net: hns3: add sync command to sync io-pgtable

To avoid errors in pgtable prefectch, add a sync command to sync
io-pagtable.

This is a supplement for the previous patch.
We want all the tx packet can be handled with tx bounce buffer path.
But it depends on the remain space of the spare buffer, checked by the
hns3_can_use_tx_bounce(). In most cases, maybe 99.99%, it returns true.
But once it return false by no available space, the packet will be handled
with the former path, which will map/unmap the skb buffer.
Then the driver will face the smmu prefetch risk again.

So add a sync command in this case to avoid smmu prefectch,
just protects corner scenes.

Fixes: 295ba23 ("net: hns3: add device version to replace pci revision")
Signed-off-by: Jian Shen <[email protected]>
Signed-off-by: Peiyang Wang <[email protected]>
Signed-off-by: Jijie Shao <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

Author: IronShen

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

@@ -381,6 +381,24 @@ static const struct hns3_rx_ptype hns3_rx_ptype_tbl[] = {
 #define HNS3_INVALID_PTYPE \
 		ARRAY_SIZE(hns3_rx_ptype_tbl)
 
+static void hns3_dma_map_sync(struct device *dev, unsigned long iova)
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_iotlb_gather iotlb_gather;
+	size_t granule;
+
+	if (!domain || !iommu_is_dma_domain(domain))
+		return;
+
+	granule = 1 << __ffs(domain->pgsize_bitmap);
+	iova = ALIGN_DOWN(iova, granule);
+	iotlb_gather.start = iova;
+	iotlb_gather.end = iova + granule - 1;
+	iotlb_gather.pgsize = granule;
+
+	iommu_iotlb_sync(domain, &iotlb_gather);
+}
+
 static irqreturn_t hns3_irq_handle(int irq, void *vector)
 {
 	struct hns3_enet_tqp_vector *tqp_vector = vector;
@@ -1728,7 +1746,9 @@ static int hns3_map_and_fill_desc(struct hns3_enet_ring *ring, void *priv,
 				  unsigned int type)
 {
 	struct hns3_desc_cb *desc_cb = &ring->desc_cb[ring->next_to_use];
+	struct hnae3_handle *handle = ring->tqp->handle;
 	struct device *dev = ring_to_dev(ring);
+	struct hnae3_ae_dev *ae_dev;
 	unsigned int size;
 	dma_addr_t dma;
 
@@ -1760,6 +1780,13 @@ static int hns3_map_and_fill_desc(struct hns3_enet_ring *ring, void *priv,
 		return -ENOMEM;
 	}
 
+	/* Add a SYNC command to sync io-pgtale to avoid errors in pgtable
+	 * prefetch
+	 */
+	ae_dev = hns3_get_ae_dev(handle);
+	if (ae_dev->dev_version >= HNAE3_DEVICE_VERSION_V3)
+		hns3_dma_map_sync(dev, dma);
+
 	desc_cb->priv = priv;
 	desc_cb->length = size;
 	desc_cb->dma = dma;