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From:   Nicolin Chen <nicolinc@nvidia.com>
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Subject: [PATCH v2 07/10] iommufd/device: Make hwpt_list list_add/del symmetric
Date:   Tue, 7 Feb 2023 13:17:59 -0800
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Because list_del() is together with iopt_table_remove_domain(), it makes
sense to have list_add_tail() together with iopt_table_add_domain().

Also place the mutex outside the iommufd_device_do_attach() call, similar
to what's in the iommufd_device_auto_get_domain() function.

Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/iommufd/device.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 10ce47484ffa..b8c3e3baccb5 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -200,6 +200,8 @@ static int iommufd_device_do_attach(struct iommufd_device *idev,
 	phys_addr_t sw_msi_start = PHYS_ADDR_MAX;
 	int rc;
 
+	lockdep_assert_held(&hwpt->ioas->mutex);
+
 	mutex_lock(&hwpt->devices_lock);
 
 	/*
@@ -243,6 +245,7 @@ static int iommufd_device_do_attach(struct iommufd_device *idev,
 						   hwpt->domain);
 			if (rc)
 				goto out_detach;
+			list_add_tail(&hwpt->hwpt_item, &hwpt->ioas->hwpt_list);
 		}
 	}
 
@@ -304,7 +307,6 @@ static int iommufd_device_auto_get_domain(struct iommufd_device *idev,
 	rc = iommufd_device_do_attach(idev, hwpt);
 	if (rc)
 		goto out_abort;
-	list_add_tail(&hwpt->hwpt_item, &ioas->hwpt_list);
 
 	mutex_unlock(&ioas->mutex);
 	iommufd_object_finalize(idev->ictx, &hwpt->obj);
@@ -343,13 +345,11 @@ int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id)
 		struct iommufd_hw_pagetable *hwpt =
 			container_of(pt_obj, struct iommufd_hw_pagetable, obj);
 
+		mutex_lock(&hwpt->ioas->mutex);
 		rc = iommufd_device_do_attach(idev, hwpt);
+		mutex_unlock(&hwpt->ioas->mutex);
 		if (rc)
 			goto out_put_pt_obj;
-
-		mutex_lock(&hwpt->ioas->mutex);
-		list_add_tail(&hwpt->hwpt_item, &hwpt->ioas->hwpt_list);
-		mutex_unlock(&hwpt->ioas->mutex);
 		break;
 	}
 	case IOMMUFD_OBJ_IOAS: {
-- 
2.39.1