Re: [PATCH v2 2/3] iommu/dma: wire-up new dma map op .get_virt_addr

From: Robin Murphy
Date: Mon Oct 28 2019 - 09:52:54 EST


On 24/10/2019 13:41, Laurentiu Tudor wrote:
From: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>

Add an implementation of the newly introduced dma map op in the
generic DMA IOMMU generic glue layer and wire it up.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
---
drivers/iommu/dma-iommu.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index f321279baf9e..15e76232d697 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1091,6 +1091,21 @@ static unsigned long iommu_dma_get_merge_boundary(struct device *dev)
return (1UL << __ffs(domain->pgsize_bitmap)) - 1;
}
+static void *iommu_dma_get_virt_addr(struct device *dev, dma_addr_t dma_handle)
+{
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);

Note that we'd generally use the iommu_get_dma_domain() fastpath...

+
+ if (domain) {

...wherein we can also assume that the device having iommu_dma_ops assigned at all implies that a DMA ops domain is in place.

Robin.

+ phys_addr_t phys;
+
+ phys = iommu_iova_to_phys(domain, dma_handle);
+ if (phys)
+ return phys_to_virt(phys);
+ }
+
+ return NULL;
+}
+
static const struct dma_map_ops iommu_dma_ops = {
.alloc = iommu_dma_alloc,
.free = iommu_dma_free,
@@ -1107,6 +1122,7 @@ static const struct dma_map_ops iommu_dma_ops = {
.map_resource = iommu_dma_map_resource,
.unmap_resource = iommu_dma_unmap_resource,
.get_merge_boundary = iommu_dma_get_merge_boundary,
+ .get_virt_addr = iommu_dma_get_virt_addr,
};
/*