[PATCH 5.12 127/363] PCI/RCEC: Fix RCiEP device to RCEC association

[Greg Kroah-Hartman]

From: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>

[ Upstream commit d9b7eae8e3424c3480fe9f40ebafbb0c96426e4c ]

rcec_assoc_rciep() used "rciep->devfn" (a single byte encoding both the
device and function number) as the device number to check whether the
corresponding bit was set in the RCEC's Association Bitmap for RCiEPs.

But per PCIe r5.0, sec 7.9.10.2, "Association Bitmap for RCiEPs", the
32-bit bitmap contains one bit per device.  That bit applies to all
functions of the device.

Fix rcec_assoc_rciep() to convert the value of "rciep->devfn" to a device
number to ensure that RCiEP devices are correctly associated with the RCEC.

Reported-and-tested-by: Wen Jin <wen.jin@xxxxxxxxx>
Fixes: 507b460f8144 ("PCI/ERR: Add pcie_link_rcec() to associate RCiEPs")
Link: https://lore.kernel.org/r/20210222011717.43266-1-qiuxu.zhuo@xxxxxxxxx
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/pci/pcie/rcec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/pcie/rcec.c b/drivers/pci/pcie/rcec.c
index 2c5c552994e4..d0bcd141ac9c 100644
--- a/drivers/pci/pcie/rcec.c
+++ b/drivers/pci/pcie/rcec.c
@@ -32,7 +32,7 @@ static bool rcec_assoc_rciep(struct pci_dev *rcec, struct pci_dev *rciep)
 
 	/* Same bus, so check bitmap */
 	for_each_set_bit(devn, &bitmap, 32)
-		if (devn == rciep->devfn)
+		if (devn == PCI_SLOT(rciep->devfn))
 			return true;
 
 	return false;
-- 
2.30.2