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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 v2] ionic: advertise 52-bit addressing limitation for MSI-X
Date: Mon,  3 Jun 2024 17:27:41 -0400
Message-ID: <20240603212747.1079134-1-drc@linux.ibm.com>
In-Reply-To: <20240530214026.774256-1-drc@linux.ibm.com>
References: <20240530214026.774256-1-drc@linux.ibm.com>
Precedence: bulk
MIME-Version: 1.0
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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@linux.ibm.com>
---
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