On 08/05/18 19:16, Dmitry Osipenko wrote:
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.
This looks like a reasonable compromise - for users of
IO_PGTABLE_QUIRK_TLBI_ON_MAP we can leave the implicit add_flush() in
place for each individual map call, but at least move the sync() out to
this callback, which should still be beneficial overall.
Modulo one possible nit below,
Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
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);
Is it worth trying to skip this in the error case when we're just going
to undo it immediately?
Robin.
+
/* 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);
--
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