PCI: Fix Intel ACS quirk UPDCR register address

BugLink: https://bugs.launchpad.net/bugs/1860179
commit d8558ac8c93d429d65d7490b512a3a67e559d0d4 upstream.

According to documentation [0] the correct offset for the Upstream Peer
Decode Configuration Register (UPDCR) is 0x1014.  It was previously defined
as 0x1114.

d99321b63b1f ("PCI: Enable quirks for PCIe ACS on Intel PCH root ports")
intended to enforce isolation between PCI devices allowing them to be put
into separate IOMMU groups.  Due to the wrong register offset the intended
isolation was not fully enforced.  This is fixed with this patch.

Please note that I did not test this patch because I have no hardware that
implements this register.

[0] https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/4th-gen-core-family-mobile-i-o-datasheet.pdf (page 325)
Fixes: d99321b63b1f ("PCI: Enable quirks for PCIe ACS on Intel PCH root ports")
Link: https://lore.kernel.org/r/7a3505df-79ba-8a28-464c-88b83eefffa6@kernkonzept.com
Signed-off-by: Steffen Liebergeld <steffen.liebergeld@kernkonzept.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org	# v3.15+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 4558d11928174c6bf6bce9e21555c3507f9f77dc..43cbe3174f22fd62dfaabefed534813c0407f63e 100644 (file)
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4619,7 +4619,7 @@ int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags)
 #define INTEL_BSPR_REG_BPPD  (1 << 9)
 
 /* Upstream Peer Decode Configuration Register */
-#define INTEL_UPDCR_REG 0x1114
+#define INTEL_UPDCR_REG 0x1014
 /* 5:0 Peer Decode Enable bits */
 #define INTEL_UPDCR_REG_MASK 0x3f