[PATCH net-next v2] ionic: advertise 52-bit addressing limitation for MSI-X

From: David Christensen
Date: Mon Jun 03 2024 - 17:28:16 EST


Current ionic devices only support 52 internal physical address
lines. This is sufficient for x86_64 systems which have similar
limitations but does not apply to all other architectures,
notably IBM POWER (ppc64). To ensure that MSI/MSI-X vectors are
not set outside the physical address limits of the NIC, set the
no_64bit_msi value of the pci_dev structure during device probe.

Signed-off-by: David Christensen <drc@xxxxxxxxxxxxx>
---
v2: Limit change to ppc64 systems as suggested
---
drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
index 6ba8d4aca0a0..a7146d50f814 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
@@ -326,6 +326,11 @@ static int ionic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
goto err_out;
}

+#ifdef CONFIG_PPC64
+ /* Ensure MSI/MSI-X interrupts lie within addressable physical memory */
+ pdev->no_64bit_msi = 1;
+#endif
+
err = ionic_setup_one(ionic);
if (err)
goto err_out;
--
2.43.0