[PATCH v6 09/18] iommu/vt-d: Combine disable_dmar_iommu() and free_dmar_iommu()

[Samiullah Khawaja <skhawaja@google.com>]

Every caller of disable_dmar_iommu() immediately follows it with a call
to free_dmar_iommu(). Combine the two helpers into release_dmar_iommu()
and simplify the teardown and error paths in init_dmars(),
intel_iommu_add(), and dmar_iommu_hotplug().

Also drop the early return when
WARN_ON(!ida_is_empty(&iommu->domain_ida)) triggers so translation is
still disabled before freeing the IOMMU resources.

Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
---
 drivers/iommu/intel/iommu.c | 30 ++++++++++--------------------
 1 file changed, 10 insertions(+), 20 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 23a1da351ddf..35ec2ae0c8d5 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -985,21 +985,17 @@ static void iommu_disable_translation(struct intel_iommu *iommu)
 	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
 }
 
-static void disable_dmar_iommu(struct intel_iommu *iommu)
+static void release_dmar_iommu(struct intel_iommu *iommu)
 {
 	/*
 	 * All iommu domains must have been detached from the devices,
 	 * hence there should be no domain IDs in use.
 	 */
-	if (WARN_ON(!ida_is_empty(&iommu->domain_ida)))
-		return;
+	WARN_ON(!ida_is_empty(&iommu->domain_ida));
 
 	if (iommu->gcmd & DMA_GCMD_TE)
 		iommu_disable_translation(iommu);
-}
 
-static void free_dmar_iommu(struct intel_iommu *iommu)
-{
 	if (iommu->copied_tables) {
 		bitmap_free(iommu->copied_tables);
 		iommu->copied_tables = NULL;
@@ -1867,10 +1863,8 @@ static int __init init_dmars(void)
 	return 0;
 
 free_iommu:
-	for_each_active_iommu(iommu, drhd) {
-		disable_dmar_iommu(iommu);
-		free_dmar_iommu(iommu);
-	}
+	for_each_active_iommu(iommu, drhd)
+		release_dmar_iommu(iommu);
 
 	return ret;
 }
@@ -2280,12 +2274,12 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
 	if (ecap_prs(iommu->ecap)) {
 		ret = intel_iommu_enable_prq(iommu);
 		if (ret)
-			goto disable_iommu;
+			goto out;
 	}
 
 	ret = dmar_set_interrupt(iommu);
 	if (ret)
-		goto disable_iommu;
+		goto out;
 
 	iommu_set_root_entry(iommu);
 	iommu_enable_translation(iommu);
@@ -2293,10 +2287,8 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
 	iommu_disable_protect_mem_regions(iommu);
 	return 0;
 
-disable_iommu:
-	disable_dmar_iommu(iommu);
 out:
-	free_dmar_iommu(iommu);
+	release_dmar_iommu(iommu);
 	return ret;
 }
 
@@ -2310,12 +2302,10 @@ int dmar_iommu_hotplug(struct dmar_drhd_unit *dmaru, bool insert)
 	if (iommu == NULL)
 		return -EINVAL;
 
-	if (insert) {
+	if (insert)
 		ret = intel_iommu_add(dmaru);
-	} else {
-		disable_dmar_iommu(iommu);
-		free_dmar_iommu(iommu);
-	}
+	else
+		release_dmar_iommu(iommu);
 
 	return ret;
 }
-- 
2.56.0.257.gf7497c7d27-goog