PCI: vmd: Correct PCI Header Type Register's multi-function check

[ Upstream commit 5827e17d0555b566c32044b0632b46f9f95054fa ]

vmd_domain_reset() attempts to find whether the device may contain multiple
functions by checking 0x80 (Multi-Function Device), however, the hdr_type
variable has already been masked with PCI_HEADER_TYPE_MASK so the check can
never true.

To fix the issue, don't mask the read with PCI_HEADER_TYPE_MASK.

Fixes: 6aab5622296b ("PCI: vmd: Clean up domain before enumeration")
Link: https://lore.kernel.org/r/20231003125300.5541-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Nirmal Patel <nirmal.patel@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index ad56df98b8e63d790a719a494104a80c669731b8..1c1c1aa940a513201acd205fa10555ed6aefbc61 100644 (file)
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -525,8 +525,7 @@ static void vmd_domain_reset(struct vmd_dev *vmd)
                        base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
                                                PCI_DEVFN(dev, 0), 0);
 
-                       hdr_type = readb(base + PCI_HEADER_TYPE) &
-                                        PCI_HEADER_TYPE_MASK;
+                       hdr_type = readb(base + PCI_HEADER_TYPE);
 
                        functions = (hdr_type & 0x80) ? 8 : 1;
                        for (fn = 0; fn < functions; fn++) {