From 0ca4e8c3c62595ca7a83981d88d3f2d066b52ef0 Mon Sep 17 00:00:00 2001 From: Steffen Liebergeld Date: Thu, 16 Jan 2020 10:19:58 +0800 Subject: [PATCH] PCI: Fix Intel ACS quirk UPDCR register address 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 Signed-off-by: Bjorn Helgaas Reviewed-by: Andrew Murray Acked-by: Ashok Raj Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang --- drivers/pci/quirks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 83e3f2c5c7e6..3a177d4c4c41 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4578,7 +4578,7 @@ 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 -- GitLab