[PATCH v1 8/9] iommu: Introduce iotlb_sync_map callback

[Dmitry Osipenko]

Introduce iotlb_sync_map() callback that is invoked in the end of
iommu_map(). This new callback allows IOMMU drivers to avoid syncing
on mapping of each contiguous chunk and sync only when whole mapping
is completed, optimizing performance of the mapping operation.

Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
---
 drivers/iommu/iommu.c | 8 ++++++--
 include/linux/iommu.h | 1 +
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d2aa23202bb9..39b2ee66aa96 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1508,13 +1508,14 @@ static size_t iommu_pgsize(struct iommu_domain *domain,
 int iommu_map(struct iommu_domain *domain, unsigned long iova,
              phys_addr_t paddr, size_t size, int prot)
 {
+       const struct iommu_ops *ops = domain->ops;
        unsigned long orig_iova = iova;
        unsigned int min_pagesz;
        size_t orig_size = size;
        phys_addr_t orig_paddr = paddr;
        int ret = 0;
 
-       if (unlikely(domain->ops->map == NULL ||
+       if (unlikely(ops->map == NULL ||
                     domain->pgsize_bitmap == 0UL))
                return -ENODEV;
 
@@ -1543,7 +1544,7 @@ int iommu_map(struct iommu_domain *domain, unsigned long 
iova,
                pr_debug("mapping: iova 0x%lx pa %pa pgsize 0x%zx\n",
                         iova, &paddr, pgsize);
 
-               ret = domain->ops->map(domain, iova, paddr, pgsize, prot);
+               ret = ops->map(domain, iova, paddr, pgsize, prot);
                if (ret)
                        break;
 
@@ -1552,6 +1553,9 @@ int iommu_map(struct iommu_domain *domain, unsigned long 
iova,
                size -= pgsize;
        }
 
+       if (ops->iotlb_sync_map)
+               ops->iotlb_sync_map(domain);
+
        /* unroll mapping in case something went wrong */
        if (ret)
                iommu_unmap(domain, orig_iova, orig_size - size);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 19938ee6eb31..5224aa376377 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -206,6 +206,7 @@ struct iommu_ops {
        void (*flush_iotlb_all)(struct iommu_domain *domain);
        void (*iotlb_range_add)(struct iommu_domain *domain,
                                unsigned long iova, size_t size);
+       void (*iotlb_sync_map)(struct iommu_domain *domain);
        void (*iotlb_sync)(struct iommu_domain *domain);
        phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, dma_addr_t 
iova);
        int (*add_device)(struct device *dev);
-- 
2.17.0