[PATCH v2 1/2] iommu/virtio: Make use of ops->iotlb_sync_map

From: Niklas Schnelle
Date: Mon Sep 18 2023 - 07:53:03 EST


Pull out the sync operation from viommu_map_pages() by implementing
ops->iotlb_sync_map. This allows the common IOMMU code to map multiple
elements of an sg with a single sync (see iommu_map_sg()). Furthermore,
it is also a requirement for IOMMU_CAP_DEFERRED_FLUSH.

Link: https://lore.kernel.org/lkml/20230726111433.1105665-1-schnelle@xxxxxxxxxxxxx/
Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
---
drivers/iommu/virtio-iommu.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 17dcd826f5c2..3649586f0e5c 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -189,6 +189,12 @@ static int viommu_sync_req(struct viommu_dev *viommu)
int ret;
unsigned long flags;

+ /*
+ * .iotlb_sync_map and .flush_iotlb_all may be called before the viommu
+ * is initialized e.g. via iommu_create_device_direct_mappings()
+ */
+ if (!viommu)
+ return 0;
spin_lock_irqsave(&viommu->request_lock, flags);
ret = __viommu_sync_req(viommu);
if (ret)
@@ -843,7 +849,7 @@ static int viommu_map_pages(struct iommu_domain *domain, unsigned long iova,
.flags = cpu_to_le32(flags),
};

- ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map));
+ ret = viommu_add_req(vdomain->viommu, &map, sizeof(map));
if (ret) {
viommu_del_mappings(vdomain, iova, end);
return ret;
@@ -912,6 +918,14 @@ static void viommu_iotlb_sync(struct iommu_domain *domain,
viommu_sync_req(vdomain->viommu);
}

+static int viommu_iotlb_sync_map(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
+{
+ struct viommu_domain *vdomain = to_viommu_domain(domain);
+
+ return viommu_sync_req(vdomain->viommu);
+}
+
static void viommu_get_resv_regions(struct device *dev, struct list_head *head)
{
struct iommu_resv_region *entry, *new_entry, *msi = NULL;
@@ -1058,6 +1072,7 @@ static struct iommu_ops viommu_ops = {
.unmap_pages = viommu_unmap_pages,
.iova_to_phys = viommu_iova_to_phys,
.iotlb_sync = viommu_iotlb_sync,
+ .iotlb_sync_map = viommu_iotlb_sync_map,
.free = viommu_domain_free,
}
};

--
2.39.2