Heiner Kallweit <hkallwe...@gmail.com> writes:
Am 18.11.2020 um 23:35 schrieb Heiner Kallweit:
Am 18.11.2020 um 22:59 schrieb Shay Agroskin:
The ENA driver uses the readless mechanism, which uses DMA, to
find
out what the DMA mask is supposed to be.
If DMA is used without setting the dma_mask first, it causes
the
Intel IOMMU driver to think that ENA is a 32-bit device and
therefore
disables IOMMU passthrough permanently.
This patch sets the dma_mask to be
ENA_MAX_PHYS_ADDR_SIZE_BITS=48
before readless initialization in
ena_device_init()->ena_com_mmio_reg_read_request_init(),
which is large enough to workaround the intel_iommu issue.
DMA mask is set again to the correct value after it's received
from the
device after readless is initialized.
Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon
Elastic Network Adapters (ENA)")
Signed-off-by: Mike Cui <mike...@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiy...@amazon.com>
Signed-off-by: Shay Agroskin <shay...@amazon.com>
---
drivers/net/ethernet/amazon/ena/ena_netdev.c | 13
+++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c
b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 574c2b5ba21e..854a22e692bf 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -4146,6 +4146,19 @@ static int ena_probe(struct pci_dev
*pdev, const struct pci_device_id *ent)
return rc;
}
+ rc = pci_set_dma_mask(pdev,
DMA_BIT_MASK(ENA_MAX_PHYS_ADDR_SIZE_BITS));
+ if (rc) {
+ dev_err(&pdev->dev, "pci_set_dma_mask failed
%d\n", rc);
+ goto err_disable_device;
+ }
+
+ rc = pci_set_consistent_dma_mask(pdev,
DMA_BIT_MASK(ENA_MAX_PHYS_ADDR_SIZE_BITS));
+ if (rc) {
+ dev_err(&pdev->dev,
"err_pci_set_consistent_dma_mask failed %d\n",
+ rc);
+ goto err_disable_device;
+ }
+
pci_set_master(pdev);
ena_dev = vzalloc(sizeof(*ena_dev));
The old pci_ dma wrappers are being phased out and shouldn't be
used in
new code. See e.g. e059c6f340f6 ("tulip: switch from 'pci_' to
'dma_' API").
So better use:
dma_set_mask_and_coherent(&pdev->dev,
DMA_BIT_MASK(ENA_MAX_PHYS_ADDR_SIZE_BITS));
Thank you for reviewing these patches. We will switch to using
dma_set_...() instead
However instead of dev_err(&pdev->dev, ..) you could use
pci_err(pdev, ..).
I see that pci_err evaluates to dev_err. While I see how using
pci_* log function helps code readability, I prefer using
dev_err here to keep the code consistent with the rest of the
driver. We'll discuss changing all log functions in future patches
to net-next if that's okay.
