 		iommu_pmu_register(iommu);
 	}
-- 
2.47.2