Received-SPF: pass (google.com: domain of linux-kernel+bounces-195945-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
From: David Christensen <drc@linux.ibm.com>
To: Shannon Nelson <shannon.nelson@amd.com>,
        Brett Creeley <brett.creeley@amd.com>,
        drivers@pensando.io (supporter:PENSANDO ETHERNET DRIVERS),
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, David Christensen <drc@linux.ibm.com>,
        netdev@vger.kernel.org (open list:PENSANDO ETHERNET DRIVERS),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH net-next] ionic: advertise 52-bit addressing limitation for MSI-X
Date: Thu, 30 May 2024 17:40:20 -0400
Message-ID: <20240530214026.774256-1-drc@linux.ibm.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

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
recently added no_64bit_msi value of the pci_dev structure
during device probe.

Signed-off-by: David Christensen <drc@linux.ibm.com>
---
 drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c | 4 ++++
 1 file changed, 4 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..1e7f507f461f 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
@@ -326,6 +326,10 @@ static int ionic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_out;
 	}
 
+	/* Ensure MSI/MSI-X interrupts lie within addressable physical memory */
+	if (IONIC_ADDR_LEN < 64)
+		pdev->no_64bit_msi = 1;
+
 	err = ionic_setup_one(ionic);
 	if (err)
 		goto err_out;
-- 
2.43.0