[RFC PATCH v1 03/15] iommu/io-pgtable: Allow TLB operations to be optional

[Jordan Crouse]

An upcoming change to arm-smmu will add auxiliary domains that will allow
a leaf driver to create and map additional pagetables for device
specific uses. By definition aux arm-smmu domains will not be allowed
to touch the hardware directly so allow for the TLB operations for
a given pagetable configuration to be NULL just in case the caller
accidentally calls for a flush with the wrong device.

Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
---

 drivers/iommu/io-pgtable.h | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h
index 47d5ae5..fbfd3c9 100644
--- a/drivers/iommu/io-pgtable.h
+++ b/drivers/iommu/io-pgtable.h
@@ -178,18 +178,22 @@ struct io_pgtable {
 
 static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
 {
-	iop->cfg.tlb->tlb_flush_all(iop->cookie);
+	if (iop->cfg.tlb)
+		iop->cfg.tlb->tlb_flush_all(iop->cookie);
 }
 
 static inline void io_pgtable_tlb_add_flush(struct io_pgtable *iop,
 		unsigned long iova, size_t size, size_t granule, bool leaf)
 {
-	iop->cfg.tlb->tlb_add_flush(iova, size, granule, leaf, iop->cookie);
+	if (iop->cfg.tlb)
+		iop->cfg.tlb->tlb_add_flush(iova, size, granule, leaf,
+			iop->cookie);
 }
 
 static inline void io_pgtable_tlb_sync(struct io_pgtable *iop)
 {
-	iop->cfg.tlb->tlb_sync(iop->cookie);
+	if (iop->cfg.tlb)
+		iop->cfg.tlb->tlb_sync(iop->cookie);
 }
 
 /**
-- 
2.7.4