[PATCH v8 1/7] iommu/arm-smmu-v3: Implement flush_iotlb_all hook

From: Robin Murphy
Date: Thu Sep 20 2018 - 12:10:38 EST


From: Zhen Lei <thunder.leizhen@xxxxxxxxxx>

.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@xxxxxxxxxx>
Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
[rm: document why it wasn't a bug]
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
drivers/iommu/arm-smmu-v3.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index e395f1ff3f81..f10c852479fc 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1781,6 +1781,14 @@ arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
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;
@@ -2008,7 +2016,7 @@ static struct iommu_ops arm_smmu_ops = {
.attach_dev = arm_smmu_attach_dev,
.map = arm_smmu_map,
.unmap = arm_smmu_unmap,
- .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,
--
2.19.0.dirty