From 03a551734cfc2b93f83950a595974e3c9cbd82fd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=3D=3FUTF-8=3Fq=3FChristian=3D20K=3DC3=3DB6nig=3F=3D?= Date: Thu, 11 Jan 2018 14:23:30 +0100 Subject: [PATCH] x86/PCI: Move and shrink AMD 64-bit window to avoid conflict MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Avoid problems with BIOS implementations which don't report all used resources to the OS by only allocating a 256GB window directly below the hardware limit (from the BKDG, sec 2.4.6). Fixes a silent reboot loop reported by Aaro Koskinen on an AMD-based MSI MS-7699/760GA-P43(FX) system. This was apparently caused by RAM or other unreported hardware that conflicted with the new window. Link: https://support.amd.com/TechDocs/49125_15h_Models_30h-3Fh_BKDG.pdf Link: https://lkml.kernel.org/r/20180105220412.fzpwqe4zljdawr36@darkstar.musicnaut.iki.fi Fixes: fa564ad96366 ("x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)") Reported-by: Aaro Koskinen Signed-off-by: Christian König [bhelgaas: changelog, comment, Fixes:] Signed-off-by: Bjorn Helgaas --- arch/x86/pci/fixup.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c index 8bad19c7473d..f6a26e3cb476 100644 --- a/arch/x86/pci/fixup.c +++ b/arch/x86/pci/fixup.c @@ -662,10 +662,11 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2033, quirk_no_aersid); */ static void pci_amd_enable_64bit_bar(struct pci_dev *dev) { - unsigned i; u32 base, limit, high; - struct resource *res, *conflict; struct pci_dev *other; + struct resource *res; + unsigned i; + int r; if (!(pci_probe & PCI_BIG_ROOT_WINDOW)) return; @@ -702,19 +703,20 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev) if (!res) return; + /* + * Allocate a 256GB window directly below the 0xfd00000000 hardware + * limit (see AMD Family 15h Models 30h-3Fh BKDG, sec 2.4.6). + */ res->name = "PCI Bus 0000:00"; res->flags = IORESOURCE_PREFETCH | IORESOURCE_MEM | IORESOURCE_MEM_64 | IORESOURCE_WINDOW; - res->start = 0x100000000ull; + res->start = 0xbd00000000ull; res->end = 0xfd00000000ull - 1; - /* Just grab the free area behind system memory for this */ - while ((conflict = request_resource_conflict(&iomem_resource, res))) { - if (conflict->end >= res->end) { - kfree(res); - return; - } - res->start = conflict->end + 1; + r = request_resource(&iomem_resource, res); + if (r) { + kfree(res); + return; } dev_info(&dev->dev, "adding root bus resource %pR (tainting kernel)\n",