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From:   Tianfei zhang <tianfei.zhang@intel.com>
To:     hao.wu@intel.com, trix@redhat.com, mdf@kernel.org,
        yilun.xu@intel.com, linux-fpga@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     corbet@lwn.net, Matthew Gerlach <matthew.gerlach@linux.intel.com>,
        Tianfei Zhang <tianfei.zhang@intel.com>
Subject: [PATCH v1 3/7] fpga: dfl: Allow for ports with no local bar space.
Date:   Mon, 14 Feb 2022 06:26:15 -0500
Message-Id: <20220214112619.219761-4-tianfei.zhang@intel.com>
In-Reply-To: <20220214112619.219761-1-tianfei.zhang@intel.com>
References: <20220214112619.219761-1-tianfei.zhang@intel.com>
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From: Matthew Gerlach <matthew.gerlach@linux.intel.com>

From a fpga partial reconfiguration standpoint, a port
may not be connected any local BAR space.  The port could
be connected to a different PCIe Physical Function (PF) or
Virtual Function (VF), in which case another driver instance
would manage the endpoint.

Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
---
 drivers/fpga/dfl-pci.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
index 4d68719e608f..8abd9b408403 100644
--- a/drivers/fpga/dfl-pci.c
+++ b/drivers/fpga/dfl-pci.c
@@ -243,6 +243,7 @@ static int find_dfls_by_default(struct pci_dev *pcidev,
 		v = readq(base + FME_HDR_CAP);
 		port_num = FIELD_GET(FME_CAP_NUM_PORTS, v);
 
+		dev_info(&pcidev->dev, "port_num = %d\n", port_num);
 		WARN_ON(port_num > MAX_DFL_FPGA_PORT_NUM);
 
 		for (i = 0; i < port_num; i++) {
@@ -258,6 +259,13 @@ static int find_dfls_by_default(struct pci_dev *pcidev,
 			 */
 			bar = FIELD_GET(FME_PORT_OFST_BAR_ID, v);
 			offset = FIELD_GET(FME_PORT_OFST_DFH_OFST, v);
+			if (bar >= PCI_STD_NUM_BARS) {
+				dev_info(&pcidev->dev, "skipping port without local BAR space %d\n",
+					 bar);
+				continue;
+			} else {
+				dev_info(&pcidev->dev, "BAR %d offset %u\n", bar, offset);
+			}
 			start = pci_resource_start(pcidev, bar) + offset;
 			len = pci_resource_len(pcidev, bar) - offset;
 
-- 
2.17.1