From: Zhen Lei <thunder.leizhen@huawei.com>
Date: Thu, 20 Sep 2018 17:10:21 +0100
Subject: iommu/arm-smmu-v3: Implement flush_iotlb_all hook
Git-commit: 07fdef34d2be6811f00c6f9e4e2a1483cf86696c
Patch-mainline: v4.20-rc1
References: fate#326252

.flush_iotlb_all is currently stubbed to arm_smmu_iotlb_sync() since the
only time it would ever need to actually do anything is for callers
doing their own explicit batching, e.g.:

	iommu_unmap_fast(domain, ...);
	iommu_unmap_fast(domain, ...);
	iommu_iotlb_flush_all(domain, ...);

where since io-pgtable still issues the TLBI commands implicitly in the
unmap instead of implementing .iotlb_range_add, the "flush" only needs
to ensure completion of those already-in-flight invalidations.

However, we're about to start using it in anger with flush queues, so
let's get a proper implementation wired up.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
[rm: document why it wasn't a bug]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
 drivers/iommu/arm-smmu-v3.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1845,6 +1845,14 @@ arm_smmu_unmap(struct iommu_domain *doma
 	return ops->unmap(ops, iova, size);
 }
 
+static void arm_smmu_flush_iotlb_all(struct iommu_domain *domain)
+{
+	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+
+	if (smmu_domain->smmu)
+		arm_smmu_tlb_inv_context(smmu_domain);
+}
+
 static void arm_smmu_iotlb_sync(struct iommu_domain *domain)
 {
 	struct arm_smmu_device *smmu = to_smmu_domain(domain)->smmu;
@@ -2073,7 +2081,7 @@ static struct iommu_ops arm_smmu_ops = {
 	.map			= arm_smmu_map,
 	.unmap			= arm_smmu_unmap,
 	.map_sg			= default_iommu_map_sg,
-	.flush_iotlb_all	= arm_smmu_iotlb_sync,
+	.flush_iotlb_all	= arm_smmu_flush_iotlb_all,
 	.iotlb_sync		= arm_smmu_iotlb_sync,
 	.iova_to_phys		= arm_smmu_iova_to_phys,
 	.add_device		= arm_smmu_add_device,